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30 files changed, 12114 insertions, 0 deletions
diff --git a/MAINTAINERS b/MAINTAINERS index f56c7e1..2e83c82 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -2246,6 +2246,14 @@ L: linux-mtd@lists.infradead.org T: git git://git.infradead.org/mtd-2.6.git S: Maintained +UNSORTED BLOCK IMAGES (UBI) +P: Artem Bityutskiy +M: dedekind@infradead.org +W: http://www.linux-mtd.infradead.org/ +L: linux-mtd@lists.infradead.org +T: git git://git.infradead.org/ubi-2.6.git +S: Maintained + MICROTEK X6 SCANNER P: Oliver Neukum M: oliver@neukum.name diff --git a/drivers/mtd/Kconfig b/drivers/mtd/Kconfig index 26f75c2..6d1b91b 100644 --- a/drivers/mtd/Kconfig +++ b/drivers/mtd/Kconfig @@ -292,5 +292,7 @@ source "drivers/mtd/nand/Kconfig" source "drivers/mtd/onenand/Kconfig" +source "drivers/mtd/ubi/Kconfig" + endmenu diff --git a/drivers/mtd/Makefile b/drivers/mtd/Makefile index c130e62..9205540 100644 --- a/drivers/mtd/Makefile +++ b/drivers/mtd/Makefile @@ -28,3 +28,5 @@ nftl-objs := nftlcore.o nftlmount.o inftl-objs := inftlcore.o inftlmount.o obj-y += chips/ maps/ devices/ nand/ onenand/ + +obj-$(CONFIG_MTD_UBI) += ubi/ diff --git a/drivers/mtd/ubi/Kconfig b/drivers/mtd/ubi/Kconfig new file mode 100644 index 0000000..b9daf15 --- /dev/null +++ b/drivers/mtd/ubi/Kconfig @@ -0,0 +1,58 @@ +# drivers/mtd/ubi/Kconfig + +menu "UBI - Unsorted block images" + depends on MTD + +config MTD_UBI + tristate "Enable UBI" + depends on MTD + select CRC32 + help + UBI is a software layer above MTD layer which admits of LVM-like + logical volumes on top of MTD devices, hides some complexities of + flash chips like wear and bad blocks and provides some other useful + capabilities. Please, consult the MTD web site for more details + (www.linux-mtd.infradead.org). + +config MTD_UBI_WL_THRESHOLD + int "UBI wear-leveling threshold" + default 4096 + range 2 65536 + depends on MTD_UBI + help + This parameter defines the maximum difference between the highest + erase counter value and the lowest erase counter value of eraseblocks + of UBI devices. When this threshold is exceeded, UBI starts performing + wear leveling by means of moving data from eraseblock with low erase + counter to eraseblocks with high erase counter. Leave the default + value if unsure. + +config MTD_UBI_BEB_RESERVE + int "Percentage of reserved eraseblocks for bad eraseblocks handling" + default 1 + range 0 25 + depends on MTD_UBI + help + If the MTD device admits of bad eraseblocks (e.g. NAND flash), UBI + reserves some amount of physical eraseblocks to handle new bad + eraseblocks. For example, if a flash physical eraseblock becomes bad, + UBI uses these reserved physical eraseblocks to relocate the bad one. + This option specifies how many physical eraseblocks will be reserved + for bad eraseblock handling (percents of total number of good flash + eraseblocks). If the underlying flash does not admit of bad + eraseblocks (e.g. NOR flash), this value is ignored and nothing is + reserved. Leave the default value if unsure. + +config MTD_UBI_GLUEBI + bool "Emulate MTD devices" + default n + depends on MTD_UBI + help + This option enables MTD devices emulation on top of UBI volumes: for + each UBI volumes an MTD device is created, and all I/O to this MTD + device is redirected to the UBI volume. This is handy to make + MTD-oriented software (like JFFS2) work on top of UBI. Do not enable + this if no legacy software will be used. + +source "drivers/mtd/ubi/Kconfig.debug" +endmenu diff --git a/drivers/mtd/ubi/Kconfig.debug b/drivers/mtd/ubi/Kconfig.debug new file mode 100644 index 0000000..1e2ee22 --- /dev/null +++ b/drivers/mtd/ubi/Kconfig.debug @@ -0,0 +1,104 @@ +comment "UBI debugging options" + depends on MTD_UBI + +config MTD_UBI_DEBUG + bool "UBI debugging" + depends on SYSFS + depends on MTD_UBI + select DEBUG_FS + select KALLSYMS_ALL + help + This option enables UBI debugging. + +config MTD_UBI_DEBUG_MSG + bool "UBI debugging messages" + depends on MTD_UBI_DEBUG + default n + help + This option enables UBI debugging messages. + +config MTD_UBI_DEBUG_PARANOID + bool "Extra self-checks" + default n + depends on MTD_UBI_DEBUG + help + This option enables extra checks in UBI code. Note this slows UBI down + significantly. + +config MTD_UBI_DEBUG_DISABLE_BGT + bool "Do not enable the UBI background thread" + depends on MTD_UBI_DEBUG + default n + help + This option switches the background thread off by default. The thread + may be also be enabled/disabled via UBI sysfs. + +config MTD_UBI_DEBUG_USERSPACE_IO + bool "Direct user-space write/erase support" + default n + depends on MTD_UBI_DEBUG + help + By default, users cannot directly write and erase individual + eraseblocks of dynamic volumes, and have to use update operation + instead. This option enables this capability - it is very useful for + debugging and testing. + +config MTD_UBI_DEBUG_EMULATE_BITFLIPS + bool "Emulate flash bit-flips" + depends on MTD_UBI_DEBUG + default n + help + This option emulates bit-flips with probability 1/50, which in turn + causes scrubbing. Useful for debugging and stressing UBI. + +config MTD_UBI_DEBUG_EMULATE_WRITE_FAILURES + bool "Emulate flash write failures" + depends on MTD_UBI_DEBUG + default n + help + This option emulates write failures with probability 1/100. Useful for + debugging and testing how UBI handlines errors. + +config MTD_UBI_DEBUG_EMULATE_ERASE_FAILURES + bool "Emulate flash erase failures" + depends on MTD_UBI_DEBUG + default n + help + This option emulates erase failures with probability 1/100. Useful for + debugging and testing how UBI handlines errors. + +menu "Additional UBI debugging messages" + depends on MTD_UBI_DEBUG + +config MTD_UBI_DEBUG_MSG_BLD + bool "Additional UBI initialization and build messages" + default n + depends on MTD_UBI_DEBUG + help + This option enables detailed UBI initialization and device build + debugging messages. + +config MTD_UBI_DEBUG_MSG_EBA + bool "Eraseblock association unit messages" + default n + depends on MTD_UBI_DEBUG + help + This option enables debugging messages from the UBI eraseblock + association unit. + +config MTD_UBI_DEBUG_MSG_WL + bool "Wear-leveling unit messages" + default n + depends on MTD_UBI_DEBUG + help + This option enables debugging messages from the UBI wear-leveling + unit. + +config MTD_UBI_DEBUG_MSG_IO + bool "Input/output unit messages" + default n + depends on MTD_UBI_DEBUG + help + This option enables debugging messages from the UBI input/output unit. + +endmenu # UBI debugging messages diff --git a/drivers/mtd/ubi/Makefile b/drivers/mtd/ubi/Makefile new file mode 100644 index 0000000..dd834e0 --- /dev/null +++ b/drivers/mtd/ubi/Makefile @@ -0,0 +1,7 @@ +obj-$(CONFIG_MTD_UBI) += ubi.o + +ubi-y += vtbl.o vmt.o upd.o build.o cdev.o kapi.o eba.o io.o wl.o scan.o +ubi-y += misc.o + +ubi-$(CONFIG_MTD_UBI_DEBUG) += debug.o +ubi-$(CONFIG_MTD_UBI_GLUEBI) += gluebi.o diff --git a/drivers/mtd/ubi/build.c b/drivers/mtd/ubi/build.c new file mode 100644 index 0000000..555d594 --- /dev/null +++ b/drivers/mtd/ubi/build.c @@ -0,0 +1,848 @@ +/* + * Copyright (c) International Business Machines Corp., 2006 + * Copyright (c) Nokia Corporation, 2007 + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See + * the GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + * Author: Artem Bityutskiy (Битюцкий Артём), + * Frank Haverkamp + */ + +/* + * This file includes UBI initialization and building of UBI devices. At the + * moment UBI devices may only be added while UBI is initialized, but dynamic + * device add/remove functionality is planned. Also, at the moment we only + * attach UBI devices by scanning, which will become a bottleneck when flashes + * reach certain large size. Then one may improve UBI and add other methods. + */ + +#include <linux/err.h> +#include <linux/module.h> +#include <linux/moduleparam.h> +#include <linux/stringify.h> +#include <linux/stat.h> +#include "ubi.h" + +/* Maximum length of the 'mtd=' parameter */ +#define MTD_PARAM_LEN_MAX 64 + +/** + * struct mtd_dev_param - MTD device parameter description data structure. + * @name: MTD device name or number string + * @vid_hdr_offs: VID header offset + * @data_offs: data offset + */ +struct mtd_dev_param +{ + char name[MTD_PARAM_LEN_MAX]; + int vid_hdr_offs; + int data_offs; +}; + +/* Numbers of elements set in the @mtd_dev_param array */ +static int mtd_devs = 0; + +/* MTD devices specification parameters */ +static struct mtd_dev_param mtd_dev_param[UBI_MAX_DEVICES]; + +/* Number of UBI devices in system */ +int ubi_devices_cnt; + +/* All UBI devices in system */ +struct ubi_device *ubi_devices[UBI_MAX_DEVICES]; + +/* Root UBI "class" object (corresponds to '/<sysfs>/class/ubi/') */ +struct class *ubi_class; + +/* "Show" method for files in '/<sysfs>/class/ubi/' */ +static ssize_t ubi_version_show(struct class *class, char *buf) +{ + return sprintf(buf, "%d\n", UBI_VERSION); +} + +/* UBI version attribute ('/<sysfs>/class/ubi/version') */ +static struct class_attribute ubi_version = + __ATTR(version, S_IRUGO, ubi_version_show, NULL); + +static ssize_t dev_attribute_show(struct device *dev, + struct device_attribute *attr, char *buf); + +/* UBI device attributes (correspond to files in '/<sysfs>/class/ubi/ubiX') */ +static struct device_attribute dev_eraseblock_size = + __ATTR(eraseblock_size, S_IRUGO, dev_attribute_show, NULL); +static struct device_attribute dev_avail_eraseblocks = + __ATTR(avail_eraseblocks, S_IRUGO, dev_attribute_show, NULL); +static struct device_attribute dev_total_eraseblocks = + __ATTR(total_eraseblocks, S_IRUGO, dev_attribute_show, NULL); +static struct device_attribute dev_volumes_count = + __ATTR(volumes_count, S_IRUGO, dev_attribute_show, NULL); +static struct device_attribute dev_max_ec = + __ATTR(max_ec, S_IRUGO, dev_attribute_show, NULL); +static struct device_attribute dev_reserved_for_bad = + __ATTR(reserved_for_bad, S_IRUGO, dev_attribute_show, NULL); +static struct device_attribute dev_bad_peb_count = + __ATTR(bad_peb_count, S_IRUGO, dev_attribute_show, NULL); +static struct device_attribute dev_max_vol_count = + __ATTR(max_vol_count, S_IRUGO, dev_attribute_show, NULL); +static struct device_attribute dev_min_io_size = + __ATTR(min_io_size, S_IRUGO, dev_attribute_show, NULL); +static struct device_attribute dev_bgt_enabled = + __ATTR(bgt_enabled, S_IRUGO, dev_attribute_show, NULL); + +/* "Show" method for files in '/<sysfs>/class/ubi/ubiX/' */ +static ssize_t dev_attribute_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + const struct ubi_device *ubi; + + ubi = container_of(dev, struct ubi_device, dev); + if (attr == &dev_eraseblock_size) + return sprintf(buf, "%d\n", ubi->leb_size); + else if (attr == &dev_avail_eraseblocks) + return sprintf(buf, "%d\n", ubi->avail_pebs); + else if (attr == &dev_total_eraseblocks) + return sprintf(buf, "%d\n", ubi->good_peb_count); + else if (attr == &dev_volumes_count) + return sprintf(buf, "%d\n", ubi->vol_count); + else if (attr == &dev_max_ec) + return sprintf(buf, "%d\n", ubi->max_ec); + else if (attr == &dev_reserved_for_bad) + return sprintf(buf, "%d\n", ubi->beb_rsvd_pebs); + else if (attr == &dev_bad_peb_count) + return sprintf(buf, "%d\n", ubi->bad_peb_count); + else if (attr == &dev_max_vol_count) + return sprintf(buf, "%d\n", ubi->vtbl_slots); + else if (attr == &dev_min_io_size) + return sprintf(buf, "%d\n", ubi->min_io_size); + else if (attr == &dev_bgt_enabled) + return sprintf(buf, "%d\n", ubi->thread_enabled); + else + BUG(); + + return 0; +} + +/* Fake "release" method for UBI devices */ +static void dev_release(struct device *dev) { } + +/** + * ubi_sysfs_init - initialize sysfs for an UBI device. + * @ubi: UBI device description object + * + * This function returns zero in case of success and a negative error code in + * case of failure. + */ +static int ubi_sysfs_init(struct ubi_device *ubi) +{ + int err; + + ubi->dev.release = dev_release; + ubi->dev.devt = MKDEV(ubi->major, 0); + ubi->dev.class = ubi_class; + sprintf(&ubi->dev.bus_id[0], UBI_NAME_STR"%d", ubi->ubi_num); + err = device_register(&ubi->dev); + if (err) + goto out; + + err = device_create_file(&ubi->dev, &dev_eraseblock_size); + if (err) + goto out_unregister; + err = device_create_file(&ubi->dev, &dev_avail_eraseblocks); + if (err) + goto out_eraseblock_size; + err = device_create_file(&ubi->dev, &dev_total_eraseblocks); + if (err) + goto out_avail_eraseblocks; + err = device_create_file(&ubi->dev, &dev_volumes_count); + if (err) + goto out_total_eraseblocks; + err = device_create_file(&ubi->dev, &dev_max_ec); + if (err) + goto out_volumes_count; + err = device_create_file(&ubi->dev, &dev_reserved_for_bad); + if (err) + goto out_volumes_max_ec; + err = device_create_file(&ubi->dev, &dev_bad_peb_count); + if (err) + goto out_reserved_for_bad; + err = device_create_file(&ubi->dev, &dev_max_vol_count); + if (err) + goto out_bad_peb_count; + err = device_create_file(&ubi->dev, &dev_min_io_size); + if (err) + goto out_max_vol_count; + err = device_create_file(&ubi->dev, &dev_bgt_enabled); + if (err) + goto out_min_io_size; + + return 0; + +out_min_io_size: + device_remove_file(&ubi->dev, &dev_min_io_size); +out_max_vol_count: + device_remove_file(&ubi->dev, &dev_max_vol_count); +out_bad_peb_count: + device_remove_file(&ubi->dev, &dev_bad_peb_count); +out_reserved_for_bad: + device_remove_file(&ubi->dev, &dev_reserved_for_bad); +out_volumes_max_ec: + device_remove_file(&ubi->dev, &dev_max_ec); +out_volumes_count: + device_remove_file(&ubi->dev, &dev_volumes_count); +out_total_eraseblocks: + device_remove_file(&ubi->dev, &dev_total_eraseblocks); +out_avail_eraseblocks: + device_remove_file(&ubi->dev, &dev_avail_eraseblocks); +out_eraseblock_size: + device_remove_file(&ubi->dev, &dev_eraseblock_size); +out_unregister: + device_unregister(&ubi->dev); +out: + ubi_err("failed to initialize sysfs for %s", ubi->ubi_name); + return err; +} + +/** + * ubi_sysfs_close - close sysfs for an UBI device. + * @ubi: UBI device description object + */ +static void ubi_sysfs_close(struct ubi_device *ubi) +{ + device_remove_file(&ubi->dev, &dev_bgt_enabled); + device_remove_file(&ubi->dev, &dev_min_io_size); + device_remove_file(&ubi->dev, &dev_max_vol_count); + device_remove_file(&ubi->dev, &dev_bad_peb_count); + device_remove_file(&ubi->dev, &dev_reserved_for_bad); + device_remove_file(&ubi->dev, &dev_max_ec); + device_remove_file(&ubi->dev, &dev_volumes_count); + device_remove_file(&ubi->dev, &dev_total_eraseblocks); + device_remove_file(&ubi->dev, &dev_avail_eraseblocks); + device_remove_file(&ubi->dev, &dev_eraseblock_size); + device_unregister(&ubi->dev); +} + +/** + * kill_volumes - destroy all volumes. + * @ubi: UBI device description object + */ +static void kill_volumes(struct ubi_device *ubi) +{ + int i; + + for (i = 0; i < ubi->vtbl_slots; i++) + if (ubi->volumes[i]) + ubi_free_volume(ubi, i); +} + +/** + * uif_init - initialize user interfaces for an UBI device. + * @ubi: UBI device description object + * + * This function returns zero in case of success and a negative error code in + * case of failure. + */ +static int uif_init(struct ubi_device *ubi) +{ + int i, err; + dev_t dev; + + mutex_init(&ubi->vtbl_mutex); + spin_lock_init(&ubi->volumes_lock); + + sprintf(ubi->ubi_name, UBI_NAME_STR "%d", ubi->ubi_num); + + /* + * Major numbers for the UBI character devices are allocated + * dynamically. Major numbers of volume character devices are + * equivalent to ones of the corresponding UBI character device. Minor + * numbers of UBI character devices are 0, while minor numbers of + * volume character devices start from 1. Thus, we allocate one major + * number and ubi->vtbl_slots + 1 minor numbers. + */ + err = alloc_chrdev_region(&dev, 0, ubi->vtbl_slots + 1, ubi->ubi_name); + if (err) { + ubi_err("cannot register UBI character devices"); + return err; + } + + cdev_init(&ubi->cdev, &ubi_cdev_operations); + ubi->major = MAJOR(dev); + dbg_msg("%s major is %u", ubi->ubi_name, ubi->major); + ubi->cdev.owner = THIS_MODULE; + + dev = MKDEV(ubi->major, 0); + err = cdev_add(&ubi->cdev, dev, 1); + if (err) { + ubi_err("cannot add character device %s", ubi->ubi_name); + goto out_unreg; + } + + err = ubi_sysfs_init(ubi); + if (err) + goto out_cdev; + + for (i = 0; i < ubi->vtbl_slots; i++) + if (ubi->volumes[i]) { + err = ubi_add_volume(ubi, i); + if (err) + goto out_volumes; + } + + return 0; + +out_volumes: + kill_volumes(ubi); + ubi_sysfs_close(ubi); +out_cdev: + cdev_del(&ubi->cdev); +out_unreg: + unregister_chrdev_region(MKDEV(ubi->major, 0), + ubi->vtbl_slots + 1); + return err; +} + +/** + * uif_close - close user interfaces for an UBI device. + * @ubi: UBI device description object + */ +static void uif_close(struct ubi_device *ubi) +{ + kill_volumes(ubi); + ubi_sysfs_close(ubi); + cdev_del(&ubi->cdev); + unregister_chrdev_region(MKDEV(ubi->major, 0), ubi->vtbl_slots + 1); +} + +/** + * attach_by_scanning - attach an MTD device using scanning method. + * @ubi: UBI device descriptor + * + * This function returns zero in case of success and a negative error code in + * case of failure. + * + * Note, currently this is the only method to attach UBI devices. Hopefully in + * the future we'll have more scalable attaching methods and avoid full media + * scanning. But even in this case scanning will be needed as a fall-back + * attaching method if there are some on-flash table corruptions. + */ +static int attach_by_scanning(struct ubi_device *ubi) +{ + int err; + struct ubi_scan_info *si; + + si = ubi_scan(ubi); + if (IS_ERR(si)) + return PTR_ERR(si); + + ubi->bad_peb_count = si->bad_peb_count; + ubi->good_peb_count = ubi->peb_count - ubi->bad_peb_count; + ubi->max_ec = si->max_ec; + ubi->mean_ec = si->mean_ec; + + err = ubi_read_volume_table(ubi, si); + if (err) + goto out_si; + + err = ubi_wl_init_scan(ubi, si); + if (err) + goto out_vtbl; + + err = ubi_eba_init_scan(ubi, si); + if (err) + goto out_wl; + + ubi_scan_destroy_si(si); + return 0; + +out_wl: + ubi_wl_close(ubi); +out_vtbl: + kfree(ubi->vtbl); +out_si: + ubi_scan_destroy_si(si); + return err; +} + +/** + * io_init - initialize I/O unit for a given UBI device. + * @ubi: UBI device description object + * + * If @ubi->vid_hdr_offset or @ubi->leb_start is zero, default offsets are + * assumed: + * o EC header is always at offset zero - this cannot be changed; + * o VID header starts just after the EC header at the closest address + * aligned to @io->@hdrs_min_io_size; + * o data starts just after the VID header at the closest address aligned to + * @io->@min_io_size + * + * This function returns zero in case of success and a negative error code in + * case of failure. + */ +static int io_init(struct ubi_device *ubi) +{ + if (ubi->mtd->numeraseregions != 0) { + /* + * Some flashes have several erase regions. Different regions + * may have different eraseblock size and other + * characteristics. It looks like mostly multi-region flashes + * have one "main" region and one or more small regions to + * store boot loader code or boot parameters or whatever. I + * guess we should just pick the largest region. But this is + * not implemented. + */ + ubi_err("multiple regions, not implemented"); + return -EINVAL; + } + + /* + * Note, in this implementation we support MTD devices with 0x7FFFFFFF + * physical eraseblocks maximum. + */ + + ubi->peb_size = ubi->mtd->erasesize; + ubi->peb_count = ubi->mtd->size / ubi->mtd->erasesize; + ubi->flash_size = ubi->mtd->size; + + if (ubi->mtd->block_isbad && ubi->mtd->block_markbad) + ubi->bad_allowed = 1; + + ubi->min_io_size = ubi->mtd->writesize; + ubi->hdrs_min_io_size = ubi->mtd->writesize >> ubi->mtd->subpage_sft; + + /* Make sure minimal I/O unit is power of 2 */ + if (ubi->min_io_size == 0 || + (ubi->min_io_size & (ubi->min_io_size - 1))) { + ubi_err("bad min. I/O unit"); + return -EINVAL; + } + + ubi_assert(ubi->hdrs_min_io_size > 0); + ubi_assert(ubi->hdrs_min_io_size <= ubi->min_io_size); + ubi_assert(ubi->min_io_size % ubi->hdrs_min_io_size == 0); + + /* Calculate default aligned sizes of EC and VID headers */ + ubi->ec_hdr_alsize = ALIGN(UBI_EC_HDR_SIZE, ubi->hdrs_min_io_size); + ubi->vid_hdr_alsize = ALIGN(UBI_VID_HDR_SIZE, ubi->hdrs_min_io_size); + + dbg_msg("min_io_size %d", ubi->min_io_size); + dbg_msg("hdrs_min_io_size %d", ubi->hdrs_min_io_size); + dbg_msg("ec_hdr_alsize %d", ubi->ec_hdr_alsize); + dbg_msg("vid_hdr_alsize %d", ubi->vid_hdr_alsize); + + if (ubi->vid_hdr_offset == 0) + /* Default offset */ + ubi->vid_hdr_offset = ubi->vid_hdr_aloffset = + ubi->ec_hdr_alsize; + else { + ubi->vid_hdr_aloffset = ubi->vid_hdr_offset & + ~(ubi->hdrs_min_io_size - 1); + ubi->vid_hdr_shift = ubi->vid_hdr_offset - + ubi->vid_hdr_aloffset; + } + + /* Similar for the data offset */ + if (ubi->leb_start == 0) { + ubi->leb_start = ubi->vid_hdr_offset + ubi->vid_hdr_alsize; + ubi->leb_start = ALIGN(ubi->leb_start, ubi->min_io_size); + } + + dbg_msg("vid_hdr_offset %d", ubi->vid_hdr_offset); + dbg_msg("vid_hdr_aloffset %d", ubi->vid_hdr_aloffset); + dbg_msg("vid_hdr_shift %d", ubi->vid_hdr_shift); + dbg_msg("leb_start %d", ubi->leb_start); + + /* The shift must be aligned to 32-bit boundary */ + if (ubi->vid_hdr_shift % 4) { + ubi_err("unaligned VID header shift %d", + ubi->vid_hdr_shift); + return -EINVAL; + } + + /* Check sanity */ + if (ubi->vid_hdr_offset < UBI_EC_HDR_SIZE || + ubi->leb_start < ubi->vid_hdr_offset + UBI_VID_HDR_SIZE || + ubi->leb_start > ubi->peb_size - UBI_VID_HDR_SIZE || + ubi->leb_start % ubi->min_io_size) { + ubi_err("bad VID header (%d) or data offsets (%d)", + ubi->vid_hdr_offset, ubi->leb_start); + return -EINVAL; + } + + /* + * It may happen that EC and VID headers are situated in one minimal + * I/O unit. In this case we can only accept this UBI image in + * read-only mode. + */ + if (ubi->vid_hdr_offset + UBI_VID_HDR_SIZE <= ubi->hdrs_min_io_size) { + ubi_warn("EC and VID headers are in the same minimal I/O unit, " + "switch to read-only mode"); + ubi->ro_mode = 1; + } + + ubi->leb_size = ubi->peb_size - ubi->leb_start; + + if (!(ubi->mtd->flags & MTD_WRITEABLE)) { + ubi_msg("MTD device %d is write-protected, attach in " + "read-only mode", ubi->mtd->index); + ubi->ro_mode = 1; + } + + dbg_msg("leb_size %d", ubi->leb_size); + dbg_msg("ro_mode %d", ubi->ro_mode); + + /* + * Note, ideally, we have to initialize ubi->bad_peb_count here. But + * unfortunately, MTD does not provide this information. We should loop + * over all physical eraseblocks and invoke mtd->block_is_bad() for + * each physical eraseblock. So, we skip ubi->bad_peb_count + * uninitialized and initialize it after scanning. + */ + + return 0; +} + +/** + * attach_mtd_dev - attach an MTD device. + * @mtd_dev: MTD device name or number string + * @vid_hdr_offset: VID header offset + * @data_offset: data offset + * + * This function attaches an MTD device to UBI. It first treats @mtd_dev as the + * MTD device name, and tries to open it by this name. If it is unable to open, + * it tries to convert @mtd_dev to an integer and open the MTD device by its + * number. Returns zero in case of success and a negative error code in case of + * failure. + */ +static int attach_mtd_dev(const char *mtd_dev, int vid_hdr_offset, + int data_offset) +{ + struct ubi_device *ubi; + struct mtd_info *mtd; + int i, err; + + mtd = get_mtd_device_nm(mtd_dev); + if (IS_ERR(mtd)) { + int mtd_num; + char *endp; + + if (PTR_ERR(mtd) != -ENODEV) + return PTR_ERR(mtd); + + /* + * Probably this is not MTD device name but MTD device number - + * check this out. + */ + mtd_num = simple_strtoul(mtd_dev, &endp, 0); + if (*endp != '\0' || mtd_dev == endp) { + ubi_err("incorrect MTD device: \"%s\"", mtd_dev); + return -ENODEV; + } + + mtd = get_mtd_device(NULL, mtd_num); + if (IS_ERR(mtd)) + return PTR_ERR(mtd); + } + + /* Check if we already have the same MTD device attached */ + for (i = 0; i < ubi_devices_cnt; i++) + if (ubi_devices[i]->mtd->index == mtd->index) { + ubi_err("mtd%d is already attached to ubi%d", + mtd->index, i); + err = -EINVAL; + goto out_mtd; + } + + ubi = ubi_devices[ubi_devices_cnt] = kzalloc(sizeof(struct ubi_device), + GFP_KERNEL); + if (!ubi) { + err = -ENOMEM; + goto out_mtd; + } + + ubi->ubi_num = ubi_devices_cnt; + ubi->mtd = mtd; + + dbg_msg("attaching mtd%d to ubi%d: VID header offset %d data offset %d", + ubi->mtd->index, ubi_devices_cnt, vid_hdr_offset, data_offset); + + ubi->vid_hdr_offset = vid_hdr_offset; + ubi->leb_start = data_offset; + err = io_init(ubi); + if (err) + goto out_free; + + err = attach_by_scanning(ubi); + if (err) { + dbg_err("failed to attach by scanning, error %d", err); + goto out_free; + } + + err = uif_init(ubi); + if (err) + goto out_detach; + + ubi_devices_cnt += 1; + + ubi_msg("attached mtd%d to ubi%d", ubi->mtd->index, ubi_devices_cnt); + ubi_msg("MTD device name: \"%s\"", ubi->mtd->name); + ubi_msg("MTD device size: %llu MiB", ubi->flash_size >> 20); + ubi_msg("physical eraseblock size: %d bytes (%d KiB)", + ubi->peb_size, ubi->peb_size >> 10); + ubi_msg("logical eraseblock size: %d bytes", ubi->leb_size); + ubi_msg("number of good PEBs: %d", ubi->good_peb_count); + ubi_msg("number of bad PEBs: %d", ubi->bad_peb_count); + ubi_msg("smallest flash I/O unit: %d", ubi->min_io_size); + ubi_msg("VID header offset: %d (aligned %d)", + ubi->vid_hdr_offset, ubi->vid_hdr_aloffset); + ubi_msg("data offset: %d", ubi->leb_start); + ubi_msg("max. allowed volumes: %d", ubi->vtbl_slots); + ubi_msg("wear-leveling threshold: %d", CONFIG_MTD_UBI_WL_THRESHOLD); + ubi_msg("number of internal volumes: %d", UBI_INT_VOL_COUNT); + ubi_msg("number of user volumes: %d", + ubi->vol_count - UBI_INT_VOL_COUNT); + ubi_msg("available PEBs: %d", ubi->avail_pebs); + ubi_msg("total number of reserved PEBs: %d", ubi->rsvd_pebs); + ubi_msg("number of PEBs reserved for bad PEB handling: %d", + ubi->beb_rsvd_pebs); + ubi_msg("max/mean erase counter: %d/%d", ubi->max_ec, ubi->mean_ec); + + /* Enable the background thread */ + if (!DBG_DISABLE_BGT) { + ubi->thread_enabled = 1; + wake_up_process(ubi->bgt_thread); + } + + return 0; + +out_detach: + ubi_eba_close(ubi); + ubi_wl_close(ubi); + kfree(ubi->vtbl); +out_free: + kfree(ubi); +out_mtd: + put_mtd_device(mtd); + ubi_devices[ubi_devices_cnt] = NULL; + return err; +} + +/** + * detach_mtd_dev - detach an MTD device. + * @ubi: UBI device description object + */ +static void detach_mtd_dev(struct ubi_device *ubi) +{ + int ubi_num = ubi->ubi_num, mtd_num = ubi->mtd->index; + + dbg_msg("detaching mtd%d from ubi%d", ubi->mtd->index, ubi_num); + uif_close(ubi); + ubi_eba_close(ubi); + ubi_wl_close(ubi); + kfree(ubi->vtbl); + put_mtd_device(ubi->mtd); + kfree(ubi_devices[ubi_num]); + ubi_devices[ubi_num] = NULL; + ubi_devices_cnt -= 1; + ubi_assert(ubi_devices_cnt >= 0); + ubi_msg("mtd%d is detached from ubi%d", mtd_num, ubi_num); +} + +static int __init ubi_init(void) +{ + int err, i, k; + + /* Ensure that EC and VID headers have correct size */ + BUILD_BUG_ON(sizeof(struct ubi_ec_hdr) != 64); + BUILD_BUG_ON(sizeof(struct ubi_vid_hdr) != 64); + + if (mtd_devs > UBI_MAX_DEVICES) { + printk("UBI error: too many MTD devices, maximum is %d\n", + UBI_MAX_DEVICES); + return -EINVAL; + } + + ubi_class = class_create(THIS_MODULE, UBI_NAME_STR); + if (IS_ERR(ubi_class)) + return PTR_ERR(ubi_class); + + err = class_create_file(ubi_class, &ubi_version); + if (err) + goto out_class; + + /* Attach MTD devices */ + for (i = 0; i < mtd_devs; i++) { + struct mtd_dev_param *p = &mtd_dev_param[i]; + + cond_resched(); + + if (!p->name) { + dbg_err("empty name"); + err = -EINVAL; + goto out_detach; + } + + err = attach_mtd_dev(p->name, p->vid_hdr_offs, p->data_offs); + if (err) + goto out_detach; + } + + return 0; + +out_detach: + for (k = 0; k < i; k++) + detach_mtd_dev(ubi_devices[k]); + class_remove_file(ubi_class, &ubi_version); +out_class: + class_destroy(ubi_class); + return err; +} +module_init(ubi_init); + +static void __exit ubi_exit(void) +{ + int i, n = ubi_devices_cnt; + + for (i = 0; i < n; i++) + detach_mtd_dev(ubi_devices[i]); + class_remove_file(ubi_class, &ubi_version); + class_destroy(ubi_class); +} +module_exit(ubi_exit); + +/** + * bytes_str_to_int - convert a string representing number of bytes to an + * integer. + * @str: the string to convert + * + * This function returns positive resulting integer in case of success and a + * negative error code in case of failure. + */ +static int __init bytes_str_to_int(const char *str) +{ + char *endp; + unsigned long result; + + result = simple_strtoul(str, &endp, 0); + if (str == endp || result < 0) { + printk("UBI error: incorrect bytes count: \"%s\"\n", str); + return -EINVAL; + } + + switch (*endp) { + case 'G': + result *= 1024; + case 'M': + result *= 1024; + case 'K': + case 'k': + result *= 1024; + if (endp[1] == 'i' && (endp[2] == '\0' || + endp[2] == 'B' || endp[2] == 'b')) + endp += 2; + case '\0': + break; + default: + printk("UBI error: incorrect bytes count: \"%s\"\n", str); + return -EINVAL; + } + + return result; +} + +/** + * ubi_mtd_param_parse - parse the 'mtd=' UBI parameter. + * @val: the parameter value to parse + * @kp: not used + * + * This function returns zero in case of success and a negative error code in + * case of error. + */ +static int __init ubi_mtd_param_parse(const char *val, struct kernel_param *kp) +{ + int i, len; + struct mtd_dev_param *p; + char buf[MTD_PARAM_LEN_MAX]; + char *pbuf = &buf[0]; + char *tokens[3] = {NULL, NULL, NULL}; + + if (mtd_devs == UBI_MAX_DEVICES) { + printk("UBI error: too many parameters, max. is %d\n", + UBI_MAX_DEVICES); + return -EINVAL; + } + + len = strnlen(val, MTD_PARAM_LEN_MAX); + if (len == MTD_PARAM_LEN_MAX) { + printk("UBI error: parameter \"%s\" is too long, max. is %d\n", + val, MTD_PARAM_LEN_MAX); + return -EINVAL; + } + + if (len == 0) { + printk("UBI warning: empty 'mtd=' parameter - ignored\n"); + return 0; + } + + strcpy(buf, val); + + /* Get rid of the final newline */ + if (buf[len - 1] == '\n') + buf[len - 1] = 0; + + for (i = 0; i < 3; i++) + tokens[i] = strsep(&pbuf, ","); + + if (pbuf) { + printk("UBI error: too many arguments at \"%s\"\n", val); + return -EINVAL; + } + + if (tokens[0] == '\0') + return -EINVAL; + + p = &mtd_dev_param[mtd_devs]; + strcpy(&p->name[0], tokens[0]); + + if (tokens[1]) + p->vid_hdr_offs = bytes_str_to_int(tokens[1]); + if (tokens[2]) + p->data_offs = bytes_str_to_int(tokens[2]); + + if (p->vid_hdr_offs < 0) + return p->vid_hdr_offs; + if (p->data_offs < 0) + return p->data_offs; + + mtd_devs += 1; + return 0; +} + +module_param_call(mtd, ubi_mtd_param_parse, NULL, NULL, 000); +MODULE_PARM_DESC(mtd, "MTD devices to attach. Parameter format: " + "mtd=<name|num>[,<vid_hdr_offs>,<data_offs>]. " + "Multiple \"mtd\" parameters may be specified.\n" + "MTD devices may be specified by their number or name. " + "Optional \"vid_hdr_offs\" and \"data_offs\" parameters " + "specify UBI VID header position and data starting " + "position to be used by UBI.\n" + "Example: mtd=content,1984,2048 mtd=4 - attach MTD device" + "with name content using VID header offset 1984 and data " + "start 2048, and MTD device number 4 using default " + "offsets"); + +MODULE_VERSION(__stringify(UBI_VERSION)); +MODULE_DESCRIPTION("UBI - Unsorted Block Images"); +MODULE_AUTHOR("Artem Bityutskiy"); +MODULE_LICENSE("GPL"); diff --git a/drivers/mtd/ubi/cdev.c b/drivers/mtd/ubi/cdev.c new file mode 100644 index 0000000..6612eb7 --- /dev/null +++ b/drivers/mtd/ubi/cdev.c @@ -0,0 +1,722 @@ +/* + * Copyright (c) International Business Machines Corp., 2006 + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See + * the GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + * Author: Artem Bityutskiy (Битюцкий Артём) + */ + +/* + * This file includes implementation of UBI character device operations. + * + * There are two kinds of character devices in UBI: UBI character devices and + * UBI volume character devices. UBI character devices allow users to + * manipulate whole volumes: create, remove, and re-size them. Volume character + * devices provide volume I/O capabilities. + * + * Major and minor numbers are assigned dynamically to both UBI and volume + * character devices. + */ + +#include <linux/module.h> +#include <linux/stat.h> +#include <linux/ioctl.h> +#include <linux/capability.h> +#include <mtd/ubi-user.h> +#include <asm/uaccess.h> +#include <asm/div64.h> +#include "ubi.h" + +/* + * Maximum sequence numbers of UBI and volume character device IOCTLs (direct + * logical eraseblock erase is a debug-only feature). + */ +#define UBI_CDEV_IOC_MAX_SEQ 2 +#ifndef CONFIG_MTD_UBI_DEBUG_USERSPACE_IO +#define VOL_CDEV_IOC_MAX_SEQ 1 +#else +#define VOL_CDEV_IOC_MAX_SEQ 2 +#endif + +/** + * major_to_device - get UBI device object by character device major number. + * @major: major number + * + * This function returns a pointer to the UBI device object. + */ +static struct ubi_device *major_to_device(int major) +{ + int i; + + for (i = 0; i < ubi_devices_cnt; i++) + if (ubi_devices[i] && ubi_devices[i]->major == major) + return ubi_devices[i]; + BUG(); +} + +/** + * get_exclusive - get exclusive access to an UBI volume. + * @desc: volume descriptor + * + * This function changes UBI volume open mode to "exclusive". Returns previous + * mode value (positive integer) in case of success and a negative error code + * in case of failure. + */ +static int get_exclusive(struct ubi_volume_desc *desc) +{ + int users, err; + struct ubi_volume *vol = desc->vol; + + spin_lock(&vol->ubi->volumes_lock); + users = vol->readers + vol->writers + vol->exclusive; + ubi_assert(users > 0); + if (users > 1) { + dbg_err("%d users for volume %d", users, vol->vol_id); + err = -EBUSY; + } else { + vol->readers = vol->writers = 0; + vol->exclusive = 1; + err = desc->mode; + desc->mode = UBI_EXCLUSIVE; + } + spin_unlock(&vol->ubi->volumes_lock); + + return err; +} + +/** + * revoke_exclusive - revoke exclusive mode. + * @desc: volume descriptor + * @mode: new mode to switch to + */ +static void revoke_exclusive(struct ubi_volume_desc *desc, int mode) +{ + struct ubi_volume *vol = desc->vol; + + spin_lock(&vol->ubi->volumes_lock); + ubi_assert(vol->readers == 0 && vol->writers == 0); + ubi_assert(vol->exclusive == 1 && desc->mode == UBI_EXCLUSIVE); + vol->exclusive = 0; + if (mode == UBI_READONLY) + vol->readers = 1; + else if (mode == UBI_READWRITE) + vol->writers = 1; + else + vol->exclusive = 1; + spin_unlock(&vol->ubi->volumes_lock); + + desc->mode = mode; +} + +static int vol_cdev_open(struct inode *inode, struct file *file) +{ + struct ubi_volume_desc *desc; + const struct ubi_device *ubi = major_to_device(imajor(inode)); + int vol_id = iminor(inode) - 1; + int mode; + + if (file->f_mode & FMODE_WRITE) + mode = UBI_READWRITE; + else + mode = UBI_READONLY; + + dbg_msg("open volume %d, mode %d", vol_id, mode); + + desc = ubi_open_volume(ubi->ubi_num, vol_id, mode); + if (IS_ERR(desc)) + return PTR_ERR(desc); + + file->private_data = desc; + return 0; +} + +static int vol_cdev_release(struct inode *inode, struct file *file) +{ + struct ubi_volume_desc *desc = file->private_data; + struct ubi_volume *vol = desc->vol; + + dbg_msg("release volume %d, mode %d", vol->vol_id, desc->mode); + + if (vol->updating) { + ubi_warn("update of volume %d not finished, volume is damaged", + vol->vol_id); + vol->updating = 0; + kfree(vol->upd_buf); + } + + ubi_close_volume(desc); + return 0; +} + +static loff_t vol_cdev_llseek(struct file *file, loff_t offset, int origin) +{ + struct ubi_volume_desc *desc = file->private_data; + struct ubi_volume *vol = desc->vol; + loff_t new_offset; + + if (vol->updating) { + /* Update is in progress, seeking is prohibited */ + dbg_err("updating"); + return -EBUSY; + } + + switch (origin) { + case 0: /* SEEK_SET */ + new_offset = offset; + break; + case 1: /* SEEK_CUR */ + new_offset = file->f_pos + offset; + break; + case 2: /* SEEK_END */ + new_offset = vol->used_bytes + offset; + break; + default: + return -EINVAL; + } + + if (new_offset < 0 || new_offset > vol->used_bytes) { + dbg_err("bad seek %lld", new_offset); + return -EINVAL; + } + + dbg_msg("seek volume %d, offset %lld, origin %d, new offset %lld", + vol->vol_id, offset, origin, new_offset); + + file->f_pos = new_offset; + return new_offset; +} + +static ssize_t vol_cdev_read(struct file *file, __user char *buf, size_t count, + loff_t *offp) +{ + struct ubi_volume_desc *desc = file->private_data; + struct ubi_volume *vol = desc->vol; + struct ubi_device *ubi = vol->ubi; + int err, lnum, off, len, vol_id = desc->vol->vol_id, tbuf_size; + size_t count_save = count; + void *tbuf; + uint64_t tmp; + + dbg_msg("read %zd bytes from offset %lld of volume %d", + count, *offp, vol_id); + + if (vol->updating) { + dbg_err("updating"); + return -EBUSY; + } + if (vol->upd_marker) { + dbg_err("damaged volume, update marker is set"); + return -EBADF; + } + if (*offp == vol->used_bytes || count == 0) + return 0; + + if (vol->corrupted) + dbg_msg("read from corrupted volume %d", vol_id); + + if (*offp + count > vol->used_bytes) + count_save = count = vol->used_bytes - *offp; + + tbuf_size = vol->usable_leb_size; + if (count < tbuf_size) + tbuf_size = ALIGN(count, ubi->min_io_size); + tbuf = kmalloc(tbuf_size, GFP_KERNEL); + if (!tbuf) + return -ENOMEM; + + len = count > tbuf_size ? tbuf_size : count; + + tmp = *offp; + off = do_div(tmp, vol->usable_leb_size); + lnum = tmp; + + do { + cond_resched(); + + if (off + len >= vol->usable_leb_size) + len = vol->usable_leb_size - off; + + err = ubi_eba_read_leb(ubi, vol_id, lnum, tbuf, off, len, 0); + if (err) + break; + + off += len; + if (off == vol->usable_leb_size) { + lnum += 1; + off -= vol->usable_leb_size; + } + + count -= len; + *offp += len; + + err = copy_to_user(buf, tbuf, len); + if (err) { + err = -EFAULT; + break; + } + + buf += len; + len = count > tbuf_size ? tbuf_size : count; + } while (count); + + kfree(tbuf); + return err ? err : count_save - count; +} + +#ifdef CONFIG_MTD_UBI_DEBUG_USERSPACE_IO + +/* + * This function allows to directly write to dynamic UBI volumes, without + * issuing the volume update operation. Available only as a debugging feature. + * Very useful for testing UBI. + */ +static ssize_t vol_cdev_direct_write(struct file *file, const char __user *buf, + size_t count, loff_t *offp) +{ + struct ubi_volume_desc *desc = file->private_data; + struct ubi_volume *vol = desc->vol; + struct ubi_device *ubi = vol->ubi; + int lnum, off, len, tbuf_size, vol_id = vol->vol_id, err = 0; + size_t count_save = count; + char *tbuf; + uint64_t tmp; + + dbg_msg("requested: write %zd bytes to offset %lld of volume %u", + count, *offp, desc->vol->vol_id); + + if (vol->vol_type == UBI_STATIC_VOLUME) + return -EROFS; + + tmp = *offp; + off = do_div(tmp, vol->usable_leb_size); + lnum = tmp; + + if (off % ubi->min_io_size) { + dbg_err("unaligned position"); + return -EINVAL; + } + + if (*offp + count > vol->used_bytes) + count_save = count = vol->used_bytes - *offp; + + /* We can write only in fractions of the minimum I/O unit */ + if (count % ubi->min_io_size) { + dbg_err("unaligned write length"); + return -EINVAL; + } + + tbuf_size = vol->usable_leb_size; + if (count < tbuf_size) + tbuf_size = ALIGN(count, ubi->min_io_size); + tbuf = kmalloc(tbuf_size, GFP_KERNEL); + if (!tbuf) + return -ENOMEM; + + len = count > tbuf_size ? tbuf_size : count; + + while (count) { + cond_resched(); + + if (off + len >= vol->usable_leb_size) + len = vol->usable_leb_size - off; + + err = copy_from_user(tbuf, buf, len); + if (err) { + err = -EFAULT; + break; + } + + err = ubi_eba_write_leb(ubi, vol_id, lnum, tbuf, off, len, + UBI_UNKNOWN); + if (err) + break; + + off += len; + if (off == vol->usable_leb_size) { + lnum += 1; + off -= vol->usable_leb_size; + } + + count -= len; + *offp += len; + buf += len; + len = count > tbuf_size ? tbuf_size : count; + } + + kfree(tbuf); + return err ? err : count_save - count; +} + +#else +#define vol_cdev_direct_write(file, buf, count, offp) -EPERM +#endif /* CONFIG_MTD_UBI_DEBUG_USERSPACE_IO */ + +static ssize_t vol_cdev_write(struct file *file, const char __user *buf, + size_t count, loff_t *offp) +{ + int err = 0; + struct ubi_volume_desc *desc = file->private_data; + struct ubi_volume *vol = desc->vol; + struct ubi_device *ubi = vol->ubi; + + if (!vol->updating) + return vol_cdev_direct_write(file, buf, count, offp); + + err = ubi_more_update_data(ubi, vol->vol_id, buf, count); + if (err < 0) { + ubi_err("cannot write %zd bytes of update data", count); + return err; + } + + if (err) { + /* + * Update is finished, @err contains number of actually written + * bytes now. + */ + count = err; + + err = ubi_check_volume(ubi, vol->vol_id); + if (err < 0) + return err; + + if (err) { + ubi_warn("volume %d on UBI device %d is corrupted", + vol->vol_id, ubi->ubi_num); + vol->corrupted = 1; + } + vol->checked = 1; + revoke_exclusive(desc, UBI_READWRITE); + } + + *offp += count; + return count; +} + +static int vol_cdev_ioctl(struct inode *inode, struct file *file, + unsigned int cmd, unsigned long arg) +{ + int err = 0; + struct ubi_volume_desc *desc = file->private_data; + struct ubi_volume *vol = desc->vol; + struct ubi_device *ubi = vol->ubi; + void __user *argp = (void __user *)arg; + + if (_IOC_NR(cmd) > VOL_CDEV_IOC_MAX_SEQ || + _IOC_TYPE(cmd) != UBI_VOL_IOC_MAGIC) + return -ENOTTY; + + if (_IOC_DIR(cmd) && _IOC_READ) + err = !access_ok(VERIFY_WRITE, argp, _IOC_SIZE(cmd)); + else if (_IOC_DIR(cmd) && _IOC_WRITE) + err = !access_ok(VERIFY_READ, argp, _IOC_SIZE(cmd)); + if (err) + return -EFAULT; + + switch (cmd) { + + /* Volume update command */ + case UBI_IOCVOLUP: + { + int64_t bytes, rsvd_bytes; + + if (!capable(CAP_SYS_RESOURCE)) { + err = -EPERM; + break; + } + + err = copy_from_user(&bytes, argp, sizeof(int64_t)); + if (err) { + err = -EFAULT; + break; + } + + if (desc->mode == UBI_READONLY) { + err = -EROFS; + break; + } + + rsvd_bytes = vol->reserved_pebs * (ubi->leb_size-vol->data_pad); + if (bytes < 0 || bytes > rsvd_bytes) { + err = -EINVAL; + break; + } + + err = get_exclusive(desc); + if (err < 0) + break; + + err = ubi_start_update(ubi, vol->vol_id, bytes); + if (bytes == 0) + revoke_exclusive(desc, UBI_READWRITE); + + file->f_pos = 0; + break; + } + +#ifdef CONFIG_MTD_UBI_DEBUG_USERSPACE_IO + /* Logical eraseblock erasure command */ + case UBI_IOCEBER: + { + int32_t lnum; + + err = __get_user(lnum, (__user int32_t *)argp); + if (err) { + err = -EFAULT; + break; + } + + if (desc->mode == UBI_READONLY) { + err = -EROFS; + break; + } + + if (lnum < 0 || lnum >= vol->reserved_pebs) { + err = -EINVAL; + break; + } + + if (vol->vol_type != UBI_DYNAMIC_VOLUME) { + err = -EROFS; + break; + } + + dbg_msg("erase LEB %d:%d", vol->vol_id, lnum); + err = ubi_eba_unmap_leb(ubi, vol->vol_id, lnum); + if (err) + break; + + err = ubi_wl_flush(ubi); + break; + } +#endif + + default: + err = -ENOTTY; + break; + } + + return err; +} + +/** + * verify_mkvol_req - verify volume creation request. + * @ubi: UBI device description object + * @req: the request to check + * + * This function zero if the request is correct, and %-EINVAL if not. + */ +static int verify_mkvol_req(const struct ubi_device *ubi, + const struct ubi_mkvol_req *req) +{ + int n, err = -EINVAL; + + if (req->bytes < 0 || req->alignment < 0 || req->vol_type < 0 || + req->name_len < 0) + goto bad; + + if ((req->vol_id < 0 || req->vol_id >= ubi->vtbl_slots) && + req->vol_id != UBI_VOL_NUM_AUTO) + goto bad; + + if (req->alignment == 0) + goto bad; + + if (req->bytes == 0) + goto bad; + + if (req->vol_type != UBI_DYNAMIC_VOLUME && + req->vol_type != UBI_STATIC_VOLUME) + goto bad; + + if (req->alignment > ubi->leb_size) + goto bad; + + n = req->alignment % ubi->min_io_size; + if (req->alignment != 1 && n) + goto bad; + + if (req->name_len > UBI_VOL_NAME_MAX) { + err = -ENAMETOOLONG; + goto bad; + } + + return 0; + +bad: + dbg_err("bad volume creation request"); + ubi_dbg_dump_mkvol_req(req); + return err; +} + +/** + * verify_rsvol_req - verify volume re-size request. + * @ubi: UBI device description object + * @req: the request to check + * + * This function returns zero if the request is correct, and %-EINVAL if not. + */ +static int verify_rsvol_req(const struct ubi_device *ubi, + const struct ubi_rsvol_req *req) +{ + if (req->bytes <= 0) + return -EINVAL; + + if (req->vol_id < 0 || req->vol_id >= ubi->vtbl_slots) + return -EINVAL; + + return 0; +} + +static int ubi_cdev_ioctl(struct inode *inode, struct file *file, + unsigned int cmd, unsigned long arg) +{ + int err = 0; + struct ubi_device *ubi; + struct ubi_volume_desc *desc; + void __user *argp = (void __user *)arg; + + if (_IOC_NR(cmd) > UBI_CDEV_IOC_MAX_SEQ || + _IOC_TYPE(cmd) != UBI_IOC_MAGIC) + return -ENOTTY; + + if (_IOC_DIR(cmd) && _IOC_READ) + err = !access_ok(VERIFY_WRITE, argp, _IOC_SIZE(cmd)); + else if (_IOC_DIR(cmd) && _IOC_WRITE) + err = !access_ok(VERIFY_READ, argp, _IOC_SIZE(cmd)); + if (err) + return -EFAULT; + + if (!capable(CAP_SYS_RESOURCE)) + return -EPERM; + + ubi = major_to_device(imajor(inode)); + if (IS_ERR(ubi)) + return PTR_ERR(ubi); + + switch (cmd) { + /* Create volume command */ + case UBI_IOCMKVOL: + { + struct ubi_mkvol_req req; + + dbg_msg("create volume"); + err = __copy_from_user(&req, argp, + sizeof(struct ubi_mkvol_req)); + if (err) { + err = -EFAULT; + break; + } + + err = verify_mkvol_req(ubi, &req); + if (err) + break; + + req.name[req.name_len] = '\0'; + + err = ubi_create_volume(ubi, &req); + if (err) + break; + + err = __put_user(req.vol_id, (__user int32_t *)argp); + if (err) + err = -EFAULT; + + break; + } + + /* Remove volume command */ + case UBI_IOCRMVOL: + { + int vol_id; + + dbg_msg("remove volume"); + err = __get_user(vol_id, (__user int32_t *)argp); + if (err) { + err = -EFAULT; + break; + } + + desc = ubi_open_volume(ubi->ubi_num, vol_id, UBI_EXCLUSIVE); + if (IS_ERR(desc)) { + err = PTR_ERR(desc); + break; + } + + err = ubi_remove_volume(desc); + if (err) + ubi_close_volume(desc); + + break; + } + + /* Re-size volume command */ + case UBI_IOCRSVOL: + { + int pebs; + uint64_t tmp; + struct ubi_rsvol_req req; + + dbg_msg("re-size volume"); + err = __copy_from_user(&req, argp, + sizeof(struct ubi_rsvol_req)); + if (err) { + err = -EFAULT; + break; + } + + err = verify_rsvol_req(ubi, &req); + if (err) + break; + + desc = ubi_open_volume(ubi->ubi_num, req.vol_id, UBI_EXCLUSIVE); + if (IS_ERR(desc)) { + err = PTR_ERR(desc); + break; + } + + tmp = req.bytes; + pebs = !!do_div(tmp, desc->vol->usable_leb_size); + pebs += tmp; + + err = ubi_resize_volume(desc, pebs); + ubi_close_volume(desc); + break; + } + + default: + err = -ENOTTY; + break; + } + + return err; +} + +/* UBI character device operations */ +struct file_operations ubi_cdev_operations = { + .owner = THIS_MODULE, + .ioctl = ubi_cdev_ioctl, + .llseek = no_llseek +}; + +/* UBI volume character device operations */ +struct file_operations ubi_vol_cdev_operations = { + .owner = THIS_MODULE, + .open = vol_cdev_open, + .release = vol_cdev_release, + .llseek = vol_cdev_llseek, + .read = vol_cdev_read, + .write = vol_cdev_write, + .ioctl = vol_cdev_ioctl +}; diff --git a/drivers/mtd/ubi/debug.c b/drivers/mtd/ubi/debug.c new file mode 100644 index 0000000..8636422 --- /dev/null +++ b/drivers/mtd/ubi/debug.c @@ -0,0 +1,224 @@ +/* + * Copyright (c) International Business Machines Corp., 2006 + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See + * the GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + * Author: Artem Bityutskiy (Битюцкий Артём) + */ + +/* + * Here we keep all the UBI debugging stuff which should normally be disabled + * and compiled-out, but it is extremely helpful when hunting bugs or doing big + * changes. + */ + +#ifdef CONFIG_MTD_UBI_DEBUG_MSG + +#include "ubi.h" + +/** + * ubi_dbg_dump_ec_hdr - dump an erase counter header. + * @ec_hdr: the erase counter header to dump + */ +void ubi_dbg_dump_ec_hdr(const struct ubi_ec_hdr *ec_hdr) +{ + dbg_msg("erase counter header dump:"); + dbg_msg("magic %#08x", ubi32_to_cpu(ec_hdr->magic)); + dbg_msg("version %d", (int)ec_hdr->version); + dbg_msg("ec %llu", (long long)ubi64_to_cpu(ec_hdr->ec)); + dbg_msg("vid_hdr_offset %d", ubi32_to_cpu(ec_hdr->vid_hdr_offset)); + dbg_msg("data_offset %d", ubi32_to_cpu(ec_hdr->data_offset)); + dbg_msg("hdr_crc %#08x", ubi32_to_cpu(ec_hdr->hdr_crc)); + dbg_msg("erase counter header hexdump:"); + ubi_dbg_hexdump(ec_hdr, UBI_EC_HDR_SIZE); +} + +/** + * ubi_dbg_dump_vid_hdr - dump a volume identifier header. + * @vid_hdr: the volume identifier header to dump + */ +void ubi_dbg_dump_vid_hdr(const struct ubi_vid_hdr *vid_hdr) +{ + dbg_msg("volume identifier header dump:"); + dbg_msg("magic %08x", ubi32_to_cpu(vid_hdr->magic)); + dbg_msg("version %d", (int)vid_hdr->version); + dbg_msg("vol_type %d", (int)vid_hdr->vol_type); + dbg_msg("copy_flag %d", (int)vid_hdr->copy_flag); + dbg_msg("compat %d", (int)vid_hdr->compat); + dbg_msg("vol_id %d", ubi32_to_cpu(vid_hdr->vol_id)); + dbg_msg("lnum %d", ubi32_to_cpu(vid_hdr->lnum)); + dbg_msg("leb_ver %u", ubi32_to_cpu(vid_hdr->leb_ver)); + dbg_msg("data_size %d", ubi32_to_cpu(vid_hdr->data_size)); + dbg_msg("used_ebs %d", ubi32_to_cpu(vid_hdr->used_ebs)); + dbg_msg("data_pad %d", ubi32_to_cpu(vid_hdr->data_pad)); + dbg_msg("sqnum %llu", + (unsigned long long)ubi64_to_cpu(vid_hdr->sqnum)); + dbg_msg("hdr_crc %08x", ubi32_to_cpu(vid_hdr->hdr_crc)); + dbg_msg("volume identifier header hexdump:"); +} + +/** + * ubi_dbg_dump_vol_info- dump volume information. + * @vol: UBI volume description object + */ +void ubi_dbg_dump_vol_info(const struct ubi_volume *vol) +{ + dbg_msg("volume information dump:"); + dbg_msg("vol_id %d", vol->vol_id); + dbg_msg("reserved_pebs %d", vol->reserved_pebs); + dbg_msg("alignment %d", vol->alignment); + dbg_msg("data_pad %d", vol->data_pad); + dbg_msg("vol_type %d", vol->vol_type); + dbg_msg("name_len %d", vol->name_len); + dbg_msg("usable_leb_size %d", vol->usable_leb_size); + dbg_msg("used_ebs %d", vol->used_ebs); + dbg_msg("used_bytes %lld", vol->used_bytes); + dbg_msg("last_eb_bytes %d", vol->last_eb_bytes); + dbg_msg("corrupted %d", vol->corrupted); + dbg_msg("upd_marker %d", vol->upd_marker); + + if (vol->name_len <= UBI_VOL_NAME_MAX && + strnlen(vol->name, vol->name_len + 1) == vol->name_len) { + dbg_msg("name %s", vol->name); + } else { + dbg_msg("the 1st 5 characters of the name: %c%c%c%c%c", + vol->name[0], vol->name[1], vol->name[2], + vol->name[3], vol->name[4]); + } +} + +/** + * ubi_dbg_dump_vtbl_record - dump a &struct ubi_vtbl_record object. + * @r: the object to dump + * @idx: volume table index + */ +void ubi_dbg_dump_vtbl_record(const struct ubi_vtbl_record *r, int idx) +{ + int name_len = ubi16_to_cpu(r->name_len); + + dbg_msg("volume table record %d dump:", idx); + dbg_msg("reserved_pebs %d", ubi32_to_cpu(r->reserved_pebs)); + dbg_msg("alignment %d", ubi32_to_cpu(r->alignment)); + dbg_msg("data_pad %d", ubi32_to_cpu(r->data_pad)); + dbg_msg("vol_type %d", (int)r->vol_type); + dbg_msg("upd_marker %d", (int)r->upd_marker); + dbg_msg("name_len %d", name_len); + + if (r->name[0] == '\0') { + dbg_msg("name NULL"); + return; + } + + if (name_len <= UBI_VOL_NAME_MAX && + strnlen(&r->name[0], name_len + 1) == name_len) { + dbg_msg("name %s", &r->name[0]); + } else { + dbg_msg("1st 5 characters of the name: %c%c%c%c%c", + r->name[0], r->name[1], r->name[2], r->name[3], + r->name[4]); + } + dbg_msg("crc %#08x", ubi32_to_cpu(r->crc)); +} + +/** + * ubi_dbg_dump_sv - dump a &struct ubi_scan_volume object. + * @sv: the object to dump + */ +void ubi_dbg_dump_sv(const struct ubi_scan_volume *sv) +{ + dbg_msg("volume scanning information dump:"); + dbg_msg("vol_id %d", sv->vol_id); + dbg_msg("highest_lnum %d", sv->highest_lnum); + dbg_msg("leb_count %d", sv->leb_count); + dbg_msg("compat %d", sv->compat); + dbg_msg("vol_type %d", sv->vol_type); + dbg_msg("used_ebs %d", sv->used_ebs); + dbg_msg("last_data_size %d", sv->last_data_size); + dbg_msg("data_pad %d", sv->data_pad); +} + +/** + * ubi_dbg_dump_seb - dump a &struct ubi_scan_leb object. + * @seb: the object to dump + * @type: object type: 0 - not corrupted, 1 - corrupted + */ +void ubi_dbg_dump_seb(const struct ubi_scan_leb *seb, int type) +{ + dbg_msg("eraseblock scanning information dump:"); + dbg_msg("ec %d", seb->ec); + dbg_msg("pnum %d", seb->pnum); + if (type == 0) { + dbg_msg("lnum %d", seb->lnum); + dbg_msg("scrub %d", seb->scrub); + dbg_msg("sqnum %llu", seb->sqnum); + dbg_msg("leb_ver %u", seb->leb_ver); + } +} + +/** + * ubi_dbg_dump_mkvol_req - dump a &struct ubi_mkvol_req object. + * @req: the object to dump + */ +void ubi_dbg_dump_mkvol_req(const struct ubi_mkvol_req *req) +{ + char nm[17]; + + dbg_msg("volume creation request dump:"); + dbg_msg("vol_id %d", req->vol_id); + dbg_msg("alignment %d", req->alignment); + dbg_msg("bytes %lld", (long long)req->bytes); + dbg_msg("vol_type %d", req->vol_type); + dbg_msg("name_len %d", req->name_len); + + memcpy(nm, req->name, 16); + nm[16] = 0; + dbg_msg("the 1st 16 characters of the name: %s", nm); +} + +#define BYTES_PER_LINE 32 + +/** + * ubi_dbg_hexdump - dump a buffer. + * @ptr: the buffer to dump + * @size: buffer size which must be multiple of 4 bytes + */ +void ubi_dbg_hexdump(const void *ptr, int size) +{ + int i, k = 0, rows, columns; + const uint8_t *p = ptr; + + size = ALIGN(size, 4); + rows = size/BYTES_PER_LINE + size % BYTES_PER_LINE; + for (i = 0; i < rows; i++) { + int j; + + cond_resched(); + columns = min(size - k, BYTES_PER_LINE) / 4; + if (columns == 0) + break; + printk(KERN_DEBUG "%5d: ", i * BYTES_PER_LINE); + for (j = 0; j < columns; j++) { + int n, N; + + N = size - k > 4 ? 4 : size - k; + for (n = 0; n < N; n++) + printk("%02x", p[k++]); + printk(" "); + } + printk("\n"); + } +} + +#endif /* CONFIG_MTD_UBI_DEBUG_MSG */ diff --git a/drivers/mtd/ubi/debug.h b/drivers/mtd/ubi/debug.h new file mode 100644 index 0000000..f816ad9 --- /dev/null +++ b/drivers/mtd/ubi/debug.h @@ -0,0 +1,161 @@ +/* + * Copyright (c) International Business Machines Corp., 2006 + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See + * the GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + * Author: Artem Bityutskiy (Битюцкий Артём) + */ + +#ifndef __UBI_DEBUG_H__ +#define __UBI_DEBUG_H__ + +#ifdef CONFIG_MTD_UBI_DEBUG +#include <linux/random.h> + +#define ubi_assert(expr) BUG_ON(!(expr)) +#define dbg_err(fmt, ...) ubi_err(fmt, ##__VA_ARGS__) +#else +#define ubi_assert(expr) ({}) +#define dbg_err(fmt, ...) ({}) +#endif + +#ifdef CONFIG_MTD_UBI_DEBUG_DISABLE_BGT +#define DBG_DISABLE_BGT 1 +#else +#define DBG_DISABLE_BGT 0 +#endif + +#ifdef CONFIG_MTD_UBI_DEBUG_MSG +/* Generic debugging message */ +#define dbg_msg(fmt, ...) \ + printk(KERN_DEBUG "UBI DBG: %s: " fmt "\n", __FUNCTION__, ##__VA_ARGS__) + +#define ubi_dbg_dump_stack() dump_stack() + +struct ubi_ec_hdr; +struct ubi_vid_hdr; +struct ubi_volume; +struct ubi_vtbl_record; +struct ubi_scan_volume; +struct ubi_scan_leb; +struct ubi_mkvol_req; + +void ubi_dbg_print(int type, const char *func, const char *fmt, ...); +void ubi_dbg_dump_ec_hdr(const struct ubi_ec_hdr *ec_hdr); +void ubi_dbg_dump_vid_hdr(const struct ubi_vid_hdr *vid_hdr); +void ubi_dbg_dump_vol_info(const struct ubi_volume *vol); +void ubi_dbg_dump_vtbl_record(const struct ubi_vtbl_record *r, int idx); +void ubi_dbg_dump_sv(const struct ubi_scan_volume *sv); +void ubi_dbg_dump_seb(const struct ubi_scan_leb *seb, int type); +void ubi_dbg_dump_mkvol_req(const struct ubi_mkvol_req *req); +void ubi_dbg_hexdump(const void *buf, int size); + +#else + +#define dbg_msg(fmt, ...) ({}) +#define ubi_dbg_dump_stack() ({}) +#define ubi_dbg_print(func, fmt, ...) ({}) +#define ubi_dbg_dump_ec_hdr(ec_hdr) ({}) +#define ubi_dbg_dump_vid_hdr(vid_hdr) ({}) +#define ubi_dbg_dump_vol_info(vol) ({}) +#define ubi_dbg_dump_vtbl_record(r, idx) ({}) +#define ubi_dbg_dump_sv(sv) ({}) +#define ubi_dbg_dump_seb(seb, type) ({}) +#define ubi_dbg_dump_mkvol_req(req) ({}) +#define ubi_dbg_hexdump(buf, size) ({}) + +#endif /* CONFIG_MTD_UBI_DEBUG_MSG */ + +#ifdef CONFIG_MTD_UBI_DEBUG_MSG_EBA +/* Messages from the eraseblock association unit */ +#define dbg_eba(fmt, ...) \ + printk(KERN_DEBUG "UBI DBG eba: %s: " fmt "\n", __FUNCTION__, \ + ##__VA_ARGS__) +#else +#define dbg_eba(fmt, ...) ({}) +#endif + +#ifdef CONFIG_MTD_UBI_DEBUG_MSG_WL +/* Messages from the wear-leveling unit */ +#define dbg_wl(fmt, ...) \ + printk(KERN_DEBUG "UBI DBG wl: %s: " fmt "\n", __FUNCTION__, \ + ##__VA_ARGS__) +#else +#define dbg_wl(fmt, ...) ({}) +#endif + +#ifdef CONFIG_MTD_UBI_DEBUG_MSG_IO +/* Messages from the input/output unit */ +#define dbg_io(fmt, ...) \ + printk(KERN_DEBUG "UBI DBG io: %s: " fmt "\n", __FUNCTION__, \ + ##__VA_ARGS__) +#else +#define dbg_io(fmt, ...) ({}) +#endif + +#ifdef CONFIG_MTD_UBI_DEBUG_MSG_BLD +/* Initialization and build messages */ +#define dbg_bld(fmt, ...) \ + printk(KERN_DEBUG "UBI DBG bld: %s: " fmt "\n", __FUNCTION__, \ + ##__VA_ARGS__) +#else +#define dbg_bld(fmt, ...) ({}) +#endif + +#ifdef CONFIG_MTD_UBI_DEBUG_EMULATE_BITFLIPS +/** + * ubi_dbg_is_bitflip - if it is time to emulate a bit-flip. + * + * Returns non-zero if a bit-flip should be emulated, otherwise returns zero. + */ +static inline int ubi_dbg_is_bitflip(void) +{ + return !(random32() % 200); +} +#else +#define ubi_dbg_is_bitflip() 0 +#endif + +#ifdef CONFIG_MTD_UBI_DEBUG_EMULATE_WRITE_FAILURES +/** + * ubi_dbg_is_write_failure - if it is time to emulate a write failure. + * + * Returns non-zero if a write failure should be emulated, otherwise returns + * zero. + */ +static inline int ubi_dbg_is_write_failure(void) +{ + return !(random32() % 500); +} +#else +#define ubi_dbg_is_write_failure() 0 +#endif + +#ifdef CONFIG_MTD_UBI_DEBUG_EMULATE_ERASE_FAILURES +/** + * ubi_dbg_is_erase_failure - if its time to emulate an erase failure. + * + * Returns non-zero if an erase failure should be emulated, otherwise returns + * zero. + */ +static inline int ubi_dbg_is_erase_failure(void) +{ + return !(random32() % 400); +} +#else +#define ubi_dbg_is_erase_failure() 0 +#endif + +#endif /* !__UBI_DEBUG_H__ */ diff --git a/drivers/mtd/ubi/eba.c b/drivers/mtd/ubi/eba.c new file mode 100644 index 0000000..d847ee1 --- /dev/null +++ b/drivers/mtd/ubi/eba.c @@ -0,0 +1,1241 @@ +/* + * Copyright (c) International Business Machines Corp., 2006 + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See + * the GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + * Author: Artem Bityutskiy (Битюцкий Артём) + */ + +/* + * The UBI Eraseblock Association (EBA) unit. + * + * This unit is responsible for I/O to/from logical eraseblock. + * + * Although in this implementation the EBA table is fully kept and managed in + * RAM, which assumes poor scalability, it might be (partially) maintained on + * flash in future implementations. + * + * The EBA unit implements per-logical eraseblock locking. Before accessing a + * logical eraseblock it is locked for reading or writing. The per-logical + * eraseblock locking is implemented by means of the lock tree. The lock tree + * is an RB-tree which refers all the currently locked logical eraseblocks. The + * lock tree elements are &struct ltree_entry objects. They are indexed by + * (@vol_id, @lnum) pairs. + * + * EBA also maintains the global sequence counter which is incremented each + * time a logical eraseblock is mapped to a physical eraseblock and it is + * stored in the volume identifier header. This means that each VID header has + * a unique sequence number. The sequence number is only increased an we assume + * 64 bits is enough to never overflow. + */ + +#include <linux/slab.h> +#include <linux/crc32.h> +#include <linux/err.h> +#include "ubi.h" + +/** + * struct ltree_entry - an entry in the lock tree. + * @rb: links RB-tree nodes + * @vol_id: volume ID of the locked logical eraseblock + * @lnum: locked logical eraseblock number + * @users: how many tasks are using this logical eraseblock or wait for it + * @mutex: read/write mutex to implement read/write access serialization to + * the (@vol_id, @lnum) logical eraseblock + * + * When a logical eraseblock is being locked - corresponding &struct ltree_entry + * object is inserted to the lock tree (@ubi->ltree). + */ +struct ltree_entry { + struct rb_node rb; + int vol_id; + int lnum; + int users; + struct rw_semaphore mutex; +}; + +/* Slab cache for lock-tree entries */ +static struct kmem_cache *ltree_slab; + +/** + * next_sqnum - get next sequence number. + * @ubi: UBI device description object + * + * This function returns next sequence number to use, which is just the current + * global sequence counter value. It also increases the global sequence + * counter. + */ +static unsigned long long next_sqnum(struct ubi_device *ubi) +{ + unsigned long long sqnum; + + spin_lock(&ubi->ltree_lock); + sqnum = ubi->global_sqnum++; + spin_unlock(&ubi->ltree_lock); + + return sqnum; +} + +/** + * ubi_get_compat - get compatibility flags of a volume. + * @ubi: UBI device description object + * @vol_id: volume ID + * + * This function returns compatibility flags for an internal volume. User + * volumes have no compatibility flags, so %0 is returned. + */ +static int ubi_get_compat(const struct ubi_device *ubi, int vol_id) +{ + if (vol_id == UBI_LAYOUT_VOL_ID) + return UBI_LAYOUT_VOLUME_COMPAT; + return 0; +} + +/** + * ltree_lookup - look up the lock tree. + * @ubi: UBI device description object + * @vol_id: volume ID + * @lnum: logical eraseblock number + * + * This function returns a pointer to the corresponding &struct ltree_entry + * object if the logical eraseblock is locked and %NULL if it is not. + * @ubi->ltree_lock has to be locked. + */ +static struct ltree_entry *ltree_lookup(struct ubi_device *ubi, int vol_id, + int lnum) +{ + struct rb_node *p; + + p = ubi->ltree.rb_node; + while (p) { + struct ltree_entry *le; + + le = rb_entry(p, struct ltree_entry, rb); + + if (vol_id < le->vol_id) + p = p->rb_left; + else if (vol_id > le->vol_id) + p = p->rb_right; + else { + if (lnum < le->lnum) + p = p->rb_left; + else if (lnum > le->lnum) + p = p->rb_right; + else + return le; + } + } + + return NULL; +} + +/** + * ltree_add_entry - add new entry to the lock tree. + * @ubi: UBI device description object + * @vol_id: volume ID + * @lnum: logical eraseblock number + * + * This function adds new entry for logical eraseblock (@vol_id, @lnum) to the + * lock tree. If such entry is already there, its usage counter is increased. + * Returns pointer to the lock tree entry or %-ENOMEM if memory allocation + * failed. + */ +static struct ltree_entry *ltree_add_entry(struct ubi_device *ubi, int vol_id, + int lnum) +{ + struct ltree_entry *le, *le1, *le_free; + + le = kmem_cache_alloc(ltree_slab, GFP_KERNEL); + if (!le) + return ERR_PTR(-ENOMEM); + + le->vol_id = vol_id; + le->lnum = lnum; + + spin_lock(&ubi->ltree_lock); + le1 = ltree_lookup(ubi, vol_id, lnum); + + if (le1) { + /* + * This logical eraseblock is already locked. The newly + * allocated lock entry is not needed. + */ + le_free = le; + le = le1; + } else { + struct rb_node **p, *parent = NULL; + + /* + * No lock entry, add the newly allocated one to the + * @ubi->ltree RB-tree. + */ + le_free = NULL; + + p = &ubi->ltree.rb_node; + while (*p) { + parent = *p; + le1 = rb_entry(parent, struct ltree_entry, rb); + + if (vol_id < le1->vol_id) + p = &(*p)->rb_left; + else if (vol_id > le1->vol_id) + p = &(*p)->rb_right; + else { + ubi_assert(lnum != le1->lnum); + if (lnum < le1->lnum) + p = &(*p)->rb_left; + else + p = &(*p)->rb_right; + } + } + + rb_link_node(&le->rb, parent, p); + rb_insert_color(&le->rb, &ubi->ltree); + } + le->users += 1; + spin_unlock(&ubi->ltree_lock); + + if (le_free) + kmem_cache_free(ltree_slab, le_free); + + return le; +} + +/** + * leb_read_lock - lock logical eraseblock for reading. + * @ubi: UBI device description object + * @vol_id: volume ID + * @lnum: logical eraseblock number + * + * This function locks a logical eraseblock for reading. Returns zero in case + * of success and a negative error code in case of failure. + */ +static int leb_read_lock(struct ubi_device *ubi, int vol_id, int lnum) +{ + struct ltree_entry *le; + + le = ltree_add_entry(ubi, vol_id, lnum); + if (IS_ERR(le)) + return PTR_ERR(le); + down_read(&le->mutex); + return 0; +} + +/** + * leb_read_unlock - unlock logical eraseblock. + * @ubi: UBI device description object + * @vol_id: volume ID + * @lnum: logical eraseblock number + */ +static void leb_read_unlock(struct ubi_device *ubi, int vol_id, int lnum) +{ + int free = 0; + struct ltree_entry *le; + + spin_lock(&ubi->ltree_lock); + le = ltree_lookup(ubi, vol_id, lnum); + le->users -= 1; + ubi_assert(le->users >= 0); + if (le->users == 0) { + rb_erase(&le->rb, &ubi->ltree); + free = 1; + } + spin_unlock(&ubi->ltree_lock); + + up_read(&le->mutex); + if (free) + kmem_cache_free(ltree_slab, le); +} + +/** + * leb_write_lock - lock logical eraseblock for writing. + * @ubi: UBI device description object + * @vol_id: volume ID + * @lnum: logical eraseblock number + * + * This function locks a logical eraseblock for writing. Returns zero in case + * of success and a negative error code in case of failure. + */ +static int leb_write_lock(struct ubi_device *ubi, int vol_id, int lnum) +{ + struct ltree_entry *le; + + le = ltree_add_entry(ubi, vol_id, lnum); + if (IS_ERR(le)) + return PTR_ERR(le); + down_write(&le->mutex); + return 0; +} + +/** + * leb_write_unlock - unlock logical eraseblock. + * @ubi: UBI device description object + * @vol_id: volume ID + * @lnum: logical eraseblock number + */ +static void leb_write_unlock(struct ubi_device *ubi, int vol_id, int lnum) +{ + int free; + struct ltree_entry *le; + + spin_lock(&ubi->ltree_lock); + le = ltree_lookup(ubi, vol_id, lnum); + le->users -= 1; + ubi_assert(le->users >= 0); + if (le->users == 0) { + rb_erase(&le->rb, &ubi->ltree); + free = 1; + } else + free = 0; + spin_unlock(&ubi->ltree_lock); + + up_write(&le->mutex); + if (free) + kmem_cache_free(ltree_slab, le); +} + +/** + * ubi_eba_unmap_leb - un-map logical eraseblock. + * @ubi: UBI device description object + * @vol_id: volume ID + * @lnum: logical eraseblock number + * + * This function un-maps logical eraseblock @lnum and schedules corresponding + * physical eraseblock for erasure. Returns zero in case of success and a + * negative error code in case of failure. + */ +int ubi_eba_unmap_leb(struct ubi_device *ubi, int vol_id, int lnum) +{ + int idx = vol_id2idx(ubi, vol_id), err, pnum; + struct ubi_volume *vol = ubi->volumes[idx]; + + if (ubi->ro_mode) + return -EROFS; + + err = leb_write_lock(ubi, vol_id, lnum); + if (err) + return err; + + pnum = vol->eba_tbl[lnum]; + if (pnum < 0) + /* This logical eraseblock is already unmapped */ + goto out_unlock; + + dbg_eba("erase LEB %d:%d, PEB %d", vol_id, lnum, pnum); + + vol->eba_tbl[lnum] = UBI_LEB_UNMAPPED; + err = ubi_wl_put_peb(ubi, pnum, 0); + +out_unlock: + leb_write_unlock(ubi, vol_id, lnum); + return err; +} + +/** + * ubi_eba_read_leb - read data. + * @ubi: UBI device description object + * @vol_id: volume ID + * @lnum: logical eraseblock number + * @buf: buffer to store the read data + * @offset: offset from where to read + * @len: how many bytes to read + * @check: data CRC check flag + * + * If the logical eraseblock @lnum is unmapped, @buf is filled with 0xFF + * bytes. The @check flag only makes sense for static volumes and forces + * eraseblock data CRC checking. + * + * In case of success this function returns zero. In case of a static volume, + * if data CRC mismatches - %-EBADMSG is returned. %-EBADMSG may also be + * returned for any volume type if an ECC error was detected by the MTD device + * driver. Other negative error cored may be returned in case of other errors. + */ +int ubi_eba_read_leb(struct ubi_device *ubi, int vol_id, int lnum, void *buf, + int offset, int len, int check) +{ + int err, pnum, scrub = 0, idx = vol_id2idx(ubi, vol_id); + struct ubi_vid_hdr *vid_hdr; + struct ubi_volume *vol = ubi->volumes[idx]; + uint32_t crc, crc1; + + err = leb_read_lock(ubi, vol_id, lnum); + if (err) + return err; + + pnum = vol->eba_tbl[lnum]; + if (pnum < 0) { + /* + * The logical eraseblock is not mapped, fill the whole buffer + * with 0xFF bytes. The exception is static volumes for which + * it is an error to read unmapped logical eraseblocks. + */ + dbg_eba("read %d bytes from offset %d of LEB %d:%d (unmapped)", + len, offset, vol_id, lnum); + leb_read_unlock(ubi, vol_id, lnum); + ubi_assert(vol->vol_type != UBI_STATIC_VOLUME); + memset(buf, 0xFF, len); + return 0; + } + + dbg_eba("read %d bytes from offset %d of LEB %d:%d, PEB %d", + len, offset, vol_id, lnum, pnum); + + if (vol->vol_type == UBI_DYNAMIC_VOLUME) + check = 0; + +retry: + if (check) { + vid_hdr = ubi_zalloc_vid_hdr(ubi); + if (!vid_hdr) { + err = -ENOMEM; + goto out_unlock; + } + + err = ubi_io_read_vid_hdr(ubi, pnum, vid_hdr, 1); + if (err && err != UBI_IO_BITFLIPS) { + if (err > 0) { + /* + * The header is either absent or corrupted. + * The former case means there is a bug - + * switch to read-only mode just in case. + * The latter case means a real corruption - we + * may try to recover data. FIXME: but this is + * not implemented. + */ + if (err == UBI_IO_BAD_VID_HDR) { + ubi_warn("bad VID header at PEB %d, LEB" + "%d:%d", pnum, vol_id, lnum); + err = -EBADMSG; + } else + ubi_ro_mode(ubi); + } + goto out_free; + } else if (err == UBI_IO_BITFLIPS) + scrub = 1; + + ubi_assert(lnum < ubi32_to_cpu(vid_hdr->used_ebs)); + ubi_assert(len == ubi32_to_cpu(vid_hdr->data_size)); + + crc = ubi32_to_cpu(vid_hdr->data_crc); + ubi_free_vid_hdr(ubi, vid_hdr); + } + + err = ubi_io_read_data(ubi, buf, pnum, offset, len); + if (err) { + if (err == UBI_IO_BITFLIPS) { + scrub = 1; + err = 0; + } else if (err == -EBADMSG) { + if (vol->vol_type == UBI_DYNAMIC_VOLUME) + goto out_unlock; + scrub = 1; + if (!check) { + ubi_msg("force data checking"); + check = 1; + goto retry; + } + } else + goto out_unlock; + } + + if (check) { + crc1 = crc32(UBI_CRC32_INIT, buf, len); + if (crc1 != crc) { + ubi_warn("CRC error: calculated %#08x, must be %#08x", + crc1, crc); + err = -EBADMSG; + goto out_unlock; + } + } + + if (scrub) + err = ubi_wl_scrub_peb(ubi, pnum); + + leb_read_unlock(ubi, vol_id, lnum); + return err; + +out_free: + ubi_free_vid_hdr(ubi, vid_hdr); +out_unlock: + leb_read_unlock(ubi, vol_id, lnum); + return err; +} + +/** + * recover_peb - recover from write failure. + * @ubi: UBI device description object + * @pnum: the physical eraseblock to recover + * @vol_id: volume ID + * @lnum: logical eraseblock number + * @buf: data which was not written because of the write failure + * @offset: offset of the failed write + * @len: how many bytes should have been written + * + * This function is called in case of a write failure and moves all good data + * from the potentially bad physical eraseblock to a good physical eraseblock. + * This function also writes the data which was not written due to the failure. + * Returns new physical eraseblock number in case of success, and a negative + * error code in case of failure. + */ +static int recover_peb(struct ubi_device *ubi, int pnum, int vol_id, int lnum, + const void *buf, int offset, int len) +{ + int err, idx = vol_id2idx(ubi, vol_id), new_pnum, data_size, tries = 0; + struct ubi_volume *vol = ubi->volumes[idx]; + struct ubi_vid_hdr *vid_hdr; + unsigned char *new_buf; + + vid_hdr = ubi_zalloc_vid_hdr(ubi); + if (!vid_hdr) { + return -ENOMEM; + } + +retry: + new_pnum = ubi_wl_get_peb(ubi, UBI_UNKNOWN); + if (new_pnum < 0) { + ubi_free_vid_hdr(ubi, vid_hdr); + return new_pnum; + } + + ubi_msg("recover PEB %d, move data to PEB %d", pnum, new_pnum); + + err = ubi_io_read_vid_hdr(ubi, pnum, vid_hdr, 1); + if (err && err != UBI_IO_BITFLIPS) { + if (err > 0) + err = -EIO; + goto out_put; + } + + vid_hdr->sqnum = cpu_to_ubi64(next_sqnum(ubi)); + err = ubi_io_write_vid_hdr(ubi, new_pnum, vid_hdr); + if (err) + goto write_error; + + data_size = offset + len; + new_buf = kmalloc(data_size, GFP_KERNEL); + if (!new_buf) { + err = -ENOMEM; + goto out_put; + } + memset(new_buf + offset, 0xFF, len); + + /* Read everything before the area where the write failure happened */ + if (offset > 0) { + err = ubi_io_read_data(ubi, new_buf, pnum, 0, offset); + if (err && err != UBI_IO_BITFLIPS) { + kfree(new_buf); + goto out_put; + } + } + + memcpy(new_buf + offset, buf, len); + + err = ubi_io_write_data(ubi, new_buf, new_pnum, 0, data_size); + if (err) { + kfree(new_buf); + goto write_error; + } + + kfree(new_buf); + ubi_free_vid_hdr(ubi, vid_hdr); + + vol->eba_tbl[lnum] = new_pnum; + ubi_wl_put_peb(ubi, pnum, 1); + + ubi_msg("data was successfully recovered"); + return 0; + +out_put: + ubi_wl_put_peb(ubi, new_pnum, 1); + ubi_free_vid_hdr(ubi, vid_hdr); + return err; + +write_error: + /* + * Bad luck? This physical eraseblock is bad too? Crud. Let's try to + * get another one. + */ + ubi_warn("failed to write to PEB %d", new_pnum); + ubi_wl_put_peb(ubi, new_pnum, 1); + if (++tries > UBI_IO_RETRIES) { + ubi_free_vid_hdr(ubi, vid_hdr); + return err; + } + ubi_msg("try again"); + goto retry; +} + +/** + * ubi_eba_write_leb - write data to dynamic volume. + * @ubi: UBI device description object + * @vol_id: volume ID + * @lnum: logical eraseblock number + * @buf: the data to write + * @offset: offset within the logical eraseblock where to write + * @len: how many bytes to write + * @dtype: data type + * + * This function writes data to logical eraseblock @lnum of a dynamic volume + * @vol_id. Returns zero in case of success and a negative error code in case + * of failure. In case of error, it is possible that something was still + * written to the flash media, but may be some garbage. + */ +int ubi_eba_write_leb(struct ubi_device *ubi, int vol_id, int lnum, + const void *buf, int offset, int len, int dtype) +{ + int idx = vol_id2idx(ubi, vol_id), err, pnum, tries = 0; + struct ubi_volume *vol = ubi->volumes[idx]; + struct ubi_vid_hdr *vid_hdr; + + if (ubi->ro_mode) + return -EROFS; + + err = leb_write_lock(ubi, vol_id, lnum); + if (err) + return err; + + pnum = vol->eba_tbl[lnum]; + if (pnum >= 0) { + dbg_eba("write %d bytes at offset %d of LEB %d:%d, PEB %d", + len, offset, vol_id, lnum, pnum); + + err = ubi_io_write_data(ubi, buf, pnum, offset, len); + if (err) { + ubi_warn("failed to write data to PEB %d", pnum); + if (err == -EIO && ubi->bad_allowed) + err = recover_peb(ubi, pnum, vol_id, lnum, buf, offset, len); + if (err) + ubi_ro_mode(ubi); + } + leb_write_unlock(ubi, vol_id, lnum); + return err; + } + + /* + * The logical eraseblock is not mapped. We have to get a free physical + * eraseblock and write the volume identifier header there first. + */ + vid_hdr = ubi_zalloc_vid_hdr(ubi); + if (!vid_hdr) { + leb_write_unlock(ubi, vol_id, lnum); + return -ENOMEM; + } + + vid_hdr->vol_type = UBI_VID_DYNAMIC; + vid_hdr->sqnum = cpu_to_ubi64(next_sqnum(ubi)); + vid_hdr->vol_id = cpu_to_ubi32(vol_id); + vid_hdr->lnum = cpu_to_ubi32(lnum); + vid_hdr->compat = ubi_get_compat(ubi, vol_id); + vid_hdr->data_pad = cpu_to_ubi32(vol->data_pad); + +retry: + pnum = ubi_wl_get_peb(ubi, dtype); + if (pnum < 0) { + ubi_free_vid_hdr(ubi, vid_hdr); + leb_write_unlock(ubi, vol_id, lnum); + return pnum; + } + + dbg_eba("write VID hdr and %d bytes at offset %d of LEB %d:%d, PEB %d", + len, offset, vol_id, lnum, pnum); + + err = ubi_io_write_vid_hdr(ubi, pnum, vid_hdr); + if (err) { + ubi_warn("failed to write VID header to LEB %d:%d, PEB %d", + vol_id, lnum, pnum); + goto write_error; + } + + err = ubi_io_write_data(ubi, buf, pnum, offset, len); + if (err) { + ubi_warn("failed to write %d bytes at offset %d of LEB %d:%d, " + "PEB %d", len, offset, vol_id, lnum, pnum); + goto write_error; + } + + vol->eba_tbl[lnum] = pnum; + + leb_write_unlock(ubi, vol_id, lnum); + ubi_free_vid_hdr(ubi, vid_hdr); + return 0; + +write_error: + if (err != -EIO || !ubi->bad_allowed) { + ubi_ro_mode(ubi); + leb_write_unlock(ubi, vol_id, lnum); + ubi_free_vid_hdr(ubi, vid_hdr); + return err; + } + + /* + * Fortunately, this is the first write operation to this physical + * eraseblock, so just put it and request a new one. We assume that if + * this physical eraseblock went bad, the erase code will handle that. + */ + err = ubi_wl_put_peb(ubi, pnum, 1); + if (err || ++tries > UBI_IO_RETRIES) { + ubi_ro_mode(ubi); + leb_write_unlock(ubi, vol_id, lnum); + ubi_free_vid_hdr(ubi, vid_hdr); + return err; + } + + vid_hdr->sqnum = cpu_to_ubi64(next_sqnum(ubi)); + ubi_msg("try another PEB"); + goto retry; +} + +/** + * ubi_eba_write_leb_st - write data to static volume. + * @ubi: UBI device description object + * @vol_id: volume ID + * @lnum: logical eraseblock number + * @buf: data to write + * @len: how many bytes to write + * @dtype: data type + * @used_ebs: how many logical eraseblocks will this volume contain + * + * This function writes data to logical eraseblock @lnum of static volume + * @vol_id. The @used_ebs argument should contain total number of logical + * eraseblock in this static volume. + * + * When writing to the last logical eraseblock, the @len argument doesn't have + * to be aligned to the minimal I/O unit size. Instead, it has to be equivalent + * to the real data size, although the @buf buffer has to contain the + * alignment. In all other cases, @len has to be aligned. + * + * It is prohibited to write more then once to logical eraseblocks of static + * volumes. This function returns zero in case of success and a negative error + * code in case of failure. + */ +int ubi_eba_write_leb_st(struct ubi_device *ubi, int vol_id, int lnum, + const void *buf, int len, int dtype, int used_ebs) +{ + int err, pnum, tries = 0, data_size = len; + int idx = vol_id2idx(ubi, vol_id); + struct ubi_volume *vol = ubi->volumes[idx]; + struct ubi_vid_hdr *vid_hdr; + uint32_t crc; + + if (ubi->ro_mode) + return -EROFS; + + if (lnum == used_ebs - 1) + /* If this is the last LEB @len may be unaligned */ + len = ALIGN(data_size, ubi->min_io_size); + else + ubi_assert(len % ubi->min_io_size == 0); + + vid_hdr = ubi_zalloc_vid_hdr(ubi); + if (!vid_hdr) + return -ENOMEM; + + err = leb_write_lock(ubi, vol_id, lnum); + if (err) { + ubi_free_vid_hdr(ubi, vid_hdr); + return err; + } + + vid_hdr->sqnum = cpu_to_ubi64(next_sqnum(ubi)); + vid_hdr->vol_id = cpu_to_ubi32(vol_id); + vid_hdr->lnum = cpu_to_ubi32(lnum); + vid_hdr->compat = ubi_get_compat(ubi, vol_id); + vid_hdr->data_pad = cpu_to_ubi32(vol->data_pad); + + crc = crc32(UBI_CRC32_INIT, buf, data_size); + vid_hdr->vol_type = UBI_VID_STATIC; + vid_hdr->data_size = cpu_to_ubi32(data_size); + vid_hdr->used_ebs = cpu_to_ubi32(used_ebs); + vid_hdr->data_crc = cpu_to_ubi32(crc); + +retry: + pnum = ubi_wl_get_peb(ubi, dtype); + if (pnum < 0) { + ubi_free_vid_hdr(ubi, vid_hdr); + leb_write_unlock(ubi, vol_id, lnum); + return pnum; + } + + dbg_eba("write VID hdr and %d bytes at LEB %d:%d, PEB %d, used_ebs %d", + len, vol_id, lnum, pnum, used_ebs); + + err = ubi_io_write_vid_hdr(ubi, pnum, vid_hdr); + if (err) { + ubi_warn("failed to write VID header to LEB %d:%d, PEB %d", + vol_id, lnum, pnum); + goto write_error; + } + + err = ubi_io_write_data(ubi, buf, pnum, 0, len); + if (err) { + ubi_warn("failed to write %d bytes of data to PEB %d", + len, pnum); + goto write_error; + } + + ubi_assert(vol->eba_tbl[lnum] < 0); + vol->eba_tbl[lnum] = pnum; + + leb_write_unlock(ubi, vol_id, lnum); + ubi_free_vid_hdr(ubi, vid_hdr); + return 0; + +write_error: + if (err != -EIO || !ubi->bad_allowed) { + /* + * This flash device does not admit of bad eraseblocks or + * something nasty and unexpected happened. Switch to read-only + * mode just in case. + */ + ubi_ro_mode(ubi); + leb_write_unlock(ubi, vol_id, lnum); + ubi_free_vid_hdr(ubi, vid_hdr); + return err; + } + + err = ubi_wl_put_peb(ubi, pnum, 1); + if (err || ++tries > UBI_IO_RETRIES) { + ubi_ro_mode(ubi); + leb_write_unlock(ubi, vol_id, lnum); + ubi_free_vid_hdr(ubi, vid_hdr); + return err; + } + + vid_hdr->sqnum = cpu_to_ubi64(next_sqnum(ubi)); + ubi_msg("try another PEB"); + goto retry; +} + +/* + * ubi_eba_atomic_leb_change - change logical eraseblock atomically. + * @ubi: UBI device description object + * @vol_id: volume ID + * @lnum: logical eraseblock number + * @buf: data to write + * @len: how many bytes to write + * @dtype: data type + * + * This function changes the contents of a logical eraseblock atomically. @buf + * has to contain new logical eraseblock data, and @len - the length of the + * data, which has to be aligned. This function guarantees that in case of an + * unclean reboot the old contents is preserved. Returns zero in case of + * success and a negative error code in case of failure. + */ +int ubi_eba_atomic_leb_change(struct ubi_device *ubi, int vol_id, int lnum, + const void *buf, int len, int dtype) +{ + int err, pnum, tries = 0, idx = vol_id2idx(ubi, vol_id); + struct ubi_volume *vol = ubi->volumes[idx]; + struct ubi_vid_hdr *vid_hdr; + uint32_t crc; + + if (ubi->ro_mode) + return -EROFS; + + vid_hdr = ubi_zalloc_vid_hdr(ubi); + if (!vid_hdr) + return -ENOMEM; + + err = leb_write_lock(ubi, vol_id, lnum); + if (err) { + ubi_free_vid_hdr(ubi, vid_hdr); + return err; + } + + vid_hdr->sqnum = cpu_to_ubi64(next_sqnum(ubi)); + vid_hdr->vol_id = cpu_to_ubi32(vol_id); + vid_hdr->lnum = cpu_to_ubi32(lnum); + vid_hdr->compat = ubi_get_compat(ubi, vol_id); + vid_hdr->data_pad = cpu_to_ubi32(vol->data_pad); + + crc = crc32(UBI_CRC32_INIT, buf, len); + vid_hdr->vol_type = UBI_VID_STATIC; + vid_hdr->data_size = cpu_to_ubi32(len); + vid_hdr->copy_flag = 1; + vid_hdr->data_crc = cpu_to_ubi32(crc); + +retry: + pnum = ubi_wl_get_peb(ubi, dtype); + if (pnum < 0) { + ubi_free_vid_hdr(ubi, vid_hdr); + leb_write_unlock(ubi, vol_id, lnum); + return pnum; + } + + dbg_eba("change LEB %d:%d, PEB %d, write VID hdr to PEB %d", + vol_id, lnum, vol->eba_tbl[lnum], pnum); + + err = ubi_io_write_vid_hdr(ubi, pnum, vid_hdr); + if (err) { + ubi_warn("failed to write VID header to LEB %d:%d, PEB %d", + vol_id, lnum, pnum); + goto write_error; + } + + err = ubi_io_write_data(ubi, buf, pnum, 0, len); + if (err) { + ubi_warn("failed to write %d bytes of data to PEB %d", + len, pnum); + goto write_error; + } + + err = ubi_wl_put_peb(ubi, vol->eba_tbl[lnum], 1); + if (err) { + ubi_free_vid_hdr(ubi, vid_hdr); + leb_write_unlock(ubi, vol_id, lnum); + return err; + } + + vol->eba_tbl[lnum] = pnum; + leb_write_unlock(ubi, vol_id, lnum); + ubi_free_vid_hdr(ubi, vid_hdr); + return 0; + +write_error: + if (err != -EIO || !ubi->bad_allowed) { + /* + * This flash device does not admit of bad eraseblocks or + * something nasty and unexpected happened. Switch to read-only + * mode just in case. + */ + ubi_ro_mode(ubi); + leb_write_unlock(ubi, vol_id, lnum); + ubi_free_vid_hdr(ubi, vid_hdr); + return err; + } + + err = ubi_wl_put_peb(ubi, pnum, 1); + if (err || ++tries > UBI_IO_RETRIES) { + ubi_ro_mode(ubi); + leb_write_unlock(ubi, vol_id, lnum); + ubi_free_vid_hdr(ubi, vid_hdr); + return err; + } + + vid_hdr->sqnum = cpu_to_ubi64(next_sqnum(ubi)); + ubi_msg("try another PEB"); + goto retry; +} + +/** + * ltree_entry_ctor - lock tree entries slab cache constructor. + * @obj: the lock-tree entry to construct + * @cache: the lock tree entry slab cache + * @flags: constructor flags + */ +static void ltree_entry_ctor(void *obj, struct kmem_cache *cache, + unsigned long flags) +{ + struct ltree_entry *le = obj; + + if ((flags & (SLAB_CTOR_VERIFY | SLAB_CTOR_CONSTRUCTOR)) != + SLAB_CTOR_CONSTRUCTOR) + return; + + le->users = 0; + init_rwsem(&le->mutex); +} + +/** + * ubi_eba_copy_leb - copy logical eraseblock. + * @ubi: UBI device description object + * @from: physical eraseblock number from where to copy + * @to: physical eraseblock number where to copy + * @vid_hdr: VID header of the @from physical eraseblock + * + * This function copies logical eraseblock from physical eraseblock @from to + * physical eraseblock @to. The @vid_hdr buffer may be changed by this + * function. Returns zero in case of success, %UBI_IO_BITFLIPS if the operation + * was canceled because bit-flips were detected at the target PEB, and a + * negative error code in case of failure. + */ +int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to, + struct ubi_vid_hdr *vid_hdr) +{ + int err, vol_id, lnum, data_size, aldata_size, pnum, idx; + struct ubi_volume *vol; + uint32_t crc; + void *buf, *buf1 = NULL; + + vol_id = ubi32_to_cpu(vid_hdr->vol_id); + lnum = ubi32_to_cpu(vid_hdr->lnum); + + dbg_eba("copy LEB %d:%d, PEB %d to PEB %d", vol_id, lnum, from, to); + + if (vid_hdr->vol_type == UBI_VID_STATIC) { + data_size = ubi32_to_cpu(vid_hdr->data_size); + aldata_size = ALIGN(data_size, ubi->min_io_size); + } else + data_size = aldata_size = + ubi->leb_size - ubi32_to_cpu(vid_hdr->data_pad); + + buf = kmalloc(aldata_size, GFP_KERNEL); + if (!buf) + return -ENOMEM; + + /* + * We do not want anybody to write to this logical eraseblock while we + * are moving it, so we lock it. + */ + err = leb_write_lock(ubi, vol_id, lnum); + if (err) { + kfree(buf); + return err; + } + + /* + * But the logical eraseblock might have been put by this time. + * Cancel if it is true. + */ + idx = vol_id2idx(ubi, vol_id); + + /* + * We may race with volume deletion/re-size, so we have to hold + * @ubi->volumes_lock. + */ + spin_lock(&ubi->volumes_lock); + vol = ubi->volumes[idx]; + if (!vol) { + dbg_eba("volume %d was removed meanwhile", vol_id); + spin_unlock(&ubi->volumes_lock); + goto out_unlock; + } + + pnum = vol->eba_tbl[lnum]; + if (pnum != from) { + dbg_eba("LEB %d:%d is no longer mapped to PEB %d, mapped to " + "PEB %d, cancel", vol_id, lnum, from, pnum); + spin_unlock(&ubi->volumes_lock); + goto out_unlock; + } + spin_unlock(&ubi->volumes_lock); + + /* OK, now the LEB is locked and we can safely start moving it */ + + dbg_eba("read %d bytes of data", aldata_size); + err = ubi_io_read_data(ubi, buf, from, 0, aldata_size); + if (err && err != UBI_IO_BITFLIPS) { + ubi_warn("error %d while reading data from PEB %d", + err, from); + goto out_unlock; + } + + /* + * Now we have got to calculate how much data we have to to copy. In + * case of a static volume it is fairly easy - the VID header contains + * the data size. In case of a dynamic volume it is more difficult - we + * have to read the contents, cut 0xFF bytes from the end and copy only + * the first part. We must do this to avoid writing 0xFF bytes as it + * may have some side-effects. And not only this. It is important not + * to include those 0xFFs to CRC because later the they may be filled + * by data. + */ + if (vid_hdr->vol_type == UBI_VID_DYNAMIC) + aldata_size = data_size = + ubi_calc_data_len(ubi, buf, data_size); + + cond_resched(); + crc = crc32(UBI_CRC32_INIT, buf, data_size); + cond_resched(); + + /* + * It may turn out to me that the whole @from physical eraseblock + * contains only 0xFF bytes. Then we have to only write the VID header + * and do not write any data. This also means we should not set + * @vid_hdr->copy_flag, @vid_hdr->data_size, and @vid_hdr->data_crc. + */ + if (data_size > 0) { + vid_hdr->copy_flag = 1; + vid_hdr->data_size = cpu_to_ubi32(data_size); + vid_hdr->data_crc = cpu_to_ubi32(crc); + } + vid_hdr->sqnum = cpu_to_ubi64(next_sqnum(ubi)); + + err = ubi_io_write_vid_hdr(ubi, to, vid_hdr); + if (err) + goto out_unlock; + + cond_resched(); + + /* Read the VID header back and check if it was written correctly */ + err = ubi_io_read_vid_hdr(ubi, to, vid_hdr, 1); + if (err) { + if (err != UBI_IO_BITFLIPS) + ubi_warn("cannot read VID header back from PEB %d", to); + goto out_unlock; + } + + if (data_size > 0) { + err = ubi_io_write_data(ubi, buf, to, 0, aldata_size); + if (err) + goto out_unlock; + + /* + * We've written the data and are going to read it back to make + * sure it was written correctly. + */ + buf1 = kmalloc(aldata_size, GFP_KERNEL); + if (!buf1) { + err = -ENOMEM; + goto out_unlock; + } + + cond_resched(); + + err = ubi_io_read_data(ubi, buf1, to, 0, aldata_size); + if (err) { + if (err != UBI_IO_BITFLIPS) + ubi_warn("cannot read data back from PEB %d", + to); + goto out_unlock; + } + + cond_resched(); + + if (memcmp(buf, buf1, aldata_size)) { + ubi_warn("read data back from PEB %d - it is different", + to); + goto out_unlock; + } + } + + ubi_assert(vol->eba_tbl[lnum] == from); + vol->eba_tbl[lnum] = to; + + leb_write_unlock(ubi, vol_id, lnum); + kfree(buf); + kfree(buf1); + + return 0; + +out_unlock: + leb_write_unlock(ubi, vol_id, lnum); + kfree(buf); + kfree(buf1); + return err; +} + +/** + * ubi_eba_init_scan - initialize the EBA unit using scanning information. + * @ubi: UBI device description object + * @si: scanning information + * + * This function returns zero in case of success and a negative error code in + * case of failure. + */ +int ubi_eba_init_scan(struct ubi_device *ubi, struct ubi_scan_info *si) +{ + int i, j, err, num_volumes; + struct ubi_scan_volume *sv; + struct ubi_volume *vol; + struct ubi_scan_leb *seb; + struct rb_node *rb; + + dbg_eba("initialize EBA unit"); + + spin_lock_init(&ubi->ltree_lock); + ubi->ltree = RB_ROOT; + + if (ubi_devices_cnt == 0) { + ltree_slab = kmem_cache_create("ubi_ltree_slab", + sizeof(struct ltree_entry), 0, + 0, <ree_entry_ctor, NULL); + if (!ltree_slab) + return -ENOMEM; + } + + ubi->global_sqnum = si->max_sqnum + 1; + num_volumes = ubi->vtbl_slots + UBI_INT_VOL_COUNT; + + for (i = 0; i < num_volumes; i++) { + vol = ubi->volumes[i]; + if (!vol) + continue; + + cond_resched(); + + vol->eba_tbl = kmalloc(vol->reserved_pebs * sizeof(int), + GFP_KERNEL); + if (!vol->eba_tbl) { + err = -ENOMEM; + goto out_free; + } + + for (j = 0; j < vol->reserved_pebs; j++) + vol->eba_tbl[j] = UBI_LEB_UNMAPPED; + + sv = ubi_scan_find_sv(si, idx2vol_id(ubi, i)); + if (!sv) + continue; + + ubi_rb_for_each_entry(rb, seb, &sv->root, u.rb) { + if (seb->lnum >= vol->reserved_pebs) + /* + * This may happen in case of an unclean reboot + * during re-size. + */ + ubi_scan_move_to_list(sv, seb, &si->erase); + vol->eba_tbl[seb->lnum] = seb->pnum; + } + } + + if (ubi->bad_allowed) { + ubi_calculate_reserved(ubi); + + if (ubi->avail_pebs < ubi->beb_rsvd_level) { + /* No enough free physical eraseblocks */ + ubi->beb_rsvd_pebs = ubi->avail_pebs; + ubi_warn("cannot reserve enough PEBs for bad PEB " + "handling, reserved %d, need %d", + ubi->beb_rsvd_pebs, ubi->beb_rsvd_level); + } else + ubi->beb_rsvd_pebs = ubi->beb_rsvd_level; + + ubi->avail_pebs -= ubi->beb_rsvd_pebs; + ubi->rsvd_pebs += ubi->beb_rsvd_pebs; + } + + dbg_eba("EBA unit is initialized"); + return 0; + +out_free: + for (i = 0; i < num_volumes; i++) { + if (!ubi->volumes[i]) + continue; + kfree(ubi->volumes[i]->eba_tbl); + } + if (ubi_devices_cnt == 0) + kmem_cache_destroy(ltree_slab); + return err; +} + +/** + * ubi_eba_close - close EBA unit. + * @ubi: UBI device description object + */ +void ubi_eba_close(const struct ubi_device *ubi) +{ + int i, num_volumes = ubi->vtbl_slots + UBI_INT_VOL_COUNT; + + dbg_eba("close EBA unit"); + + for (i = 0; i < num_volumes; i++) { + if (!ubi->volumes[i]) + continue; + kfree(ubi->volumes[i]->eba_tbl); + } + if (ubi_devices_cnt == 1) + kmem_cache_destroy(ltree_slab); +} diff --git a/drivers/mtd/ubi/gluebi.c b/drivers/mtd/ubi/gluebi.c new file mode 100644 index 0000000..fc9478d --- /dev/null +++ b/drivers/mtd/ubi/gluebi.c @@ -0,0 +1,323 @@ +/* + * Copyright (c) International Business Machines Corp., 2006 + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See + * the GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + * Author: Artem Bityutskiy (Битюцкий Артём), Joern Engel + */ + +/* + * This file includes implementation of fake MTD devices for each UBI volume. + * This sounds strange, but it is in fact quite useful to make MTD-oriented + * software (including all the legacy software) to work on top of UBI. + * + * Gluebi emulates MTD devices of "MTD_UBIVOLUME" type. Their minimal I/O unit + * size (mtd->writesize) is equivalent to the UBI minimal I/O unit. The + * eraseblock size is equivalent to the logical eraseblock size of the volume. + */ + +#include <asm/div64.h> +#include "ubi.h" + +/** + * gluebi_get_device - get MTD device reference. + * @mtd: the MTD device description object + * + * This function is called every time the MTD device is being opened and + * implements the MTD get_device() operation. Returns zero in case of success + * and a negative error code in case of failure. + */ +static int gluebi_get_device(struct mtd_info *mtd) +{ + struct ubi_volume *vol; + + vol = container_of(mtd, struct ubi_volume, gluebi_mtd); + + /* + * We do not introduce locks for gluebi reference count because the + * get_device()/put_device() calls are already serialized at MTD. + */ + if (vol->gluebi_refcount > 0) { + /* + * The MTD device is already referenced and this is just one + * more reference. MTD allows many users to open the same + * volume simultaneously and do not distinguish between + * readers/writers/exclusive openers as UBI does. So we do not + * open the UBI volume again - just increase the reference + * counter and return. + */ + vol->gluebi_refcount += 1; + return 0; + } + + /* + * This is the first reference to this UBI volume via the MTD device + * interface. Open the corresponding volume in read-write mode. + */ + vol->gluebi_desc = ubi_open_volume(vol->ubi->ubi_num, vol->vol_id, + UBI_READWRITE); + if (IS_ERR(vol->gluebi_desc)) + return PTR_ERR(vol->gluebi_desc); + vol->gluebi_refcount += 1; + return 0; +} + +/** + * gluebi_put_device - put MTD device reference. + * @mtd: the MTD device description object + * + * This function is called every time the MTD device is being put. Returns + * zero in case of success and a negative error code in case of failure. + */ +static void gluebi_put_device(struct mtd_info *mtd) +{ + struct ubi_volume *vol; + + vol = container_of(mtd, struct ubi_volume, gluebi_mtd); + vol->gluebi_refcount -= 1; + ubi_assert(vol->gluebi_refcount >= 0); + if (vol->gluebi_refcount == 0) + ubi_close_volume(vol->gluebi_desc); +} + +/** + * gluebi_read - read operation of emulated MTD devices. + * @mtd: MTD device description object + * @from: absolute offset from where to read + * @len: how many bytes to read + * @retlen: count of read bytes is returned here + * @buf: buffer to store the read data + * + * This function returns zero in case of success and a negative error code in + * case of failure. + */ +static int gluebi_read(struct mtd_info *mtd, loff_t from, size_t len, + size_t *retlen, unsigned char *buf) +{ + int err = 0, lnum, offs, total_read; + struct ubi_volume *vol; + struct ubi_device *ubi; + uint64_t tmp = from; + + dbg_msg("read %zd bytes from offset %lld", len, from); + + if (len < 0 || from < 0 || from + len > mtd->size) + return -EINVAL; + + vol = container_of(mtd, struct ubi_volume, gluebi_mtd); + ubi = vol->ubi; + + offs = do_div(tmp, mtd->erasesize); + lnum = tmp; + + total_read = len; + while (total_read) { + size_t to_read = mtd->erasesize - offs; + + if (to_read > total_read) + to_read = total_read; + + err = ubi_eba_read_leb(ubi, vol->vol_id, lnum, buf, offs, + to_read, 0); + if (err) + break; + + lnum += 1; + offs = 0; + total_read -= to_read; + buf += to_read; + } + + *retlen = len - total_read; + return err; +} + +/** + * gluebi_write - write operation of emulated MTD devices. + * @mtd: MTD device description object + * @to: absolute offset where to write + * @len: how many bytes to write + * @retlen: count of written bytes is returned here + * @buf: buffer with data to write + * + * This function returns zero in case of success and a negative error code in + * case of failure. + */ +static int gluebi_write(struct mtd_info *mtd, loff_t to, size_t len, + size_t *retlen, const u_char *buf) +{ + int err = 0, lnum, offs, total_written; + struct ubi_volume *vol; + struct ubi_device *ubi; + uint64_t tmp = to; + + dbg_msg("write %zd bytes to offset %lld", len, to); + + if (len < 0 || to < 0 || len + to > mtd->size) + return -EINVAL; + + vol = container_of(mtd, struct ubi_volume, gluebi_mtd); + ubi = vol->ubi; + + if (ubi->ro_mode) + return -EROFS; + + offs = do_div(tmp, mtd->erasesize); + lnum = tmp; + + if (len % mtd->writesize || offs % mtd->writesize) + return -EINVAL; + + total_written = len; + while (total_written) { + size_t to_write = mtd->erasesize - offs; + + if (to_write > total_written) + to_write = total_written; + + err = ubi_eba_write_leb(ubi, vol->vol_id, lnum, buf, offs, + to_write, UBI_UNKNOWN); + if (err) + break; + + lnum += 1; + offs = 0; + total_written -= to_write; + buf += to_write; + } + + *retlen = len - total_written; + return err; +} + +/** + * gluebi_erase - erase operation of emulated MTD devices. + * @mtd: the MTD device description object + * @instr: the erase operation description + * + * This function calls the erase callback when finishes. Returns zero in case + * of success and a negative error code in case of failure. + */ +static int gluebi_erase(struct mtd_info *mtd, struct erase_info *instr) +{ + int err, i, lnum, count; + struct ubi_volume *vol; + struct ubi_device *ubi; + + dbg_msg("erase %u bytes at offset %u", instr->len, instr->addr); + + if (instr->addr < 0 || instr->addr > mtd->size - mtd->erasesize) + return -EINVAL; + + if (instr->len < 0 || instr->addr + instr->len > mtd->size) + return -EINVAL; + + if (instr->addr % mtd->writesize || instr->len % mtd->writesize) + return -EINVAL; + + lnum = instr->addr / mtd->erasesize; + count = instr->len / mtd->erasesize; + + vol = container_of(mtd, struct ubi_volume, gluebi_mtd); + ubi = vol->ubi; + + if (ubi->ro_mode) + return -EROFS; + + for (i = 0; i < count; i++) { + err = ubi_eba_unmap_leb(ubi, vol->vol_id, lnum + i); + if (err) + goto out_err; + } + + /* + * MTD erase operations are synchronous, so we have to make sure the + * physical eraseblock is wiped out. + */ + err = ubi_wl_flush(ubi); + if (err) + goto out_err; + + instr->state = MTD_ERASE_DONE; + mtd_erase_callback(instr); + return 0; + +out_err: + instr->state = MTD_ERASE_FAILED; + instr->fail_addr = lnum * mtd->erasesize; + return err; +} + +/** + * ubi_create_gluebi - initialize gluebi for an UBI volume. + * @ubi: UBI device description object + * @vol: volume description object + * + * This function is called when an UBI volume is created in order to create + * corresponding fake MTD device. Returns zero in case of success and a + * negative error code in case of failure. + */ +int ubi_create_gluebi(struct ubi_device *ubi, struct ubi_volume *vol) +{ + struct mtd_info *mtd = &vol->gluebi_mtd; + + mtd->name = kmemdup(vol->name, vol->name_len + 1, GFP_KERNEL); + if (!mtd->name) + return -ENOMEM; + + mtd->type = MTD_UBIVOLUME; + if (!ubi->ro_mode) + mtd->flags = MTD_WRITEABLE; + mtd->writesize = ubi->min_io_size; + mtd->owner = THIS_MODULE; + mtd->size = vol->usable_leb_size * vol->reserved_pebs; + mtd->erasesize = vol->usable_leb_size; + mtd->read = gluebi_read; + mtd->write = gluebi_write; + mtd->erase = gluebi_erase; + mtd->get_device = gluebi_get_device; + mtd->put_device = gluebi_put_device; + + if (add_mtd_device(mtd)) { + ubi_err("cannot not add MTD device\n"); + kfree(mtd->name); + return -ENFILE; + } + + dbg_msg("added mtd%d (\"%s\"), size %u, EB size %u", + mtd->index, mtd->name, mtd->size, mtd->erasesize); + return 0; +} + +/** + * ubi_destroy_gluebi - close gluebi for an UBI volume. + * @vol: volume description object + * + * This function is called when an UBI volume is removed in order to remove + * corresponding fake MTD device. Returns zero in case of success and a + * negative error code in case of failure. + */ +int ubi_destroy_gluebi(struct ubi_volume *vol) +{ + int err; + struct mtd_info *mtd = &vol->gluebi_mtd; + + dbg_msg("remove mtd%d", mtd->index); + err = del_mtd_device(mtd); + if (err) + return err; + kfree(mtd->name); + return 0; +} diff --git a/drivers/mtd/ubi/io.c b/drivers/mtd/ubi/io.c new file mode 100644 index 0000000..438914d --- /dev/null +++ b/drivers/mtd/ubi/io.c @@ -0,0 +1,1259 @@ +/* + * Copyright (c) International Business Machines Corp., 2006 + * Copyright (c) Nokia Corporation, 2006, 2007 + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See + * the GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + * Author: Artem Bityutskiy (Битюцкий Артём) + */ + +/* + * UBI input/output unit. + * + * This unit provides a uniform way to work with all kinds of the underlying + * MTD devices. It also implements handy functions for reading and writing UBI + * headers. + * + * We are trying to have a paranoid mindset and not to trust to what we read + * from the flash media in order to be more secure and robust. So this unit + * validates every single header it reads from the flash media. + * + * Some words about how the eraseblock headers are stored. + * + * The erase counter header is always stored at offset zero. By default, the + * VID header is stored after the EC header at the closest aligned offset + * (i.e. aligned to the minimum I/O unit size). Data starts next to the VID + * header at the closest aligned offset. But this default layout may be + * changed. For example, for different reasons (e.g., optimization) UBI may be + * asked to put the VID header at further offset, and even at an unaligned + * offset. Of course, if the offset of the VID header is unaligned, UBI adds + * proper padding in front of it. Data offset may also be changed but it has to + * be aligned. + * + * About minimal I/O units. In general, UBI assumes flash device model where + * there is only one minimal I/O unit size. E.g., in case of NOR flash it is 1, + * in case of NAND flash it is a NAND page, etc. This is reported by MTD in the + * @ubi->mtd->writesize field. But as an exception, UBI admits of using another + * (smaller) minimal I/O unit size for EC and VID headers to make it possible + * to do different optimizations. + * + * This is extremely useful in case of NAND flashes which admit of several + * write operations to one NAND page. In this case UBI can fit EC and VID + * headers at one NAND page. Thus, UBI may use "sub-page" size as the minimal + * I/O unit for the headers (the @ubi->hdrs_min_io_size field). But it still + * reports NAND page size (@ubi->min_io_size) as a minimal I/O unit for the UBI + * users. + * + * Example: some Samsung NANDs with 2KiB pages allow 4x 512-byte writes, so + * although the minimal I/O unit is 2K, UBI uses 512 bytes for EC and VID + * headers. + * + * Q: why not just to treat sub-page as a minimal I/O unit of this flash + * device, e.g., make @ubi->min_io_size = 512 in the example above? + * + * A: because when writing a sub-page, MTD still writes a full 2K page but the + * bytes which are no relevant to the sub-page are 0xFF. So, basically, writing + * 4x512 sub-pages is 4 times slower then writing one 2KiB NAND page. Thus, we + * prefer to use sub-pages only for EV and VID headers. + * + * As it was noted above, the VID header may start at a non-aligned offset. + * For example, in case of a 2KiB page NAND flash with a 512 bytes sub-page, + * the VID header may reside at offset 1984 which is the last 64 bytes of the + * last sub-page (EC header is always at offset zero). This causes some + * difficulties when reading and writing VID headers. + * + * Suppose we have a 64-byte buffer and we read a VID header at it. We change + * the data and want to write this VID header out. As we can only write in + * 512-byte chunks, we have to allocate one more buffer and copy our VID header + * to offset 448 of this buffer. + * + * The I/O unit does the following trick in order to avoid this extra copy. + * It always allocates a @ubi->vid_hdr_alsize bytes buffer for the VID header + * and returns a pointer to offset @ubi->vid_hdr_shift of this buffer. When the + * VID header is being written out, it shifts the VID header pointer back and + * writes the whole sub-page. + */ + +#include <linux/crc32.h> +#include <linux/err.h> +#include "ubi.h" + +#ifdef CONFIG_MTD_UBI_DEBUG_PARANOID +static int paranoid_check_not_bad(const struct ubi_device *ubi, int pnum); +static int paranoid_check_peb_ec_hdr(const struct ubi_device *ubi, int pnum); +static int paranoid_check_ec_hdr(const struct ubi_device *ubi, int pnum, + const struct ubi_ec_hdr *ec_hdr); +static int paranoid_check_peb_vid_hdr(const struct ubi_device *ubi, int pnum); +static int paranoid_check_vid_hdr(const struct ubi_device *ubi, int pnum, + const struct ubi_vid_hdr *vid_hdr); +static int paranoid_check_all_ff(const struct ubi_device *ubi, int pnum, + int offset, int len); +#else +#define paranoid_check_not_bad(ubi, pnum) 0 +#define paranoid_check_peb_ec_hdr(ubi, pnum) 0 +#define paranoid_check_ec_hdr(ubi, pnum, ec_hdr) 0 +#define paranoid_check_peb_vid_hdr(ubi, pnum) 0 +#define paranoid_check_vid_hdr(ubi, pnum, vid_hdr) 0 +#define paranoid_check_all_ff(ubi, pnum, offset, len) 0 +#endif + +/** + * ubi_io_read - read data from a physical eraseblock. + * @ubi: UBI device description object + * @buf: buffer where to store the read data + * @pnum: physical eraseblock number to read from + * @offset: offset within the physical eraseblock from where to read + * @len: how many bytes to read + * + * This function reads data from offset @offset of physical eraseblock @pnum + * and stores the read data in the @buf buffer. The following return codes are + * possible: + * + * o %0 if all the requested data were successfully read; + * o %UBI_IO_BITFLIPS if all the requested data were successfully read, but + * correctable bit-flips were detected; this is harmless but may indicate + * that this eraseblock may become bad soon (but do not have to); + * o %-EBADMSG if the MTD subsystem reported about data data integrity + * problems, for example it can me an ECC error in case of NAND; this most + * probably means that the data is corrupted; + * o %-EIO if some I/O error occurred; + * o other negative error codes in case of other errors. + */ +int ubi_io_read(const struct ubi_device *ubi, void *buf, int pnum, int offset, + int len) +{ + int err, retries = 0; + size_t read; + loff_t addr; + + dbg_io("read %d bytes from PEB %d:%d", len, pnum, offset); + + ubi_assert(pnum >= 0 && pnum < ubi->peb_count); + ubi_assert(offset >= 0 && offset + len <= ubi->peb_size); + ubi_assert(len > 0); + + err = paranoid_check_not_bad(ubi, pnum); + if (err) + return err > 0 ? -EINVAL : err; + + addr = (loff_t)pnum * ubi->peb_size + offset; +retry: + err = ubi->mtd->read(ubi->mtd, addr, len, &read, buf); + if (err) { + if (err == -EUCLEAN) { + /* + * -EUCLEAN is reported if there was a bit-flip which + * was corrected, so this is harmless. + */ + ubi_msg("fixable bit-flip detected at PEB %d", pnum); + ubi_assert(len == read); + return UBI_IO_BITFLIPS; + } + + if (read != len && retries++ < UBI_IO_RETRIES) { + dbg_io("error %d while reading %d bytes from PEB %d:%d, " + "read only %zd bytes, retry", + err, len, pnum, offset, read); + yield(); + goto retry; + } + + ubi_err("error %d while reading %d bytes from PEB %d:%d, " + "read %zd bytes", err, len, pnum, offset, read); + ubi_dbg_dump_stack(); + } else { + ubi_assert(len == read); + + if (ubi_dbg_is_bitflip()) { + dbg_msg("bit-flip (emulated)"); + err = UBI_IO_BITFLIPS; + } + } + + return err; +} + +/** + * ubi_io_write - write data to a physical eraseblock. + * @ubi: UBI device description object + * @buf: buffer with the data to write + * @pnum: physical eraseblock number to write to + * @offset: offset within the physical eraseblock where to write + * @len: how many bytes to write + * + * This function writes @len bytes of data from buffer @buf to offset @offset + * of physical eraseblock @pnum. If all the data were successfully written, + * zero is returned. If an error occurred, this function returns a negative + * error code. If %-EIO is returned, the physical eraseblock most probably went + * bad. + * + * Note, in case of an error, it is possible that something was still written + * to the flash media, but may be some garbage. + */ +int ubi_io_write(const struct ubi_device *ubi, const void *buf, int pnum, + int offset, int len) +{ + int err; + size_t written; + loff_t addr; + + dbg_io("write %d bytes to PEB %d:%d", len, pnum, offset); + + ubi_assert(pnum >= 0 && pnum < ubi->peb_count); + ubi_assert(offset >= 0 && offset + len <= ubi->peb_size); + ubi_assert(offset % ubi->hdrs_min_io_size == 0); + ubi_assert(len > 0 && len % ubi->hdrs_min_io_size == 0); + + if (ubi->ro_mode) { + ubi_err("read-only mode"); + return -EROFS; + } + + /* The below has to be compiled out if paranoid checks are disabled */ + + err = paranoid_check_not_bad(ubi, pnum); + if (err) + return err > 0 ? -EINVAL : err; + + /* The area we are writing to has to contain all 0xFF bytes */ + err = paranoid_check_all_ff(ubi, pnum, offset, len); + if (err) + return err > 0 ? -EINVAL : err; + + if (offset >= ubi->leb_start) { + /* + * We write to the data area of the physical eraseblock. Make + * sure it has valid EC and VID headers. + */ + err = paranoid_check_peb_ec_hdr(ubi, pnum); + if (err) + return err > 0 ? -EINVAL : err; + err = paranoid_check_peb_vid_hdr(ubi, pnum); + if (err) + return err > 0 ? -EINVAL : err; + } + + if (ubi_dbg_is_write_failure()) { + dbg_err("cannot write %d bytes to PEB %d:%d " + "(emulated)", len, pnum, offset); + ubi_dbg_dump_stack(); + return -EIO; + } + + addr = (loff_t)pnum * ubi->peb_size + offset; + err = ubi->mtd->write(ubi->mtd, addr, len, &written, buf); + if (err) { + ubi_err("error %d while writing %d bytes to PEB %d:%d, written" + " %zd bytes", err, len, pnum, offset, written); + ubi_dbg_dump_stack(); + } else + ubi_assert(written == len); + + return err; +} + +/** + * erase_callback - MTD erasure call-back. + * @ei: MTD erase information object. + * + * Note, even though MTD erase interface is asynchronous, all the current + * implementations are synchronous anyway. + */ +static void erase_callback(struct erase_info *ei) +{ + wake_up_interruptible((wait_queue_head_t *)ei->priv); +} + +/** + * do_sync_erase - synchronously erase a physical eraseblock. + * @ubi: UBI device description object + * @pnum: the physical eraseblock number to erase + * + * This function synchronously erases physical eraseblock @pnum and returns + * zero in case of success and a negative error code in case of failure. If + * %-EIO is returned, the physical eraseblock most probably went bad. + */ +static int do_sync_erase(const struct ubi_device *ubi, int pnum) +{ + int err, retries = 0; + struct erase_info ei; + wait_queue_head_t wq; + + dbg_io("erase PEB %d", pnum); + +retry: + init_waitqueue_head(&wq); + memset(&ei, 0, sizeof(struct erase_info)); + + ei.mtd = ubi->mtd; + ei.addr = pnum * ubi->peb_size; + ei.len = ubi->peb_size; + ei.callback = erase_callback; + ei.priv = (unsigned long)&wq; + + err = ubi->mtd->erase(ubi->mtd, &ei); + if (err) { + if (retries++ < UBI_IO_RETRIES) { + dbg_io("error %d while erasing PEB %d, retry", + err, pnum); + yield(); + goto retry; + } + ubi_err("cannot erase PEB %d, error %d", pnum, err); + ubi_dbg_dump_stack(); + return err; + } + + err = wait_event_interruptible(wq, ei.state == MTD_ERASE_DONE || + ei.state == MTD_ERASE_FAILED); + if (err) { + ubi_err("interrupted PEB %d erasure", pnum); + return -EINTR; + } + + if (ei.state == MTD_ERASE_FAILED) { + if (retries++ < UBI_IO_RETRIES) { + dbg_io("error while erasing PEB %d, retry", pnum); + yield(); + goto retry; + } + ubi_err("cannot erase PEB %d", pnum); + ubi_dbg_dump_stack(); + return -EIO; + } + + err = paranoid_check_all_ff(ubi, pnum, 0, ubi->peb_size); + if (err) + return err > 0 ? -EINVAL : err; + + if (ubi_dbg_is_erase_failure() && !err) { + dbg_err("cannot erase PEB %d (emulated)", pnum); + return -EIO; + } + + return 0; +} + +/** + * check_pattern - check if buffer contains only a certain byte pattern. + * @buf: buffer to check + * @patt: the pattern to check + * @size: buffer size in bytes + * + * This function returns %1 in there are only @patt bytes in @buf, and %0 if + * something else was also found. + */ +static int check_pattern(const void *buf, uint8_t patt, int size) +{ + int i; + + for (i = 0; i < size; i++) + if (((const uint8_t *)buf)[i] != patt) + return 0; + return 1; +} + +/* Patterns to write to a physical eraseblock when torturing it */ +static uint8_t patterns[] = {0xa5, 0x5a, 0x0}; + +/** + * torture_peb - test a supposedly bad physical eraseblock. + * @ubi: UBI device description object + * @pnum: the physical eraseblock number to test + * + * This function returns %-EIO if the physical eraseblock did not pass the + * test, a positive number of erase operations done if the test was + * successfully passed, and other negative error codes in case of other errors. + */ +static int torture_peb(const struct ubi_device *ubi, int pnum) +{ + void *buf; + int err, i, patt_count; + + buf = kmalloc(ubi->peb_size, GFP_KERNEL); + if (!buf) + return -ENOMEM; + + patt_count = ARRAY_SIZE(patterns); + ubi_assert(patt_count > 0); + + for (i = 0; i < patt_count; i++) { + err = do_sync_erase(ubi, pnum); + if (err) + goto out; + + /* Make sure the PEB contains only 0xFF bytes */ + err = ubi_io_read(ubi, buf, pnum, 0, ubi->peb_size); + if (err) + goto out; + + err = check_pattern(buf, 0xFF, ubi->peb_size); + if (err == 0) { + ubi_err("erased PEB %d, but a non-0xFF byte found", + pnum); + err = -EIO; + goto out; + } + + /* Write a pattern and check it */ + memset(buf, patterns[i], ubi->peb_size); + err = ubi_io_write(ubi, buf, pnum, 0, ubi->peb_size); + if (err) + goto out; + + memset(buf, ~patterns[i], ubi->peb_size); + err = ubi_io_read(ubi, buf, pnum, 0, ubi->peb_size); + if (err) + goto out; + + err = check_pattern(buf, patterns[i], ubi->peb_size); + if (err == 0) { + ubi_err("pattern %x checking failed for PEB %d", + patterns[i], pnum); + err = -EIO; + goto out; + } + } + + err = patt_count; + +out: + if (err == UBI_IO_BITFLIPS || err == -EBADMSG) + /* + * If a bit-flip or data integrity error was detected, the test + * has not passed because it happened on a freshly erased + * physical eraseblock which means something is wrong with it. + */ + err = -EIO; + kfree(buf); + return err; +} + +/** + * ubi_io_sync_erase - synchronously erase a physical eraseblock. + * @ubi: UBI device description object + * @pnum: physical eraseblock number to erase + * @torture: if this physical eraseblock has to be tortured + * + * This function synchronously erases physical eraseblock @pnum. If @torture + * flag is not zero, the physical eraseblock is checked by means of writing + * different patterns to it and reading them back. If the torturing is enabled, + * the physical eraseblock is erased more then once. + * + * This function returns the number of erasures made in case of success, %-EIO + * if the erasure failed or the torturing test failed, and other negative error + * codes in case of other errors. Note, %-EIO means that the physical + * eraseblock is bad. + */ +int ubi_io_sync_erase(const struct ubi_device *ubi, int pnum, int torture) +{ + int err, ret = 0; + + ubi_assert(pnum >= 0 && pnum < ubi->peb_count); + + err = paranoid_check_not_bad(ubi, pnum); + if (err != 0) + return err > 0 ? -EINVAL : err; + + if (ubi->ro_mode) { + ubi_err("read-only mode"); + return -EROFS; + } + + if (torture) { + ret = torture_peb(ubi, pnum); + if (ret < 0) + return ret; + } + + err = do_sync_erase(ubi, pnum); + if (err) + return err; + + return ret + 1; +} + +/** + * ubi_io_is_bad - check if a physical eraseblock is bad. + * @ubi: UBI device description object + * @pnum: the physical eraseblock number to check + * + * This function returns a positive number if the physical eraseblock is bad, + * zero if not, and a negative error code if an error occurred. + */ +int ubi_io_is_bad(const struct ubi_device *ubi, int pnum) +{ + struct mtd_info *mtd = ubi->mtd; + + ubi_assert(pnum >= 0 && pnum < ubi->peb_count); + + if (ubi->bad_allowed) { + int ret; + + ret = mtd->block_isbad(mtd, (loff_t)pnum * ubi->peb_size); + if (ret < 0) + ubi_err("error %d while checking if PEB %d is bad", + ret, pnum); + else if (ret) + dbg_io("PEB %d is bad", pnum); + return ret; + } + + return 0; +} + +/** + * ubi_io_mark_bad - mark a physical eraseblock as bad. + * @ubi: UBI device description object + * @pnum: the physical eraseblock number to mark + * + * This function returns zero in case of success and a negative error code in + * case of failure. + */ +int ubi_io_mark_bad(const struct ubi_device *ubi, int pnum) +{ + int err; + struct mtd_info *mtd = ubi->mtd; + + ubi_assert(pnum >= 0 && pnum < ubi->peb_count); + + if (ubi->ro_mode) { + ubi_err("read-only mode"); + return -EROFS; + } + + if (!ubi->bad_allowed) + return 0; + + err = mtd->block_markbad(mtd, (loff_t)pnum * ubi->peb_size); + if (err) + ubi_err("cannot mark PEB %d bad, error %d", pnum, err); + return err; +} + +/** + * validate_ec_hdr - validate an erase counter header. + * @ubi: UBI device description object + * @ec_hdr: the erase counter header to check + * + * This function returns zero if the erase counter header is OK, and %1 if + * not. + */ +static int validate_ec_hdr(const struct ubi_device *ubi, + const struct ubi_ec_hdr *ec_hdr) +{ + long long ec; + int vid_hdr_offset, leb_start; + + ec = ubi64_to_cpu(ec_hdr->ec); + vid_hdr_offset = ubi32_to_cpu(ec_hdr->vid_hdr_offset); + leb_start = ubi32_to_cpu(ec_hdr->data_offset); + + if (ec_hdr->version != UBI_VERSION) { + ubi_err("node with incompatible UBI version found: " + "this UBI version is %d, image version is %d", + UBI_VERSION, (int)ec_hdr->version); + goto bad; + } + + if (vid_hdr_offset != ubi->vid_hdr_offset) { + ubi_err("bad VID header offset %d, expected %d", + vid_hdr_offset, ubi->vid_hdr_offset); + goto bad; + } + + if (leb_start != ubi->leb_start) { + ubi_err("bad data offset %d, expected %d", + leb_start, ubi->leb_start); + goto bad; + } + + if (ec < 0 || ec > UBI_MAX_ERASECOUNTER) { + ubi_err("bad erase counter %lld", ec); + goto bad; + } + + return 0; + +bad: + ubi_err("bad EC header"); + ubi_dbg_dump_ec_hdr(ec_hdr); + ubi_dbg_dump_stack(); + return 1; +} + +/** + * ubi_io_read_ec_hdr - read and check an erase counter header. + * @ubi: UBI device description object + * @pnum: physical eraseblock to read from + * @ec_hdr: a &struct ubi_ec_hdr object where to store the read erase counter + * header + * @verbose: be verbose if the header is corrupted or was not found + * + * This function reads erase counter header from physical eraseblock @pnum and + * stores it in @ec_hdr. This function also checks CRC checksum of the read + * erase counter header. The following codes may be returned: + * + * o %0 if the CRC checksum is correct and the header was successfully read; + * o %UBI_IO_BITFLIPS if the CRC is correct, but bit-flips were detected + * and corrected by the flash driver; this is harmless but may indicate that + * this eraseblock may become bad soon (but may be not); + * o %UBI_IO_BAD_EC_HDR if the erase counter header is corrupted (a CRC error); + * o %UBI_IO_PEB_EMPTY if the physical eraseblock is empty; + * o a negative error code in case of failure. + */ +int ubi_io_read_ec_hdr(const struct ubi_device *ubi, int pnum, + struct ubi_ec_hdr *ec_hdr, int verbose) +{ + int err, read_err = 0; + uint32_t crc, magic, hdr_crc; + + dbg_io("read EC header from PEB %d", pnum); + ubi_assert(pnum >= 0 && pnum < ubi->peb_count); + + err = ubi_io_read(ubi, ec_hdr, pnum, 0, UBI_EC_HDR_SIZE); + if (err) { + if (err != UBI_IO_BITFLIPS && err != -EBADMSG) + return err; + + /* + * We read all the data, but either a correctable bit-flip + * occurred, or MTD reported about some data integrity error, + * like an ECC error in case of NAND. The former is harmless, + * the later may mean that the read data is corrupted. But we + * have a CRC check-sum and we will detect this. If the EC + * header is still OK, we just report this as there was a + * bit-flip. + */ + read_err = err; + } + + magic = ubi32_to_cpu(ec_hdr->magic); + if (magic != UBI_EC_HDR_MAGIC) { + /* + * The magic field is wrong. Let's check if we have read all + * 0xFF. If yes, this physical eraseblock is assumed to be + * empty. + * + * But if there was a read error, we do not test it for all + * 0xFFs. Even if it does contain all 0xFFs, this error + * indicates that something is still wrong with this physical + * eraseblock and we anyway cannot treat it as empty. + */ + if (read_err != -EBADMSG && + check_pattern(ec_hdr, 0xFF, UBI_EC_HDR_SIZE)) { + /* The physical eraseblock is supposedly empty */ + + /* + * The below is just a paranoid check, it has to be + * compiled out if paranoid checks are disabled. + */ + err = paranoid_check_all_ff(ubi, pnum, 0, + ubi->peb_size); + if (err) + return err > 0 ? UBI_IO_BAD_EC_HDR : err; + + if (verbose) + ubi_warn("no EC header found at PEB %d, " + "only 0xFF bytes", pnum); + return UBI_IO_PEB_EMPTY; + } + + /* + * This is not a valid erase counter header, and these are not + * 0xFF bytes. Report that the header is corrupted. + */ + if (verbose) { + ubi_warn("bad magic number at PEB %d: %08x instead of " + "%08x", pnum, magic, UBI_EC_HDR_MAGIC); + ubi_dbg_dump_ec_hdr(ec_hdr); + } + return UBI_IO_BAD_EC_HDR; + } + + crc = crc32(UBI_CRC32_INIT, ec_hdr, UBI_EC_HDR_SIZE_CRC); + hdr_crc = ubi32_to_cpu(ec_hdr->hdr_crc); + + if (hdr_crc != crc) { + if (verbose) { + ubi_warn("bad EC header CRC at PEB %d, calculated %#08x," + " read %#08x", pnum, crc, hdr_crc); + ubi_dbg_dump_ec_hdr(ec_hdr); + } + return UBI_IO_BAD_EC_HDR; + } + + /* And of course validate what has just been read from the media */ + err = validate_ec_hdr(ubi, ec_hdr); + if (err) { + ubi_err("validation failed for PEB %d", pnum); + return -EINVAL; + } + + return read_err ? UBI_IO_BITFLIPS : 0; +} + +/** + * ubi_io_write_ec_hdr - write an erase counter header. + * @ubi: UBI device description object + * @pnum: physical eraseblock to write to + * @ec_hdr: the erase counter header to write + * + * This function writes erase counter header described by @ec_hdr to physical + * eraseblock @pnum. It also fills most fields of @ec_hdr before writing, so + * the caller do not have to fill them. Callers must only fill the @ec_hdr->ec + * field. + * + * This function returns zero in case of success and a negative error code in + * case of failure. If %-EIO is returned, the physical eraseblock most probably + * went bad. + */ +int ubi_io_write_ec_hdr(const struct ubi_device *ubi, int pnum, + struct ubi_ec_hdr *ec_hdr) +{ + int err; + uint32_t crc; + + dbg_io("write EC header to PEB %d", pnum); + ubi_assert(pnum >= 0 && pnum < ubi->peb_count); + + ec_hdr->magic = cpu_to_ubi32(UBI_EC_HDR_MAGIC); + ec_hdr->version = UBI_VERSION; + ec_hdr->vid_hdr_offset = cpu_to_ubi32(ubi->vid_hdr_offset); + ec_hdr->data_offset = cpu_to_ubi32(ubi->leb_start); + crc = crc32(UBI_CRC32_INIT, ec_hdr, UBI_EC_HDR_SIZE_CRC); + ec_hdr->hdr_crc = cpu_to_ubi32(crc); + + err = paranoid_check_ec_hdr(ubi, pnum, ec_hdr); + if (err) + return -EINVAL; + + err = ubi_io_write(ubi, ec_hdr, pnum, 0, ubi->ec_hdr_alsize); + return err; +} + +/** + * validate_vid_hdr - validate a volume identifier header. + * @ubi: UBI device description object + * @vid_hdr: the volume identifier header to check + * + * This function checks that data stored in the volume identifier header + * @vid_hdr. Returns zero if the VID header is OK and %1 if not. + */ +static int validate_vid_hdr(const struct ubi_device *ubi, + const struct ubi_vid_hdr *vid_hdr) +{ + int vol_type = vid_hdr->vol_type; + int copy_flag = vid_hdr->copy_flag; + int vol_id = ubi32_to_cpu(vid_hdr->vol_id); + int lnum = ubi32_to_cpu(vid_hdr->lnum); + int compat = vid_hdr->compat; + int data_size = ubi32_to_cpu(vid_hdr->data_size); + int used_ebs = ubi32_to_cpu(vid_hdr->used_ebs); + int data_pad = ubi32_to_cpu(vid_hdr->data_pad); + int data_crc = ubi32_to_cpu(vid_hdr->data_crc); + int usable_leb_size = ubi->leb_size - data_pad; + + if (copy_flag != 0 && copy_flag != 1) { + dbg_err("bad copy_flag"); + goto bad; + } + + if (vol_id < 0 || lnum < 0 || data_size < 0 || used_ebs < 0 || + data_pad < 0) { + dbg_err("negative values"); + goto bad; + } + + if (vol_id >= UBI_MAX_VOLUMES && vol_id < UBI_INTERNAL_VOL_START) { + dbg_err("bad vol_id"); + goto bad; + } + + if (vol_id < UBI_INTERNAL_VOL_START && compat != 0) { + dbg_err("bad compat"); + goto bad; + } + + if (vol_id >= UBI_INTERNAL_VOL_START && compat != UBI_COMPAT_DELETE && + compat != UBI_COMPAT_RO && compat != UBI_COMPAT_PRESERVE && + compat != UBI_COMPAT_REJECT) { + dbg_err("bad compat"); + goto bad; + } + + if (vol_type != UBI_VID_DYNAMIC && vol_type != UBI_VID_STATIC) { + dbg_err("bad vol_type"); + goto bad; + } + + if (data_pad >= ubi->leb_size / 2) { + dbg_err("bad data_pad"); + goto bad; + } + + if (vol_type == UBI_VID_STATIC) { + /* + * Although from high-level point of view static volumes may + * contain zero bytes of data, but no VID headers can contain + * zero at these fields, because they empty volumes do not have + * mapped logical eraseblocks. + */ + if (used_ebs == 0) { + dbg_err("zero used_ebs"); + goto bad; + } + if (data_size == 0) { + dbg_err("zero data_size"); + goto bad; + } + if (lnum < used_ebs - 1) { + if (data_size != usable_leb_size) { + dbg_err("bad data_size"); + goto bad; + } + } else if (lnum == used_ebs - 1) { + if (data_size == 0) { + dbg_err("bad data_size at last LEB"); + goto bad; + } + } else { + dbg_err("too high lnum"); + goto bad; + } + } else { + if (copy_flag == 0) { + if (data_crc != 0) { + dbg_err("non-zero data CRC"); + goto bad; + } + if (data_size != 0) { + dbg_err("non-zero data_size"); + goto bad; + } + } else { + if (data_size == 0) { + dbg_err("zero data_size of copy"); + goto bad; + } + } + if (used_ebs != 0) { + dbg_err("bad used_ebs"); + goto bad; + } + } + + return 0; + +bad: + ubi_err("bad VID header"); + ubi_dbg_dump_vid_hdr(vid_hdr); + ubi_dbg_dump_stack(); + return 1; +} + +/** + * ubi_io_read_vid_hdr - read and check a volume identifier header. + * @ubi: UBI device description object + * @pnum: physical eraseblock number to read from + * @vid_hdr: &struct ubi_vid_hdr object where to store the read volume + * identifier header + * @verbose: be verbose if the header is corrupted or wasn't found + * + * This function reads the volume identifier header from physical eraseblock + * @pnum and stores it in @vid_hdr. It also checks CRC checksum of the read + * volume identifier header. The following codes may be returned: + * + * o %0 if the CRC checksum is correct and the header was successfully read; + * o %UBI_IO_BITFLIPS if the CRC is correct, but bit-flips were detected + * and corrected by the flash driver; this is harmless but may indicate that + * this eraseblock may become bad soon; + * o %UBI_IO_BAD_VID_HRD if the volume identifier header is corrupted (a CRC + * error detected); + * o %UBI_IO_PEB_FREE if the physical eraseblock is free (i.e., there is no VID + * header there); + * o a negative error code in case of failure. + */ +int ubi_io_read_vid_hdr(const struct ubi_device *ubi, int pnum, + struct ubi_vid_hdr *vid_hdr, int verbose) +{ + int err, read_err = 0; + uint32_t crc, magic, hdr_crc; + void *p; + + dbg_io("read VID header from PEB %d", pnum); + ubi_assert(pnum >= 0 && pnum < ubi->peb_count); + + p = (char *)vid_hdr - ubi->vid_hdr_shift; + err = ubi_io_read(ubi, p, pnum, ubi->vid_hdr_aloffset, + ubi->vid_hdr_alsize); + if (err) { + if (err != UBI_IO_BITFLIPS && err != -EBADMSG) + return err; + + /* + * We read all the data, but either a correctable bit-flip + * occurred, or MTD reported about some data integrity error, + * like an ECC error in case of NAND. The former is harmless, + * the later may mean the read data is corrupted. But we have a + * CRC check-sum and we will identify this. If the VID header is + * still OK, we just report this as there was a bit-flip. + */ + read_err = err; + } + + magic = ubi32_to_cpu(vid_hdr->magic); + if (magic != UBI_VID_HDR_MAGIC) { + /* + * If we have read all 0xFF bytes, the VID header probably does + * not exist and the physical eraseblock is assumed to be free. + * + * But if there was a read error, we do not test the data for + * 0xFFs. Even if it does contain all 0xFFs, this error + * indicates that something is still wrong with this physical + * eraseblock and it cannot be regarded as free. + */ + if (read_err != -EBADMSG && + check_pattern(vid_hdr, 0xFF, UBI_VID_HDR_SIZE)) { + /* The physical eraseblock is supposedly free */ + + /* + * The below is just a paranoid check, it has to be + * compiled out if paranoid checks are disabled. + */ + err = paranoid_check_all_ff(ubi, pnum, ubi->leb_start, + ubi->leb_size); + if (err) + return err > 0 ? UBI_IO_BAD_VID_HDR : err; + + if (verbose) + ubi_warn("no VID header found at PEB %d, " + "only 0xFF bytes", pnum); + return UBI_IO_PEB_FREE; + } + + /* + * This is not a valid VID header, and these are not 0xFF + * bytes. Report that the header is corrupted. + */ + if (verbose) { + ubi_warn("bad magic number at PEB %d: %08x instead of " + "%08x", pnum, magic, UBI_VID_HDR_MAGIC); + ubi_dbg_dump_vid_hdr(vid_hdr); + } + return UBI_IO_BAD_VID_HDR; + } + + crc = crc32(UBI_CRC32_INIT, vid_hdr, UBI_VID_HDR_SIZE_CRC); + hdr_crc = ubi32_to_cpu(vid_hdr->hdr_crc); + + if (hdr_crc != crc) { + if (verbose) { + ubi_warn("bad CRC at PEB %d, calculated %#08x, " + "read %#08x", pnum, crc, hdr_crc); + ubi_dbg_dump_vid_hdr(vid_hdr); + } + return UBI_IO_BAD_VID_HDR; + } + + /* Validate the VID header that we have just read */ + err = validate_vid_hdr(ubi, vid_hdr); + if (err) { + ubi_err("validation failed for PEB %d", pnum); + return -EINVAL; + } + + return read_err ? UBI_IO_BITFLIPS : 0; +} + +/** + * ubi_io_write_vid_hdr - write a volume identifier header. + * @ubi: UBI device description object + * @pnum: the physical eraseblock number to write to + * @vid_hdr: the volume identifier header to write + * + * This function writes the volume identifier header described by @vid_hdr to + * physical eraseblock @pnum. This function automatically fills the + * @vid_hdr->magic and the @vid_hdr->version fields, as well as calculates + * header CRC checksum and stores it at vid_hdr->hdr_crc. + * + * This function returns zero in case of success and a negative error code in + * case of failure. If %-EIO is returned, the physical eraseblock probably went + * bad. + */ +int ubi_io_write_vid_hdr(const struct ubi_device *ubi, int pnum, + struct ubi_vid_hdr *vid_hdr) +{ + int err; + uint32_t crc; + void *p; + + dbg_io("write VID header to PEB %d", pnum); + ubi_assert(pnum >= 0 && pnum < ubi->peb_count); + + err = paranoid_check_peb_ec_hdr(ubi, pnum); + if (err) + return err > 0 ? -EINVAL: err; + + vid_hdr->magic = cpu_to_ubi32(UBI_VID_HDR_MAGIC); + vid_hdr->version = UBI_VERSION; + crc = crc32(UBI_CRC32_INIT, vid_hdr, UBI_VID_HDR_SIZE_CRC); + vid_hdr->hdr_crc = cpu_to_ubi32(crc); + + err = paranoid_check_vid_hdr(ubi, pnum, vid_hdr); + if (err) + return -EINVAL; + + p = (char *)vid_hdr - ubi->vid_hdr_shift; + err = ubi_io_write(ubi, p, pnum, ubi->vid_hdr_aloffset, + ubi->vid_hdr_alsize); + return err; +} + +#ifdef CONFIG_MTD_UBI_DEBUG_PARANOID + +/** + * paranoid_check_not_bad - ensure that a physical eraseblock is not bad. + * @ubi: UBI device description object + * @pnum: physical eraseblock number to check + * + * This function returns zero if the physical eraseblock is good, a positive + * number if it is bad and a negative error code if an error occurred. + */ +static int paranoid_check_not_bad(const struct ubi_device *ubi, int pnum) +{ + int err; + + err = ubi_io_is_bad(ubi, pnum); + if (!err) + return err; + + ubi_err("paranoid check failed for PEB %d", pnum); + ubi_dbg_dump_stack(); + return err; +} + +/** + * paranoid_check_ec_hdr - check if an erase counter header is all right. + * @ubi: UBI device description object + * @pnum: physical eraseblock number the erase counter header belongs to + * @ec_hdr: the erase counter header to check + * + * This function returns zero if the erase counter header contains valid + * values, and %1 if not. + */ +static int paranoid_check_ec_hdr(const struct ubi_device *ubi, int pnum, + const struct ubi_ec_hdr *ec_hdr) +{ + int err; + uint32_t magic; + + magic = ubi32_to_cpu(ec_hdr->magic); + if (magic != UBI_EC_HDR_MAGIC) { + ubi_err("bad magic %#08x, must be %#08x", + magic, UBI_EC_HDR_MAGIC); + goto fail; + } + + err = validate_ec_hdr(ubi, ec_hdr); + if (err) { + ubi_err("paranoid check failed for PEB %d", pnum); + goto fail; + } + + return 0; + +fail: + ubi_dbg_dump_ec_hdr(ec_hdr); + ubi_dbg_dump_stack(); + return 1; +} + +/** + * paranoid_check_peb_ec_hdr - check that the erase counter header of a + * physical eraseblock is in-place and is all right. + * @ubi: UBI device description object + * @pnum: the physical eraseblock number to check + * + * This function returns zero if the erase counter header is all right, %1 if + * not, and a negative error code if an error occurred. + */ +static int paranoid_check_peb_ec_hdr(const struct ubi_device *ubi, int pnum) +{ + int err; + uint32_t crc, hdr_crc; + struct ubi_ec_hdr *ec_hdr; + + ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL); + if (!ec_hdr) + return -ENOMEM; + + err = ubi_io_read(ubi, ec_hdr, pnum, 0, UBI_EC_HDR_SIZE); + if (err && err != UBI_IO_BITFLIPS && err != -EBADMSG) + goto exit; + + crc = crc32(UBI_CRC32_INIT, ec_hdr, UBI_EC_HDR_SIZE_CRC); + hdr_crc = ubi32_to_cpu(ec_hdr->hdr_crc); + if (hdr_crc != crc) { + ubi_err("bad CRC, calculated %#08x, read %#08x", crc, hdr_crc); + ubi_err("paranoid check failed for PEB %d", pnum); + ubi_dbg_dump_ec_hdr(ec_hdr); + ubi_dbg_dump_stack(); + err = 1; + goto exit; + } + + err = paranoid_check_ec_hdr(ubi, pnum, ec_hdr); + +exit: + kfree(ec_hdr); + return err; +} + +/** + * paranoid_check_vid_hdr - check that a volume identifier header is all right. + * @ubi: UBI device description object + * @pnum: physical eraseblock number the volume identifier header belongs to + * @vid_hdr: the volume identifier header to check + * + * This function returns zero if the volume identifier header is all right, and + * %1 if not. + */ +static int paranoid_check_vid_hdr(const struct ubi_device *ubi, int pnum, + const struct ubi_vid_hdr *vid_hdr) +{ + int err; + uint32_t magic; + + magic = ubi32_to_cpu(vid_hdr->magic); + if (magic != UBI_VID_HDR_MAGIC) { + ubi_err("bad VID header magic %#08x at PEB %d, must be %#08x", + magic, pnum, UBI_VID_HDR_MAGIC); + goto fail; + } + + err = validate_vid_hdr(ubi, vid_hdr); + if (err) { + ubi_err("paranoid check failed for PEB %d", pnum); + goto fail; + } + + return err; + +fail: + ubi_err("paranoid check failed for PEB %d", pnum); + ubi_dbg_dump_vid_hdr(vid_hdr); + ubi_dbg_dump_stack(); + return 1; + +} + +/** + * paranoid_check_peb_vid_hdr - check that the volume identifier header of a + * physical eraseblock is in-place and is all right. + * @ubi: UBI device description object + * @pnum: the physical eraseblock number to check + * + * This function returns zero if the volume identifier header is all right, + * %1 if not, and a negative error code if an error occurred. + */ +static int paranoid_check_peb_vid_hdr(const struct ubi_device *ubi, int pnum) +{ + int err; + uint32_t crc, hdr_crc; + struct ubi_vid_hdr *vid_hdr; + void *p; + + vid_hdr = ubi_zalloc_vid_hdr(ubi); + if (!vid_hdr) + return -ENOMEM; + + p = (char *)vid_hdr - ubi->vid_hdr_shift; + err = ubi_io_read(ubi, p, pnum, ubi->vid_hdr_aloffset, + ubi->vid_hdr_alsize); + if (err && err != UBI_IO_BITFLIPS && err != -EBADMSG) + goto exit; + + crc = crc32(UBI_CRC32_INIT, vid_hdr, UBI_EC_HDR_SIZE_CRC); + hdr_crc = ubi32_to_cpu(vid_hdr->hdr_crc); + if (hdr_crc != crc) { + ubi_err("bad VID header CRC at PEB %d, calculated %#08x, " + "read %#08x", pnum, crc, hdr_crc); + ubi_err("paranoid check failed for PEB %d", pnum); + ubi_dbg_dump_vid_hdr(vid_hdr); + ubi_dbg_dump_stack(); + err = 1; + goto exit; + } + + err = paranoid_check_vid_hdr(ubi, pnum, vid_hdr); + +exit: + ubi_free_vid_hdr(ubi, vid_hdr); + return err; +} + +/** + * paranoid_check_all_ff - check that a region of flash is empty. + * @ubi: UBI device description object + * @pnum: the physical eraseblock number to check + * @offset: the starting offset within the physical eraseblock to check + * @len: the length of the region to check + * + * This function returns zero if only 0xFF bytes are present at offset + * @offset of the physical eraseblock @pnum, %1 if not, and a negative error + * code if an error occurred. + */ +static int paranoid_check_all_ff(const struct ubi_device *ubi, int pnum, + int offset, int len) +{ + size_t read; + int err; + void *buf; + loff_t addr = (loff_t)pnum * ubi->peb_size + offset; + + buf = kzalloc(len, GFP_KERNEL); + if (!buf) + return -ENOMEM; + + err = ubi->mtd->read(ubi->mtd, addr, len, &read, buf); + if (err && err != -EUCLEAN) { + ubi_err("error %d while reading %d bytes from PEB %d:%d, " + "read %zd bytes", err, len, pnum, offset, read); + goto error; + } + + err = check_pattern(buf, 0xFF, len); + if (err == 0) { + ubi_err("flash region at PEB %d:%d, length %d does not " + "contain all 0xFF bytes", pnum, offset, len); + goto fail; + } + + kfree(buf); + return 0; + +fail: + ubi_err("paranoid check failed for PEB %d", pnum); + dbg_msg("hex dump of the %d-%d region", offset, offset + len); + ubi_dbg_hexdump(buf, len); + err = 1; +error: + ubi_dbg_dump_stack(); + kfree(buf); + return err; +} + +#endif /* CONFIG_MTD_UBI_DEBUG_PARANOID */ diff --git a/drivers/mtd/ubi/kapi.c b/drivers/mtd/ubi/kapi.c new file mode 100644 index 0000000..d352c45 --- /dev/null +++ b/drivers/mtd/ubi/kapi.c @@ -0,0 +1,575 @@ +/* + * Copyright (c) International Business Machines Corp., 2006 + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See + * the GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + * Author: Artem Bityutskiy (Битюцкий Артём) + */ + +/* This file mostly implements UBI kernel API functions */ + +#include <linux/module.h> +#include <linux/err.h> +#include <asm/div64.h> +#include "ubi.h" + +/** + * ubi_get_device_info - get information about UBI device. + * @ubi_num: UBI device number + * @di: the information is stored here + * + * This function returns %0 in case of success and a %-ENODEV if there is no + * such UBI device. + */ +int ubi_get_device_info(int ubi_num, struct ubi_device_info *di) +{ + const struct ubi_device *ubi; + + if (!try_module_get(THIS_MODULE)) + return -ENODEV; + + if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES || + !ubi_devices[ubi_num]) { + module_put(THIS_MODULE); + return -ENODEV; + } + + ubi = ubi_devices[ubi_num]; + di->ubi_num = ubi->ubi_num; + di->leb_size = ubi->leb_size; + di->min_io_size = ubi->min_io_size; + di->ro_mode = ubi->ro_mode; + di->cdev = MKDEV(ubi->major, 0); + module_put(THIS_MODULE); + return 0; +} +EXPORT_SYMBOL_GPL(ubi_get_device_info); + +/** + * ubi_get_volume_info - get information about UBI volume. + * @desc: volume descriptor + * @vi: the information is stored here + */ +void ubi_get_volume_info(struct ubi_volume_desc *desc, + struct ubi_volume_info *vi) +{ + const struct ubi_volume *vol = desc->vol; + const struct ubi_device *ubi = vol->ubi; + + vi->vol_id = vol->vol_id; + vi->ubi_num = ubi->ubi_num; + vi->size = vol->reserved_pebs; + vi->used_bytes = vol->used_bytes; + vi->vol_type = vol->vol_type; + vi->corrupted = vol->corrupted; + vi->upd_marker = vol->upd_marker; + vi->alignment = vol->alignment; + vi->usable_leb_size = vol->usable_leb_size; + vi->name_len = vol->name_len; + vi->name = vol->name; + vi->cdev = MKDEV(ubi->major, vi->vol_id + 1); +} +EXPORT_SYMBOL_GPL(ubi_get_volume_info); + +/** + * ubi_open_volume - open UBI volume. + * @ubi_num: UBI device number + * @vol_id: volume ID + * @mode: open mode + * + * The @mode parameter specifies if the volume should be opened in read-only + * mode, read-write mode, or exclusive mode. The exclusive mode guarantees that + * nobody else will be able to open this volume. UBI allows to have many volume + * readers and one writer at a time. + * + * If a static volume is being opened for the first time since boot, it will be + * checked by this function, which means it will be fully read and the CRC + * checksum of each logical eraseblock will be checked. + * + * This function returns volume descriptor in case of success and a negative + * error code in case of failure. + */ +struct ubi_volume_desc *ubi_open_volume(int ubi_num, int vol_id, int mode) +{ + int err; + struct ubi_volume_desc *desc; + struct ubi_device *ubi = ubi_devices[ubi_num]; + struct ubi_volume *vol; + + dbg_msg("open device %d volume %d, mode %d", ubi_num, vol_id, mode); + + err = -ENODEV; + if (!try_module_get(THIS_MODULE)) + return ERR_PTR(err); + + if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES || !ubi) + goto out_put; + + err = -EINVAL; + if (vol_id < 0 || vol_id >= ubi->vtbl_slots) + goto out_put; + if (mode != UBI_READONLY && mode != UBI_READWRITE && + mode != UBI_EXCLUSIVE) + goto out_put; + + desc = kmalloc(sizeof(struct ubi_volume_desc), GFP_KERNEL); + if (!desc) { + err = -ENOMEM; + goto out_put; + } + + spin_lock(&ubi->volumes_lock); + vol = ubi->volumes[vol_id]; + if (!vol) { + err = -ENODEV; + goto out_unlock; + } + + err = -EBUSY; + switch (mode) { + case UBI_READONLY: + if (vol->exclusive) + goto out_unlock; + vol->readers += 1; + break; + + case UBI_READWRITE: + if (vol->exclusive || vol->writers > 0) + goto out_unlock; + vol->writers += 1; + break; + + case UBI_EXCLUSIVE: + if (vol->exclusive || vol->writers || vol->readers) + goto out_unlock; + vol->exclusive = 1; + break; + } + spin_unlock(&ubi->volumes_lock); + + desc->vol = vol; + desc->mode = mode; + + /* + * To prevent simultaneous checks of the same volume we use @vtbl_mutex, + * although it is not the purpose it was introduced for. + */ + mutex_lock(&ubi->vtbl_mutex); + if (!vol->checked) { + /* This is the first open - check the volume */ + err = ubi_check_volume(ubi, vol_id); + if (err < 0) { + mutex_unlock(&ubi->vtbl_mutex); + ubi_close_volume(desc); + return ERR_PTR(err); + } + if (err == 1) { + ubi_warn("volume %d on UBI device %d is corrupted", + vol_id, ubi->ubi_num); + vol->corrupted = 1; + } + vol->checked = 1; + } + mutex_unlock(&ubi->vtbl_mutex); + return desc; + +out_unlock: + spin_unlock(&ubi->volumes_lock); + kfree(desc); +out_put: + module_put(THIS_MODULE); + return ERR_PTR(err); +} +EXPORT_SYMBOL_GPL(ubi_open_volume); + +/** + * ubi_open_volume_nm - open UBI volume by name. + * @ubi_num: UBI device number + * @name: volume name + * @mode: open mode + * + * This function is similar to 'ubi_open_volume()', but opens a volume by name. + */ +struct ubi_volume_desc *ubi_open_volume_nm(int ubi_num, const char *name, + int mode) +{ + int i, vol_id = -1, len; + struct ubi_volume_desc *ret; + struct ubi_device *ubi; + + dbg_msg("open volume %s, mode %d", name, mode); + + if (!name) + return ERR_PTR(-EINVAL); + + len = strnlen(name, UBI_VOL_NAME_MAX + 1); + if (len > UBI_VOL_NAME_MAX) + return ERR_PTR(-EINVAL); + + ret = ERR_PTR(-ENODEV); + if (!try_module_get(THIS_MODULE)) + return ret; + + if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES || !ubi_devices[ubi_num]) + goto out_put; + + ubi = ubi_devices[ubi_num]; + + spin_lock(&ubi->volumes_lock); + /* Walk all volumes of this UBI device */ + for (i = 0; i < ubi->vtbl_slots; i++) { + struct ubi_volume *vol = ubi->volumes[i]; + + if (vol && len == vol->name_len && !strcmp(name, vol->name)) { + vol_id = i; + break; + } + } + spin_unlock(&ubi->volumes_lock); + + if (vol_id < 0) + goto out_put; + + ret = ubi_open_volume(ubi_num, vol_id, mode); + +out_put: + module_put(THIS_MODULE); + return ret; +} +EXPORT_SYMBOL_GPL(ubi_open_volume_nm); + +/** + * ubi_close_volume - close UBI volume. + * @desc: volume descriptor + */ +void ubi_close_volume(struct ubi_volume_desc *desc) +{ + struct ubi_volume *vol = desc->vol; + + dbg_msg("close volume %d, mode %d", vol->vol_id, desc->mode); + + spin_lock(&vol->ubi->volumes_lock); + switch (desc->mode) { + case UBI_READONLY: + vol->readers -= 1; + break; + case UBI_READWRITE: + vol->writers -= 1; + break; + case UBI_EXCLUSIVE: + vol->exclusive = 0; + } + spin_unlock(&vol->ubi->volumes_lock); + + kfree(desc); + module_put(THIS_MODULE); +} +EXPORT_SYMBOL_GPL(ubi_close_volume); + +/** + * ubi_leb_read - read data. + * @desc: volume descriptor + * @lnum: logical eraseblock number to read from + * @buf: buffer where to store the read data + * @offset: offset within the logical eraseblock to read from + * @len: how many bytes to read + * @check: whether UBI has to check the read data's CRC or not. + * + * This function reads data from offset @offset of logical eraseblock @lnum and + * stores the data at @buf. When reading from static volumes, @check specifies + * whether the data has to be checked or not. If yes, the whole logical + * eraseblock will be read and its CRC checksum will be checked (i.e., the CRC + * checksum is per-eraseblock). So checking may substantially slow down the + * read speed. The @check argument is ignored for dynamic volumes. + * + * In case of success, this function returns zero. In case of failure, this + * function returns a negative error code. + * + * %-EBADMSG error code is returned: + * o for both static and dynamic volumes if MTD driver has detected a data + * integrity problem (unrecoverable ECC checksum mismatch in case of NAND); + * o for static volumes in case of data CRC mismatch. + * + * If the volume is damaged because of an interrupted update this function just + * returns immediately with %-EBADF error code. + */ +int ubi_leb_read(struct ubi_volume_desc *desc, int lnum, char *buf, int offset, + int len, int check) +{ + struct ubi_volume *vol = desc->vol; + struct ubi_device *ubi = vol->ubi; + int err, vol_id = vol->vol_id; + + dbg_msg("read %d bytes from LEB %d:%d:%d", len, vol_id, lnum, offset); + + if (vol_id < 0 || vol_id >= ubi->vtbl_slots || lnum < 0 || + lnum >= vol->used_ebs || offset < 0 || len < 0 || + offset + len > vol->usable_leb_size) + return -EINVAL; + + if (vol->vol_type == UBI_STATIC_VOLUME && lnum == vol->used_ebs - 1 && + offset + len > vol->last_eb_bytes) + return -EINVAL; + + if (vol->upd_marker) + return -EBADF; + if (len == 0) + return 0; + + err = ubi_eba_read_leb(ubi, vol_id, lnum, buf, offset, len, check); + if (err && err == -EBADMSG && vol->vol_type == UBI_STATIC_VOLUME) { + ubi_warn("mark volume %d as corrupted", vol_id); + vol->corrupted = 1; + } + + return err; +} +EXPORT_SYMBOL_GPL(ubi_leb_read); + +/** + * ubi_leb_write - write data. + * @desc: volume descriptor + * @lnum: logical eraseblock number to write to + * @buf: data to write + * @offset: offset within the logical eraseblock where to write + * @len: how many bytes to write + * @dtype: expected data type + * + * This function writes @len bytes of data from @buf to offset @offset of + * logical eraseblock @lnum. The @dtype argument describes expected lifetime of + * the data. + * + * This function takes care of physical eraseblock write failures. If write to + * the physical eraseblock write operation fails, the logical eraseblock is + * re-mapped to another physical eraseblock, the data is recovered, and the + * write finishes. UBI has a pool of reserved physical eraseblocks for this. + * + * If all the data were successfully written, zero is returned. If an error + * occurred and UBI has not been able to recover from it, this function returns + * a negative error code. Note, in case of an error, it is possible that + * something was still written to the flash media, but that may be some + * garbage. + * + * If the volume is damaged because of an interrupted update this function just + * returns immediately with %-EBADF code. + */ +int ubi_leb_write(struct ubi_volume_desc *desc, int lnum, const void *buf, + int offset, int len, int dtype) +{ + struct ubi_volume *vol = desc->vol; + struct ubi_device *ubi = vol->ubi; + int vol_id = vol->vol_id; + + dbg_msg("write %d bytes to LEB %d:%d:%d", len, vol_id, lnum, offset); + + if (vol_id < 0 || vol_id >= ubi->vtbl_slots) + return -EINVAL; + + if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME) + return -EROFS; + + if (lnum < 0 || lnum >= vol->reserved_pebs || offset < 0 || len < 0 || + offset + len > vol->usable_leb_size || offset % ubi->min_io_size || + len % ubi->min_io_size) + return -EINVAL; + + if (dtype != UBI_LONGTERM && dtype != UBI_SHORTTERM && + dtype != UBI_UNKNOWN) + return -EINVAL; + + if (vol->upd_marker) + return -EBADF; + + if (len == 0) + return 0; + + return ubi_eba_write_leb(ubi, vol_id, lnum, buf, offset, len, dtype); +} +EXPORT_SYMBOL_GPL(ubi_leb_write); + +/* + * ubi_leb_change - change logical eraseblock atomically. + * @desc: volume descriptor + * @lnum: logical eraseblock number to change + * @buf: data to write + * @len: how many bytes to write + * @dtype: expected data type + * + * This function changes the contents of a logical eraseblock atomically. @buf + * has to contain new logical eraseblock data, and @len - the length of the + * data, which has to be aligned. The length may be shorter then the logical + * eraseblock size, ant the logical eraseblock may be appended to more times + * later on. This function guarantees that in case of an unclean reboot the old + * contents is preserved. Returns zero in case of success and a negative error + * code in case of failure. + */ +int ubi_leb_change(struct ubi_volume_desc *desc, int lnum, const void *buf, + int len, int dtype) +{ + struct ubi_volume *vol = desc->vol; + struct ubi_device *ubi = vol->ubi; + int vol_id = vol->vol_id; + + dbg_msg("atomically write %d bytes to LEB %d:%d", len, vol_id, lnum); + + if (vol_id < 0 || vol_id >= ubi->vtbl_slots) + return -EINVAL; + + if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME) + return -EROFS; + + if (lnum < 0 || lnum >= vol->reserved_pebs || len < 0 || + len > vol->usable_leb_size || len % ubi->min_io_size) + return -EINVAL; + + if (dtype != UBI_LONGTERM && dtype != UBI_SHORTTERM && + dtype != UBI_UNKNOWN) + return -EINVAL; + + if (vol->upd_marker) + return -EBADF; + + if (len == 0) + return 0; + + return ubi_eba_atomic_leb_change(ubi, vol_id, lnum, buf, len, dtype); +} +EXPORT_SYMBOL_GPL(ubi_leb_change); + +/** + * ubi_leb_erase - erase logical eraseblock. + * @desc: volume descriptor + * @lnum: logical eraseblock number + * + * This function un-maps logical eraseblock @lnum and synchronously erases the + * correspondent physical eraseblock. Returns zero in case of success and a + * negative error code in case of failure. + * + * If the volume is damaged because of an interrupted update this function just + * returns immediately with %-EBADF code. + */ +int ubi_leb_erase(struct ubi_volume_desc *desc, int lnum) +{ + struct ubi_volume *vol = desc->vol; + struct ubi_device *ubi = vol->ubi; + int err, vol_id = vol->vol_id; + + dbg_msg("erase LEB %d:%d", vol_id, lnum); + + if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME) + return -EROFS; + + if (lnum < 0 || lnum >= vol->reserved_pebs) + return -EINVAL; + + if (vol->upd_marker) + return -EBADF; + + err = ubi_eba_unmap_leb(ubi, vol_id, lnum); + if (err) + return err; + + return ubi_wl_flush(ubi); +} +EXPORT_SYMBOL_GPL(ubi_leb_erase); + +/** + * ubi_leb_unmap - un-map logical eraseblock. + * @desc: volume descriptor + * @lnum: logical eraseblock number + * + * This function un-maps logical eraseblock @lnum and schedules the + * corresponding physical eraseblock for erasure, so that it will eventually be + * physically erased in background. This operation is much faster then the + * erase operation. + * + * Unlike erase, the un-map operation does not guarantee that the logical + * eraseblock will contain all 0xFF bytes when UBI is initialized again. For + * example, if several logical eraseblocks are un-mapped, and an unclean reboot + * happens after this, the logical eraseblocks will not necessarily be + * un-mapped again when this MTD device is attached. They may actually be + * mapped to the same physical eraseblocks again. So, this function has to be + * used with care. + * + * In other words, when un-mapping a logical eraseblock, UBI does not store + * any information about this on the flash media, it just marks the logical + * eraseblock as "un-mapped" in RAM. If UBI is detached before the physical + * eraseblock is physically erased, it will be mapped again to the same logical + * eraseblock when the MTD device is attached again. + * + * The main and obvious use-case of this function is when the contents of a + * logical eraseblock has to be re-written. Then it is much more efficient to + * first un-map it, then write new data, rather then first erase it, then write + * new data. Note, once new data has been written to the logical eraseblock, + * UBI guarantees that the old contents has gone forever. In other words, if an + * unclean reboot happens after the logical eraseblock has been un-mapped and + * then written to, it will contain the last written data. + * + * This function returns zero in case of success and a negative error code in + * case of failure. If the volume is damaged because of an interrupted update + * this function just returns immediately with %-EBADF code. + */ +int ubi_leb_unmap(struct ubi_volume_desc *desc, int lnum) +{ + struct ubi_volume *vol = desc->vol; + struct ubi_device *ubi = vol->ubi; + int vol_id = vol->vol_id; + + dbg_msg("unmap LEB %d:%d", vol_id, lnum); + + if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME) + return -EROFS; + + if (lnum < 0 || lnum >= vol->reserved_pebs) + return -EINVAL; + + if (vol->upd_marker) + return -EBADF; + + return ubi_eba_unmap_leb(ubi, vol_id, lnum); +} +EXPORT_SYMBOL_GPL(ubi_leb_unmap); + +/** + * ubi_is_mapped - check if logical eraseblock is mapped. + * @desc: volume descriptor + * @lnum: logical eraseblock number + * + * This function checks if logical eraseblock @lnum is mapped to a physical + * eraseblock. If a logical eraseblock is un-mapped, this does not necessarily + * mean it will still be un-mapped after the UBI device is re-attached. The + * logical eraseblock may become mapped to the physical eraseblock it was last + * mapped to. + * + * This function returns %1 if the LEB is mapped, %0 if not, and a negative + * error code in case of failure. If the volume is damaged because of an + * interrupted update this function just returns immediately with %-EBADF error + * code. + */ +int ubi_is_mapped(struct ubi_volume_desc *desc, int lnum) +{ + struct ubi_volume *vol = desc->vol; + + dbg_msg("test LEB %d:%d", vol->vol_id, lnum); + + if (lnum < 0 || lnum >= vol->reserved_pebs) + return -EINVAL; + + if (vol->upd_marker) + return -EBADF; + + return vol->eba_tbl[lnum] >= 0; +} +EXPORT_SYMBOL_GPL(ubi_is_mapped); diff --git a/drivers/mtd/ubi/misc.c b/drivers/mtd/ubi/misc.c new file mode 100644 index 0000000..38d4e67 --- /dev/null +++ b/drivers/mtd/ubi/misc.c @@ -0,0 +1,105 @@ +/* + * Copyright (c) International Business Machines Corp., 2006 + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See + * the GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + * Author: Artem Bityutskiy (Битюцкий Артём) + */ + +/* Here we keep miscellaneous functions which are used all over the UBI code */ + +#include "ubi.h" + +/** + * calc_data_len - calculate how much real data is stored in a buffer. + * @ubi: UBI device description object + * @buf: a buffer with the contents of the physical eraseblock + * @length: the buffer length + * + * This function calculates how much "real data" is stored in @buf and returnes + * the length. Continuous 0xFF bytes at the end of the buffer are not + * considered as "real data". + */ +int ubi_calc_data_len(const struct ubi_device *ubi, const void *buf, + int length) +{ + int i; + + ubi_assert(length % ubi->min_io_size == 0); + + for (i = length - 1; i >= 0; i--) + if (((const uint8_t *)buf)[i] != 0xFF) + break; + + /* The resulting length must be aligned to the minimum flash I/O size */ + length = ALIGN(i + 1, ubi->min_io_size); + return length; +} + +/** + * ubi_check_volume - check the contents of a static volume. + * @ubi: UBI device description object + * @vol_id: ID of the volume to check + * + * This function checks if static volume @vol_id is corrupted by fully reading + * it and checking data CRC. This function returns %0 if the volume is not + * corrupted, %1 if it is corrupted and a negative error code in case of + * failure. Dynamic volumes are not checked and zero is returned immediately. + */ +int ubi_check_volume(struct ubi_device *ubi, int vol_id) +{ + void *buf; + int err = 0, i; + struct ubi_volume *vol = ubi->volumes[vol_id]; + + if (vol->vol_type != UBI_STATIC_VOLUME) + return 0; + + buf = kmalloc(vol->usable_leb_size, GFP_KERNEL); + if (!buf) + return -ENOMEM; + + for (i = 0; i < vol->used_ebs; i++) { + int size; + + if (i == vol->used_ebs - 1) + size = vol->last_eb_bytes; + else + size = vol->usable_leb_size; + + err = ubi_eba_read_leb(ubi, vol_id, i, buf, 0, size, 1); + if (err) { + if (err == -EBADMSG) + err = 1; + break; + } + } + + kfree(buf); + return err; +} + +/** + * ubi_calculate_rsvd_pool - calculate how many PEBs must be reserved for bad + * eraseblock handling. + * @ubi: UBI device description object + */ +void ubi_calculate_reserved(struct ubi_device *ubi) +{ + ubi->beb_rsvd_level = ubi->good_peb_count/100; + ubi->beb_rsvd_level *= CONFIG_MTD_UBI_BEB_RESERVE; + if (ubi->beb_rsvd_level < MIN_RESEVED_PEBS) + ubi->beb_rsvd_level = MIN_RESEVED_PEBS; +} diff --git a/drivers/mtd/ubi/scan.c b/drivers/mtd/ubi/scan.c new file mode 100644 index 0000000..473f320 --- /dev/null +++ b/drivers/mtd/ubi/scan.c @@ -0,0 +1,1368 @@ +/* + * Copyright (c) International Business Machines Corp., 2006 + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See + * the GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + * Author: Artem Bityutskiy (Битюцкий Артём) + */ + +/* + * UBI scanning unit. + * + * This unit is responsible for scanning the flash media, checking UBI + * headers and providing complete information about the UBI flash image. + * + * The scanning information is reoresented by a &struct ubi_scan_info' object. + * Information about found volumes is represented by &struct ubi_scan_volume + * objects which are kept in volume RB-tree with root at the @volumes field. + * The RB-tree is indexed by the volume ID. + * + * Found logical eraseblocks are represented by &struct ubi_scan_leb objects. + * These objects are kept in per-volume RB-trees with the root at the + * corresponding &struct ubi_scan_volume object. To put it differently, we keep + * an RB-tree of per-volume objects and each of these objects is the root of + * RB-tree of per-eraseblock objects. + * + * Corrupted physical eraseblocks are put to the @corr list, free physical + * eraseblocks are put to the @free list and the physical eraseblock to be + * erased are put to the @erase list. + */ + +#include <linux/err.h> +#include <linux/crc32.h> +#include "ubi.h" + +#ifdef CONFIG_MTD_UBI_DEBUG_PARANOID +static int paranoid_check_si(const struct ubi_device *ubi, + struct ubi_scan_info *si); +#else +#define paranoid_check_si(ubi, si) 0 +#endif + +/* Temporary variables used during scanning */ +static struct ubi_ec_hdr *ech; +static struct ubi_vid_hdr *vidh; + +int ubi_scan_add_to_list(struct ubi_scan_info *si, int pnum, int ec, + struct list_head *list) +{ + struct ubi_scan_leb *seb; + + if (list == &si->free) + dbg_bld("add to free: PEB %d, EC %d", pnum, ec); + else if (list == &si->erase) + dbg_bld("add to erase: PEB %d, EC %d", pnum, ec); + else if (list == &si->corr) + dbg_bld("add to corrupted: PEB %d, EC %d", pnum, ec); + else if (list == &si->alien) + dbg_bld("add to alien: PEB %d, EC %d", pnum, ec); + else + BUG(); + + seb = kmalloc(sizeof(struct ubi_scan_leb), GFP_KERNEL); + if (!seb) + return -ENOMEM; + + seb->pnum = pnum; + seb->ec = ec; + list_add_tail(&seb->u.list, list); + return 0; +} + +/** + * commit_to_mean_value - commit intermediate results to the final mean erase + * counter value. + * @si: scanning information + * + * This is a helper function which calculates partial mean erase counter mean + * value and adds it to the resulting mean value. As we can work only in + * integer arithmetic and we want to calculate the mean value of erase counter + * accurately, we first sum erase counter values in @si->ec_sum variable and + * count these components in @si->ec_count. If this temporary @si->ec_sum is + * going to overflow, we calculate the partial mean value + * (@si->ec_sum/@si->ec_count) and add it to @si->mean_ec. + */ +static void commit_to_mean_value(struct ubi_scan_info *si) +{ + si->ec_sum /= si->ec_count; + if (si->ec_sum % si->ec_count >= si->ec_count / 2) + si->mean_ec += 1; + si->mean_ec += si->ec_sum; +} + +/** + * validate_vid_hdr - check that volume identifier header is correct and + * consistent. + * @vid_hdr: the volume identifier header to check + * @sv: information about the volume this logical eraseblock belongs to + * @pnum: physical eraseblock number the VID header came from + * + * This function checks that data stored in @vid_hdr is consistent. Returns + * non-zero if an inconsistency was found and zero if not. + * + * Note, UBI does sanity check of everything it reads from the flash media. + * Most of the checks are done in the I/O unit. Here we check that the + * information in the VID header is consistent to the information in other VID + * headers of the same volume. + */ +static int validate_vid_hdr(const struct ubi_vid_hdr *vid_hdr, + const struct ubi_scan_volume *sv, int pnum) +{ + int vol_type = vid_hdr->vol_type; + int vol_id = ubi32_to_cpu(vid_hdr->vol_id); + int used_ebs = ubi32_to_cpu(vid_hdr->used_ebs); + int data_pad = ubi32_to_cpu(vid_hdr->data_pad); + + if (sv->leb_count != 0) { + int sv_vol_type; + + /* + * This is not the first logical eraseblock belonging to this + * volume. Ensure that the data in its VID header is consistent + * to the data in previous logical eraseblock headers. + */ + + if (vol_id != sv->vol_id) { + dbg_err("inconsistent vol_id"); + goto bad; + } + + if (sv->vol_type == UBI_STATIC_VOLUME) + sv_vol_type = UBI_VID_STATIC; + else + sv_vol_type = UBI_VID_DYNAMIC; + + if (vol_type != sv_vol_type) { + dbg_err("inconsistent vol_type"); + goto bad; + } + + if (used_ebs != sv->used_ebs) { + dbg_err("inconsistent used_ebs"); + goto bad; + } + + if (data_pad != sv->data_pad) { + dbg_err("inconsistent data_pad"); + goto bad; + } + } + + return 0; + +bad: + ubi_err("inconsistent VID header at PEB %d", pnum); + ubi_dbg_dump_vid_hdr(vid_hdr); + ubi_dbg_dump_sv(sv); + return -EINVAL; +} + +/** + * add_volume - add volume to the scanning information. + * @si: scanning information + * @vol_id: ID of the volume to add + * @pnum: physical eraseblock number + * @vid_hdr: volume identifier header + * + * If the volume corresponding to the @vid_hdr logical eraseblock is already + * present in the scanning information, this function does nothing. Otherwise + * it adds corresponding volume to the scanning information. Returns a pointer + * to the scanning volume object in case of success and a negative error code + * in case of failure. + */ +static struct ubi_scan_volume *add_volume(struct ubi_scan_info *si, int vol_id, + int pnum, + const struct ubi_vid_hdr *vid_hdr) +{ + struct ubi_scan_volume *sv; + struct rb_node **p = &si->volumes.rb_node, *parent = NULL; + + ubi_assert(vol_id == ubi32_to_cpu(vid_hdr->vol_id)); + + /* Walk the volume RB-tree to look if this volume is already present */ + while (*p) { + parent = *p; + sv = rb_entry(parent, struct ubi_scan_volume, rb); + + if (vol_id == sv->vol_id) + return sv; + + if (vol_id > sv->vol_id) + p = &(*p)->rb_left; + else + p = &(*p)->rb_right; + } + + /* The volume is absent - add it */ + sv = kmalloc(sizeof(struct ubi_scan_volume), GFP_KERNEL); + if (!sv) + return ERR_PTR(-ENOMEM); + + sv->highest_lnum = sv->leb_count = 0; + si->max_sqnum = 0; + sv->vol_id = vol_id; + sv->root = RB_ROOT; + sv->used_ebs = ubi32_to_cpu(vid_hdr->used_ebs); + sv->data_pad = ubi32_to_cpu(vid_hdr->data_pad); + sv->compat = vid_hdr->compat; + sv->vol_type = vid_hdr->vol_type == UBI_VID_DYNAMIC ? UBI_DYNAMIC_VOLUME + : UBI_STATIC_VOLUME; + if (vol_id > si->highest_vol_id) + si->highest_vol_id = vol_id; + + rb_link_node(&sv->rb, parent, p); + rb_insert_color(&sv->rb, &si->volumes); + si->vols_found += 1; + dbg_bld("added volume %d", vol_id); + return sv; +} + +/** + * compare_lebs - find out which logical eraseblock is newer. + * @ubi: UBI device description object + * @seb: first logical eraseblock to compare + * @pnum: physical eraseblock number of the second logical eraseblock to + * compare + * @vid_hdr: volume identifier header of the second logical eraseblock + * + * This function compares 2 copies of a LEB and informs which one is newer. In + * case of success this function returns a positive value, in case of failure, a + * negative error code is returned. The success return codes use the following + * bits: + * o bit 0 is cleared: the first PEB (described by @seb) is newer then the + * second PEB (described by @pnum and @vid_hdr); + * o bit 0 is set: the second PEB is newer; + * o bit 1 is cleared: no bit-flips were detected in the newer LEB; + * o bit 1 is set: bit-flips were detected in the newer LEB; + * o bit 2 is cleared: the older LEB is not corrupted; + * o bit 2 is set: the older LEB is corrupted. + */ +static int compare_lebs(const struct ubi_device *ubi, + const struct ubi_scan_leb *seb, int pnum, + const struct ubi_vid_hdr *vid_hdr) +{ + void *buf; + int len, err, second_is_newer, bitflips = 0, corrupted = 0; + uint32_t data_crc, crc; + struct ubi_vid_hdr *vidh = NULL; + unsigned long long sqnum2 = ubi64_to_cpu(vid_hdr->sqnum); + + if (seb->sqnum == 0 && sqnum2 == 0) { + long long abs, v1 = seb->leb_ver, v2 = ubi32_to_cpu(vid_hdr->leb_ver); + + /* + * UBI constantly increases the logical eraseblock version + * number and it can overflow. Thus, we have to bear in mind + * that versions that are close to %0xFFFFFFFF are less then + * versions that are close to %0. + * + * The UBI WL unit guarantees that the number of pending tasks + * is not greater then %0x7FFFFFFF. So, if the difference + * between any two versions is greater or equivalent to + * %0x7FFFFFFF, there was an overflow and the logical + * eraseblock with lower version is actually newer then the one + * with higher version. + * + * FIXME: but this is anyway obsolete and will be removed at + * some point. + */ + + dbg_bld("using old crappy leb_ver stuff"); + + abs = v1 - v2; + if (abs < 0) + abs = -abs; + + if (abs < 0x7FFFFFFF) + /* Non-overflow situation */ + second_is_newer = (v2 > v1); + else + second_is_newer = (v2 < v1); + } else + /* Obviously the LEB with lower sequence counter is older */ + second_is_newer = sqnum2 > seb->sqnum; + + /* + * Now we know which copy is newer. If the copy flag of the PEB with + * newer version is not set, then we just return, otherwise we have to + * check data CRC. For the second PEB we already have the VID header, + * for the first one - we'll need to re-read it from flash. + * + * FIXME: this may be optimized so that we wouldn't read twice. + */ + + if (second_is_newer) { + if (!vid_hdr->copy_flag) { + /* It is not a copy, so it is newer */ + dbg_bld("second PEB %d is newer, copy_flag is unset", + pnum); + return 1; + } + } else { + pnum = seb->pnum; + + vidh = ubi_zalloc_vid_hdr(ubi); + if (!vidh) + return -ENOMEM; + + err = ubi_io_read_vid_hdr(ubi, pnum, vidh, 0); + if (err) { + if (err == UBI_IO_BITFLIPS) + bitflips = 1; + else { + dbg_err("VID of PEB %d header is bad, but it " + "was OK earlier", pnum); + if (err > 0) + err = -EIO; + + goto out_free_vidh; + } + } + + if (!vidh->copy_flag) { + /* It is not a copy, so it is newer */ + dbg_bld("first PEB %d is newer, copy_flag is unset", + pnum); + err = bitflips << 1; + goto out_free_vidh; + } + + vid_hdr = vidh; + } + + /* Read the data of the copy and check the CRC */ + + len = ubi32_to_cpu(vid_hdr->data_size); + buf = kmalloc(len, GFP_KERNEL); + if (!buf) { + err = -ENOMEM; + goto out_free_vidh; + } + + err = ubi_io_read_data(ubi, buf, pnum, 0, len); + if (err && err != UBI_IO_BITFLIPS) + goto out_free_buf; + + data_crc = ubi32_to_cpu(vid_hdr->data_crc); + crc = crc32(UBI_CRC32_INIT, buf, len); + if (crc != data_crc) { + dbg_bld("PEB %d CRC error: calculated %#08x, must be %#08x", + pnum, crc, data_crc); + corrupted = 1; + bitflips = 0; + second_is_newer = !second_is_newer; + } else { + dbg_bld("PEB %d CRC is OK", pnum); + bitflips = !!err; + } + + kfree(buf); + ubi_free_vid_hdr(ubi, vidh); + + if (second_is_newer) + dbg_bld("second PEB %d is newer, copy_flag is set", pnum); + else + dbg_bld("first PEB %d is newer, copy_flag is set", pnum); + + return second_is_newer | (bitflips << 1) | (corrupted << 2); + +out_free_buf: + kfree(buf); +out_free_vidh: + ubi_free_vid_hdr(ubi, vidh); + ubi_assert(err < 0); + return err; +} + +/** + * ubi_scan_add_used - add information about a physical eraseblock to the + * scanning information. + * @ubi: UBI device description object + * @si: scanning information + * @pnum: the physical eraseblock number + * @ec: erase counter + * @vid_hdr: the volume identifier header + * @bitflips: if bit-flips were detected when this physical eraseblock was read + * + * This function returns zero in case of success and a negative error code in + * case of failure. + */ +int ubi_scan_add_used(const struct ubi_device *ubi, struct ubi_scan_info *si, + int pnum, int ec, const struct ubi_vid_hdr *vid_hdr, + int bitflips) +{ + int err, vol_id, lnum; + uint32_t leb_ver; + unsigned long long sqnum; + struct ubi_scan_volume *sv; + struct ubi_scan_leb *seb; + struct rb_node **p, *parent = NULL; + + vol_id = ubi32_to_cpu(vid_hdr->vol_id); + lnum = ubi32_to_cpu(vid_hdr->lnum); + sqnum = ubi64_to_cpu(vid_hdr->sqnum); + leb_ver = ubi32_to_cpu(vid_hdr->leb_ver); + + dbg_bld("PEB %d, LEB %d:%d, EC %d, sqnum %llu, ver %u, bitflips %d", + pnum, vol_id, lnum, ec, sqnum, leb_ver, bitflips); + + sv = add_volume(si, vol_id, pnum, vid_hdr); + if (IS_ERR(sv) < 0) + return PTR_ERR(sv); + + /* + * Walk the RB-tree of logical eraseblocks of volume @vol_id to look + * if this is the first instance of this logical eraseblock or not. + */ + p = &sv->root.rb_node; + while (*p) { + int cmp_res; + + parent = *p; + seb = rb_entry(parent, struct ubi_scan_leb, u.rb); + if (lnum != seb->lnum) { + if (lnum < seb->lnum) + p = &(*p)->rb_left; + else + p = &(*p)->rb_right; + continue; + } + + /* + * There is already a physical eraseblock describing the same + * logical eraseblock present. + */ + + dbg_bld("this LEB already exists: PEB %d, sqnum %llu, " + "LEB ver %u, EC %d", seb->pnum, seb->sqnum, + seb->leb_ver, seb->ec); + + /* + * Make sure that the logical eraseblocks have different + * versions. Otherwise the image is bad. + */ + if (seb->leb_ver == leb_ver && leb_ver != 0) { + ubi_err("two LEBs with same version %u", leb_ver); + ubi_dbg_dump_seb(seb, 0); + ubi_dbg_dump_vid_hdr(vid_hdr); + return -EINVAL; + } + + /* + * Make sure that the logical eraseblocks have different + * sequence numbers. Otherwise the image is bad. + * + * FIXME: remove 'sqnum != 0' check when leb_ver is removed. + */ + if (seb->sqnum == sqnum && sqnum != 0) { + ubi_err("two LEBs with same sequence number %llu", + sqnum); + ubi_dbg_dump_seb(seb, 0); + ubi_dbg_dump_vid_hdr(vid_hdr); + return -EINVAL; + } + + /* + * Now we have to drop the older one and preserve the newer + * one. + */ + cmp_res = compare_lebs(ubi, seb, pnum, vid_hdr); + if (cmp_res < 0) + return cmp_res; + + if (cmp_res & 1) { + /* + * This logical eraseblock is newer then the one + * found earlier. + */ + err = validate_vid_hdr(vid_hdr, sv, pnum); + if (err) + return err; + + if (cmp_res & 4) + err = ubi_scan_add_to_list(si, seb->pnum, + seb->ec, &si->corr); + else + err = ubi_scan_add_to_list(si, seb->pnum, + seb->ec, &si->erase); + if (err) + return err; + + seb->ec = ec; + seb->pnum = pnum; + seb->scrub = ((cmp_res & 2) || bitflips); + seb->sqnum = sqnum; + seb->leb_ver = leb_ver; + + if (sv->highest_lnum == lnum) + sv->last_data_size = + ubi32_to_cpu(vid_hdr->data_size); + + return 0; + } else { + /* + * This logical eraseblock is older then the one found + * previously. + */ + if (cmp_res & 4) + return ubi_scan_add_to_list(si, pnum, ec, + &si->corr); + else + return ubi_scan_add_to_list(si, pnum, ec, + &si->erase); + } + } + + /* + * We've met this logical eraseblock for the first time, add it to the + * scanning information. + */ + + err = validate_vid_hdr(vid_hdr, sv, pnum); + if (err) + return err; + + seb = kmalloc(sizeof(struct ubi_scan_leb), GFP_KERNEL); + if (!seb) + return -ENOMEM; + + seb->ec = ec; + seb->pnum = pnum; + seb->lnum = lnum; + seb->sqnum = sqnum; + seb->scrub = bitflips; + seb->leb_ver = leb_ver; + + if (sv->highest_lnum <= lnum) { + sv->highest_lnum = lnum; + sv->last_data_size = ubi32_to_cpu(vid_hdr->data_size); + } + + if (si->max_sqnum < sqnum) + si->max_sqnum = sqnum; + + sv->leb_count += 1; + rb_link_node(&seb->u.rb, parent, p); + rb_insert_color(&seb->u.rb, &sv->root); + return 0; +} + +/** + * ubi_scan_find_sv - find information about a particular volume in the + * scanning information. + * @si: scanning information + * @vol_id: the requested volume ID + * + * This function returns a pointer to the volume description or %NULL if there + * are no data about this volume in the scanning information. + */ +struct ubi_scan_volume *ubi_scan_find_sv(const struct ubi_scan_info *si, + int vol_id) +{ + struct ubi_scan_volume *sv; + struct rb_node *p = si->volumes.rb_node; + + while (p) { + sv = rb_entry(p, struct ubi_scan_volume, rb); + + if (vol_id == sv->vol_id) + return sv; + + if (vol_id > sv->vol_id) + p = p->rb_left; + else + p = p->rb_right; + } + + return NULL; +} + +/** + * ubi_scan_find_seb - find information about a particular logical + * eraseblock in the volume scanning information. + * @sv: a pointer to the volume scanning information + * @lnum: the requested logical eraseblock + * + * This function returns a pointer to the scanning logical eraseblock or %NULL + * if there are no data about it in the scanning volume information. + */ +struct ubi_scan_leb *ubi_scan_find_seb(const struct ubi_scan_volume *sv, + int lnum) +{ + struct ubi_scan_leb *seb; + struct rb_node *p = sv->root.rb_node; + + while (p) { + seb = rb_entry(p, struct ubi_scan_leb, u.rb); + + if (lnum == seb->lnum) + return seb; + + if (lnum > seb->lnum) + p = p->rb_left; + else + p = p->rb_right; + } + + return NULL; +} + +/** + * ubi_scan_rm_volume - delete scanning information about a volume. + * @si: scanning information + * @sv: the volume scanning information to delete + */ +void ubi_scan_rm_volume(struct ubi_scan_info *si, struct ubi_scan_volume *sv) +{ + struct rb_node *rb; + struct ubi_scan_leb *seb; + + dbg_bld("remove scanning information about volume %d", sv->vol_id); + + while ((rb = rb_first(&sv->root))) { + seb = rb_entry(rb, struct ubi_scan_leb, u.rb); + rb_erase(&seb->u.rb, &sv->root); + list_add_tail(&seb->u.list, &si->erase); + } + + rb_erase(&sv->rb, &si->volumes); + kfree(sv); + si->vols_found -= 1; +} + +/** + * ubi_scan_erase_peb - erase a physical eraseblock. + * @ubi: UBI device description object + * @si: scanning information + * @pnum: physical eraseblock number to erase; + * @ec: erase counter value to write (%UBI_SCAN_UNKNOWN_EC if it is unknown) + * + * This function erases physical eraseblock 'pnum', and writes the erase + * counter header to it. This function should only be used on UBI device + * initialization stages, when the EBA unit had not been yet initialized. This + * function returns zero in case of success and a negative error code in case + * of failure. + */ +int ubi_scan_erase_peb(const struct ubi_device *ubi, + const struct ubi_scan_info *si, int pnum, int ec) +{ + int err; + struct ubi_ec_hdr *ec_hdr; + + ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL); + if (!ec_hdr) + return -ENOMEM; + + if ((long long)ec >= UBI_MAX_ERASECOUNTER) { + /* + * Erase counter overflow. Upgrade UBI and use 64-bit + * erase counters internally. + */ + ubi_err("erase counter overflow at PEB %d, EC %d", pnum, ec); + return -EINVAL; + } + + ec_hdr->ec = cpu_to_ubi64(ec); + + err = ubi_io_sync_erase(ubi, pnum, 0); + if (err < 0) + goto out_free; + + err = ubi_io_write_ec_hdr(ubi, pnum, ec_hdr); + +out_free: + kfree(ec_hdr); + return err; +} + +/** + * ubi_scan_get_free_peb - get a free physical eraseblock. + * @ubi: UBI device description object + * @si: scanning information + * + * This function returns a free physical eraseblock. It is supposed to be + * called on the UBI initialization stages when the wear-leveling unit is not + * initialized yet. This function picks a physical eraseblocks from one of the + * lists, writes the EC header if it is needed, and removes it from the list. + * + * This function returns scanning physical eraseblock information in case of + * success and an error code in case of failure. + */ +struct ubi_scan_leb *ubi_scan_get_free_peb(const struct ubi_device *ubi, + struct ubi_scan_info *si) +{ + int err = 0, i; + struct ubi_scan_leb *seb; + + if (!list_empty(&si->free)) { + seb = list_entry(si->free.next, struct ubi_scan_leb, u.list); + list_del(&seb->u.list); + dbg_bld("return free PEB %d, EC %d", seb->pnum, seb->ec); + return seb; + } + + for (i = 0; i < 2; i++) { + struct list_head *head; + struct ubi_scan_leb *tmp_seb; + + if (i == 0) + head = &si->erase; + else + head = &si->corr; + + /* + * We try to erase the first physical eraseblock from the @head + * list and pick it if we succeed, or try to erase the + * next one if not. And so forth. We don't want to take care + * about bad eraseblocks here - they'll be handled later. + */ + list_for_each_entry_safe(seb, tmp_seb, head, u.list) { + if (seb->ec == UBI_SCAN_UNKNOWN_EC) + seb->ec = si->mean_ec; + + err = ubi_scan_erase_peb(ubi, si, seb->pnum, seb->ec+1); + if (err) + continue; + + seb->ec += 1; + list_del(&seb->u.list); + dbg_bld("return PEB %d, EC %d", seb->pnum, seb->ec); + return seb; + } + } + + ubi_err("no eraseblocks found"); + return ERR_PTR(-ENOSPC); +} + +/** + * process_eb - read UBI headers, check them and add corresponding data + * to the scanning information. + * @ubi: UBI device description object + * @si: scanning information + * @pnum: the physical eraseblock number + * + * This function returns a zero if the physical eraseblock was succesfully + * handled and a negative error code in case of failure. + */ +static int process_eb(struct ubi_device *ubi, struct ubi_scan_info *si, int pnum) +{ + long long ec; + int err, bitflips = 0, vol_id, ec_corr = 0; + + dbg_bld("scan PEB %d", pnum); + + /* Skip bad physical eraseblocks */ + err = ubi_io_is_bad(ubi, pnum); + if (err < 0) + return err; + else if (err) { + /* + * FIXME: this is actually duty of the I/O unit to initialize + * this, but MTD does not provide enough information. + */ + si->bad_peb_count += 1; + return 0; + } + + err = ubi_io_read_ec_hdr(ubi, pnum, ech, 0); + if (err < 0) + return err; + else if (err == UBI_IO_BITFLIPS) + bitflips = 1; + else if (err == UBI_IO_PEB_EMPTY) + return ubi_scan_add_to_list(si, pnum, UBI_SCAN_UNKNOWN_EC, + &si->erase); + else if (err == UBI_IO_BAD_EC_HDR) { + /* + * We have to also look at the VID header, possibly it is not + * corrupted. Set %bitflips flag in order to make this PEB be + * moved and EC be re-created. + */ + ec_corr = 1; + ec = UBI_SCAN_UNKNOWN_EC; + bitflips = 1; + } + + si->is_empty = 0; + + if (!ec_corr) { + /* Make sure UBI version is OK */ + if (ech->version != UBI_VERSION) { + ubi_err("this UBI version is %d, image version is %d", + UBI_VERSION, (int)ech->version); + return -EINVAL; + } + + ec = ubi64_to_cpu(ech->ec); + if (ec > UBI_MAX_ERASECOUNTER) { + /* + * Erase counter overflow. The EC headers have 64 bits + * reserved, but we anyway make use of only 31 bit + * values, as this seems to be enough for any existing + * flash. Upgrade UBI and use 64-bit erase counters + * internally. + */ + ubi_err("erase counter overflow, max is %d", + UBI_MAX_ERASECOUNTER); + ubi_dbg_dump_ec_hdr(ech); + return -EINVAL; + } + } + + /* OK, we've done with the EC header, let's look at the VID header */ + + err = ubi_io_read_vid_hdr(ubi, pnum, vidh, 0); + if (err < 0) + return err; + else if (err == UBI_IO_BITFLIPS) + bitflips = 1; + else if (err == UBI_IO_BAD_VID_HDR || + (err == UBI_IO_PEB_FREE && ec_corr)) { + /* VID header is corrupted */ + err = ubi_scan_add_to_list(si, pnum, ec, &si->corr); + if (err) + return err; + goto adjust_mean_ec; + } else if (err == UBI_IO_PEB_FREE) { + /* No VID header - the physical eraseblock is free */ + err = ubi_scan_add_to_list(si, pnum, ec, &si->free); + if (err) + return err; + goto adjust_mean_ec; + } + + vol_id = ubi32_to_cpu(vidh->vol_id); + if (vol_id > UBI_MAX_VOLUMES && vol_id != UBI_LAYOUT_VOL_ID) { + int lnum = ubi32_to_cpu(vidh->lnum); + + /* Unsupported internal volume */ + switch (vidh->compat) { + case UBI_COMPAT_DELETE: + ubi_msg("\"delete\" compatible internal volume %d:%d" + " found, remove it", vol_id, lnum); + err = ubi_scan_add_to_list(si, pnum, ec, &si->corr); + if (err) + return err; + break; + + case UBI_COMPAT_RO: + ubi_msg("read-only compatible internal volume %d:%d" + " found, switch to read-only mode", + vol_id, lnum); + ubi->ro_mode = 1; + break; + + case UBI_COMPAT_PRESERVE: + ubi_msg("\"preserve\" compatible internal volume %d:%d" + " found", vol_id, lnum); + err = ubi_scan_add_to_list(si, pnum, ec, &si->alien); + if (err) + return err; + si->alien_peb_count += 1; + return 0; + + case UBI_COMPAT_REJECT: + ubi_err("incompatible internal volume %d:%d found", + vol_id, lnum); + return -EINVAL; + } + } + + /* Both UBI headers seem to be fine */ + err = ubi_scan_add_used(ubi, si, pnum, ec, vidh, bitflips); + if (err) + return err; + +adjust_mean_ec: + if (!ec_corr) { + if (si->ec_sum + ec < ec) { + commit_to_mean_value(si); + si->ec_sum = 0; + si->ec_count = 0; + } else { + si->ec_sum += ec; + si->ec_count += 1; + } + + if (ec > si->max_ec) + si->max_ec = ec; + if (ec < si->min_ec) + si->min_ec = ec; + } + + return 0; +} + +/** + * ubi_scan - scan an MTD device. + * @ubi: UBI device description object + * + * This function does full scanning of an MTD device and returns complete + * information about it. In case of failure, an error code is returned. + */ +struct ubi_scan_info *ubi_scan(struct ubi_device *ubi) +{ + int err, pnum; + struct rb_node *rb1, *rb2; + struct ubi_scan_volume *sv; + struct ubi_scan_leb *seb; + struct ubi_scan_info *si; + + si = kzalloc(sizeof(struct ubi_scan_info), GFP_KERNEL); + if (!si) + return ERR_PTR(-ENOMEM); + + INIT_LIST_HEAD(&si->corr); + INIT_LIST_HEAD(&si->free); + INIT_LIST_HEAD(&si->erase); + INIT_LIST_HEAD(&si->alien); + si->volumes = RB_ROOT; + si->is_empty = 1; + + err = -ENOMEM; + ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL); + if (!ech) + goto out_si; + + vidh = ubi_zalloc_vid_hdr(ubi); + if (!vidh) + goto out_ech; + + for (pnum = 0; pnum < ubi->peb_count; pnum++) { + cond_resched(); + + dbg_msg("process PEB %d", pnum); + err = process_eb(ubi, si, pnum); + if (err < 0) + goto out_vidh; + } + + dbg_msg("scanning is finished"); + + /* Finish mean erase counter calculations */ + if (si->ec_count) + commit_to_mean_value(si); + + if (si->is_empty) + ubi_msg("empty MTD device detected"); + + /* + * In case of unknown erase counter we use the mean erase counter + * value. + */ + ubi_rb_for_each_entry(rb1, sv, &si->volumes, rb) { + ubi_rb_for_each_entry(rb2, seb, &sv->root, u.rb) + if (seb->ec == UBI_SCAN_UNKNOWN_EC) + seb->ec = si->mean_ec; + } + + list_for_each_entry(seb, &si->free, u.list) { + if (seb->ec == UBI_SCAN_UNKNOWN_EC) + seb->ec = si->mean_ec; + } + + list_for_each_entry(seb, &si->corr, u.list) + if (seb->ec == UBI_SCAN_UNKNOWN_EC) + seb->ec = si->mean_ec; + + list_for_each_entry(seb, &si->erase, u.list) + if (seb->ec == UBI_SCAN_UNKNOWN_EC) + seb->ec = si->mean_ec; + + err = paranoid_check_si(ubi, si); + if (err) { + if (err > 0) + err = -EINVAL; + goto out_vidh; + } + + ubi_free_vid_hdr(ubi, vidh); + kfree(ech); + + return si; + +out_vidh: + ubi_free_vid_hdr(ubi, vidh); +out_ech: + kfree(ech); +out_si: + ubi_scan_destroy_si(si); + return ERR_PTR(err); +} + +/** + * destroy_sv - free the scanning volume information + * @sv: scanning volume information + * + * This function destroys the volume RB-tree (@sv->root) and the scanning + * volume information. + */ +static void destroy_sv(struct ubi_scan_volume *sv) +{ + struct ubi_scan_leb *seb; + struct rb_node *this = sv->root.rb_node; + + while (this) { + if (this->rb_left) + this = this->rb_left; + else if (this->rb_right) + this = this->rb_right; + else { + seb = rb_entry(this, struct ubi_scan_leb, u.rb); + this = rb_parent(this); + if (this) { + if (this->rb_left == &seb->u.rb) + this->rb_left = NULL; + else + this->rb_right = NULL; + } + + kfree(seb); + } + } + kfree(sv); +} + +/** + * ubi_scan_destroy_si - destroy scanning information. + * @si: scanning information + */ +void ubi_scan_destroy_si(struct ubi_scan_info *si) +{ + struct ubi_scan_leb *seb, *seb_tmp; + struct ubi_scan_volume *sv; + struct rb_node *rb; + + list_for_each_entry_safe(seb, seb_tmp, &si->alien, u.list) { + list_del(&seb->u.list); + kfree(seb); + } + list_for_each_entry_safe(seb, seb_tmp, &si->erase, u.list) { + list_del(&seb->u.list); + kfree(seb); + } + list_for_each_entry_safe(seb, seb_tmp, &si->corr, u.list) { + list_del(&seb->u.list); + kfree(seb); + } + list_for_each_entry_safe(seb, seb_tmp, &si->free, u.list) { + list_del(&seb->u.list); + kfree(seb); + } + + /* Destroy the volume RB-tree */ + rb = si->volumes.rb_node; + while (rb) { + if (rb->rb_left) + rb = rb->rb_left; + else if (rb->rb_right) + rb = rb->rb_right; + else { + sv = rb_entry(rb, struct ubi_scan_volume, rb); + + rb = rb_parent(rb); + if (rb) { + if (rb->rb_left == &sv->rb) + rb->rb_left = NULL; + else + rb->rb_right = NULL; + } + + destroy_sv(sv); + } + } + + kfree(si); +} + +#ifdef CONFIG_MTD_UBI_DEBUG_PARANOID + +/** + * paranoid_check_si - check if the scanning information is correct and + * consistent. + * @ubi: UBI device description object + * @si: scanning information + * + * This function returns zero if the scanning information is all right, %1 if + * not and a negative error code if an error occurred. + */ +static int paranoid_check_si(const struct ubi_device *ubi, + struct ubi_scan_info *si) +{ + int pnum, err, vols_found = 0; + struct rb_node *rb1, *rb2; + struct ubi_scan_volume *sv; + struct ubi_scan_leb *seb, *last_seb; + uint8_t *buf; + + /* + * At first, check that scanning information is ok. + */ + ubi_rb_for_each_entry(rb1, sv, &si->volumes, rb) { + int leb_count = 0; + + cond_resched(); + + vols_found += 1; + + if (si->is_empty) { + ubi_err("bad is_empty flag"); + goto bad_sv; + } + + if (sv->vol_id < 0 || sv->highest_lnum < 0 || + sv->leb_count < 0 || sv->vol_type < 0 || sv->used_ebs < 0 || + sv->data_pad < 0 || sv->last_data_size < 0) { + ubi_err("negative values"); + goto bad_sv; + } + + if (sv->vol_id >= UBI_MAX_VOLUMES && + sv->vol_id < UBI_INTERNAL_VOL_START) { + ubi_err("bad vol_id"); + goto bad_sv; + } + + if (sv->vol_id > si->highest_vol_id) { + ubi_err("highest_vol_id is %d, but vol_id %d is there", + si->highest_vol_id, sv->vol_id); + goto out; + } + + if (sv->vol_type != UBI_DYNAMIC_VOLUME && + sv->vol_type != UBI_STATIC_VOLUME) { + ubi_err("bad vol_type"); + goto bad_sv; + } + + if (sv->data_pad > ubi->leb_size / 2) { + ubi_err("bad data_pad"); + goto bad_sv; + } + + last_seb = NULL; + ubi_rb_for_each_entry(rb2, seb, &sv->root, u.rb) { + cond_resched(); + + last_seb = seb; + leb_count += 1; + + if (seb->pnum < 0 || seb->ec < 0) { + ubi_err("negative values"); + goto bad_seb; + } + + if (seb->ec < si->min_ec) { + ubi_err("bad si->min_ec (%d), %d found", + si->min_ec, seb->ec); + goto bad_seb; + } + + if (seb->ec > si->max_ec) { + ubi_err("bad si->max_ec (%d), %d found", + si->max_ec, seb->ec); + goto bad_seb; + } + + if (seb->pnum >= ubi->peb_count) { + ubi_err("too high PEB number %d, total PEBs %d", + seb->pnum, ubi->peb_count); + goto bad_seb; + } + + if (sv->vol_type == UBI_STATIC_VOLUME) { + if (seb->lnum >= sv->used_ebs) { + ubi_err("bad lnum or used_ebs"); + goto bad_seb; + } + } else { + if (sv->used_ebs != 0) { + ubi_err("non-zero used_ebs"); + goto bad_seb; + } + } + + if (seb->lnum > sv->highest_lnum) { + ubi_err("incorrect highest_lnum or lnum"); + goto bad_seb; + } + } + + if (sv->leb_count != leb_count) { + ubi_err("bad leb_count, %d objects in the tree", + leb_count); + goto bad_sv; + } + + if (!last_seb) + continue; + + seb = last_seb; + + if (seb->lnum != sv->highest_lnum) { + ubi_err("bad highest_lnum"); + goto bad_seb; + } + } + + if (vols_found != si->vols_found) { + ubi_err("bad si->vols_found %d, should be %d", + si->vols_found, vols_found); + goto out; + } + + /* Check that scanning information is correct */ + ubi_rb_for_each_entry(rb1, sv, &si->volumes, rb) { + last_seb = NULL; + ubi_rb_for_each_entry(rb2, seb, &sv->root, u.rb) { + int vol_type; + + cond_resched(); + + last_seb = seb; + + err = ubi_io_read_vid_hdr(ubi, seb->pnum, vidh, 1); + if (err && err != UBI_IO_BITFLIPS) { + ubi_err("VID header is not OK (%d)", err); + if (err > 0) + err = -EIO; + return err; + } + + vol_type = vidh->vol_type == UBI_VID_DYNAMIC ? + UBI_DYNAMIC_VOLUME : UBI_STATIC_VOLUME; + if (sv->vol_type != vol_type) { + ubi_err("bad vol_type"); + goto bad_vid_hdr; + } + + if (seb->sqnum != ubi64_to_cpu(vidh->sqnum)) { + ubi_err("bad sqnum %llu", seb->sqnum); + goto bad_vid_hdr; + } + + if (sv->vol_id != ubi32_to_cpu(vidh->vol_id)) { + ubi_err("bad vol_id %d", sv->vol_id); + goto bad_vid_hdr; + } + + if (sv->compat != vidh->compat) { + ubi_err("bad compat %d", vidh->compat); + goto bad_vid_hdr; + } + + if (seb->lnum != ubi32_to_cpu(vidh->lnum)) { + ubi_err("bad lnum %d", seb->lnum); + goto bad_vid_hdr; + } + + if (sv->used_ebs != ubi32_to_cpu(vidh->used_ebs)) { + ubi_err("bad used_ebs %d", sv->used_ebs); + goto bad_vid_hdr; + } + + if (sv->data_pad != ubi32_to_cpu(vidh->data_pad)) { + ubi_err("bad data_pad %d", sv->data_pad); + goto bad_vid_hdr; + } + + if (seb->leb_ver != ubi32_to_cpu(vidh->leb_ver)) { + ubi_err("bad leb_ver %u", seb->leb_ver); + goto bad_vid_hdr; + } + } + + if (!last_seb) + continue; + + if (sv->highest_lnum != ubi32_to_cpu(vidh->lnum)) { + ubi_err("bad highest_lnum %d", sv->highest_lnum); + goto bad_vid_hdr; + } + + if (sv->last_data_size != ubi32_to_cpu(vidh->data_size)) { + ubi_err("bad last_data_size %d", sv->last_data_size); + goto bad_vid_hdr; + } + } + + /* + * Make sure that all the physical eraseblocks are in one of the lists + * or trees. + */ + buf = kmalloc(ubi->peb_count, GFP_KERNEL); + if (!buf) + return -ENOMEM; + + memset(buf, 1, ubi->peb_count); + for (pnum = 0; pnum < ubi->peb_count; pnum++) { + err = ubi_io_is_bad(ubi, pnum); + if (err < 0) + return err; + else if (err) + buf[pnum] = 0; + } + + ubi_rb_for_each_entry(rb1, sv, &si->volumes, rb) + ubi_rb_for_each_entry(rb2, seb, &sv->root, u.rb) + buf[seb->pnum] = 0; + + list_for_each_entry(seb, &si->free, u.list) + buf[seb->pnum] = 0; + + list_for_each_entry(seb, &si->corr, u.list) + buf[seb->pnum] = 0; + + list_for_each_entry(seb, &si->erase, u.list) + buf[seb->pnum] = 0; + + list_for_each_entry(seb, &si->alien, u.list) + buf[seb->pnum] = 0; + + err = 0; + for (pnum = 0; pnum < ubi->peb_count; pnum++) + if (buf[pnum]) { + ubi_err("PEB %d is not referred", pnum); + err = 1; + } + + kfree(buf); + if (err) + goto out; + return 0; + +bad_seb: + ubi_err("bad scanning information about LEB %d", seb->lnum); + ubi_dbg_dump_seb(seb, 0); + ubi_dbg_dump_sv(sv); + goto out; + +bad_sv: + ubi_err("bad scanning information about volume %d", sv->vol_id); + ubi_dbg_dump_sv(sv); + goto out; + +bad_vid_hdr: + ubi_err("bad scanning information about volume %d", sv->vol_id); + ubi_dbg_dump_sv(sv); + ubi_dbg_dump_vid_hdr(vidh); + +out: + ubi_dbg_dump_stack(); + return 1; +} + +#endif /* CONFIG_MTD_UBI_DEBUG_PARANOID */ diff --git a/drivers/mtd/ubi/scan.h b/drivers/mtd/ubi/scan.h new file mode 100644 index 0000000..3949f61 --- /dev/null +++ b/drivers/mtd/ubi/scan.h @@ -0,0 +1,167 @@ +/* + * Copyright (c) International Business Machines Corp., 2006 + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See + * the GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + * Author: Artem Bityutskiy (Битюцкий Артём) + */ + +#ifndef __UBI_SCAN_H__ +#define __UBI_SCAN_H__ + +/* The erase counter value for this physical eraseblock is unknown */ +#define UBI_SCAN_UNKNOWN_EC (-1) + +/** + * struct ubi_scan_leb - scanning information about a physical eraseblock. + * @ec: erase counter (%UBI_SCAN_UNKNOWN_EC if it is unknown) + * @pnum: physical eraseblock number + * @lnum: logical eraseblock number + * @scrub: if this physical eraseblock needs scrubbing + * @sqnum: sequence number + * @u: unions RB-tree or @list links + * @u.rb: link in the per-volume RB-tree of &struct ubi_scan_leb objects + * @u.list: link in one of the eraseblock lists + * @leb_ver: logical eraseblock version (obsolete) + * + * One object of this type is allocated for each physical eraseblock during + * scanning. + */ +struct ubi_scan_leb { + int ec; + int pnum; + int lnum; + int scrub; + unsigned long long sqnum; + union { + struct rb_node rb; + struct list_head list; + } u; + uint32_t leb_ver; +}; + +/** + * struct ubi_scan_volume - scanning information about a volume. + * @vol_id: volume ID + * @highest_lnum: highest logical eraseblock number in this volume + * @leb_count: number of logical eraseblocks in this volume + * @vol_type: volume type + * @used_ebs: number of used logical eraseblocks in this volume (only for + * static volumes) + * @last_data_size: amount of data in the last logical eraseblock of this + * volume (always equivalent to the usable logical eraseblock size in case of + * dynamic volumes) + * @data_pad: how many bytes at the end of logical eraseblocks of this volume + * are not used (due to volume alignment) + * @compat: compatibility flags of this volume + * @rb: link in the volume RB-tree + * @root: root of the RB-tree containing all the eraseblock belonging to this + * volume (&struct ubi_scan_leb objects) + * + * One object of this type is allocated for each volume during scanning. + */ +struct ubi_scan_volume { + int vol_id; + int highest_lnum; + int leb_count; + int vol_type; + int used_ebs; + int last_data_size; + int data_pad; + int compat; + struct rb_node rb; + struct rb_root root; +}; + +/** + * struct ubi_scan_info - UBI scanning information. + * @volumes: root of the volume RB-tree + * @corr: list of corrupted physical eraseblocks + * @free: list of free physical eraseblocks + * @erase: list of physical eraseblocks which have to be erased + * @alien: list of physical eraseblocks which should not be used by UBI (e.g., + * @bad_peb_count: count of bad physical eraseblocks + * those belonging to "preserve"-compatible internal volumes) + * @vols_found: number of volumes found during scanning + * @highest_vol_id: highest volume ID + * @alien_peb_count: count of physical eraseblocks in the @alien list + * @is_empty: flag indicating whether the MTD device is empty or not + * @min_ec: lowest erase counter value + * @max_ec: highest erase counter value + * @max_sqnum: highest sequence number value + * @mean_ec: mean erase counter value + * @ec_sum: a temporary variable used when calculating @mean_ec + * @ec_count: a temporary variable used when calculating @mean_ec + * + * This data structure contains the result of scanning and may be used by other + * UBI units to build final UBI data structures, further error-recovery and so + * on. + */ +struct ubi_scan_info { + struct rb_root volumes; + struct list_head corr; + struct list_head free; + struct list_head erase; + struct list_head alien; + int bad_peb_count; + int vols_found; + int highest_vol_id; + int alien_peb_count; + int is_empty; + int min_ec; + int max_ec; + unsigned long long max_sqnum; + int mean_ec; + int ec_sum; + int ec_count; +}; + +struct ubi_device; +struct ubi_vid_hdr; + +/* + * ubi_scan_move_to_list - move a physical eraseblock from the volume tree to a + * list. + * + * @sv: volume scanning information + * @seb: scanning eraseblock infprmation + * @list: the list to move to + */ +static inline void ubi_scan_move_to_list(struct ubi_scan_volume *sv, + struct ubi_scan_leb *seb, + struct list_head *list) +{ + rb_erase(&seb->u.rb, &sv->root); + list_add_tail(&seb->u.list, list); +} + +int ubi_scan_add_to_list(struct ubi_scan_info *si, int pnum, int ec, + struct list_head *list); +int ubi_scan_add_used(const struct ubi_device *ubi, struct ubi_scan_info *si, + int pnum, int ec, const struct ubi_vid_hdr *vid_hdr, + int bitflips); +struct ubi_scan_volume *ubi_scan_find_sv(const struct ubi_scan_info *si, + int vol_id); +struct ubi_scan_leb *ubi_scan_find_seb(const struct ubi_scan_volume *sv, + int lnum); +void ubi_scan_rm_volume(struct ubi_scan_info *si, struct ubi_scan_volume *sv); +struct ubi_scan_leb *ubi_scan_get_free_peb(const struct ubi_device *ubi, + struct ubi_scan_info *si); +int ubi_scan_erase_peb(const struct ubi_device *ubi, + const struct ubi_scan_info *si, int pnum, int ec); +struct ubi_scan_info *ubi_scan(struct ubi_device *ubi); +void ubi_scan_destroy_si(struct ubi_scan_info *si); + +#endif /* !__UBI_SCAN_H__ */ diff --git a/drivers/mtd/ubi/ubi.h b/drivers/mtd/ubi/ubi.h new file mode 100644 index 0000000..feb647f --- /dev/null +++ b/drivers/mtd/ubi/ubi.h @@ -0,0 +1,535 @@ +/* + * Copyright (c) International Business Machines Corp., 2006 + * Copyright (c) Nokia Corporation, 2006, 2007 + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See + * the GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + * Author: Artem Bityutskiy (Битюцкий Артём) + */ + +#ifndef __UBI_UBI_H__ +#define __UBI_UBI_H__ + +#include <linux/init.h> +#include <linux/types.h> +#include <linux/list.h> +#include <linux/rbtree.h> +#include <linux/sched.h> +#include <linux/wait.h> +#include <linux/mutex.h> +#include <linux/rwsem.h> +#include <linux/spinlock.h> +#include <linux/fs.h> +#include <linux/cdev.h> +#include <linux/device.h> +#include <linux/string.h> +#include <linux/mtd/mtd.h> + +#include <mtd/ubi-header.h> +#include <linux/mtd/ubi.h> + +#include "scan.h" +#include "debug.h" + +/* Maximum number of supported UBI devices */ +#define UBI_MAX_DEVICES 32 + +/* UBI name used for character devices, sysfs, etc */ +#define UBI_NAME_STR "ubi" + +/* Normal UBI messages */ +#define ubi_msg(fmt, ...) printk(KERN_NOTICE "UBI: " fmt "\n", ##__VA_ARGS__) +/* UBI warning messages */ +#define ubi_warn(fmt, ...) printk(KERN_WARNING "UBI warning: %s: " fmt "\n", \ + __FUNCTION__, ##__VA_ARGS__) +/* UBI error messages */ +#define ubi_err(fmt, ...) printk(KERN_ERR "UBI error: %s: " fmt "\n", \ + __FUNCTION__, ##__VA_ARGS__) + +/* Lowest number PEBs reserved for bad PEB handling */ +#define MIN_RESEVED_PEBS 2 + +/* Background thread name pattern */ +#define UBI_BGT_NAME_PATTERN "ubi_bgt%dd" + +/* This marker in the EBA table means that the LEB is um-mapped */ +#define UBI_LEB_UNMAPPED -1 + +/* + * In case of errors, UBI tries to repeat the operation several times before + * returning error. The below constant defines how many times UBI re-tries. + */ +#define UBI_IO_RETRIES 3 + +/* + * Error codes returned by the I/O unit. + * + * UBI_IO_PEB_EMPTY: the physical eraseblock is empty, i.e. it contains only + * 0xFF bytes + * UBI_IO_PEB_FREE: the physical eraseblock is free, i.e. it contains only a + * valid erase counter header, and the rest are %0xFF bytes + * UBI_IO_BAD_EC_HDR: the erase counter header is corrupted (bad magic or CRC) + * UBI_IO_BAD_VID_HDR: the volume identifier header is corrupted (bad magic or + * CRC) + * UBI_IO_BITFLIPS: bit-flips were detected and corrected + */ +enum { + UBI_IO_PEB_EMPTY = 1, + UBI_IO_PEB_FREE, + UBI_IO_BAD_EC_HDR, + UBI_IO_BAD_VID_HDR, + UBI_IO_BITFLIPS +}; + +extern int ubi_devices_cnt; +extern struct ubi_device *ubi_devices[]; + +struct ubi_volume_desc; + +/** + * struct ubi_volume - UBI volume description data structure. + * @dev: device object to make use of the the Linux device model + * @cdev: character device object to create character device + * @ubi: reference to the UBI device description object + * @vol_id: volume ID + * @readers: number of users holding this volume in read-only mode + * @writers: number of users holding this volume in read-write mode + * @exclusive: whether somebody holds this volume in exclusive mode + * @removed: if the volume was removed + * @checked: if this static volume was checked + * + * @reserved_pebs: how many physical eraseblocks are reserved for this volume + * @vol_type: volume type (%UBI_DYNAMIC_VOLUME or %UBI_STATIC_VOLUME) + * @usable_leb_size: logical eraseblock size without padding + * @used_ebs: how many logical eraseblocks in this volume contain data + * @last_eb_bytes: how many bytes are stored in the last logical eraseblock + * @used_bytes: how many bytes of data this volume contains + * @upd_marker: non-zero if the update marker is set for this volume + * @corrupted: non-zero if the volume is corrupted (static volumes only) + * @alignment: volume alignment + * @data_pad: how many bytes are not used at the end of physical eraseblocks to + * satisfy the requested alignment + * @name_len: volume name length + * @name: volume name + * + * @updating: whether the volume is being updated + * @upd_ebs: how many eraseblocks are expected to be updated + * @upd_bytes: how many bytes are expected to be received + * @upd_received: how many update bytes were already received + * @upd_buf: update buffer which is used to collect update data + * + * @eba_tbl: EBA table of this volume (LEB->PEB mapping) + * + * @gluebi_desc: gluebi UBI volume descriptor + * @gluebi_refcount: reference count of the gluebi MTD device + * @gluebi_mtd: MTD device description object of the gluebi MTD device + * + * The @corrupted field indicates that the volume's contents is corrupted. + * Since UBI protects only static volumes, this field is not relevant to + * dynamic volumes - it is user's responsibility to assure their data + * integrity. + * + * The @upd_marker flag indicates that this volume is either being updated at + * the moment or is damaged because of an unclean reboot. + */ +struct ubi_volume { + struct device dev; + struct cdev cdev; + struct ubi_device *ubi; + int vol_id; + int readers; + int writers; + int exclusive; + int removed; + int checked; + + int reserved_pebs; + int vol_type; + int usable_leb_size; + int used_ebs; + int last_eb_bytes; + long long used_bytes; + int upd_marker; + int corrupted; + int alignment; + int data_pad; + int name_len; + char name[UBI_VOL_NAME_MAX+1]; + + int updating; + int upd_ebs; + long long upd_bytes; + long long upd_received; + void *upd_buf; + + int *eba_tbl; + +#ifdef CONFIG_MTD_UBI_GLUEBI + /* Gluebi-related stuff may be compiled out */ + struct ubi_volume_desc *gluebi_desc; + int gluebi_refcount; + struct mtd_info gluebi_mtd; +#endif +}; + +/** + * struct ubi_volume_desc - descriptor of the UBI volume returned when it is + * opened. + * @vol: reference to the corresponding volume description object + * @mode: open mode (%UBI_READONLY, %UBI_READWRITE, or %UBI_EXCLUSIVE) + */ +struct ubi_volume_desc { + struct ubi_volume *vol; + int mode; +}; + +struct ubi_wl_entry; + +/** + * struct ubi_device - UBI device description structure + * @dev: class device object to use the the Linux device model + * @cdev: character device object to create character device + * @ubi_num: UBI device number + * @ubi_name: UBI device name + * @major: character device major number + * @vol_count: number of volumes in this UBI device + * @volumes: volumes of this UBI device + * @volumes_lock: protects @volumes, @rsvd_pebs, @avail_pebs, beb_rsvd_pebs, + * @beb_rsvd_level, @bad_peb_count, @good_peb_count, @vol_count, @vol->readers, + * @vol->writers, @vol->exclusive, @vol->removed, @vol->mapping and + * @vol->eba_tbl. + * + * @rsvd_pebs: count of reserved physical eraseblocks + * @avail_pebs: count of available physical eraseblocks + * @beb_rsvd_pebs: how many physical eraseblocks are reserved for bad PEB + * handling + * @beb_rsvd_level: normal level of PEBs reserved for bad PEB handling + * + * @vtbl_slots: how many slots are available in the volume table + * @vtbl_size: size of the volume table in bytes + * @vtbl: in-RAM volume table copy + * + * @max_ec: current highest erase counter value + * @mean_ec: current mean erase counter value + * + * global_sqnum: global sequence number + * @ltree_lock: protects the lock tree and @global_sqnum + * @ltree: the lock tree + * @vtbl_mutex: protects on-flash volume table + * + * @used: RB-tree of used physical eraseblocks + * @free: RB-tree of free physical eraseblocks + * @scrub: RB-tree of physical eraseblocks which need scrubbing + * @prot: protection trees + * @prot.pnum: protection tree indexed by physical eraseblock numbers + * @prot.aec: protection tree indexed by absolute erase counter value + * @wl_lock: protects the @used, @free, @prot, @lookuptbl, @abs_ec, @move_from, + * @move_to, @move_to_put @erase_pending, @wl_scheduled, and @works + * fields + * @wl_scheduled: non-zero if the wear-leveling was scheduled + * @lookuptbl: a table to quickly find a &struct ubi_wl_entry object for any + * physical eraseblock + * @abs_ec: absolute erase counter + * @move_from: physical eraseblock from where the data is being moved + * @move_to: physical eraseblock where the data is being moved to + * @move_from_put: if the "from" PEB was put + * @move_to_put: if the "to" PEB was put + * @works: list of pending works + * @works_count: count of pending works + * @bgt_thread: background thread description object + * @thread_enabled: if the background thread is enabled + * @bgt_name: background thread name + * + * @flash_size: underlying MTD device size (in bytes) + * @peb_count: count of physical eraseblocks on the MTD device + * @peb_size: physical eraseblock size + * @bad_peb_count: count of bad physical eraseblocks + * @good_peb_count: count of good physical eraseblocks + * @min_io_size: minimal input/output unit size of the underlying MTD device + * @hdrs_min_io_size: minimal I/O unit size used for VID and EC headers + * @ro_mode: if the UBI device is in read-only mode + * @leb_size: logical eraseblock size + * @leb_start: starting offset of logical eraseblocks within physical + * eraseblocks + * @ec_hdr_alsize: size of the EC header aligned to @hdrs_min_io_size + * @vid_hdr_alsize: size of the VID header aligned to @hdrs_min_io_size + * @vid_hdr_offset: starting offset of the volume identifier header (might be + * unaligned) + * @vid_hdr_aloffset: starting offset of the VID header aligned to + * @hdrs_min_io_size + * @vid_hdr_shift: contains @vid_hdr_offset - @vid_hdr_aloffset + * @bad_allowed: whether the MTD device admits of bad physical eraseblocks or + * not + * @mtd: MTD device descriptor + */ +struct ubi_device { + struct cdev cdev; + struct device dev; + int ubi_num; + char ubi_name[sizeof(UBI_NAME_STR)+5]; + int major; + int vol_count; + struct ubi_volume *volumes[UBI_MAX_VOLUMES+UBI_INT_VOL_COUNT]; + spinlock_t volumes_lock; + + int rsvd_pebs; + int avail_pebs; + int beb_rsvd_pebs; + int beb_rsvd_level; + + int vtbl_slots; + int vtbl_size; + struct ubi_vtbl_record *vtbl; + struct mutex vtbl_mutex; + + int max_ec; + int mean_ec; + + /* EBA unit's stuff */ + unsigned long long global_sqnum; + spinlock_t ltree_lock; + struct rb_root ltree; + + /* Wear-leveling unit's stuff */ + struct rb_root used; + struct rb_root free; + struct rb_root scrub; + struct { + struct rb_root pnum; + struct rb_root aec; + } prot; + spinlock_t wl_lock; + int wl_scheduled; + struct ubi_wl_entry **lookuptbl; + unsigned long long abs_ec; + struct ubi_wl_entry *move_from; + struct ubi_wl_entry *move_to; + int move_from_put; + int move_to_put; + struct list_head works; + int works_count; + struct task_struct *bgt_thread; + int thread_enabled; + char bgt_name[sizeof(UBI_BGT_NAME_PATTERN)+2]; + + /* I/O unit's stuff */ + long long flash_size; + int peb_count; + int peb_size; + int bad_peb_count; + int good_peb_count; + int min_io_size; + int hdrs_min_io_size; + int ro_mode; + int leb_size; + int leb_start; + int ec_hdr_alsize; + int vid_hdr_alsize; + int vid_hdr_offset; + int vid_hdr_aloffset; + int vid_hdr_shift; + int bad_allowed; + struct mtd_info *mtd; +}; + +extern struct file_operations ubi_cdev_operations; +extern struct file_operations ubi_vol_cdev_operations; +extern struct class *ubi_class; + +/* vtbl.c */ +int ubi_change_vtbl_record(struct ubi_device *ubi, int idx, + struct ubi_vtbl_record *vtbl_rec); +int ubi_read_volume_table(struct ubi_device *ubi, struct ubi_scan_info *si); + +/* vmt.c */ +int ubi_create_volume(struct ubi_device *ubi, struct ubi_mkvol_req *req); +int ubi_remove_volume(struct ubi_volume_desc *desc); +int ubi_resize_volume(struct ubi_volume_desc *desc, int reserved_pebs); +int ubi_add_volume(struct ubi_device *ubi, int vol_id); +void ubi_free_volume(struct ubi_device *ubi, int vol_id); + +/* upd.c */ +int ubi_start_update(struct ubi_device *ubi, int vol_id, long long bytes); +int ubi_more_update_data(struct ubi_device *ubi, int vol_id, + const void __user *buf, int count); + +/* misc.c */ +int ubi_calc_data_len(const struct ubi_device *ubi, const void *buf, int length); +int ubi_check_volume(struct ubi_device *ubi, int vol_id); +void ubi_calculate_reserved(struct ubi_device *ubi); + +/* gluebi.c */ +#ifdef CONFIG_MTD_UBI_GLUEBI +int ubi_create_gluebi(struct ubi_device *ubi, struct ubi_volume *vol); +int ubi_destroy_gluebi(struct ubi_volume *vol); +#else +#define ubi_create_gluebi(ubi, vol) 0 +#define ubi_destroy_gluebi(vol) 0 +#endif + +/* eba.c */ +int ubi_eba_unmap_leb(struct ubi_device *ubi, int vol_id, int lnum); +int ubi_eba_read_leb(struct ubi_device *ubi, int vol_id, int lnum, void *buf, + int offset, int len, int check); +int ubi_eba_write_leb(struct ubi_device *ubi, int vol_id, int lnum, + const void *buf, int offset, int len, int dtype); +int ubi_eba_write_leb_st(struct ubi_device *ubi, int vol_id, int lnum, + const void *buf, int len, int dtype, + int used_ebs); +int ubi_eba_atomic_leb_change(struct ubi_device *ubi, int vol_id, int lnum, + const void *buf, int len, int dtype); +int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to, + struct ubi_vid_hdr *vid_hdr); +int ubi_eba_init_scan(struct ubi_device *ubi, struct ubi_scan_info *si); +void ubi_eba_close(const struct ubi_device *ubi); + +/* wl.c */ +int ubi_wl_get_peb(struct ubi_device *ubi, int dtype); +int ubi_wl_put_peb(struct ubi_device *ubi, int pnum, int torture); +int ubi_wl_flush(struct ubi_device *ubi); +int ubi_wl_scrub_peb(struct ubi_device *ubi, int pnum); +int ubi_wl_init_scan(struct ubi_device *ubi, struct ubi_scan_info *si); +void ubi_wl_close(struct ubi_device *ubi); + +/* io.c */ +int ubi_io_read(const struct ubi_device *ubi, void *buf, int pnum, int offset, + int len); +int ubi_io_write(const struct ubi_device *ubi, const void *buf, int pnum, + int offset, int len); +int ubi_io_sync_erase(const struct ubi_device *ubi, int pnum, int torture); +int ubi_io_is_bad(const struct ubi_device *ubi, int pnum); +int ubi_io_mark_bad(const struct ubi_device *ubi, int pnum); +int ubi_io_read_ec_hdr(const struct ubi_device *ubi, int pnum, + struct ubi_ec_hdr *ec_hdr, int verbose); +int ubi_io_write_ec_hdr(const struct ubi_device *ubi, int pnum, + struct ubi_ec_hdr *ec_hdr); +int ubi_io_read_vid_hdr(const struct ubi_device *ubi, int pnum, + struct ubi_vid_hdr *vid_hdr, int verbose); +int ubi_io_write_vid_hdr(const struct ubi_device *ubi, int pnum, + struct ubi_vid_hdr *vid_hdr); + +/* + * ubi_rb_for_each_entry - walk an RB-tree. + * @rb: a pointer to type 'struct rb_node' to to use as a loop counter + * @pos: a pointer to RB-tree entry type to use as a loop counter + * @root: RB-tree's root + * @member: the name of the 'struct rb_node' within the RB-tree entry + */ +#define ubi_rb_for_each_entry(rb, pos, root, member) \ + for (rb = rb_first(root), \ + pos = (rb ? container_of(rb, typeof(*pos), member) : NULL); \ + rb; \ + rb = rb_next(rb), pos = container_of(rb, typeof(*pos), member)) + +/** + * ubi_zalloc_vid_hdr - allocate a volume identifier header object. + * @ubi: UBI device description object + * + * This function returns a pointer to the newly allocated and zero-filled + * volume identifier header object in case of success and %NULL in case of + * failure. + */ +static inline struct ubi_vid_hdr *ubi_zalloc_vid_hdr(const struct ubi_device *ubi) +{ + void *vid_hdr; + + vid_hdr = kzalloc(ubi->vid_hdr_alsize, GFP_KERNEL); + if (!vid_hdr) + return NULL; + + /* + * VID headers may be stored at un-aligned flash offsets, so we shift + * the pointer. + */ + return vid_hdr + ubi->vid_hdr_shift; +} + +/** + * ubi_free_vid_hdr - free a volume identifier header object. + * @ubi: UBI device description object + * @vid_hdr: the object to free + */ +static inline void ubi_free_vid_hdr(const struct ubi_device *ubi, + struct ubi_vid_hdr *vid_hdr) +{ + void *p = vid_hdr; + + if (!p) + return; + + kfree(p - ubi->vid_hdr_shift); +} + +/* + * This function is equivalent to 'ubi_io_read()', but @offset is relative to + * the beginning of the logical eraseblock, not to the beginning of the + * physical eraseblock. + */ +static inline int ubi_io_read_data(const struct ubi_device *ubi, void *buf, + int pnum, int offset, int len) +{ + ubi_assert(offset >= 0); + return ubi_io_read(ubi, buf, pnum, offset + ubi->leb_start, len); +} + +/* + * This function is equivalent to 'ubi_io_write()', but @offset is relative to + * the beginning of the logical eraseblock, not to the beginning of the + * physical eraseblock. + */ +static inline int ubi_io_write_data(const struct ubi_device *ubi, const void *buf, + int pnum, int offset, int len) +{ + ubi_assert(offset >= 0); + return ubi_io_write(ubi, buf, pnum, offset + ubi->leb_start, len); +} + +/** + * ubi_ro_mode - switch to read-only mode. + * @ubi: UBI device description object + */ +static inline void ubi_ro_mode(struct ubi_device *ubi) +{ + ubi->ro_mode = 1; + ubi_warn("switch to read-only mode"); +} + +/** + * vol_id2idx - get table index by volume ID. + * @ubi: UBI device description object + * @vol_id: volume ID + */ +static inline int vol_id2idx(const struct ubi_device *ubi, int vol_id) +{ + if (vol_id >= UBI_INTERNAL_VOL_START) + return vol_id - UBI_INTERNAL_VOL_START + ubi->vtbl_slots; + else + return vol_id; +} + +/** + * idx2vol_id - get volume ID by table index. + * @ubi: UBI device description object + * @idx: table index + */ +static inline int idx2vol_id(const struct ubi_device *ubi, int idx) +{ + if (idx >= ubi->vtbl_slots) + return idx - ubi->vtbl_slots + UBI_INTERNAL_VOL_START; + else + return idx; +} + +#endif /* !__UBI_UBI_H__ */ diff --git a/drivers/mtd/ubi/upd.c b/drivers/mtd/ubi/upd.c new file mode 100644 index 0000000..8925b97 --- /dev/null +++ b/drivers/mtd/ubi/upd.c @@ -0,0 +1,348 @@ +/* + * Copyright (c) International Business Machines Corp., 2006 + * Copyright (c) Nokia Corporation, 2006 + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See + * the GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + * Author: Artem Bityutskiy (Битюцкий Артём) + * + * Jan 2007: Alexander Schmidt, hacked per-volume update. + */ + +/* + * This file contains implementation of the volume update functionality. + * + * The update operation is based on the per-volume update marker which is + * stored in the volume table. The update marker is set before the update + * starts, and removed after the update has been finished. So if the update was + * interrupted by an unclean re-boot or due to some other reasons, the update + * marker stays on the flash media and UBI finds it when it attaches the MTD + * device next time. If the update marker is set for a volume, the volume is + * treated as damaged and most I/O operations are prohibited. Only a new update + * operation is allowed. + * + * Note, in general it is possible to implement the update operation as a + * transaction with a roll-back capability. + */ + +#include <linux/err.h> +#include <asm/uaccess.h> +#include <asm/div64.h> +#include "ubi.h" + +/** + * set_update_marker - set update marker. + * @ubi: UBI device description object + * @vol_id: volume ID + * + * This function sets the update marker flag for volume @vol_id. Returns zero + * in case of success and a negative error code in case of failure. + */ +static int set_update_marker(struct ubi_device *ubi, int vol_id) +{ + int err; + struct ubi_vtbl_record vtbl_rec; + struct ubi_volume *vol = ubi->volumes[vol_id]; + + dbg_msg("set update marker for volume %d", vol_id); + + if (vol->upd_marker) { + ubi_assert(ubi->vtbl[vol_id].upd_marker); + dbg_msg("already set"); + return 0; + } + + memcpy(&vtbl_rec, &ubi->vtbl[vol_id], sizeof(struct ubi_vtbl_record)); + vtbl_rec.upd_marker = 1; + + err = ubi_change_vtbl_record(ubi, vol_id, &vtbl_rec); + vol->upd_marker = 1; + return err; +} + +/** + * clear_update_marker - clear update marker. + * @ubi: UBI device description object + * @vol_id: volume ID + * @bytes: new data size in bytes + * + * This function clears the update marker for volume @vol_id, sets new volume + * data size and clears the "corrupted" flag (static volumes only). Returns + * zero in case of success and a negative error code in case of failure. + */ +static int clear_update_marker(struct ubi_device *ubi, int vol_id, long long bytes) +{ + int err; + uint64_t tmp; + struct ubi_vtbl_record vtbl_rec; + struct ubi_volume *vol = ubi->volumes[vol_id]; + + dbg_msg("clear update marker for volume %d", vol_id); + + memcpy(&vtbl_rec, &ubi->vtbl[vol_id], sizeof(struct ubi_vtbl_record)); + ubi_assert(vol->upd_marker && vtbl_rec.upd_marker); + vtbl_rec.upd_marker = 0; + + if (vol->vol_type == UBI_STATIC_VOLUME) { + vol->corrupted = 0; + vol->used_bytes = tmp = bytes; + vol->last_eb_bytes = do_div(tmp, vol->usable_leb_size); + vol->used_ebs = tmp; + if (vol->last_eb_bytes) + vol->used_ebs += 1; + else + vol->last_eb_bytes = vol->usable_leb_size; + } + + err = ubi_change_vtbl_record(ubi, vol_id, &vtbl_rec); + vol->upd_marker = 0; + return err; +} + +/** + * ubi_start_update - start volume update. + * @ubi: UBI device description object + * @vol_id: volume ID + * @bytes: update bytes + * + * This function starts volume update operation. If @bytes is zero, the volume + * is just wiped out. Returns zero in case of success and a negative error code + * in case of failure. + */ +int ubi_start_update(struct ubi_device *ubi, int vol_id, long long bytes) +{ + int i, err; + uint64_t tmp; + struct ubi_volume *vol = ubi->volumes[vol_id]; + + dbg_msg("start update of volume %d, %llu bytes", vol_id, bytes); + vol->updating = 1; + + err = set_update_marker(ubi, vol_id); + if (err) + return err; + + /* Before updating - wipe out the volume */ + for (i = 0; i < vol->reserved_pebs; i++) { + err = ubi_eba_unmap_leb(ubi, vol_id, i); + if (err) + return err; + } + + if (bytes == 0) { + err = clear_update_marker(ubi, vol_id, 0); + if (err) + return err; + err = ubi_wl_flush(ubi); + if (!err) + vol->updating = 0; + } + + vol->upd_buf = kmalloc(ubi->leb_size, GFP_KERNEL); + if (!vol->upd_buf) + return -ENOMEM; + + tmp = bytes; + vol->upd_ebs = !!do_div(tmp, vol->usable_leb_size); + vol->upd_ebs += tmp; + vol->upd_bytes = bytes; + vol->upd_received = 0; + return 0; +} + +/** + * write_leb - write update data. + * @ubi: UBI device description object + * @vol_id: volume ID + * @lnum: logical eraseblock number + * @buf: data to write + * @len: data size + * @used_ebs: how many logical eraseblocks will this volume contain (static + * volumes only) + * + * This function writes update data to corresponding logical eraseblock. In + * case of dynamic volume, this function checks if the data contains 0xFF bytes + * at the end. If yes, the 0xFF bytes are cut and not written. So if the whole + * buffer contains only 0xFF bytes, the LEB is left unmapped. + * + * The reason why we skip the trailing 0xFF bytes in case of dynamic volume is + * that we want to make sure that more data may be appended to the logical + * eraseblock in future. Indeed, writing 0xFF bytes may have side effects and + * this PEB won't be writable anymore. So if one writes the file-system image + * to the UBI volume where 0xFFs mean free space - UBI makes sure this free + * space is writable after the update. + * + * We do not do this for static volumes because they are read-only. But this + * also cannot be done because we have to store per-LEB CRC and the correct + * data length. + * + * This function returns zero in case of success and a negative error code in + * case of failure. + */ +static int write_leb(struct ubi_device *ubi, int vol_id, int lnum, void *buf, + int len, int used_ebs) +{ + int err, l; + struct ubi_volume *vol = ubi->volumes[vol_id]; + + if (vol->vol_type == UBI_DYNAMIC_VOLUME) { + l = ALIGN(len, ubi->min_io_size); + memset(buf + len, 0xFF, l - len); + + l = ubi_calc_data_len(ubi, buf, l); + if (l == 0) { + dbg_msg("all %d bytes contain 0xFF - skip", len); + return 0; + } + if (len != l) + dbg_msg("skip last %d bytes (0xFF)", len - l); + + err = ubi_eba_write_leb(ubi, vol_id, lnum, buf, 0, l, + UBI_UNKNOWN); + } else { + /* + * When writing static volume, and this is the last logical + * eraseblock, the length (@len) does not have to be aligned to + * the minimal flash I/O unit. The 'ubi_eba_write_leb_st()' + * function accepts exact (unaligned) length and stores it in + * the VID header. And it takes care of proper alignment by + * padding the buffer. Here we just make sure the padding will + * contain zeros, not random trash. + */ + memset(buf + len, 0, vol->usable_leb_size - len); + err = ubi_eba_write_leb_st(ubi, vol_id, lnum, buf, len, + UBI_UNKNOWN, used_ebs); + } + + return err; +} + +/** + * ubi_more_update_data - write more update data. + * @vol: volume description object + * @buf: write data (user-space memory buffer) + * @count: how much bytes to write + * + * This function writes more data to the volume which is being updated. It may + * be called arbitrary number of times until all of the update data arrive. + * This function returns %0 in case of success, number of bytes written during + * the last call if the whole volume update was successfully finished, and a + * negative error code in case of failure. + */ +int ubi_more_update_data(struct ubi_device *ubi, int vol_id, + const void __user *buf, int count) +{ + uint64_t tmp; + struct ubi_volume *vol = ubi->volumes[vol_id]; + int lnum, offs, err = 0, len, to_write = count; + + dbg_msg("write %d of %lld bytes, %lld already passed", + count, vol->upd_bytes, vol->upd_received); + + if (ubi->ro_mode) + return -EROFS; + + tmp = vol->upd_received; + offs = do_div(tmp, vol->usable_leb_size); + lnum = tmp; + + if (vol->upd_received + count > vol->upd_bytes) + to_write = count = vol->upd_bytes - vol->upd_received; + + /* + * When updating volumes, we accumulate whole logical eraseblock of + * data and write it at once. + */ + if (offs != 0) { + /* + * This is a write to the middle of the logical eraseblock. We + * copy the data to our update buffer and wait for more data or + * flush it if the whole eraseblock is written or the update + * is finished. + */ + + len = vol->usable_leb_size - offs; + if (len > count) + len = count; + + err = copy_from_user(vol->upd_buf + offs, buf, len); + if (err) + return -EFAULT; + + if (offs + len == vol->usable_leb_size || + vol->upd_received + len == vol->upd_bytes) { + int flush_len = offs + len; + + /* + * OK, we gathered either the whole eraseblock or this + * is the last chunk, it's time to flush the buffer. + */ + ubi_assert(flush_len <= vol->usable_leb_size); + err = write_leb(ubi, vol_id, lnum, vol->upd_buf, + flush_len, vol->upd_ebs); + if (err) + return err; + } + + vol->upd_received += len; + count -= len; + buf += len; + lnum += 1; + } + + /* + * If we've got more to write, let's continue. At this point we know we + * are starting from the beginning of an eraseblock. + */ + while (count) { + if (count > vol->usable_leb_size) + len = vol->usable_leb_size; + else + len = count; + + err = copy_from_user(vol->upd_buf, buf, len); + if (err) + return -EFAULT; + + if (len == vol->usable_leb_size || + vol->upd_received + len == vol->upd_bytes) { + err = write_leb(ubi, vol_id, lnum, vol->upd_buf, len, + vol->upd_ebs); + if (err) + break; + } + + vol->upd_received += len; + count -= len; + lnum += 1; + buf += len; + } + + ubi_assert(vol->upd_received <= vol->upd_bytes); + if (vol->upd_received == vol->upd_bytes) { + /* The update is finished, clear the update marker */ + err = clear_update_marker(ubi, vol_id, vol->upd_bytes); + if (err) + return err; + err = ubi_wl_flush(ubi); + if (err == 0) { + err = to_write; + kfree(vol->upd_buf); + vol->updating = 0; + } + } + + return err; +} diff --git a/drivers/mtd/ubi/vmt.c b/drivers/mtd/ubi/vmt.c new file mode 100644 index 0000000..622d0d1 --- /dev/null +++ b/drivers/mtd/ubi/vmt.c @@ -0,0 +1,809 @@ +/* + * Copyright (c) International Business Machines Corp., 2006 + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See + * the GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + * Author: Artem Bityutskiy (Битюцкий Артём) + */ + +/* + * This file contains implementation of volume creation, deletion, updating and + * resizing. + */ + +#include <linux/err.h> +#include <asm/div64.h> +#include "ubi.h" + +#ifdef CONFIG_MTD_UBI_DEBUG_PARANOID +static void paranoid_check_volumes(struct ubi_device *ubi); +#else +#define paranoid_check_volumes(ubi) +#endif + +static ssize_t vol_attribute_show(struct device *dev, + struct device_attribute *attr, char *buf); + +/* Device attributes corresponding to files in '/<sysfs>/class/ubi/ubiX_Y' */ +static struct device_attribute vol_reserved_ebs = + __ATTR(reserved_ebs, S_IRUGO, vol_attribute_show, NULL); +static struct device_attribute vol_type = + __ATTR(type, S_IRUGO, vol_attribute_show, NULL); +static struct device_attribute vol_name = + __ATTR(name, S_IRUGO, vol_attribute_show, NULL); +static struct device_attribute vol_corrupted = + __ATTR(corrupted, S_IRUGO, vol_attribute_show, NULL); +static struct device_attribute vol_alignment = + __ATTR(alignment, S_IRUGO, vol_attribute_show, NULL); +static struct device_attribute vol_usable_eb_size = + __ATTR(usable_eb_size, S_IRUGO, vol_attribute_show, NULL); +static struct device_attribute vol_data_bytes = + __ATTR(data_bytes, S_IRUGO, vol_attribute_show, NULL); +static struct device_attribute vol_upd_marker = + __ATTR(upd_marker, S_IRUGO, vol_attribute_show, NULL); + +/* + * "Show" method for files in '/<sysfs>/class/ubi/ubiX_Y/'. + * + * Consider a situation: + * A. process 1 opens a sysfs file related to volume Y, say + * /<sysfs>/class/ubi/ubiX_Y/reserved_ebs; + * B. process 2 removes volume Y; + * C. process 1 starts reading the /<sysfs>/class/ubi/ubiX_Y/reserved_ebs file; + * + * What we want to do in a situation like that is to return error when the file + * is read. This is done by means of the 'removed' flag and the 'vol_lock' of + * the UBI volume description object. + */ +static ssize_t vol_attribute_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + int ret; + struct ubi_volume *vol = container_of(dev, struct ubi_volume, dev); + + spin_lock(&vol->ubi->volumes_lock); + if (vol->removed) { + spin_unlock(&vol->ubi->volumes_lock); + return -ENODEV; + } + if (attr == &vol_reserved_ebs) + ret = sprintf(buf, "%d\n", vol->reserved_pebs); + else if (attr == &vol_type) { + const char *tp; + tp = vol->vol_type == UBI_DYNAMIC_VOLUME ? "dynamic" : "static"; + ret = sprintf(buf, "%s\n", tp); + } else if (attr == &vol_name) + ret = sprintf(buf, "%s\n", vol->name); + else if (attr == &vol_corrupted) + ret = sprintf(buf, "%d\n", vol->corrupted); + else if (attr == &vol_alignment) + ret = sprintf(buf, "%d\n", vol->alignment); + else if (attr == &vol_usable_eb_size) { + ret = sprintf(buf, "%d\n", vol->usable_leb_size); + } else if (attr == &vol_data_bytes) + ret = sprintf(buf, "%lld\n", vol->used_bytes); + else if (attr == &vol_upd_marker) + ret = sprintf(buf, "%d\n", vol->upd_marker); + else + BUG(); + spin_unlock(&vol->ubi->volumes_lock); + return ret; +} + +/* Release method for volume devices */ +static void vol_release(struct device *dev) +{ + struct ubi_volume *vol = container_of(dev, struct ubi_volume, dev); + ubi_assert(vol->removed); + kfree(vol); +} + +/** + * volume_sysfs_init - initialize sysfs for new volume. + * @ubi: UBI device description object + * @vol: volume description object + * + * This function returns zero in case of success and a negative error code in + * case of failure. + * + * Note, this function does not free allocated resources in case of failure - + * the caller does it. This is because this would cause release() here and the + * caller would oops. + */ +static int volume_sysfs_init(struct ubi_device *ubi, struct ubi_volume *vol) +{ + int err; + + err = device_create_file(&vol->dev, &vol_reserved_ebs); + if (err) + return err; + err = device_create_file(&vol->dev, &vol_type); + if (err) + return err; + err = device_create_file(&vol->dev, &vol_name); + if (err) + return err; + err = device_create_file(&vol->dev, &vol_corrupted); + if (err) + return err; + err = device_create_file(&vol->dev, &vol_alignment); + if (err) + return err; + err = device_create_file(&vol->dev, &vol_usable_eb_size); + if (err) + return err; + err = device_create_file(&vol->dev, &vol_data_bytes); + if (err) + return err; + err = device_create_file(&vol->dev, &vol_upd_marker); + if (err) + return err; + return 0; +} + +/** + * volume_sysfs_close - close sysfs for a volume. + * @vol: volume description object + */ +static void volume_sysfs_close(struct ubi_volume *vol) +{ + device_remove_file(&vol->dev, &vol_upd_marker); + device_remove_file(&vol->dev, &vol_data_bytes); + device_remove_file(&vol->dev, &vol_usable_eb_size); + device_remove_file(&vol->dev, &vol_alignment); + device_remove_file(&vol->dev, &vol_corrupted); + device_remove_file(&vol->dev, &vol_name); + device_remove_file(&vol->dev, &vol_type); + device_remove_file(&vol->dev, &vol_reserved_ebs); + device_unregister(&vol->dev); +} + +/** + * ubi_create_volume - create volume. + * @ubi: UBI device description object + * @req: volume creation request + * + * This function creates volume described by @req. If @req->vol_id id + * %UBI_VOL_NUM_AUTO, this function automatically assigne ID to the new volume + * and saves it in @req->vol_id. Returns zero in case of success and a negative + * error code in case of failure. + */ +int ubi_create_volume(struct ubi_device *ubi, struct ubi_mkvol_req *req) +{ + int i, err, vol_id = req->vol_id; + struct ubi_volume *vol; + struct ubi_vtbl_record vtbl_rec; + uint64_t bytes; + + if (ubi->ro_mode) + return -EROFS; + + vol = kzalloc(sizeof(struct ubi_volume), GFP_KERNEL); + if (!vol) + return -ENOMEM; + + spin_lock(&ubi->volumes_lock); + + if (vol_id == UBI_VOL_NUM_AUTO) { + /* Find unused volume ID */ + dbg_msg("search for vacant volume ID"); + for (i = 0; i < ubi->vtbl_slots; i++) + if (!ubi->volumes[i]) { + vol_id = i; + break; + } + + if (vol_id == UBI_VOL_NUM_AUTO) { + dbg_err("out of volume IDs"); + err = -ENFILE; + goto out_unlock; + } + req->vol_id = vol_id; + } + + dbg_msg("volume ID %d, %llu bytes, type %d, name %s", + vol_id, (unsigned long long)req->bytes, + (int)req->vol_type, req->name); + + /* Ensure that this volume does not exist */ + err = -EEXIST; + if (ubi->volumes[vol_id]) { + dbg_err("volume %d already exists", vol_id); + goto out_unlock; + } + + /* Ensure that the name is unique */ + for (i = 0; i < ubi->vtbl_slots; i++) + if (ubi->volumes[i] && + ubi->volumes[i]->name_len == req->name_len && + strcmp(ubi->volumes[i]->name, req->name) == 0) { + dbg_err("volume \"%s\" exists (ID %d)", req->name, i); + goto out_unlock; + } + + /* Calculate how many eraseblocks are requested */ + vol->usable_leb_size = ubi->leb_size - ubi->leb_size % req->alignment; + bytes = req->bytes; + if (do_div(bytes, vol->usable_leb_size)) + vol->reserved_pebs = 1; + vol->reserved_pebs += bytes; + + /* Reserve physical eraseblocks */ + if (vol->reserved_pebs > ubi->avail_pebs) { + dbg_err("not enough PEBs, only %d available", ubi->avail_pebs); + spin_unlock(&ubi->volumes_lock); + err = -ENOSPC; + goto out_unlock; + } + ubi->avail_pebs -= vol->reserved_pebs; + ubi->rsvd_pebs += vol->reserved_pebs; + + vol->vol_id = vol_id; + vol->alignment = req->alignment; + vol->data_pad = ubi->leb_size % vol->alignment; + vol->vol_type = req->vol_type; + vol->name_len = req->name_len; + memcpy(vol->name, req->name, vol->name_len + 1); + vol->exclusive = 1; + vol->ubi = ubi; + ubi->volumes[vol_id] = vol; + spin_unlock(&ubi->volumes_lock); + + /* + * Finish all pending erases because there may be some LEBs belonging + * to the same volume ID. + */ + err = ubi_wl_flush(ubi); + if (err) + goto out_acc; + + vol->eba_tbl = kmalloc(vol->reserved_pebs * sizeof(int), GFP_KERNEL); + if (!vol->eba_tbl) { + err = -ENOMEM; + goto out_acc; + } + + for (i = 0; i < vol->reserved_pebs; i++) + vol->eba_tbl[i] = UBI_LEB_UNMAPPED; + + if (vol->vol_type == UBI_DYNAMIC_VOLUME) { + vol->used_ebs = vol->reserved_pebs; + vol->last_eb_bytes = vol->usable_leb_size; + vol->used_bytes = vol->used_ebs * vol->usable_leb_size; + } else { + bytes = vol->used_bytes; + vol->last_eb_bytes = do_div(bytes, vol->usable_leb_size); + vol->used_ebs = bytes; + if (vol->last_eb_bytes) + vol->used_ebs += 1; + else + vol->last_eb_bytes = vol->usable_leb_size; + } + + /* Register character device for the volume */ + cdev_init(&vol->cdev, &ubi_vol_cdev_operations); + vol->cdev.owner = THIS_MODULE; + err = cdev_add(&vol->cdev, MKDEV(ubi->major, vol_id + 1), 1); + if (err) { + ubi_err("cannot add character device for volume %d", vol_id); + goto out_mapping; + } + + err = ubi_create_gluebi(ubi, vol); + if (err) + goto out_cdev; + + vol->dev.release = vol_release; + vol->dev.parent = &ubi->dev; + vol->dev.devt = MKDEV(ubi->major, vol->vol_id + 1); + vol->dev.class = ubi_class; + sprintf(&vol->dev.bus_id[0], "%s_%d", ubi->ubi_name, vol->vol_id); + err = device_register(&vol->dev); + if (err) + goto out_gluebi; + + err = volume_sysfs_init(ubi, vol); + if (err) + goto out_sysfs; + + /* Fill volume table record */ + memset(&vtbl_rec, 0, sizeof(struct ubi_vtbl_record)); + vtbl_rec.reserved_pebs = cpu_to_ubi32(vol->reserved_pebs); + vtbl_rec.alignment = cpu_to_ubi32(vol->alignment); + vtbl_rec.data_pad = cpu_to_ubi32(vol->data_pad); + vtbl_rec.name_len = cpu_to_ubi16(vol->name_len); + if (vol->vol_type == UBI_DYNAMIC_VOLUME) + vtbl_rec.vol_type = UBI_VID_DYNAMIC; + else + vtbl_rec.vol_type = UBI_VID_STATIC; + memcpy(vtbl_rec.name, vol->name, vol->name_len + 1); + + err = ubi_change_vtbl_record(ubi, vol_id, &vtbl_rec); + if (err) + goto out_sysfs; + + spin_lock(&ubi->volumes_lock); + ubi->vol_count += 1; + vol->exclusive = 0; + spin_unlock(&ubi->volumes_lock); + + paranoid_check_volumes(ubi); + return 0; + +out_gluebi: + err = ubi_destroy_gluebi(vol); +out_cdev: + cdev_del(&vol->cdev); +out_mapping: + kfree(vol->eba_tbl); +out_acc: + spin_lock(&ubi->volumes_lock); + ubi->rsvd_pebs -= vol->reserved_pebs; + ubi->avail_pebs += vol->reserved_pebs; +out_unlock: + spin_unlock(&ubi->volumes_lock); + kfree(vol); + return err; + + /* + * We are registered, so @vol is destroyed in the release function and + * we have to de-initialize differently. + */ +out_sysfs: + err = ubi_destroy_gluebi(vol); + cdev_del(&vol->cdev); + kfree(vol->eba_tbl); + spin_lock(&ubi->volumes_lock); + ubi->rsvd_pebs -= vol->reserved_pebs; + ubi->avail_pebs += vol->reserved_pebs; + spin_unlock(&ubi->volumes_lock); + volume_sysfs_close(vol); + return err; +} + +/** + * ubi_remove_volume - remove volume. + * @desc: volume descriptor + * + * This function removes volume described by @desc. The volume has to be opened + * in "exclusive" mode. Returns zero in case of success and a negative error + * code in case of failure. + */ +int ubi_remove_volume(struct ubi_volume_desc *desc) +{ + struct ubi_volume *vol = desc->vol; + struct ubi_device *ubi = vol->ubi; + int i, err, vol_id = vol->vol_id, reserved_pebs = vol->reserved_pebs; + + dbg_msg("remove UBI volume %d", vol_id); + ubi_assert(desc->mode == UBI_EXCLUSIVE); + ubi_assert(vol == ubi->volumes[vol_id]); + + if (ubi->ro_mode) + return -EROFS; + + err = ubi_destroy_gluebi(vol); + if (err) + return err; + + err = ubi_change_vtbl_record(ubi, vol_id, NULL); + if (err) + return err; + + for (i = 0; i < vol->reserved_pebs; i++) { + err = ubi_eba_unmap_leb(ubi, vol_id, i); + if (err) + return err; + } + + spin_lock(&ubi->volumes_lock); + vol->removed = 1; + ubi->volumes[vol_id] = NULL; + spin_unlock(&ubi->volumes_lock); + + kfree(vol->eba_tbl); + vol->eba_tbl = NULL; + cdev_del(&vol->cdev); + volume_sysfs_close(vol); + kfree(desc); + + spin_lock(&ubi->volumes_lock); + ubi->rsvd_pebs -= reserved_pebs; + ubi->avail_pebs += reserved_pebs; + i = ubi->beb_rsvd_level - ubi->beb_rsvd_pebs; + if (i > 0) { + i = ubi->avail_pebs >= i ? i : ubi->avail_pebs; + ubi->avail_pebs -= i; + ubi->rsvd_pebs += i; + ubi->beb_rsvd_pebs += i; + if (i > 0) + ubi_msg("reserve more %d PEBs", i); + } + ubi->vol_count -= 1; + spin_unlock(&ubi->volumes_lock); + + paranoid_check_volumes(ubi); + module_put(THIS_MODULE); + return 0; +} + +/** + * ubi_resize_volume - re-size volume. + * @desc: volume descriptor + * @reserved_pebs: new size in physical eraseblocks + * + * This function returns zero in case of success, and a negative error code in + * case of failure. + */ +int ubi_resize_volume(struct ubi_volume_desc *desc, int reserved_pebs) +{ + int i, err, pebs, *new_mapping; + struct ubi_volume *vol = desc->vol; + struct ubi_device *ubi = vol->ubi; + struct ubi_vtbl_record vtbl_rec; + int vol_id = vol->vol_id; + + if (ubi->ro_mode) + return -EROFS; + + dbg_msg("re-size volume %d to from %d to %d PEBs", + vol_id, vol->reserved_pebs, reserved_pebs); + ubi_assert(desc->mode == UBI_EXCLUSIVE); + ubi_assert(vol == ubi->volumes[vol_id]); + + if (vol->vol_type == UBI_STATIC_VOLUME && + reserved_pebs < vol->used_ebs) { + dbg_err("too small size %d, %d LEBs contain data", + reserved_pebs, vol->used_ebs); + return -EINVAL; + } + + /* If the size is the same, we have nothing to do */ + if (reserved_pebs == vol->reserved_pebs) + return 0; + + new_mapping = kmalloc(reserved_pebs * sizeof(int), GFP_KERNEL); + if (!new_mapping) + return -ENOMEM; + + for (i = 0; i < reserved_pebs; i++) + new_mapping[i] = UBI_LEB_UNMAPPED; + + /* Reserve physical eraseblocks */ + pebs = reserved_pebs - vol->reserved_pebs; + if (pebs > 0) { + spin_lock(&ubi->volumes_lock); + if (pebs > ubi->avail_pebs) { + dbg_err("not enough PEBs: requested %d, available %d", + pebs, ubi->avail_pebs); + spin_unlock(&ubi->volumes_lock); + err = -ENOSPC; + goto out_free; + } + ubi->avail_pebs -= pebs; + ubi->rsvd_pebs += pebs; + for (i = 0; i < vol->reserved_pebs; i++) + new_mapping[i] = vol->eba_tbl[i]; + kfree(vol->eba_tbl); + vol->eba_tbl = new_mapping; + spin_unlock(&ubi->volumes_lock); + } + + /* Change volume table record */ + memcpy(&vtbl_rec, &ubi->vtbl[vol_id], sizeof(struct ubi_vtbl_record)); + vtbl_rec.reserved_pebs = cpu_to_ubi32(reserved_pebs); + err = ubi_change_vtbl_record(ubi, vol_id, &vtbl_rec); + if (err) + goto out_acc; + + if (pebs < 0) { + for (i = 0; i < -pebs; i++) { + err = ubi_eba_unmap_leb(ubi, vol_id, reserved_pebs + i); + if (err) + goto out_acc; + } + spin_lock(&ubi->volumes_lock); + ubi->rsvd_pebs += pebs; + ubi->avail_pebs -= pebs; + pebs = ubi->beb_rsvd_level - ubi->beb_rsvd_pebs; + if (pebs > 0) { + pebs = ubi->avail_pebs >= pebs ? pebs : ubi->avail_pebs; + ubi->avail_pebs -= pebs; + ubi->rsvd_pebs += pebs; + ubi->beb_rsvd_pebs += pebs; + if (pebs > 0) + ubi_msg("reserve more %d PEBs", pebs); + } + for (i = 0; i < reserved_pebs; i++) + new_mapping[i] = vol->eba_tbl[i]; + kfree(vol->eba_tbl); + vol->eba_tbl = new_mapping; + spin_unlock(&ubi->volumes_lock); + } + + vol->reserved_pebs = reserved_pebs; + if (vol->vol_type == UBI_DYNAMIC_VOLUME) { + vol->used_ebs = reserved_pebs; + vol->last_eb_bytes = vol->usable_leb_size; + vol->used_bytes = vol->used_ebs * vol->usable_leb_size; + } + + paranoid_check_volumes(ubi); + return 0; + +out_acc: + if (pebs > 0) { + spin_lock(&ubi->volumes_lock); + ubi->rsvd_pebs -= pebs; + ubi->avail_pebs += pebs; + spin_unlock(&ubi->volumes_lock); + } +out_free: + kfree(new_mapping); + return err; +} + +/** + * ubi_add_volume - add volume. + * @ubi: UBI device description object + * @vol_id: volume ID + * + * This function adds an existin volume and initializes all its data + * structures. Returnes zero in case of success and a negative error code in + * case of failure. + */ +int ubi_add_volume(struct ubi_device *ubi, int vol_id) +{ + int err; + struct ubi_volume *vol = ubi->volumes[vol_id]; + + dbg_msg("add volume %d", vol_id); + ubi_dbg_dump_vol_info(vol); + ubi_assert(vol); + + /* Register character device for the volume */ + cdev_init(&vol->cdev, &ubi_vol_cdev_operations); + vol->cdev.owner = THIS_MODULE; + err = cdev_add(&vol->cdev, MKDEV(ubi->major, vol->vol_id + 1), 1); + if (err) { + ubi_err("cannot add character device for volume %d", vol_id); + return err; + } + + err = ubi_create_gluebi(ubi, vol); + if (err) + goto out_cdev; + + vol->dev.release = vol_release; + vol->dev.parent = &ubi->dev; + vol->dev.devt = MKDEV(ubi->major, vol->vol_id + 1); + vol->dev.class = ubi_class; + sprintf(&vol->dev.bus_id[0], "%s_%d", ubi->ubi_name, vol->vol_id); + err = device_register(&vol->dev); + if (err) + goto out_gluebi; + + err = volume_sysfs_init(ubi, vol); + if (err) { + cdev_del(&vol->cdev); + err = ubi_destroy_gluebi(vol); + volume_sysfs_close(vol); + return err; + } + + paranoid_check_volumes(ubi); + return 0; + +out_gluebi: + err = ubi_destroy_gluebi(vol); +out_cdev: + cdev_del(&vol->cdev); + return err; +} + +/** + * ubi_free_volume - free volume. + * @ubi: UBI device description object + * @vol_id: volume ID + * + * This function frees all resources for volume @vol_id but does not remove it. + * Used only when the UBI device is detached. + */ +void ubi_free_volume(struct ubi_device *ubi, int vol_id) +{ + int err; + struct ubi_volume *vol = ubi->volumes[vol_id]; + + dbg_msg("free volume %d", vol_id); + ubi_assert(vol); + + vol->removed = 1; + err = ubi_destroy_gluebi(vol); + ubi->volumes[vol_id] = NULL; + cdev_del(&vol->cdev); + volume_sysfs_close(vol); +} + +#ifdef CONFIG_MTD_UBI_DEBUG_PARANOID + +/** + * paranoid_check_volume - check volume information. + * @ubi: UBI device description object + * @vol_id: volume ID + */ +static void paranoid_check_volume(const struct ubi_device *ubi, int vol_id) +{ + int idx = vol_id2idx(ubi, vol_id); + int reserved_pebs, alignment, data_pad, vol_type, name_len, upd_marker; + const struct ubi_volume *vol = ubi->volumes[idx]; + long long n; + const char *name; + + reserved_pebs = ubi32_to_cpu(ubi->vtbl[vol_id].reserved_pebs); + + if (!vol) { + if (reserved_pebs) { + ubi_err("no volume info, but volume exists"); + goto fail; + } + return; + } + + if (vol->reserved_pebs < 0 || vol->alignment < 0 || vol->data_pad < 0 || + vol->name_len < 0) { + ubi_err("negative values"); + goto fail; + } + if (vol->alignment > ubi->leb_size || vol->alignment == 0) { + ubi_err("bad alignment"); + goto fail; + } + + n = vol->alignment % ubi->min_io_size; + if (vol->alignment != 1 && n) { + ubi_err("alignment is not multiple of min I/O unit"); + goto fail; + } + + n = ubi->leb_size % vol->alignment; + if (vol->data_pad != n) { + ubi_err("bad data_pad, has to be %lld", n); + goto fail; + } + + if (vol->vol_type != UBI_DYNAMIC_VOLUME && + vol->vol_type != UBI_STATIC_VOLUME) { + ubi_err("bad vol_type"); + goto fail; + } + + if (vol->upd_marker != 0 && vol->upd_marker != 1) { + ubi_err("bad upd_marker"); + goto fail; + } + + if (vol->upd_marker && vol->corrupted) { + dbg_err("update marker and corrupted simultaneously"); + goto fail; + } + + if (vol->reserved_pebs > ubi->good_peb_count) { + ubi_err("too large reserved_pebs"); + goto fail; + } + + n = ubi->leb_size - vol->data_pad; + if (vol->usable_leb_size != ubi->leb_size - vol->data_pad) { + ubi_err("bad usable_leb_size, has to be %lld", n); + goto fail; + } + + if (vol->name_len > UBI_VOL_NAME_MAX) { + ubi_err("too long volume name, max is %d", UBI_VOL_NAME_MAX); + goto fail; + } + + if (!vol->name) { + ubi_err("NULL volume name"); + goto fail; + } + + n = strnlen(vol->name, vol->name_len + 1); + if (n != vol->name_len) { + ubi_err("bad name_len %lld", n); + goto fail; + } + + n = vol->used_ebs * vol->usable_leb_size; + if (vol->vol_type == UBI_DYNAMIC_VOLUME) { + if (vol->corrupted != 0) { + ubi_err("corrupted dynamic volume"); + goto fail; + } + if (vol->used_ebs != vol->reserved_pebs) { + ubi_err("bad used_ebs"); + goto fail; + } + if (vol->last_eb_bytes != vol->usable_leb_size) { + ubi_err("bad last_eb_bytes"); + goto fail; + } + if (vol->used_bytes != n) { + ubi_err("bad used_bytes"); + goto fail; + } + } else { + if (vol->corrupted != 0 && vol->corrupted != 1) { + ubi_err("bad corrupted"); + goto fail; + } + if (vol->used_ebs < 0 || vol->used_ebs > vol->reserved_pebs) { + ubi_err("bad used_ebs"); + goto fail; + } + if (vol->last_eb_bytes < 0 || + vol->last_eb_bytes > vol->usable_leb_size) { + ubi_err("bad last_eb_bytes"); + goto fail; + } + if (vol->used_bytes < 0 || vol->used_bytes > n || + vol->used_bytes < n - vol->usable_leb_size) { + ubi_err("bad used_bytes"); + goto fail; + } + } + + alignment = ubi32_to_cpu(ubi->vtbl[vol_id].alignment); + data_pad = ubi32_to_cpu(ubi->vtbl[vol_id].data_pad); + name_len = ubi16_to_cpu(ubi->vtbl[vol_id].name_len); + upd_marker = ubi->vtbl[vol_id].upd_marker; + name = &ubi->vtbl[vol_id].name[0]; + if (ubi->vtbl[vol_id].vol_type == UBI_VID_DYNAMIC) + vol_type = UBI_DYNAMIC_VOLUME; + else + vol_type = UBI_STATIC_VOLUME; + + if (alignment != vol->alignment || data_pad != vol->data_pad || + upd_marker != vol->upd_marker || vol_type != vol->vol_type || + name_len!= vol->name_len || strncmp(name, vol->name, name_len)) { + ubi_err("volume info is different"); + goto fail; + } + + return; + +fail: + ubi_err("paranoid check failed"); + ubi_dbg_dump_vol_info(vol); + ubi_dbg_dump_vtbl_record(&ubi->vtbl[vol_id], vol_id); + BUG(); +} + +/** + * paranoid_check_volumes - check information about all volumes. + * @ubi: UBI device description object + */ +static void paranoid_check_volumes(struct ubi_device *ubi) +{ + int i; + + mutex_lock(&ubi->vtbl_mutex); + spin_lock(&ubi->volumes_lock); + for (i = 0; i < ubi->vtbl_slots; i++) + paranoid_check_volume(ubi, i); + spin_unlock(&ubi->volumes_lock); + mutex_unlock(&ubi->vtbl_mutex); +} +#endif diff --git a/drivers/mtd/ubi/vtbl.c b/drivers/mtd/ubi/vtbl.c new file mode 100644 index 0000000..b6fd6bb --- /dev/null +++ b/drivers/mtd/ubi/vtbl.c @@ -0,0 +1,809 @@ +/* + * Copyright (c) International Business Machines Corp., 2006 + * Copyright (c) Nokia Corporation, 2006, 2007 + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See + * the GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + * Author: Artem Bityutskiy (Битюцкий Артём) + */ + +/* + * This file includes volume table manipulation code. The volume table is an + * on-flash table containing volume meta-data like name, number of reserved + * physical eraseblocks, type, etc. The volume table is stored in the so-called + * "layout volume". + * + * The layout volume is an internal volume which is organized as follows. It + * consists of two logical eraseblocks - LEB 0 and LEB 1. Each logical + * eraseblock stores one volume table copy, i.e. LEB 0 and LEB 1 duplicate each + * other. This redundancy guarantees robustness to unclean reboots. The volume + * table is basically an array of volume table records. Each record contains + * full information about the volume and protected by a CRC checksum. + * + * The volume table is changed, it is first changed in RAM. Then LEB 0 is + * erased, and the updated volume table is written back to LEB 0. Then same for + * LEB 1. This scheme guarantees recoverability from unclean reboots. + * + * In this UBI implementation the on-flash volume table does not contain any + * information about how many data static volumes contain. This information may + * be found from the scanning data. + * + * But it would still be beneficial to store this information in the volume + * table. For example, suppose we have a static volume X, and all its physical + * eraseblocks became bad for some reasons. Suppose we are attaching the + * corresponding MTD device, the scanning has found no logical eraseblocks + * corresponding to the volume X. According to the volume table volume X does + * exist. So we don't know whether it is just empty or all its physical + * eraseblocks went bad. So we cannot alarm the user about this corruption. + * + * The volume table also stores so-called "update marker", which is used for + * volume updates. Before updating the volume, the update marker is set, and + * after the update operation is finished, the update marker is cleared. So if + * the update operation was interrupted (e.g. by an unclean reboot) - the + * update marker is still there and we know that the volume's contents is + * damaged. + */ + +#include <linux/crc32.h> +#include <linux/err.h> +#include <asm/div64.h> +#include "ubi.h" + +#ifdef CONFIG_MTD_UBI_DEBUG_PARANOID +static void paranoid_vtbl_check(const struct ubi_device *ubi); +#else +#define paranoid_vtbl_check(ubi) +#endif + +/* Empty volume table record */ +static struct ubi_vtbl_record empty_vtbl_record; + +/** + * ubi_change_vtbl_record - change volume table record. + * @ubi: UBI device description object + * @idx: table index to change + * @vtbl_rec: new volume table record + * + * This function changes volume table record @idx. If @vtbl_rec is %NULL, empty + * volume table record is written. The caller does not have to calculate CRC of + * the record as it is done by this function. Returns zero in case of success + * and a negative error code in case of failure. + */ +int ubi_change_vtbl_record(struct ubi_device *ubi, int idx, + struct ubi_vtbl_record *vtbl_rec) +{ + int i, err; + uint32_t crc; + + ubi_assert(idx >= 0 && idx < ubi->vtbl_slots); + + if (!vtbl_rec) + vtbl_rec = &empty_vtbl_record; + else { + crc = crc32(UBI_CRC32_INIT, vtbl_rec, UBI_VTBL_RECORD_SIZE_CRC); + vtbl_rec->crc = cpu_to_ubi32(crc); + } + + dbg_msg("change record %d", idx); + ubi_dbg_dump_vtbl_record(vtbl_rec, idx); + + mutex_lock(&ubi->vtbl_mutex); + memcpy(&ubi->vtbl[idx], vtbl_rec, sizeof(struct ubi_vtbl_record)); + for (i = 0; i < UBI_LAYOUT_VOLUME_EBS; i++) { + err = ubi_eba_unmap_leb(ubi, UBI_LAYOUT_VOL_ID, i); + if (err) { + mutex_unlock(&ubi->vtbl_mutex); + return err; + } + err = ubi_eba_write_leb(ubi, UBI_LAYOUT_VOL_ID, i, ubi->vtbl, 0, + ubi->vtbl_size, UBI_LONGTERM); + if (err) { + mutex_unlock(&ubi->vtbl_mutex); + return err; + } + } + + paranoid_vtbl_check(ubi); + mutex_unlock(&ubi->vtbl_mutex); + return ubi_wl_flush(ubi); +} + +/** + * vol_til_check - check if volume table is not corrupted and contains sensible + * data. + * + * @ubi: UBI device description object + * @vtbl: volume table + * + * This function returns zero if @vtbl is all right, %1 if CRC is incorrect, + * and %-EINVAL if it contains inconsistent data. + */ +static int vtbl_check(const struct ubi_device *ubi, + const struct ubi_vtbl_record *vtbl) +{ + int i, n, reserved_pebs, alignment, data_pad, vol_type, name_len; + int upd_marker; + uint32_t crc; + const char *name; + + for (i = 0; i < ubi->vtbl_slots; i++) { + cond_resched(); + + reserved_pebs = ubi32_to_cpu(vtbl[i].reserved_pebs); + alignment = ubi32_to_cpu(vtbl[i].alignment); + data_pad = ubi32_to_cpu(vtbl[i].data_pad); + upd_marker = vtbl[i].upd_marker; + vol_type = vtbl[i].vol_type; + name_len = ubi16_to_cpu(vtbl[i].name_len); + name = &vtbl[i].name[0]; + + crc = crc32(UBI_CRC32_INIT, &vtbl[i], UBI_VTBL_RECORD_SIZE_CRC); + if (ubi32_to_cpu(vtbl[i].crc) != crc) { + ubi_err("bad CRC at record %u: %#08x, not %#08x", + i, crc, ubi32_to_cpu(vtbl[i].crc)); + ubi_dbg_dump_vtbl_record(&vtbl[i], i); + return 1; + } + + if (reserved_pebs == 0) { + if (memcmp(&vtbl[i], &empty_vtbl_record, + UBI_VTBL_RECORD_SIZE)) { + dbg_err("bad empty record"); + goto bad; + } + continue; + } + + if (reserved_pebs < 0 || alignment < 0 || data_pad < 0 || + name_len < 0) { + dbg_err("negative values"); + goto bad; + } + + if (alignment > ubi->leb_size || alignment == 0) { + dbg_err("bad alignment"); + goto bad; + } + + n = alignment % ubi->min_io_size; + if (alignment != 1 && n) { + dbg_err("alignment is not multiple of min I/O unit"); + goto bad; + } + + n = ubi->leb_size % alignment; + if (data_pad != n) { + dbg_err("bad data_pad, has to be %d", n); + goto bad; + } + + if (vol_type != UBI_VID_DYNAMIC && vol_type != UBI_VID_STATIC) { + dbg_err("bad vol_type"); + goto bad; + } + + if (upd_marker != 0 && upd_marker != 1) { + dbg_err("bad upd_marker"); + goto bad; + } + + if (reserved_pebs > ubi->good_peb_count) { + dbg_err("too large reserved_pebs, good PEBs %d", + ubi->good_peb_count); + goto bad; + } + + if (name_len > UBI_VOL_NAME_MAX) { + dbg_err("too long volume name, max %d", + UBI_VOL_NAME_MAX); + goto bad; + } + + if (name[0] == '\0') { + dbg_err("NULL volume name"); + goto bad; + } + + if (name_len != strnlen(name, name_len + 1)) { + dbg_err("bad name_len"); + goto bad; + } + } + + /* Checks that all names are unique */ + for (i = 0; i < ubi->vtbl_slots - 1; i++) { + for (n = i + 1; n < ubi->vtbl_slots; n++) { + int len1 = ubi16_to_cpu(vtbl[i].name_len); + int len2 = ubi16_to_cpu(vtbl[n].name_len); + + if (len1 > 0 && len1 == len2 && + !strncmp(vtbl[i].name, vtbl[n].name, len1)) { + ubi_err("volumes %d and %d have the same name" + " \"%s\"", i, n, vtbl[i].name); + ubi_dbg_dump_vtbl_record(&vtbl[i], i); + ubi_dbg_dump_vtbl_record(&vtbl[n], n); + return -EINVAL; + } + } + } + + return 0; + +bad: + ubi_err("volume table check failed, record %d", i); + ubi_dbg_dump_vtbl_record(&vtbl[i], i); + return -EINVAL; +} + +/** + * create_vtbl - create a copy of volume table. + * @ubi: UBI device description object + * @si: scanning information + * @copy: number of the volume table copy + * @vtbl: contents of the volume table + * + * This function returns zero in case of success and a negative error code in + * case of failure. + */ +static int create_vtbl(const struct ubi_device *ubi, struct ubi_scan_info *si, + int copy, void *vtbl) +{ + int err, tries = 0; + static struct ubi_vid_hdr *vid_hdr; + struct ubi_scan_volume *sv; + struct ubi_scan_leb *new_seb, *old_seb = NULL; + + ubi_msg("create volume table (copy #%d)", copy + 1); + + vid_hdr = ubi_zalloc_vid_hdr(ubi); + if (!vid_hdr) + return -ENOMEM; + + /* + * Check if there is a logical eraseblock which would have to contain + * this volume table copy was found during scanning. It has to be wiped + * out. + */ + sv = ubi_scan_find_sv(si, UBI_LAYOUT_VOL_ID); + if (sv) + old_seb = ubi_scan_find_seb(sv, copy); + +retry: + new_seb = ubi_scan_get_free_peb(ubi, si); + if (IS_ERR(new_seb)) { + err = PTR_ERR(new_seb); + goto out_free; + } + + vid_hdr->vol_type = UBI_VID_DYNAMIC; + vid_hdr->vol_id = cpu_to_ubi32(UBI_LAYOUT_VOL_ID); + vid_hdr->compat = UBI_LAYOUT_VOLUME_COMPAT; + vid_hdr->data_size = vid_hdr->used_ebs = + vid_hdr->data_pad = cpu_to_ubi32(0); + vid_hdr->lnum = cpu_to_ubi32(copy); + vid_hdr->sqnum = cpu_to_ubi64(++si->max_sqnum); + vid_hdr->leb_ver = cpu_to_ubi32(old_seb ? old_seb->leb_ver + 1: 0); + + /* The EC header is already there, write the VID header */ + err = ubi_io_write_vid_hdr(ubi, new_seb->pnum, vid_hdr); + if (err) + goto write_error; + + /* Write the layout volume contents */ + err = ubi_io_write_data(ubi, vtbl, new_seb->pnum, 0, ubi->vtbl_size); + if (err) + goto write_error; + + /* + * And add it to the scanning information. Don't delete the old + * @old_seb as it will be deleted and freed in 'ubi_scan_add_used()'. + */ + err = ubi_scan_add_used(ubi, si, new_seb->pnum, new_seb->ec, + vid_hdr, 0); + kfree(new_seb); + ubi_free_vid_hdr(ubi, vid_hdr); + return err; + +write_error: + kfree(new_seb); + /* May be this physical eraseblock went bad, try to pick another one */ + if (++tries <= 5) { + err = ubi_scan_add_to_list(si, new_seb->pnum, new_seb->ec, + &si->corr); + if (!err) + goto retry; + } +out_free: + ubi_free_vid_hdr(ubi, vid_hdr); + return err; + +} + +/** + * process_lvol - process the layout volume. + * @ubi: UBI device description object + * @si: scanning information + * @sv: layout volume scanning information + * + * This function is responsible for reading the layout volume, ensuring it is + * not corrupted, and recovering from corruptions if needed. Returns volume + * table in case of success and a negative error code in case of failure. + */ +static struct ubi_vtbl_record *process_lvol(const struct ubi_device *ubi, + struct ubi_scan_info *si, + struct ubi_scan_volume *sv) +{ + int err; + struct rb_node *rb; + struct ubi_scan_leb *seb; + struct ubi_vtbl_record *leb[UBI_LAYOUT_VOLUME_EBS] = { NULL, NULL }; + int leb_corrupted[UBI_LAYOUT_VOLUME_EBS] = {1, 1}; + + /* + * UBI goes through the following steps when it changes the layout + * volume: + * a. erase LEB 0; + * b. write new data to LEB 0; + * c. erase LEB 1; + * d. write new data to LEB 1. + * + * Before the change, both LEBs contain the same data. + * + * Due to unclean reboots, the contents of LEB 0 may be lost, but there + * should LEB 1. So it is OK if LEB 0 is corrupted while LEB 1 is not. + * Similarly, LEB 1 may be lost, but there should be LEB 0. And + * finally, unclean reboots may result in a situation when neither LEB + * 0 nor LEB 1 are corrupted, but they are different. In this case, LEB + * 0 contains more recent information. + * + * So the plan is to first check LEB 0. Then + * a. if LEB 0 is OK, it must be containing the most resent data; then + * we compare it with LEB 1, and if they are different, we copy LEB + * 0 to LEB 1; + * b. if LEB 0 is corrupted, but LEB 1 has to be OK, and we copy LEB 1 + * to LEB 0. + */ + + dbg_msg("check layout volume"); + + /* Read both LEB 0 and LEB 1 into memory */ + ubi_rb_for_each_entry(rb, seb, &sv->root, u.rb) { + leb[seb->lnum] = kzalloc(ubi->vtbl_size, GFP_KERNEL); + if (!leb[seb->lnum]) { + err = -ENOMEM; + goto out_free; + } + + err = ubi_io_read_data(ubi, leb[seb->lnum], seb->pnum, 0, + ubi->vtbl_size); + if (err == UBI_IO_BITFLIPS || err == -EBADMSG) + /* Scrub the PEB later */ + seb->scrub = 1; + else if (err) + goto out_free; + } + + err = -EINVAL; + if (leb[0]) { + leb_corrupted[0] = vtbl_check(ubi, leb[0]); + if (leb_corrupted[0] < 0) + goto out_free; + } + + if (!leb_corrupted[0]) { + /* LEB 0 is OK */ + if (leb[1]) + leb_corrupted[1] = memcmp(leb[0], leb[1], ubi->vtbl_size); + if (leb_corrupted[1]) { + ubi_warn("volume table copy #2 is corrupted"); + err = create_vtbl(ubi, si, 1, leb[0]); + if (err) + goto out_free; + ubi_msg("volume table was restored"); + } + + /* Both LEB 1 and LEB 2 are OK and consistent */ + kfree(leb[1]); + return leb[0]; + } else { + /* LEB 0 is corrupted or does not exist */ + if (leb[1]) { + leb_corrupted[1] = vtbl_check(ubi, leb[1]); + if (leb_corrupted[1] < 0) + goto out_free; + } + if (leb_corrupted[1]) { + /* Both LEB 0 and LEB 1 are corrupted */ + ubi_err("both volume tables are corrupted"); + goto out_free; + } + + ubi_warn("volume table copy #1 is corrupted"); + err = create_vtbl(ubi, si, 0, leb[1]); + if (err) + goto out_free; + ubi_msg("volume table was restored"); + + kfree(leb[0]); + return leb[1]; + } + +out_free: + kfree(leb[0]); + kfree(leb[1]); + return ERR_PTR(err); +} + +/** + * create_empty_lvol - create empty layout volume. + * @ubi: UBI device description object + * @si: scanning information + * + * This function returns volume table contents in case of success and a + * negative error code in case of failure. + */ +static struct ubi_vtbl_record *create_empty_lvol(const struct ubi_device *ubi, + struct ubi_scan_info *si) +{ + int i; + struct ubi_vtbl_record *vtbl; + + vtbl = kzalloc(ubi->vtbl_size, GFP_KERNEL); + if (!vtbl) + return ERR_PTR(-ENOMEM); + + for (i = 0; i < ubi->vtbl_slots; i++) + memcpy(&vtbl[i], &empty_vtbl_record, UBI_VTBL_RECORD_SIZE); + + for (i = 0; i < UBI_LAYOUT_VOLUME_EBS; i++) { + int err; + + err = create_vtbl(ubi, si, i, vtbl); + if (err) { + kfree(vtbl); + return ERR_PTR(err); + } + } + + return vtbl; +} + +/** + * init_volumes - initialize volume information for existing volumes. + * @ubi: UBI device description object + * @si: scanning information + * @vtbl: volume table + * + * This function allocates volume description objects for existing volumes. + * Returns zero in case of success and a negative error code in case of + * failure. + */ +static int init_volumes(struct ubi_device *ubi, const struct ubi_scan_info *si, + const struct ubi_vtbl_record *vtbl) +{ + int i, reserved_pebs = 0; + struct ubi_scan_volume *sv; + struct ubi_volume *vol; + + for (i = 0; i < ubi->vtbl_slots; i++) { + cond_resched(); + + if (ubi32_to_cpu(vtbl[i].reserved_pebs) == 0) + continue; /* Empty record */ + + vol = kzalloc(sizeof(struct ubi_volume), GFP_KERNEL); + if (!vol) + return -ENOMEM; + + vol->reserved_pebs = ubi32_to_cpu(vtbl[i].reserved_pebs); + vol->alignment = ubi32_to_cpu(vtbl[i].alignment); + vol->data_pad = ubi32_to_cpu(vtbl[i].data_pad); + vol->vol_type = vtbl[i].vol_type == UBI_VID_DYNAMIC ? + UBI_DYNAMIC_VOLUME : UBI_STATIC_VOLUME; + vol->name_len = ubi16_to_cpu(vtbl[i].name_len); + vol->usable_leb_size = ubi->leb_size - vol->data_pad; + memcpy(vol->name, vtbl[i].name, vol->name_len); + vol->name[vol->name_len] = '\0'; + vol->vol_id = i; + + ubi_assert(!ubi->volumes[i]); + ubi->volumes[i] = vol; + ubi->vol_count += 1; + vol->ubi = ubi; + reserved_pebs += vol->reserved_pebs; + + /* + * In case of dynamic volume UBI knows nothing about how many + * data is stored there. So assume the whole volume is used. + */ + if (vol->vol_type == UBI_DYNAMIC_VOLUME) { + vol->used_ebs = vol->reserved_pebs; + vol->last_eb_bytes = vol->usable_leb_size; + vol->used_bytes = vol->used_ebs * vol->usable_leb_size; + continue; + } + + /* Static volumes only */ + sv = ubi_scan_find_sv(si, i); + if (!sv) { + /* + * No eraseblocks belonging to this volume found. We + * don't actually know whether this static volume is + * completely corrupted or just contains no data. And + * we cannot know this as long as data size is not + * stored on flash. So we just assume the volume is + * empty. FIXME: this should be handled. + */ + continue; + } + + if (sv->leb_count != sv->used_ebs) { + /* + * We found a static volume which misses several + * eraseblocks. Treat it as corrupted. + */ + ubi_warn("static volume %d misses %d LEBs - corrupted", + sv->vol_id, sv->used_ebs - sv->leb_count); + vol->corrupted = 1; + continue; + } + + vol->used_ebs = sv->used_ebs; + vol->used_bytes = (vol->used_ebs - 1) * vol->usable_leb_size; + vol->used_bytes += sv->last_data_size; + vol->last_eb_bytes = sv->last_data_size; + } + + vol = kzalloc(sizeof(struct ubi_volume), GFP_KERNEL); + if (!vol) + return -ENOMEM; + + vol->reserved_pebs = UBI_LAYOUT_VOLUME_EBS; + vol->alignment = 1; + vol->vol_type = UBI_DYNAMIC_VOLUME; + vol->name_len = sizeof(UBI_LAYOUT_VOLUME_NAME) - 1; + memcpy(vol->name, UBI_LAYOUT_VOLUME_NAME, vol->name_len + 1); + vol->usable_leb_size = ubi->leb_size; + vol->used_ebs = vol->reserved_pebs; + vol->last_eb_bytes = vol->reserved_pebs; + vol->used_bytes = vol->used_ebs * (ubi->leb_size - vol->data_pad); + vol->vol_id = UBI_LAYOUT_VOL_ID; + + ubi_assert(!ubi->volumes[i]); + ubi->volumes[vol_id2idx(ubi, vol->vol_id)] = vol; + reserved_pebs += vol->reserved_pebs; + ubi->vol_count += 1; + vol->ubi = ubi; + + if (reserved_pebs > ubi->avail_pebs) + ubi_err("not enough PEBs, required %d, available %d", + reserved_pebs, ubi->avail_pebs); + ubi->rsvd_pebs += reserved_pebs; + ubi->avail_pebs -= reserved_pebs; + + return 0; +} + +/** + * check_sv - check volume scanning information. + * @vol: UBI volume description object + * @sv: volume scanning information + * + * This function returns zero if the volume scanning information is consistent + * to the data read from the volume tabla, and %-EINVAL if not. + */ +static int check_sv(const struct ubi_volume *vol, + const struct ubi_scan_volume *sv) +{ + if (sv->highest_lnum >= vol->reserved_pebs) { + dbg_err("bad highest_lnum"); + goto bad; + } + if (sv->leb_count > vol->reserved_pebs) { + dbg_err("bad leb_count"); + goto bad; + } + if (sv->vol_type != vol->vol_type) { + dbg_err("bad vol_type"); + goto bad; + } + if (sv->used_ebs > vol->reserved_pebs) { + dbg_err("bad used_ebs"); + goto bad; + } + if (sv->data_pad != vol->data_pad) { + dbg_err("bad data_pad"); + goto bad; + } + return 0; + +bad: + ubi_err("bad scanning information"); + ubi_dbg_dump_sv(sv); + ubi_dbg_dump_vol_info(vol); + return -EINVAL; +} + +/** + * check_scanning_info - check that scanning information. + * @ubi: UBI device description object + * @si: scanning information + * + * Even though we protect on-flash data by CRC checksums, we still don't trust + * the media. This function ensures that scanning information is consistent to + * the information read from the volume table. Returns zero if the scanning + * information is OK and %-EINVAL if it is not. + */ +static int check_scanning_info(const struct ubi_device *ubi, + struct ubi_scan_info *si) +{ + int err, i; + struct ubi_scan_volume *sv; + struct ubi_volume *vol; + + if (si->vols_found > UBI_INT_VOL_COUNT + ubi->vtbl_slots) { + ubi_err("scanning found %d volumes, maximum is %d + %d", + si->vols_found, UBI_INT_VOL_COUNT, ubi->vtbl_slots); + return -EINVAL; + } + + if (si->highest_vol_id >= ubi->vtbl_slots + UBI_INT_VOL_COUNT&& + si->highest_vol_id < UBI_INTERNAL_VOL_START) { + ubi_err("too large volume ID %d found by scanning", + si->highest_vol_id); + return -EINVAL; + } + + + for (i = 0; i < ubi->vtbl_slots + UBI_INT_VOL_COUNT; i++) { + cond_resched(); + + sv = ubi_scan_find_sv(si, i); + vol = ubi->volumes[i]; + if (!vol) { + if (sv) + ubi_scan_rm_volume(si, sv); + continue; + } + + if (vol->reserved_pebs == 0) { + ubi_assert(i < ubi->vtbl_slots); + + if (!sv) + continue; + + /* + * During scanning we found a volume which does not + * exist according to the information in the volume + * table. This must have happened due to an unclean + * reboot while the volume was being removed. Discard + * these eraseblocks. + */ + ubi_msg("finish volume %d removal", sv->vol_id); + ubi_scan_rm_volume(si, sv); + } else if (sv) { + err = check_sv(vol, sv); + if (err) + return err; + } + } + + return 0; +} + +/** + * ubi_read_volume_table - read volume table. + * information. + * @ubi: UBI device description object + * @si: scanning information + * + * This function reads volume table, checks it, recover from errors if needed, + * or creates it if needed. Returns zero in case of success and a negative + * error code in case of failure. + */ +int ubi_read_volume_table(struct ubi_device *ubi, struct ubi_scan_info *si) +{ + int i, err; + struct ubi_scan_volume *sv; + + empty_vtbl_record.crc = cpu_to_ubi32(0xf116c36b); + + /* + * The number of supported volumes is limited by the eraseblock size + * and by the UBI_MAX_VOLUMES constant. + */ + ubi->vtbl_slots = ubi->leb_size / UBI_VTBL_RECORD_SIZE; + if (ubi->vtbl_slots > UBI_MAX_VOLUMES) + ubi->vtbl_slots = UBI_MAX_VOLUMES; + + ubi->vtbl_size = ubi->vtbl_slots * UBI_VTBL_RECORD_SIZE; + ubi->vtbl_size = ALIGN(ubi->vtbl_size, ubi->min_io_size); + + sv = ubi_scan_find_sv(si, UBI_LAYOUT_VOL_ID); + if (!sv) { + /* + * No logical eraseblocks belonging to the layout volume were + * found. This could mean that the flash is just empty. In + * this case we create empty layout volume. + * + * But if flash is not empty this must be a corruption or the + * MTD device just contains garbage. + */ + if (si->is_empty) { + ubi->vtbl = create_empty_lvol(ubi, si); + if (IS_ERR(ubi->vtbl)) + return PTR_ERR(ubi->vtbl); + } else { + ubi_err("the layout volume was not found"); + return -EINVAL; + } + } else { + if (sv->leb_count > UBI_LAYOUT_VOLUME_EBS) { + /* This must not happen with proper UBI images */ + dbg_err("too many LEBs (%d) in layout volume", + sv->leb_count); + return -EINVAL; + } + + ubi->vtbl = process_lvol(ubi, si, sv); + if (IS_ERR(ubi->vtbl)) + return PTR_ERR(ubi->vtbl); + } + + ubi->avail_pebs = ubi->good_peb_count; + + /* + * The layout volume is OK, initialize the corresponding in-RAM data + * structures. + */ + err = init_volumes(ubi, si, ubi->vtbl); + if (err) + goto out_free; + + /* + * Get sure that the scanning information is consistent to the + * information stored in the volume table. + */ + err = check_scanning_info(ubi, si); + if (err) + goto out_free; + + return 0; + +out_free: + kfree(ubi->vtbl); + for (i = 0; i < ubi->vtbl_slots + UBI_INT_VOL_COUNT; i++) + if (ubi->volumes[i]) { + kfree(ubi->volumes[i]); + ubi->volumes[i] = NULL; + } + return err; +} + +#ifdef CONFIG_MTD_UBI_DEBUG_PARANOID + +/** + * paranoid_vtbl_check - check volume table. + * @ubi: UBI device description object + */ +static void paranoid_vtbl_check(const struct ubi_device *ubi) +{ + if (vtbl_check(ubi, ubi->vtbl)) { + ubi_err("paranoid check failed"); + BUG(); + } +} + +#endif /* CONFIG_MTD_UBI_DEBUG_PARANOID */ diff --git a/drivers/mtd/ubi/wl.c b/drivers/mtd/ubi/wl.c new file mode 100644 index 0000000..9ecaf77 --- /dev/null +++ b/drivers/mtd/ubi/wl.c @@ -0,0 +1,1671 @@ +/* + * Copyright (c) International Business Machines Corp., 2006 + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See + * the GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + * Authors: Artem Bityutskiy (Битюцкий Артём), Thomas Gleixner + */ + +/* + * UBI wear-leveling unit. + * + * This unit is responsible for wear-leveling. It works in terms of physical + * eraseblocks and erase counters and knows nothing about logical eraseblocks, + * volumes, etc. From this unit's perspective all physical eraseblocks are of + * two types - used and free. Used physical eraseblocks are those that were + * "get" by the 'ubi_wl_get_peb()' function, and free physical eraseblocks are + * those that were put by the 'ubi_wl_put_peb()' function. + * + * Physical eraseblocks returned by 'ubi_wl_get_peb()' have only erase counter + * header. The rest of the physical eraseblock contains only 0xFF bytes. + * + * When physical eraseblocks are returned to the WL unit by means of the + * 'ubi_wl_put_peb()' function, they are scheduled for erasure. The erasure is + * done asynchronously in context of the per-UBI device background thread, + * which is also managed by the WL unit. + * + * The wear-leveling is ensured by means of moving the contents of used + * physical eraseblocks with low erase counter to free physical eraseblocks + * with high erase counter. + * + * The 'ubi_wl_get_peb()' function accepts data type hints which help to pick + * an "optimal" physical eraseblock. For example, when it is known that the + * physical eraseblock will be "put" soon because it contains short-term data, + * the WL unit may pick a free physical eraseblock with low erase counter, and + * so forth. + * + * If the WL unit fails to erase a physical eraseblock, it marks it as bad. + * + * This unit is also responsible for scrubbing. If a bit-flip is detected in a + * physical eraseblock, it has to be moved. Technically this is the same as + * moving it for wear-leveling reasons. + * + * As it was said, for the UBI unit all physical eraseblocks are either "free" + * or "used". Free eraseblock are kept in the @wl->free RB-tree, while used + * eraseblocks are kept in a set of different RB-trees: @wl->used, + * @wl->prot.pnum, @wl->prot.aec, and @wl->scrub. + * + * Note, in this implementation, we keep a small in-RAM object for each physical + * eraseblock. This is surely not a scalable solution. But it appears to be good + * enough for moderately large flashes and it is simple. In future, one may + * re-work this unit and make it more scalable. + * + * At the moment this unit does not utilize the sequence number, which was + * introduced relatively recently. But it would be wise to do this because the + * sequence number of a logical eraseblock characterizes how old is it. For + * example, when we move a PEB with low erase counter, and we need to pick the + * target PEB, we pick a PEB with the highest EC if our PEB is "old" and we + * pick target PEB with an average EC if our PEB is not very "old". This is a + * room for future re-works of the WL unit. + * + * FIXME: looks too complex, should be simplified (later). + */ + +#include <linux/slab.h> +#include <linux/crc32.h> +#include <linux/freezer.h> +#include <linux/kthread.h> +#include "ubi.h" + +/* Number of physical eraseblocks reserved for wear-leveling purposes */ +#define WL_RESERVED_PEBS 1 + +/* + * How many erase cycles are short term, unknown, and long term physical + * eraseblocks protected. + */ +#define ST_PROTECTION 16 +#define U_PROTECTION 10 +#define LT_PROTECTION 4 + +/* + * Maximum difference between two erase counters. If this threshold is + * exceeded, the WL unit starts moving data from used physical eraseblocks with + * low erase counter to free physical eraseblocks with high erase counter. + */ +#define UBI_WL_THRESHOLD CONFIG_MTD_UBI_WL_THRESHOLD + +/* + * When a physical eraseblock is moved, the WL unit has to pick the target + * physical eraseblock to move to. The simplest way would be just to pick the + * one with the highest erase counter. But in certain workloads this could lead + * to an unlimited wear of one or few physical eraseblock. Indeed, imagine a + * situation when the picked physical eraseblock is constantly erased after the + * data is written to it. So, we have a constant which limits the highest erase + * counter of the free physical eraseblock to pick. Namely, the WL unit does + * not pick eraseblocks with erase counter greater then the lowest erase + * counter plus %WL_FREE_MAX_DIFF. + */ +#define WL_FREE_MAX_DIFF (2*UBI_WL_THRESHOLD) + +/* + * Maximum number of consecutive background thread failures which is enough to + * switch to read-only mode. + */ +#define WL_MAX_FAILURES 32 + +/** + * struct ubi_wl_entry - wear-leveling entry. + * @rb: link in the corresponding RB-tree + * @ec: erase counter + * @pnum: physical eraseblock number + * + * Each physical eraseblock has a corresponding &struct wl_entry object which + * may be kept in different RB-trees. + */ +struct ubi_wl_entry { + struct rb_node rb; + int ec; + int pnum; +}; + +/** + * struct ubi_wl_prot_entry - PEB protection entry. + * @rb_pnum: link in the @wl->prot.pnum RB-tree + * @rb_aec: link in the @wl->prot.aec RB-tree + * @abs_ec: the absolute erase counter value when the protection ends + * @e: the wear-leveling entry of the physical eraseblock under protection + * + * When the WL unit returns a physical eraseblock, the physical eraseblock is + * protected from being moved for some "time". For this reason, the physical + * eraseblock is not directly moved from the @wl->free tree to the @wl->used + * tree. There is one more tree in between where this physical eraseblock is + * temporarily stored (@wl->prot). + * + * All this protection stuff is needed because: + * o we don't want to move physical eraseblocks just after we have given them + * to the user; instead, we first want to let users fill them up with data; + * + * o there is a chance that the user will put the physical eraseblock very + * soon, so it makes sense not to move it for some time, but wait; this is + * especially important in case of "short term" physical eraseblocks. + * + * Physical eraseblocks stay protected only for limited time. But the "time" is + * measured in erase cycles in this case. This is implemented with help of the + * absolute erase counter (@wl->abs_ec). When it reaches certain value, the + * physical eraseblocks are moved from the protection trees (@wl->prot.*) to + * the @wl->used tree. + * + * Protected physical eraseblocks are searched by physical eraseblock number + * (when they are put) and by the absolute erase counter (to check if it is + * time to move them to the @wl->used tree). So there are actually 2 RB-trees + * storing the protected physical eraseblocks: @wl->prot.pnum and + * @wl->prot.aec. They are referred to as the "protection" trees. The + * first one is indexed by the physical eraseblock number. The second one is + * indexed by the absolute erase counter. Both trees store + * &struct ubi_wl_prot_entry objects. + * + * Each physical eraseblock has 2 main states: free and used. The former state + * corresponds to the @wl->free tree. The latter state is split up on several + * sub-states: + * o the WL movement is allowed (@wl->used tree); + * o the WL movement is temporarily prohibited (@wl->prot.pnum and + * @wl->prot.aec trees); + * o scrubbing is needed (@wl->scrub tree). + * + * Depending on the sub-state, wear-leveling entries of the used physical + * eraseblocks may be kept in one of those trees. + */ +struct ubi_wl_prot_entry { + struct rb_node rb_pnum; + struct rb_node rb_aec; + unsigned long long abs_ec; + struct ubi_wl_entry *e; +}; + +/** + * struct ubi_work - UBI work description data structure. + * @list: a link in the list of pending works + * @func: worker function + * @priv: private data of the worker function + * + * @e: physical eraseblock to erase + * @torture: if the physical eraseblock has to be tortured + * + * The @func pointer points to the worker function. If the @cancel argument is + * not zero, the worker has to free the resources and exit immediately. The + * worker has to return zero in case of success and a negative error code in + * case of failure. + */ +struct ubi_work { + struct list_head list; + int (*func)(struct ubi_device *ubi, struct ubi_work *wrk, int cancel); + /* The below fields are only relevant to erasure works */ + struct ubi_wl_entry *e; + int torture; +}; + +#ifdef CONFIG_MTD_UBI_DEBUG_PARANOID +static int paranoid_check_ec(const struct ubi_device *ubi, int pnum, int ec); +static int paranoid_check_in_wl_tree(struct ubi_wl_entry *e, + struct rb_root *root); +#else +#define paranoid_check_ec(ubi, pnum, ec) 0 +#define paranoid_check_in_wl_tree(e, root) +#endif + +/* Slab cache for wear-leveling entries */ +static struct kmem_cache *wl_entries_slab; + +/** + * tree_empty - a helper function to check if an RB-tree is empty. + * @root: the root of the tree + * + * This function returns non-zero if the RB-tree is empty and zero if not. + */ +static inline int tree_empty(struct rb_root *root) +{ + return root->rb_node == NULL; +} + +/** + * wl_tree_add - add a wear-leveling entry to a WL RB-tree. + * @e: the wear-leveling entry to add + * @root: the root of the tree + * + * Note, we use (erase counter, physical eraseblock number) pairs as keys in + * the @ubi->used and @ubi->free RB-trees. + */ +static void wl_tree_add(struct ubi_wl_entry *e, struct rb_root *root) +{ + struct rb_node **p, *parent = NULL; + + p = &root->rb_node; + while (*p) { + struct ubi_wl_entry *e1; + + parent = *p; + e1 = rb_entry(parent, struct ubi_wl_entry, rb); + + if (e->ec < e1->ec) + p = &(*p)->rb_left; + else if (e->ec > e1->ec) + p = &(*p)->rb_right; + else { + ubi_assert(e->pnum != e1->pnum); + if (e->pnum < e1->pnum) + p = &(*p)->rb_left; + else + p = &(*p)->rb_right; + } + } + + rb_link_node(&e->rb, parent, p); + rb_insert_color(&e->rb, root); +} + + +/* + * Helper functions to add and delete wear-leveling entries from different + * trees. + */ + +static void free_tree_add(struct ubi_device *ubi, struct ubi_wl_entry *e) +{ + wl_tree_add(e, &ubi->free); +} +static inline void used_tree_add(struct ubi_device *ubi, + struct ubi_wl_entry *e) +{ + wl_tree_add(e, &ubi->used); +} +static inline void scrub_tree_add(struct ubi_device *ubi, + struct ubi_wl_entry *e) +{ + wl_tree_add(e, &ubi->scrub); +} +static inline void free_tree_del(struct ubi_device *ubi, + struct ubi_wl_entry *e) +{ + paranoid_check_in_wl_tree(e, &ubi->free); + rb_erase(&e->rb, &ubi->free); +} +static inline void used_tree_del(struct ubi_device *ubi, + struct ubi_wl_entry *e) +{ + paranoid_check_in_wl_tree(e, &ubi->used); + rb_erase(&e->rb, &ubi->used); +} +static inline void scrub_tree_del(struct ubi_device *ubi, + struct ubi_wl_entry *e) +{ + paranoid_check_in_wl_tree(e, &ubi->scrub); + rb_erase(&e->rb, &ubi->scrub); +} + +/** + * do_work - do one pending work. + * @ubi: UBI device description object + * + * This function returns zero in case of success and a negative error code in + * case of failure. + */ +static int do_work(struct ubi_device *ubi) +{ + int err; + struct ubi_work *wrk; + + spin_lock(&ubi->wl_lock); + + if (list_empty(&ubi->works)) { + spin_unlock(&ubi->wl_lock); + return 0; + } + + wrk = list_entry(ubi->works.next, struct ubi_work, list); + list_del(&wrk->list); + spin_unlock(&ubi->wl_lock); + + /* + * Call the worker function. Do not touch the work structure + * after this call as it will have been freed or reused by that + * time by the worker function. + */ + err = wrk->func(ubi, wrk, 0); + if (err) + ubi_err("work failed with error code %d", err); + + spin_lock(&ubi->wl_lock); + ubi->works_count -= 1; + ubi_assert(ubi->works_count >= 0); + spin_unlock(&ubi->wl_lock); + return err; +} + +/** + * produce_free_peb - produce a free physical eraseblock. + * @ubi: UBI device description object + * + * This function tries to make a free PEB by means of synchronous execution of + * pending works. This may be needed if, for example the background thread is + * disabled. Returns zero in case of success and a negative error code in case + * of failure. + */ +static int produce_free_peb(struct ubi_device *ubi) +{ + int err; + + spin_lock(&ubi->wl_lock); + while (tree_empty(&ubi->free)) { + spin_unlock(&ubi->wl_lock); + + dbg_wl("do one work synchronously"); + err = do_work(ubi); + if (err) + return err; + + spin_lock(&ubi->wl_lock); + } + spin_unlock(&ubi->wl_lock); + + return 0; +} + +/** + * in_wl_tree - check if wear-leveling entry is present in a WL RB-tree. + * @e: the wear-leveling entry to check + * @root: the root of the tree + * + * This function returns non-zero if @e is in the @root RB-tree and zero if it + * is not. + */ +static int in_wl_tree(struct ubi_wl_entry *e, struct rb_root *root) +{ + struct rb_node *p; + + p = root->rb_node; + while (p) { + struct ubi_wl_entry *e1; + + e1 = rb_entry(p, struct ubi_wl_entry, rb); + + if (e->pnum == e1->pnum) { + ubi_assert(e == e1); + return 1; + } + + if (e->ec < e1->ec) + p = p->rb_left; + else if (e->ec > e1->ec) + p = p->rb_right; + else { + ubi_assert(e->pnum != e1->pnum); + if (e->pnum < e1->pnum) + p = p->rb_left; + else + p = p->rb_right; + } + } + + return 0; +} + +/** + * prot_tree_add - add physical eraseblock to protection trees. + * @ubi: UBI device description object + * @e: the physical eraseblock to add + * @pe: protection entry object to use + * @abs_ec: absolute erase counter value when this physical eraseblock has + * to be removed from the protection trees. + * + * @wl->lock has to be locked. + */ +static void prot_tree_add(struct ubi_device *ubi, struct ubi_wl_entry *e, + struct ubi_wl_prot_entry *pe, int abs_ec) +{ + struct rb_node **p, *parent = NULL; + struct ubi_wl_prot_entry *pe1; + + pe->e = e; + pe->abs_ec = ubi->abs_ec + abs_ec; + + p = &ubi->prot.pnum.rb_node; + while (*p) { + parent = *p; + pe1 = rb_entry(parent, struct ubi_wl_prot_entry, rb_pnum); + + if (e->pnum < pe1->e->pnum) + p = &(*p)->rb_left; + else + p = &(*p)->rb_right; + } + rb_link_node(&pe->rb_pnum, parent, p); + rb_insert_color(&pe->rb_pnum, &ubi->prot.pnum); + + p = &ubi->prot.aec.rb_node; + parent = NULL; + while (*p) { + parent = *p; + pe1 = rb_entry(parent, struct ubi_wl_prot_entry, rb_aec); + + if (pe->abs_ec < pe1->abs_ec) + p = &(*p)->rb_left; + else + p = &(*p)->rb_right; + } + rb_link_node(&pe->rb_aec, parent, p); + rb_insert_color(&pe->rb_aec, &ubi->prot.aec); +} + +/** + * find_wl_entry - find wear-leveling entry closest to certain erase counter. + * @root: the RB-tree where to look for + * @max: highest possible erase counter + * + * This function looks for a wear leveling entry with erase counter closest to + * @max and less then @max. + */ +static struct ubi_wl_entry *find_wl_entry(struct rb_root *root, int max) +{ + struct rb_node *p; + struct ubi_wl_entry *e; + + e = rb_entry(rb_first(root), struct ubi_wl_entry, rb); + max += e->ec; + + p = root->rb_node; + while (p) { + struct ubi_wl_entry *e1; + + e1 = rb_entry(p, struct ubi_wl_entry, rb); + if (e1->ec >= max) + p = p->rb_left; + else { + p = p->rb_right; + e = e1; + } + } + + return e; +} + +/** + * ubi_wl_get_peb - get a physical eraseblock. + * @ubi: UBI device description object + * @dtype: type of data which will be stored in this physical eraseblock + * + * This function returns a physical eraseblock in case of success and a + * negative error code in case of failure. Might sleep. + */ +int ubi_wl_get_peb(struct ubi_device *ubi, int dtype) +{ + int err, protect, medium_ec; + struct ubi_wl_entry *e, *first, *last; + struct ubi_wl_prot_entry *pe; + + ubi_assert(dtype == UBI_LONGTERM || dtype == UBI_SHORTTERM || + dtype == UBI_UNKNOWN); + + pe = kmalloc(sizeof(struct ubi_wl_prot_entry), GFP_KERNEL); + if (!pe) + return -ENOMEM; + +retry: + spin_lock(&ubi->wl_lock); + if (tree_empty(&ubi->free)) { + if (ubi->works_count == 0) { + ubi_assert(list_empty(&ubi->works)); + ubi_err("no free eraseblocks"); + spin_unlock(&ubi->wl_lock); + kfree(pe); + return -ENOSPC; + } + spin_unlock(&ubi->wl_lock); + + err = produce_free_peb(ubi); + if (err < 0) { + kfree(pe); + return err; + } + goto retry; + } + + switch (dtype) { + case UBI_LONGTERM: + /* + * For long term data we pick a physical eraseblock + * with high erase counter. But the highest erase + * counter we can pick is bounded by the the lowest + * erase counter plus %WL_FREE_MAX_DIFF. + */ + e = find_wl_entry(&ubi->free, WL_FREE_MAX_DIFF); + protect = LT_PROTECTION; + break; + case UBI_UNKNOWN: + /* + * For unknown data we pick a physical eraseblock with + * medium erase counter. But we by no means can pick a + * physical eraseblock with erase counter greater or + * equivalent than the lowest erase counter plus + * %WL_FREE_MAX_DIFF. + */ + first = rb_entry(rb_first(&ubi->free), + struct ubi_wl_entry, rb); + last = rb_entry(rb_last(&ubi->free), + struct ubi_wl_entry, rb); + + if (last->ec - first->ec < WL_FREE_MAX_DIFF) + e = rb_entry(ubi->free.rb_node, + struct ubi_wl_entry, rb); + else { + medium_ec = (first->ec + WL_FREE_MAX_DIFF)/2; + e = find_wl_entry(&ubi->free, medium_ec); + } + protect = U_PROTECTION; + break; + case UBI_SHORTTERM: + /* + * For short term data we pick a physical eraseblock + * with the lowest erase counter as we expect it will + * be erased soon. + */ + e = rb_entry(rb_first(&ubi->free), + struct ubi_wl_entry, rb); + protect = ST_PROTECTION; + break; + default: + protect = 0; + e = NULL; + BUG(); + } + + /* + * Move the physical eraseblock to the protection trees where it will + * be protected from being moved for some time. + */ + free_tree_del(ubi, e); + prot_tree_add(ubi, e, pe, protect); + + dbg_wl("PEB %d EC %d, protection %d", e->pnum, e->ec, protect); + spin_unlock(&ubi->wl_lock); + + return e->pnum; +} + +/** + * prot_tree_del - remove a physical eraseblock from the protection trees + * @ubi: UBI device description object + * @pnum: the physical eraseblock to remove + */ +static void prot_tree_del(struct ubi_device *ubi, int pnum) +{ + struct rb_node *p; + struct ubi_wl_prot_entry *pe = NULL; + + p = ubi->prot.pnum.rb_node; + while (p) { + + pe = rb_entry(p, struct ubi_wl_prot_entry, rb_pnum); + + if (pnum == pe->e->pnum) + break; + + if (pnum < pe->e->pnum) + p = p->rb_left; + else + p = p->rb_right; + } + + ubi_assert(pe->e->pnum == pnum); + rb_erase(&pe->rb_aec, &ubi->prot.aec); + rb_erase(&pe->rb_pnum, &ubi->prot.pnum); + kfree(pe); +} + +/** + * sync_erase - synchronously erase a physical eraseblock. + * @ubi: UBI device description object + * @e: the the physical eraseblock to erase + * @torture: if the physical eraseblock has to be tortured + * + * This function returns zero in case of success and a negative error code in + * case of failure. + */ +static int sync_erase(struct ubi_device *ubi, struct ubi_wl_entry *e, int torture) +{ + int err; + struct ubi_ec_hdr *ec_hdr; + unsigned long long ec = e->ec; + + dbg_wl("erase PEB %d, old EC %llu", e->pnum, ec); + + err = paranoid_check_ec(ubi, e->pnum, e->ec); + if (err > 0) + return -EINVAL; + + ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL); + if (!ec_hdr) + return -ENOMEM; + + err = ubi_io_sync_erase(ubi, e->pnum, torture); + if (err < 0) + goto out_free; + + ec += err; + if (ec > UBI_MAX_ERASECOUNTER) { + /* + * Erase counter overflow. Upgrade UBI and use 64-bit + * erase counters internally. + */ + ubi_err("erase counter overflow at PEB %d, EC %llu", + e->pnum, ec); + err = -EINVAL; + goto out_free; + } + + dbg_wl("erased PEB %d, new EC %llu", e->pnum, ec); + + ec_hdr->ec = cpu_to_ubi64(ec); + + err = ubi_io_write_ec_hdr(ubi, e->pnum, ec_hdr); + if (err) + goto out_free; + + e->ec = ec; + spin_lock(&ubi->wl_lock); + if (e->ec > ubi->max_ec) + ubi->max_ec = e->ec; + spin_unlock(&ubi->wl_lock); + +out_free: + kfree(ec_hdr); + return err; +} + +/** + * check_protection_over - check if it is time to stop protecting some + * physical eraseblocks. + * @ubi: UBI device description object + * + * This function is called after each erase operation, when the absolute erase + * counter is incremented, to check if some physical eraseblock have not to be + * protected any longer. These physical eraseblocks are moved from the + * protection trees to the used tree. + */ +static void check_protection_over(struct ubi_device *ubi) +{ + struct ubi_wl_prot_entry *pe; + + /* + * There may be several protected physical eraseblock to remove, + * process them all. + */ + while (1) { + spin_lock(&ubi->wl_lock); + if (tree_empty(&ubi->prot.aec)) { + spin_unlock(&ubi->wl_lock); + break; + } + + pe = rb_entry(rb_first(&ubi->prot.aec), + struct ubi_wl_prot_entry, rb_aec); + + if (pe->abs_ec > ubi->abs_ec) { + spin_unlock(&ubi->wl_lock); + break; + } + + dbg_wl("PEB %d protection over, abs_ec %llu, PEB abs_ec %llu", + pe->e->pnum, ubi->abs_ec, pe->abs_ec); + rb_erase(&pe->rb_aec, &ubi->prot.aec); + rb_erase(&pe->rb_pnum, &ubi->prot.pnum); + used_tree_add(ubi, pe->e); + spin_unlock(&ubi->wl_lock); + + kfree(pe); + cond_resched(); + } +} + +/** + * schedule_ubi_work - schedule a work. + * @ubi: UBI device description object + * @wrk: the work to schedule + * + * This function enqueues a work defined by @wrk to the tail of the pending + * works list. + */ +static void schedule_ubi_work(struct ubi_device *ubi, struct ubi_work *wrk) +{ + spin_lock(&ubi->wl_lock); + list_add_tail(&wrk->list, &ubi->works); + ubi_assert(ubi->works_count >= 0); + ubi->works_count += 1; + if (ubi->thread_enabled) + wake_up_process(ubi->bgt_thread); + spin_unlock(&ubi->wl_lock); +} + +static int erase_worker(struct ubi_device *ubi, struct ubi_work *wl_wrk, + int cancel); + +/** + * schedule_erase - schedule an erase work. + * @ubi: UBI device description object + * @e: the WL entry of the physical eraseblock to erase + * @torture: if the physical eraseblock has to be tortured + * + * This function returns zero in case of success and a %-ENOMEM in case of + * failure. + */ +static int schedule_erase(struct ubi_device *ubi, struct ubi_wl_entry *e, + int torture) +{ + struct ubi_work *wl_wrk; + + dbg_wl("schedule erasure of PEB %d, EC %d, torture %d", + e->pnum, e->ec, torture); + + wl_wrk = kmalloc(sizeof(struct ubi_work), GFP_KERNEL); + if (!wl_wrk) + return -ENOMEM; + + wl_wrk->func = &erase_worker; + wl_wrk->e = e; + wl_wrk->torture = torture; + + schedule_ubi_work(ubi, wl_wrk); + return 0; +} + +/** + * wear_leveling_worker - wear-leveling worker function. + * @ubi: UBI device description object + * @wrk: the work object + * @cancel: non-zero if the worker has to free memory and exit + * + * This function copies a more worn out physical eraseblock to a less worn out + * one. Returns zero in case of success and a negative error code in case of + * failure. + */ +static int wear_leveling_worker(struct ubi_device *ubi, struct ubi_work *wrk, + int cancel) +{ + int err, put = 0; + struct ubi_wl_entry *e1, *e2; + struct ubi_vid_hdr *vid_hdr; + + kfree(wrk); + + if (cancel) + return 0; + + vid_hdr = ubi_zalloc_vid_hdr(ubi); + if (!vid_hdr) + return -ENOMEM; + + spin_lock(&ubi->wl_lock); + + /* + * Only one WL worker at a time is supported at this implementation, so + * make sure a PEB is not being moved already. + */ + if (ubi->move_to || tree_empty(&ubi->free) || + (tree_empty(&ubi->used) && tree_empty(&ubi->scrub))) { + /* + * Only one WL worker at a time is supported at this + * implementation, so if a LEB is already being moved, cancel. + * + * No free physical eraseblocks? Well, we cancel wear-leveling + * then. It will be triggered again when a free physical + * eraseblock appears. + * + * No used physical eraseblocks? They must be temporarily + * protected from being moved. They will be moved to the + * @ubi->used tree later and the wear-leveling will be + * triggered again. + */ + dbg_wl("cancel WL, a list is empty: free %d, used %d", + tree_empty(&ubi->free), tree_empty(&ubi->used)); + ubi->wl_scheduled = 0; + spin_unlock(&ubi->wl_lock); + ubi_free_vid_hdr(ubi, vid_hdr); + return 0; + } + + if (tree_empty(&ubi->scrub)) { + /* + * Now pick the least worn-out used physical eraseblock and a + * highly worn-out free physical eraseblock. If the erase + * counters differ much enough, start wear-leveling. + */ + e1 = rb_entry(rb_first(&ubi->used), struct ubi_wl_entry, rb); + e2 = find_wl_entry(&ubi->free, WL_FREE_MAX_DIFF); + + if (!(e2->ec - e1->ec >= UBI_WL_THRESHOLD)) { + dbg_wl("no WL needed: min used EC %d, max free EC %d", + e1->ec, e2->ec); + ubi->wl_scheduled = 0; + spin_unlock(&ubi->wl_lock); + ubi_free_vid_hdr(ubi, vid_hdr); + return 0; + } + used_tree_del(ubi, e1); + dbg_wl("move PEB %d EC %d to PEB %d EC %d", + e1->pnum, e1->ec, e2->pnum, e2->ec); + } else { + e1 = rb_entry(rb_first(&ubi->scrub), struct ubi_wl_entry, rb); + e2 = find_wl_entry(&ubi->free, WL_FREE_MAX_DIFF); + scrub_tree_del(ubi, e1); + dbg_wl("scrub PEB %d to PEB %d", e1->pnum, e2->pnum); + } + + free_tree_del(ubi, e2); + ubi_assert(!ubi->move_from && !ubi->move_to); + ubi_assert(!ubi->move_to_put && !ubi->move_from_put); + ubi->move_from = e1; + ubi->move_to = e2; + spin_unlock(&ubi->wl_lock); + + /* + * Now we are going to copy physical eraseblock @e1->pnum to @e2->pnum. + * We so far do not know which logical eraseblock our physical + * eraseblock (@e1) belongs to. We have to read the volume identifier + * header first. + */ + + err = ubi_io_read_vid_hdr(ubi, e1->pnum, vid_hdr, 0); + if (err && err != UBI_IO_BITFLIPS) { + if (err == UBI_IO_PEB_FREE) { + /* + * We are trying to move PEB without a VID header. UBI + * always write VID headers shortly after the PEB was + * given, so we have a situation when it did not have + * chance to write it down because it was preempted. + * Just re-schedule the work, so that next time it will + * likely have the VID header in place. + */ + dbg_wl("PEB %d has no VID header", e1->pnum); + err = 0; + } else { + ubi_err("error %d while reading VID header from PEB %d", + err, e1->pnum); + if (err > 0) + err = -EIO; + } + goto error; + } + + err = ubi_eba_copy_leb(ubi, e1->pnum, e2->pnum, vid_hdr); + if (err) { + if (err == UBI_IO_BITFLIPS) + err = 0; + goto error; + } + + ubi_free_vid_hdr(ubi, vid_hdr); + spin_lock(&ubi->wl_lock); + if (!ubi->move_to_put) + used_tree_add(ubi, e2); + else + put = 1; + ubi->move_from = ubi->move_to = NULL; + ubi->move_from_put = ubi->move_to_put = 0; + ubi->wl_scheduled = 0; + spin_unlock(&ubi->wl_lock); + + if (put) { + /* + * Well, the target PEB was put meanwhile, schedule it for + * erasure. + */ + dbg_wl("PEB %d was put meanwhile, erase", e2->pnum); + err = schedule_erase(ubi, e2, 0); + if (err) { + kmem_cache_free(wl_entries_slab, e2); + ubi_ro_mode(ubi); + } + } + + err = schedule_erase(ubi, e1, 0); + if (err) { + kmem_cache_free(wl_entries_slab, e1); + ubi_ro_mode(ubi); + } + + dbg_wl("done"); + return err; + + /* + * Some error occurred. @e1 was not changed, so return it back. @e2 + * might be changed, schedule it for erasure. + */ +error: + if (err) + dbg_wl("error %d occurred, cancel operation", err); + ubi_assert(err <= 0); + + ubi_free_vid_hdr(ubi, vid_hdr); + spin_lock(&ubi->wl_lock); + ubi->wl_scheduled = 0; + if (ubi->move_from_put) + put = 1; + else + used_tree_add(ubi, e1); + ubi->move_from = ubi->move_to = NULL; + ubi->move_from_put = ubi->move_to_put = 0; + spin_unlock(&ubi->wl_lock); + + if (put) { + /* + * Well, the target PEB was put meanwhile, schedule it for + * erasure. + */ + dbg_wl("PEB %d was put meanwhile, erase", e1->pnum); + err = schedule_erase(ubi, e1, 0); + if (err) { + kmem_cache_free(wl_entries_slab, e1); + ubi_ro_mode(ubi); + } + } + + err = schedule_erase(ubi, e2, 0); + if (err) { + kmem_cache_free(wl_entries_slab, e2); + ubi_ro_mode(ubi); + } + + yield(); + return err; +} + +/** + * ensure_wear_leveling - schedule wear-leveling if it is needed. + * @ubi: UBI device description object + * + * This function checks if it is time to start wear-leveling and schedules it + * if yes. This function returns zero in case of success and a negative error + * code in case of failure. + */ +static int ensure_wear_leveling(struct ubi_device *ubi) +{ + int err = 0; + struct ubi_wl_entry *e1; + struct ubi_wl_entry *e2; + struct ubi_work *wrk; + + spin_lock(&ubi->wl_lock); + if (ubi->wl_scheduled) + /* Wear-leveling is already in the work queue */ + goto out_unlock; + + /* + * If the ubi->scrub tree is not empty, scrubbing is needed, and the + * the WL worker has to be scheduled anyway. + */ + if (tree_empty(&ubi->scrub)) { + if (tree_empty(&ubi->used) || tree_empty(&ubi->free)) + /* No physical eraseblocks - no deal */ + goto out_unlock; + + /* + * We schedule wear-leveling only if the difference between the + * lowest erase counter of used physical eraseblocks and a high + * erase counter of free physical eraseblocks is greater then + * %UBI_WL_THRESHOLD. + */ + e1 = rb_entry(rb_first(&ubi->used), struct ubi_wl_entry, rb); + e2 = find_wl_entry(&ubi->free, WL_FREE_MAX_DIFF); + + if (!(e2->ec - e1->ec >= UBI_WL_THRESHOLD)) + goto out_unlock; + dbg_wl("schedule wear-leveling"); + } else + dbg_wl("schedule scrubbing"); + + ubi->wl_scheduled = 1; + spin_unlock(&ubi->wl_lock); + + wrk = kmalloc(sizeof(struct ubi_work), GFP_KERNEL); + if (!wrk) { + err = -ENOMEM; + goto out_cancel; + } + + wrk->func = &wear_leveling_worker; + schedule_ubi_work(ubi, wrk); + return err; + +out_cancel: + spin_lock(&ubi->wl_lock); + ubi->wl_scheduled = 0; +out_unlock: + spin_unlock(&ubi->wl_lock); + return err; +} + +/** + * erase_worker - physical eraseblock erase worker function. + * @ubi: UBI device description object + * @wl_wrk: the work object + * @cancel: non-zero if the worker has to free memory and exit + * + * This function erases a physical eraseblock and perform torture testing if + * needed. It also takes care about marking the physical eraseblock bad if + * needed. Returns zero in case of success and a negative error code in case of + * failure. + */ +static int erase_worker(struct ubi_device *ubi, struct ubi_work *wl_wrk, + int cancel) +{ + int err; + struct ubi_wl_entry *e = wl_wrk->e; + int pnum = e->pnum; + + if (cancel) { + dbg_wl("cancel erasure of PEB %d EC %d", pnum, e->ec); + kfree(wl_wrk); + kmem_cache_free(wl_entries_slab, e); + return 0; + } + + dbg_wl("erase PEB %d EC %d", pnum, e->ec); + + err = sync_erase(ubi, e, wl_wrk->torture); + if (!err) { + /* Fine, we've erased it successfully */ + kfree(wl_wrk); + + spin_lock(&ubi->wl_lock); + ubi->abs_ec += 1; + free_tree_add(ubi, e); + spin_unlock(&ubi->wl_lock); + + /* + * One more erase operation has happened, take care about protected + * physical eraseblocks. + */ + check_protection_over(ubi); + + /* And take care about wear-leveling */ + err = ensure_wear_leveling(ubi); + return err; + } + + kfree(wl_wrk); + kmem_cache_free(wl_entries_slab, e); + + if (err != -EIO) { + /* + * If this is not %-EIO, we have no idea what to do. Scheduling + * this physical eraseblock for erasure again would cause + * errors again and again. Well, lets switch to RO mode. + */ + ubi_ro_mode(ubi); + return err; + } + + /* It is %-EIO, the PEB went bad */ + + if (!ubi->bad_allowed) { + ubi_err("bad physical eraseblock %d detected", pnum); + ubi_ro_mode(ubi); + err = -EIO; + } else { + int need; + + spin_lock(&ubi->volumes_lock); + need = ubi->beb_rsvd_level - ubi->beb_rsvd_pebs + 1; + if (need > 0) { + need = ubi->avail_pebs >= need ? need : ubi->avail_pebs; + ubi->avail_pebs -= need; + ubi->rsvd_pebs += need; + ubi->beb_rsvd_pebs += need; + if (need > 0) + ubi_msg("reserve more %d PEBs", need); + } + + if (ubi->beb_rsvd_pebs == 0) { + spin_unlock(&ubi->volumes_lock); + ubi_err("no reserved physical eraseblocks"); + ubi_ro_mode(ubi); + return -EIO; + } + + spin_unlock(&ubi->volumes_lock); + ubi_msg("mark PEB %d as bad", pnum); + + err = ubi_io_mark_bad(ubi, pnum); + if (err) { + ubi_ro_mode(ubi); + return err; + } + + spin_lock(&ubi->volumes_lock); + ubi->beb_rsvd_pebs -= 1; + ubi->bad_peb_count += 1; + ubi->good_peb_count -= 1; + ubi_calculate_reserved(ubi); + if (ubi->beb_rsvd_pebs == 0) + ubi_warn("last PEB from the reserved pool was used"); + spin_unlock(&ubi->volumes_lock); + } + + return err; +} + +/** + * ubi_wl_put_peb - return a physical eraseblock to the wear-leveling + * unit. + * @ubi: UBI device description object + * @pnum: physical eraseblock to return + * @torture: if this physical eraseblock has to be tortured + * + * This function is called to return physical eraseblock @pnum to the pool of + * free physical eraseblocks. The @torture flag has to be set if an I/O error + * occurred to this @pnum and it has to be tested. This function returns zero + * in case of success and a negative error code in case of failure. + */ +int ubi_wl_put_peb(struct ubi_device *ubi, int pnum, int torture) +{ + int err; + struct ubi_wl_entry *e; + + dbg_wl("PEB %d", pnum); + ubi_assert(pnum >= 0); + ubi_assert(pnum < ubi->peb_count); + + spin_lock(&ubi->wl_lock); + + e = ubi->lookuptbl[pnum]; + if (e == ubi->move_from) { + /* + * User is putting the physical eraseblock which was selected to + * be moved. It will be scheduled for erasure in the + * wear-leveling worker. + */ + dbg_wl("PEB %d is being moved", pnum); + ubi_assert(!ubi->move_from_put); + ubi->move_from_put = 1; + spin_unlock(&ubi->wl_lock); + return 0; + } else if (e == ubi->move_to) { + /* + * User is putting the physical eraseblock which was selected + * as the target the data is moved to. It may happen if the EBA + * unit already re-mapped the LEB but the WL unit did has not + * put the PEB to the "used" tree. + */ + dbg_wl("PEB %d is the target of data moving", pnum); + ubi_assert(!ubi->move_to_put); + ubi->move_to_put = 1; + spin_unlock(&ubi->wl_lock); + return 0; + } else { + if (in_wl_tree(e, &ubi->used)) + used_tree_del(ubi, e); + else if (in_wl_tree(e, &ubi->scrub)) + scrub_tree_del(ubi, e); + else + prot_tree_del(ubi, e->pnum); + } + spin_unlock(&ubi->wl_lock); + + err = schedule_erase(ubi, e, torture); + if (err) { + spin_lock(&ubi->wl_lock); + used_tree_add(ubi, e); + spin_unlock(&ubi->wl_lock); + } + + return err; +} + +/** + * ubi_wl_scrub_peb - schedule a physical eraseblock for scrubbing. + * @ubi: UBI device description object + * @pnum: the physical eraseblock to schedule + * + * If a bit-flip in a physical eraseblock is detected, this physical eraseblock + * needs scrubbing. This function schedules a physical eraseblock for + * scrubbing which is done in background. This function returns zero in case of + * success and a negative error code in case of failure. + */ +int ubi_wl_scrub_peb(struct ubi_device *ubi, int pnum) +{ + struct ubi_wl_entry *e; + + ubi_msg("schedule PEB %d for scrubbing", pnum); + +retry: + spin_lock(&ubi->wl_lock); + e = ubi->lookuptbl[pnum]; + if (e == ubi->move_from || in_wl_tree(e, &ubi->scrub)) { + spin_unlock(&ubi->wl_lock); + return 0; + } + + if (e == ubi->move_to) { + /* + * This physical eraseblock was used to move data to. The data + * was moved but the PEB was not yet inserted to the proper + * tree. We should just wait a little and let the WL worker + * proceed. + */ + spin_unlock(&ubi->wl_lock); + dbg_wl("the PEB %d is not in proper tree, retry", pnum); + yield(); + goto retry; + } + + if (in_wl_tree(e, &ubi->used)) + used_tree_del(ubi, e); + else + prot_tree_del(ubi, pnum); + + scrub_tree_add(ubi, e); + spin_unlock(&ubi->wl_lock); + + /* + * Technically scrubbing is the same as wear-leveling, so it is done + * by the WL worker. + */ + return ensure_wear_leveling(ubi); +} + +/** + * ubi_wl_flush - flush all pending works. + * @ubi: UBI device description object + * + * This function returns zero in case of success and a negative error code in + * case of failure. + */ +int ubi_wl_flush(struct ubi_device *ubi) +{ + int err, pending_count; + + pending_count = ubi->works_count; + + dbg_wl("flush (%d pending works)", pending_count); + + /* + * Erase while the pending works queue is not empty, but not more then + * the number of currently pending works. + */ + while (pending_count-- > 0) { + err = do_work(ubi); + if (err) + return err; + } + + return 0; +} + +/** + * tree_destroy - destroy an RB-tree. + * @root: the root of the tree to destroy + */ +static void tree_destroy(struct rb_root *root) +{ + struct rb_node *rb; + struct ubi_wl_entry *e; + + rb = root->rb_node; + while (rb) { + if (rb->rb_left) + rb = rb->rb_left; + else if (rb->rb_right) + rb = rb->rb_right; + else { + e = rb_entry(rb, struct ubi_wl_entry, rb); + + rb = rb_parent(rb); + if (rb) { + if (rb->rb_left == &e->rb) + rb->rb_left = NULL; + else + rb->rb_right = NULL; + } + + kmem_cache_free(wl_entries_slab, e); + } + } +} + +/** + * ubi_thread - UBI background thread. + * @u: the UBI device description object pointer + */ +static int ubi_thread(void *u) +{ + int failures = 0; + struct ubi_device *ubi = u; + + ubi_msg("background thread \"%s\" started, PID %d", + ubi->bgt_name, current->pid); + + for (;;) { + int err; + + if (kthread_should_stop()) + goto out; + + if (try_to_freeze()) + continue; + + spin_lock(&ubi->wl_lock); + if (list_empty(&ubi->works) || ubi->ro_mode || + !ubi->thread_enabled) { + set_current_state(TASK_INTERRUPTIBLE); + spin_unlock(&ubi->wl_lock); + schedule(); + continue; + } + spin_unlock(&ubi->wl_lock); + + err = do_work(ubi); + if (err) { + ubi_err("%s: work failed with error code %d", + ubi->bgt_name, err); + if (failures++ > WL_MAX_FAILURES) { + /* + * Too many failures, disable the thread and + * switch to read-only mode. + */ + ubi_msg("%s: %d consecutive failures", + ubi->bgt_name, WL_MAX_FAILURES); + ubi_ro_mode(ubi); + break; + } + } else + failures = 0; + + cond_resched(); + } + +out: + dbg_wl("background thread \"%s\" is killed", ubi->bgt_name); + return 0; +} + +/** + * cancel_pending - cancel all pending works. + * @ubi: UBI device description object + */ +static void cancel_pending(struct ubi_device *ubi) +{ + while (!list_empty(&ubi->works)) { + struct ubi_work *wrk; + + wrk = list_entry(ubi->works.next, struct ubi_work, list); + list_del(&wrk->list); + wrk->func(ubi, wrk, 1); + ubi->works_count -= 1; + ubi_assert(ubi->works_count >= 0); + } +} + +/** + * ubi_wl_init_scan - initialize the wear-leveling unit using scanning + * information. + * @ubi: UBI device description object + * @si: scanning information + * + * This function returns zero in case of success, and a negative error code in + * case of failure. + */ +int ubi_wl_init_scan(struct ubi_device *ubi, struct ubi_scan_info *si) +{ + int err; + struct rb_node *rb1, *rb2; + struct ubi_scan_volume *sv; + struct ubi_scan_leb *seb, *tmp; + struct ubi_wl_entry *e; + + + ubi->used = ubi->free = ubi->scrub = RB_ROOT; + ubi->prot.pnum = ubi->prot.aec = RB_ROOT; + spin_lock_init(&ubi->wl_lock); + ubi->max_ec = si->max_ec; + INIT_LIST_HEAD(&ubi->works); + + sprintf(ubi->bgt_name, UBI_BGT_NAME_PATTERN, ubi->ubi_num); + + ubi->bgt_thread = kthread_create(ubi_thread, ubi, ubi->bgt_name); + if (IS_ERR(ubi->bgt_thread)) { + err = PTR_ERR(ubi->bgt_thread); + ubi_err("cannot spawn \"%s\", error %d", ubi->bgt_name, + err); + return err; + } + + if (ubi_devices_cnt == 0) { + wl_entries_slab = kmem_cache_create("ubi_wl_entry_slab", + sizeof(struct ubi_wl_entry), + 0, 0, NULL, NULL); + if (!wl_entries_slab) + return -ENOMEM; + } + + err = -ENOMEM; + ubi->lookuptbl = kzalloc(ubi->peb_count * sizeof(void *), GFP_KERNEL); + if (!ubi->lookuptbl) + goto out_free; + + list_for_each_entry_safe(seb, tmp, &si->erase, u.list) { + cond_resched(); + + e = kmem_cache_alloc(wl_entries_slab, GFP_KERNEL); + if (!e) + goto out_free; + + e->pnum = seb->pnum; + e->ec = seb->ec; + ubi->lookuptbl[e->pnum] = e; + if (schedule_erase(ubi, e, 0)) { + kmem_cache_free(wl_entries_slab, e); + goto out_free; + } + } + + list_for_each_entry(seb, &si->free, u.list) { + cond_resched(); + + e = kmem_cache_alloc(wl_entries_slab, GFP_KERNEL); + if (!e) + goto out_free; + + e->pnum = seb->pnum; + e->ec = seb->ec; + ubi_assert(e->ec >= 0); + free_tree_add(ubi, e); + ubi->lookuptbl[e->pnum] = e; + } + + list_for_each_entry(seb, &si->corr, u.list) { + cond_resched(); + + e = kmem_cache_alloc(wl_entries_slab, GFP_KERNEL); + if (!e) + goto out_free; + + e->pnum = seb->pnum; + e->ec = seb->ec; + ubi->lookuptbl[e->pnum] = e; + if (schedule_erase(ubi, e, 0)) { + kmem_cache_free(wl_entries_slab, e); + goto out_free; + } + } + + ubi_rb_for_each_entry(rb1, sv, &si->volumes, rb) { + ubi_rb_for_each_entry(rb2, seb, &sv->root, u.rb) { + cond_resched(); + + e = kmem_cache_alloc(wl_entries_slab, GFP_KERNEL); + if (!e) + goto out_free; + + e->pnum = seb->pnum; + e->ec = seb->ec; + ubi->lookuptbl[e->pnum] = e; + if (!seb->scrub) { + dbg_wl("add PEB %d EC %d to the used tree", + e->pnum, e->ec); + used_tree_add(ubi, e); + } else { + dbg_wl("add PEB %d EC %d to the scrub tree", + e->pnum, e->ec); + scrub_tree_add(ubi, e); + } + } + } + + if (WL_RESERVED_PEBS > ubi->avail_pebs) { + ubi_err("no enough physical eraseblocks (%d, need %d)", + ubi->avail_pebs, WL_RESERVED_PEBS); + goto out_free; + } + ubi->avail_pebs -= WL_RESERVED_PEBS; + ubi->rsvd_pebs += WL_RESERVED_PEBS; + + /* Schedule wear-leveling if needed */ + err = ensure_wear_leveling(ubi); + if (err) + goto out_free; + + return 0; + +out_free: + cancel_pending(ubi); + tree_destroy(&ubi->used); + tree_destroy(&ubi->free); + tree_destroy(&ubi->scrub); + kfree(ubi->lookuptbl); + if (ubi_devices_cnt == 0) + kmem_cache_destroy(wl_entries_slab); + return err; +} + +/** + * protection_trees_destroy - destroy the protection RB-trees. + * @ubi: UBI device description object + */ +static void protection_trees_destroy(struct ubi_device *ubi) +{ + struct rb_node *rb; + struct ubi_wl_prot_entry *pe; + + rb = ubi->prot.aec.rb_node; + while (rb) { + if (rb->rb_left) + rb = rb->rb_left; + else if (rb->rb_right) + rb = rb->rb_right; + else { + pe = rb_entry(rb, struct ubi_wl_prot_entry, rb_aec); + + rb = rb_parent(rb); + if (rb) { + if (rb->rb_left == &pe->rb_aec) + rb->rb_left = NULL; + else + rb->rb_right = NULL; + } + + kmem_cache_free(wl_entries_slab, pe->e); + kfree(pe); + } + } +} + +/** + * ubi_wl_close - close the wear-leveling unit. + * @ubi: UBI device description object + */ +void ubi_wl_close(struct ubi_device *ubi) +{ + dbg_wl("disable \"%s\"", ubi->bgt_name); + if (ubi->bgt_thread) + kthread_stop(ubi->bgt_thread); + + dbg_wl("close the UBI wear-leveling unit"); + + cancel_pending(ubi); + protection_trees_destroy(ubi); + tree_destroy(&ubi->used); + tree_destroy(&ubi->free); + tree_destroy(&ubi->scrub); + kfree(ubi->lookuptbl); + if (ubi_devices_cnt == 1) + kmem_cache_destroy(wl_entries_slab); +} + +#ifdef CONFIG_MTD_UBI_DEBUG_PARANOID + +/** + * paranoid_check_ec - make sure that the erase counter of a physical eraseblock + * is correct. + * @ubi: UBI device description object + * @pnum: the physical eraseblock number to check + * @ec: the erase counter to check + * + * This function returns zero if the erase counter of physical eraseblock @pnum + * is equivalent to @ec, %1 if not, and a negative error code if an error + * occurred. + */ +static int paranoid_check_ec(const struct ubi_device *ubi, int pnum, int ec) +{ + int err; + long long read_ec; + struct ubi_ec_hdr *ec_hdr; + + ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL); + if (!ec_hdr) + return -ENOMEM; + + err = ubi_io_read_ec_hdr(ubi, pnum, ec_hdr, 0); + if (err && err != UBI_IO_BITFLIPS) { + /* The header does not have to exist */ + err = 0; + goto out_free; + } + + read_ec = ubi64_to_cpu(ec_hdr->ec); + if (ec != read_ec) { + ubi_err("paranoid check failed for PEB %d", pnum); + ubi_err("read EC is %lld, should be %d", read_ec, ec); + ubi_dbg_dump_stack(); + err = 1; + } else + err = 0; + +out_free: + kfree(ec_hdr); + return err; +} + +/** + * paranoid_check_in_wl_tree - make sure that a wear-leveling entry is present + * in a WL RB-tree. + * @e: the wear-leveling entry to check + * @root: the root of the tree + * + * This function returns zero if @e is in the @root RB-tree and %1 if it + * is not. + */ +static int paranoid_check_in_wl_tree(struct ubi_wl_entry *e, + struct rb_root *root) +{ + if (in_wl_tree(e, root)) + return 0; + + ubi_err("paranoid check failed for PEB %d, EC %d, RB-tree %p ", + e->pnum, e->ec, root); + ubi_dbg_dump_stack(); + return 1; +} + +#endif /* CONFIG_MTD_UBI_DEBUG_PARANOID */ diff --git a/fs/jffs2/fs.c b/fs/jffs2/fs.c index abb90c0..8a649f6 100644 --- a/fs/jffs2/fs.c +++ b/fs/jffs2/fs.c @@ -672,6 +672,13 @@ static int jffs2_flash_setup(struct jffs2_sb_info *c) { return ret; } + /* and an UBI volume */ + if (jffs2_ubivol(c)) { + ret = jffs2_ubivol_setup(c); + if (ret) + return ret; + } + return ret; } @@ -690,4 +697,9 @@ void jffs2_flash_cleanup(struct jffs2_sb_info *c) { if (jffs2_nor_wbuf_flash(c)) { jffs2_nor_wbuf_flash_cleanup(c); } + + /* and an UBI volume */ + if (jffs2_ubivol(c)) { + jffs2_ubivol_cleanup(c); + } } diff --git a/fs/jffs2/os-linux.h b/fs/jffs2/os-linux.h index e07a0ed..8d92e45 100644 --- a/fs/jffs2/os-linux.h +++ b/fs/jffs2/os-linux.h @@ -98,6 +98,9 @@ static inline void jffs2_init_inode_info(struct jffs2_inode_info *f) #define jffs2_nor_wbuf_flash(c) (0) #define jffs2_nor_wbuf_flash_setup(c) (0) #define jffs2_nor_wbuf_flash_cleanup(c) do {} while (0) +#define jffs2_ubivol(c) (0) +#define jffs2_ubivol_setup(c) (0) +#define jffs2_ubivol_cleanup(c) do {} while (0) #else /* NAND and/or ECC'd NOR support present */ @@ -133,6 +136,9 @@ void jffs2_nand_flash_cleanup(struct jffs2_sb_info *c); #define jffs2_dataflash(c) (c->mtd->type == MTD_DATAFLASH) int jffs2_dataflash_setup(struct jffs2_sb_info *c); void jffs2_dataflash_cleanup(struct jffs2_sb_info *c); +#define jffs2_ubivol(c) (c->mtd->type == MTD_UBIVOLUME) +int jffs2_ubivol_setup(struct jffs2_sb_info *c); +void jffs2_ubivol_cleanup(struct jffs2_sb_info *c); #define jffs2_nor_wbuf_flash(c) (c->mtd->type == MTD_NORFLASH && ! (c->mtd->flags & MTD_BIT_WRITEABLE)) int jffs2_nor_wbuf_flash_setup(struct jffs2_sb_info *c); diff --git a/fs/jffs2/wbuf.c b/fs/jffs2/wbuf.c index 4fac6dd..ab86031 100644 --- a/fs/jffs2/wbuf.c +++ b/fs/jffs2/wbuf.c @@ -1208,3 +1208,27 @@ int jffs2_nor_wbuf_flash_setup(struct jffs2_sb_info *c) { void jffs2_nor_wbuf_flash_cleanup(struct jffs2_sb_info *c) { kfree(c->wbuf); } + +int jffs2_ubivol_setup(struct jffs2_sb_info *c) { + c->cleanmarker_size = 0; + + if (c->mtd->writesize == 1) + /* We do not need write-buffer */ + return 0; + + init_rwsem(&c->wbuf_sem); + + c->wbuf_pagesize = c->mtd->writesize; + c->wbuf_ofs = 0xFFFFFFFF; + c->wbuf = kmalloc(c->wbuf_pagesize, GFP_KERNEL); + if (!c->wbuf) + return -ENOMEM; + + printk(KERN_INFO "JFFS2 write-buffering enabled buffer (%d) erasesize (%d)\n", c->wbuf_pagesize, c->sector_size); + + return 0; +} + +void jffs2_ubivol_cleanup(struct jffs2_sb_info *c) { + kfree(c->wbuf); +} diff --git a/include/linux/mtd/ubi.h b/include/linux/mtd/ubi.h new file mode 100644 index 0000000..3d967b6 --- /dev/null +++ b/include/linux/mtd/ubi.h @@ -0,0 +1,202 @@ +/* + * Copyright (c) International Business Machines Corp., 2006 + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See + * the GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + * Author: Artem Bityutskiy (Битюцкий Артём) + */ + +#ifndef __LINUX_UBI_H__ +#define __LINUX_UBI_H__ + +#include <asm/ioctl.h> +#include <linux/types.h> +#include <mtd/ubi-user.h> + +/* + * UBI data type hint constants. + * + * UBI_LONGTERM: long-term data + * UBI_SHORTTERM: short-term data + * UBI_UNKNOWN: data persistence is unknown + * + * These constants are used when data is written to UBI volumes in order to + * help the UBI wear-leveling unit to find more appropriate physical + * eraseblocks. + */ +enum { + UBI_LONGTERM = 1, + UBI_SHORTTERM, + UBI_UNKNOWN +}; + +/* + * enum ubi_open_mode - UBI volume open mode constants. + * + * UBI_READONLY: read-only mode + * UBI_READWRITE: read-write mode + * UBI_EXCLUSIVE: exclusive mode + */ +enum { + UBI_READONLY = 1, + UBI_READWRITE, + UBI_EXCLUSIVE +}; + +/** + * struct ubi_volume_info - UBI volume description data structure. + * @vol_id: volume ID + * @ubi_num: UBI device number this volume belongs to + * @size: how many physical eraseblocks are reserved for this volume + * @used_bytes: how many bytes of data this volume contains + * @used_ebs: how many physical eraseblocks of this volume actually contain any + * data + * @vol_type: volume type (%UBI_DYNAMIC_VOLUME or %UBI_STATIC_VOLUME) + * @corrupted: non-zero if the volume is corrupted (static volumes only) + * @upd_marker: non-zero if the volume has update marker set + * @alignment: volume alignment + * @usable_leb_size: how many bytes are available in logical eraseblocks of + * this volume + * @name_len: volume name length + * @name: volume name + * @cdev: UBI volume character device major and minor numbers + * + * The @corrupted flag is only relevant to static volumes and is always zero + * for dynamic ones. This is because UBI does not care about dynamic volume + * data protection and only cares about protecting static volume data. + * + * The @upd_marker flag is set if the volume update operation was interrupted. + * Before touching the volume data during the update operation, UBI first sets + * the update marker flag for this volume. If the volume update operation was + * further interrupted, the update marker indicates this. If the update marker + * is set, the contents of the volume is certainly damaged and a new volume + * update operation has to be started. + * + * To put it differently, @corrupted and @upd_marker fields have different + * semantics: + * o the @corrupted flag means that this static volume is corrupted for some + * reasons, but not because an interrupted volume update + * o the @upd_marker field means that the volume is damaged because of an + * interrupted update operation. + * + * I.e., the @corrupted flag is never set if the @upd_marker flag is set. + * + * The @used_bytes and @used_ebs fields are only really needed for static + * volumes and contain the number of bytes stored in this static volume and how + * many eraseblock this data occupies. In case of dynamic volumes, the + * @used_bytes field is equivalent to @size*@usable_leb_size, and the @used_ebs + * field is equivalent to @size. + * + * In general, logical eraseblock size is a property of the UBI device, not + * of the UBI volume. Indeed, the logical eraseblock size depends on the + * physical eraseblock size and on how much bytes UBI headers consume. But + * because of the volume alignment (@alignment), the usable size of logical + * eraseblocks if a volume may be less. The following equation is true: + * @usable_leb_size = LEB size - (LEB size mod @alignment), + * where LEB size is the logical eraseblock size defined by the UBI device. + * + * The alignment is multiple to the minimal flash input/output unit size or %1 + * if all the available space is used. + * + * To put this differently, alignment may be considered is a way to change + * volume logical eraseblock sizes. + */ +struct ubi_volume_info { + int ubi_num; + int vol_id; + int size; + long long used_bytes; + int used_ebs; + int vol_type; + int corrupted; + int upd_marker; + int alignment; + int usable_leb_size; + int name_len; + const char *name; + dev_t cdev; +}; + +/** + * struct ubi_device_info - UBI device description data structure. + * @ubi_num: ubi device number + * @leb_size: logical eraseblock size on this UBI device + * @min_io_size: minimal I/O unit size + * @ro_mode: if this device is in read-only mode + * @cdev: UBI character device major and minor numbers + * + * Note, @leb_size is the logical eraseblock size offered by the UBI device. + * Volumes of this UBI device may have smaller logical eraseblock size if their + * alignment is not equivalent to %1. + */ +struct ubi_device_info { + int ubi_num; + int leb_size; + int min_io_size; + int ro_mode; + dev_t cdev; +}; + +/* UBI descriptor given to users when they open UBI volumes */ +struct ubi_volume_desc; + +int ubi_get_device_info(int ubi_num, struct ubi_device_info *di); +void ubi_get_volume_info(struct ubi_volume_desc *desc, + struct ubi_volume_info *vi); +struct ubi_volume_desc *ubi_open_volume(int ubi_num, int vol_id, int mode); +struct ubi_volume_desc *ubi_open_volume_nm(int ubi_num, const char *name, + int mode); +void ubi_close_volume(struct ubi_volume_desc *desc); +int ubi_leb_read(struct ubi_volume_desc *desc, int lnum, char *buf, int offset, + int len, int check); +int ubi_leb_write(struct ubi_volume_desc *desc, int lnum, const void *buf, + int offset, int len, int dtype); +int ubi_leb_change(struct ubi_volume_desc *desc, int lnum, const void *buf, + int len, int dtype); +int ubi_leb_erase(struct ubi_volume_desc *desc, int lnum); +int ubi_leb_unmap(struct ubi_volume_desc *desc, int lnum); +int ubi_is_mapped(struct ubi_volume_desc *desc, int lnum); + +/* + * This function is the same as the 'ubi_leb_read()' function, but it does not + * provide the checking capability. + */ +static inline int ubi_read(struct ubi_volume_desc *desc, int lnum, char *buf, + int offset, int len) +{ + return ubi_leb_read(desc, lnum, buf, offset, len, 0); +} + +/* + * This function is the same as the 'ubi_leb_write()' functions, but it does + * not have the data type argument. + */ +static inline int ubi_write(struct ubi_volume_desc *desc, int lnum, + const void *buf, int offset, int len) +{ + return ubi_leb_write(desc, lnum, buf, offset, len, UBI_UNKNOWN); +} + +/* + * This function is the same as the 'ubi_leb_change()' functions, but it does + * not have the data type argument. + */ +static inline int ubi_change(struct ubi_volume_desc *desc, int lnum, + const void *buf, int len) +{ + return ubi_leb_change(desc, lnum, buf, len, UBI_UNKNOWN); +} + +#endif /* !__LINUX_UBI_H__ */ diff --git a/include/mtd/Kbuild b/include/mtd/Kbuild index e0fe92b..4d46b3b 100644 --- a/include/mtd/Kbuild +++ b/include/mtd/Kbuild @@ -3,3 +3,5 @@ header-y += jffs2-user.h header-y += mtd-abi.h header-y += mtd-user.h header-y += nftl-user.h +header-y += ubi-header.h +header-y += ubi-user.h diff --git a/include/mtd/mtd-abi.h b/include/mtd/mtd-abi.h index 8e501a7..f71dac4 100644 --- a/include/mtd/mtd-abi.h +++ b/include/mtd/mtd-abi.h @@ -24,6 +24,7 @@ struct mtd_oob_buf { #define MTD_NORFLASH 3 #define MTD_NANDFLASH 4 #define MTD_DATAFLASH 6 +#define MTD_UBIVOLUME 7 #define MTD_WRITEABLE 0x400 /* Device is writeable */ #define MTD_BIT_WRITEABLE 0x800 /* Single bits can be flipped */ diff --git a/include/mtd/ubi-header.h b/include/mtd/ubi-header.h new file mode 100644 index 0000000..fa479c7 --- /dev/null +++ b/include/mtd/ubi-header.h @@ -0,0 +1,360 @@ +/* + * Copyright (c) International Business Machines Corp., 2006 + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See + * the GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + * Authors: Artem Bityutskiy (Битюцкий Артём) + * Thomas Gleixner + * Frank Haverkamp + * Oliver Lohmann + * Andreas Arnez + */ + +/* + * This file defines the layout of UBI headers and all the other UBI on-flash + * data structures. May be included by user-space. + */ + +#ifndef __UBI_HEADER_H__ +#define __UBI_HEADER_H__ + +#include <asm/byteorder.h> + +/* The version of UBI images supported by this implementation */ +#define UBI_VERSION 1 + +/* The highest erase counter value supported by this implementation */ +#define UBI_MAX_ERASECOUNTER 0x7FFFFFFF + +/* The initial CRC32 value used when calculating CRC checksums */ +#define UBI_CRC32_INIT 0xFFFFFFFFU + +/* Erase counter header magic number (ASCII "UBI#") */ +#define UBI_EC_HDR_MAGIC 0x55424923 +/* Volume identifier header magic number (ASCII "UBI!") */ +#define UBI_VID_HDR_MAGIC 0x55424921 + +/* + * Volume type constants used in the volume identifier header. + * + * @UBI_VID_DYNAMIC: dynamic volume + * @UBI_VID_STATIC: static volume + */ +enum { + UBI_VID_DYNAMIC = 1, + UBI_VID_STATIC = 2 +}; + +/* + * Compatibility constants used by internal volumes. + * + * @UBI_COMPAT_DELETE: delete this internal volume before anything is written + * to the flash + * @UBI_COMPAT_RO: attach this device in read-only mode + * @UBI_COMPAT_PRESERVE: preserve this internal volume - do not touch its + * physical eraseblocks, don't allow the wear-leveling unit to move them + * @UBI_COMPAT_REJECT: reject this UBI image + */ +enum { + UBI_COMPAT_DELETE = 1, + UBI_COMPAT_RO = 2, + UBI_COMPAT_PRESERVE = 4, + UBI_COMPAT_REJECT = 5 +}; + +/* + * ubi16_t/ubi32_t/ubi64_t - 16, 32, and 64-bit integers used in UBI on-flash + * data structures. + */ +typedef struct { + uint16_t int16; +} __attribute__ ((packed)) ubi16_t; + +typedef struct { + uint32_t int32; +} __attribute__ ((packed)) ubi32_t; + +typedef struct { + uint64_t int64; +} __attribute__ ((packed)) ubi64_t; + +/* + * In this implementation of UBI uses the big-endian format for on-flash + * integers. The below are the corresponding conversion macros. + */ +#define cpu_to_ubi16(x) ((ubi16_t){__cpu_to_be16(x)}) +#define ubi16_to_cpu(x) ((uint16_t)__be16_to_cpu((x).int16)) + +#define cpu_to_ubi32(x) ((ubi32_t){__cpu_to_be32(x)}) +#define ubi32_to_cpu(x) ((uint32_t)__be32_to_cpu((x).int32)) + +#define cpu_to_ubi64(x) ((ubi64_t){__cpu_to_be64(x)}) +#define ubi64_to_cpu(x) ((uint64_t)__be64_to_cpu((x).int64)) + +/* Sizes of UBI headers */ +#define UBI_EC_HDR_SIZE sizeof(struct ubi_ec_hdr) +#define UBI_VID_HDR_SIZE sizeof(struct ubi_vid_hdr) + +/* Sizes of UBI headers without the ending CRC */ +#define UBI_EC_HDR_SIZE_CRC (UBI_EC_HDR_SIZE - sizeof(ubi32_t)) +#define UBI_VID_HDR_SIZE_CRC (UBI_VID_HDR_SIZE - sizeof(ubi32_t)) + +/** + * struct ubi_ec_hdr - UBI erase counter header. + * @magic: erase counter header magic number (%UBI_EC_HDR_MAGIC) + * @version: version of UBI implementation which is supposed to accept this + * UBI image + * @padding1: reserved for future, zeroes + * @ec: the erase counter + * @vid_hdr_offset: where the VID header starts + * @data_offset: where the user data start + * @padding2: reserved for future, zeroes + * @hdr_crc: erase counter header CRC checksum + * + * The erase counter header takes 64 bytes and has a plenty of unused space for + * future usage. The unused fields are zeroed. The @version field is used to + * indicate the version of UBI implementation which is supposed to be able to + * work with this UBI image. If @version is greater then the current UBI + * version, the image is rejected. This may be useful in future if something + * is changed radically. This field is duplicated in the volume identifier + * header. + * + * The @vid_hdr_offset and @data_offset fields contain the offset of the the + * volume identifier header and user data, relative to the beginning of the + * physical eraseblock. These values have to be the same for all physical + * eraseblocks. + */ +struct ubi_ec_hdr { + ubi32_t magic; + uint8_t version; + uint8_t padding1[3]; + ubi64_t ec; /* Warning: the current limit is 31-bit anyway! */ + ubi32_t vid_hdr_offset; + ubi32_t data_offset; + uint8_t padding2[36]; + ubi32_t hdr_crc; +} __attribute__ ((packed)); + +/** + * struct ubi_vid_hdr - on-flash UBI volume identifier header. + * @magic: volume identifier header magic number (%UBI_VID_HDR_MAGIC) + * @version: UBI implementation version which is supposed to accept this UBI + * image (%UBI_VERSION) + * @vol_type: volume type (%UBI_VID_DYNAMIC or %UBI_VID_STATIC) + * @copy_flag: if this logical eraseblock was copied from another physical + * eraseblock (for wear-leveling reasons) + * @compat: compatibility of this volume (%0, %UBI_COMPAT_DELETE, + * %UBI_COMPAT_IGNORE, %UBI_COMPAT_PRESERVE, or %UBI_COMPAT_REJECT) + * @vol_id: ID of this volume + * @lnum: logical eraseblock number + * @leb_ver: version of this logical eraseblock (IMPORTANT: obsolete, to be + * removed, kept only for not breaking older UBI users) + * @data_size: how many bytes of data this logical eraseblock contains + * @used_ebs: total number of used logical eraseblocks in this volume + * @data_pad: how many bytes at the end of this physical eraseblock are not + * used + * @data_crc: CRC checksum of the data stored in this logical eraseblock + * @padding1: reserved for future, zeroes + * @sqnum: sequence number + * @padding2: reserved for future, zeroes + * @hdr_crc: volume identifier header CRC checksum + * + * The @sqnum is the value of the global sequence counter at the time when this + * VID header was created. The global sequence counter is incremented each time + * UBI writes a new VID header to the flash, i.e. when it maps a logical + * eraseblock to a new physical eraseblock. The global sequence counter is an + * unsigned 64-bit integer and we assume it never overflows. The @sqnum + * (sequence number) is used to distinguish between older and newer versions of + * logical eraseblocks. + * + * There are 2 situations when there may be more then one physical eraseblock + * corresponding to the same logical eraseblock, i.e., having the same @vol_id + * and @lnum values in the volume identifier header. Suppose we have a logical + * eraseblock L and it is mapped to the physical eraseblock P. + * + * 1. Because UBI may erase physical eraseblocks asynchronously, the following + * situation is possible: L is asynchronously erased, so P is scheduled for + * erasure, then L is written to,i.e. mapped to another physical eraseblock P1, + * so P1 is written to, then an unclean reboot happens. Result - there are 2 + * physical eraseblocks P and P1 corresponding to the same logical eraseblock + * L. But P1 has greater sequence number, so UBI picks P1 when it attaches the + * flash. + * + * 2. From time to time UBI moves logical eraseblocks to other physical + * eraseblocks for wear-leveling reasons. If, for example, UBI moves L from P + * to P1, and an unclean reboot happens before P is physically erased, there + * are two physical eraseblocks P and P1 corresponding to L and UBI has to + * select one of them when the flash is attached. The @sqnum field says which + * PEB is the original (obviously P will have lower @sqnum) and the copy. But + * it is not enough to select the physical eraseblock with the higher sequence + * number, because the unclean reboot could have happen in the middle of the + * copying process, so the data in P is corrupted. It is also not enough to + * just select the physical eraseblock with lower sequence number, because the + * data there may be old (consider a case if more data was added to P1 after + * the copying). Moreover, the unclean reboot may happen when the erasure of P + * was just started, so it result in unstable P, which is "mostly" OK, but + * still has unstable bits. + * + * UBI uses the @copy_flag field to indicate that this logical eraseblock is a + * copy. UBI also calculates data CRC when the data is moved and stores it at + * the @data_crc field of the copy (P1). So when UBI needs to pick one physical + * eraseblock of two (P or P1), the @copy_flag of the newer one (P1) is + * examined. If it is cleared, the situation* is simple and the newer one is + * picked. If it is set, the data CRC of the copy (P1) is examined. If the CRC + * checksum is correct, this physical eraseblock is selected (P1). Otherwise + * the older one (P) is selected. + * + * Note, there is an obsolete @leb_ver field which was used instead of @sqnum + * in the past. But it is not used anymore and we keep it in order to be able + * to deal with old UBI images. It will be removed at some point. + * + * There are 2 sorts of volumes in UBI: user volumes and internal volumes. + * Internal volumes are not seen from outside and are used for various internal + * UBI purposes. In this implementation there is only one internal volume - the + * layout volume. Internal volumes are the main mechanism of UBI extensions. + * For example, in future one may introduce a journal internal volume. Internal + * volumes have their own reserved range of IDs. + * + * The @compat field is only used for internal volumes and contains the "degree + * of their compatibility". It is always zero for user volumes. This field + * provides a mechanism to introduce UBI extensions and to be still compatible + * with older UBI binaries. For example, if someone introduced a journal in + * future, he would probably use %UBI_COMPAT_DELETE compatibility for the + * journal volume. And in this case, older UBI binaries, which know nothing + * about the journal volume, would just delete this volume and work perfectly + * fine. This is similar to what Ext2fs does when it is fed by an Ext3fs image + * - it just ignores the Ext3fs journal. + * + * The @data_crc field contains the CRC checksum of the contents of the logical + * eraseblock if this is a static volume. In case of dynamic volumes, it does + * not contain the CRC checksum as a rule. The only exception is when the + * data of the physical eraseblock was moved by the wear-leveling unit, then + * the wear-leveling unit calculates the data CRC and stores it in the + * @data_crc field. And of course, the @copy_flag is %in this case. + * + * The @data_size field is used only for static volumes because UBI has to know + * how many bytes of data are stored in this eraseblock. For dynamic volumes, + * this field usually contains zero. The only exception is when the data of the + * physical eraseblock was moved to another physical eraseblock for + * wear-leveling reasons. In this case, UBI calculates CRC checksum of the + * contents and uses both @data_crc and @data_size fields. In this case, the + * @data_size field contains data size. + * + * The @used_ebs field is used only for static volumes and indicates how many + * eraseblocks the data of the volume takes. For dynamic volumes this field is + * not used and always contains zero. + * + * The @data_pad is calculated when volumes are created using the alignment + * parameter. So, effectively, the @data_pad field reduces the size of logical + * eraseblocks of this volume. This is very handy when one uses block-oriented + * software (say, cramfs) on top of the UBI volume. + */ +struct ubi_vid_hdr { + ubi32_t magic; + uint8_t version; + uint8_t vol_type; + uint8_t copy_flag; + uint8_t compat; + ubi32_t vol_id; + ubi32_t lnum; + ubi32_t leb_ver; /* obsolete, to be removed, don't use */ + ubi32_t data_size; + ubi32_t used_ebs; + ubi32_t data_pad; + ubi32_t data_crc; + uint8_t padding1[4]; + ubi64_t sqnum; + uint8_t padding2[12]; + ubi32_t hdr_crc; +} __attribute__ ((packed)); + +/* Internal UBI volumes count */ +#define UBI_INT_VOL_COUNT 1 + +/* + * Starting ID of internal volumes. There is reserved room for 4096 internal + * volumes. + */ +#define UBI_INTERNAL_VOL_START (0x7FFFFFFF - 4096) + +/* The layout volume contains the volume table */ + +#define UBI_LAYOUT_VOL_ID UBI_INTERNAL_VOL_START +#define UBI_LAYOUT_VOLUME_EBS 2 +#define UBI_LAYOUT_VOLUME_NAME "layout volume" +#define UBI_LAYOUT_VOLUME_COMPAT UBI_COMPAT_REJECT + +/* The maximum number of volumes per one UBI device */ +#define UBI_MAX_VOLUMES 128 + +/* The maximum volume name length */ +#define UBI_VOL_NAME_MAX 127 + +/* Size of the volume table record */ +#define UBI_VTBL_RECORD_SIZE sizeof(struct ubi_vtbl_record) + +/* Size of the volume table record without the ending CRC */ +#define UBI_VTBL_RECORD_SIZE_CRC (UBI_VTBL_RECORD_SIZE - sizeof(ubi32_t)) + +/** + * struct ubi_vtbl_record - a record in the volume table. + * @reserved_pebs: how many physical eraseblocks are reserved for this volume + * @alignment: volume alignment + * @data_pad: how many bytes are unused at the end of the each physical + * eraseblock to satisfy the requested alignment + * @vol_type: volume type (%UBI_DYNAMIC_VOLUME or %UBI_STATIC_VOLUME) + * @upd_marker: if volume update was started but not finished + * @name_len: volume name length + * @name: the volume name + * @padding2: reserved, zeroes + * @crc: a CRC32 checksum of the record + * + * The volume table records are stored in the volume table, which is stored in + * the layout volume. The layout volume consists of 2 logical eraseblock, each + * of which contains a copy of the volume table (i.e., the volume table is + * duplicated). The volume table is an array of &struct ubi_vtbl_record + * objects indexed by the volume ID. + * + * If the size of the logical eraseblock is large enough to fit + * %UBI_MAX_VOLUMES records, the volume table contains %UBI_MAX_VOLUMES + * records. Otherwise, it contains as many records as it can fit (i.e., size of + * logical eraseblock divided by sizeof(struct ubi_vtbl_record)). + * + * The @upd_marker flag is used to implement volume update. It is set to %1 + * before update and set to %0 after the update. So if the update operation was + * interrupted, UBI knows that the volume is corrupted. + * + * The @alignment field is specified when the volume is created and cannot be + * later changed. It may be useful, for example, when a block-oriented file + * system works on top of UBI. The @data_pad field is calculated using the + * logical eraseblock size and @alignment. The alignment must be multiple to the + * minimal flash I/O unit. If @alignment is 1, all the available space of + * the physical eraseblocks is used. + * + * Empty records contain all zeroes and the CRC checksum of those zeroes. + */ +struct ubi_vtbl_record { + ubi32_t reserved_pebs; + ubi32_t alignment; + ubi32_t data_pad; + uint8_t vol_type; + uint8_t upd_marker; + ubi16_t name_len; + uint8_t name[UBI_VOL_NAME_MAX+1]; + uint8_t padding2[24]; + ubi32_t crc; +} __attribute__ ((packed)); + +#endif /* !__UBI_HEADER_H__ */ diff --git a/include/mtd/ubi-user.h b/include/mtd/ubi-user.h new file mode 100644 index 0000000..fe06ded --- /dev/null +++ b/include/mtd/ubi-user.h @@ -0,0 +1,161 @@ +/* + * Copyright (c) International Business Machines Corp., 2006 + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See + * the GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + * Author: Artem Bityutskiy (Битюцкий Артём) + */ + +#ifndef __UBI_USER_H__ +#define __UBI_USER_H__ + +/* + * UBI volume creation + * ~~~~~~~~~~~~~~~~~~~ + * + * UBI volumes are created via the %UBI_IOCMKVOL IOCTL command of UBI character + * device. A &struct ubi_mkvol_req object has to be properly filled and a + * pointer to it has to be passed to the IOCTL. + * + * UBI volume deletion + * ~~~~~~~~~~~~~~~~~~~ + * + * To delete a volume, the %UBI_IOCRMVOL IOCTL command of the UBI character + * device should be used. A pointer to the 32-bit volume ID hast to be passed + * to the IOCTL. + * + * UBI volume re-size + * ~~~~~~~~~~~~~~~~~~ + * + * To re-size a volume, the %UBI_IOCRSVOL IOCTL command of the UBI character + * device should be used. A &struct ubi_rsvol_req object has to be properly + * filled and a pointer to it has to be passed to the IOCTL. + * + * UBI volume update + * ~~~~~~~~~~~~~~~~~ + * + * Volume update should be done via the %UBI_IOCVOLUP IOCTL command of the + * corresponding UBI volume character device. A pointer to a 64-bit update + * size should be passed to the IOCTL. After then, UBI expects user to write + * this number of bytes to the volume character device. The update is finished + * when the claimed number of bytes is passed. So, the volume update sequence + * is something like: + * + * fd = open("/dev/my_volume"); + * ioctl(fd, UBI_IOCVOLUP, &image_size); + * write(fd, buf, image_size); + * close(fd); + */ + +/* + * When a new volume is created, users may either specify the volume number they + * want to create or to let UBI automatically assign a volume number using this + * constant. + */ +#define UBI_VOL_NUM_AUTO (-1) + +/* Maximum volume name length */ +#define UBI_MAX_VOLUME_NAME 127 + +/* IOCTL commands of UBI character devices */ + +#define UBI_IOC_MAGIC 'o' + +/* Create an UBI volume */ +#define UBI_IOCMKVOL _IOW(UBI_IOC_MAGIC, 0, struct ubi_mkvol_req) +/* Remove an UBI volume */ +#define UBI_IOCRMVOL _IOW(UBI_IOC_MAGIC, 1, int32_t) +/* Re-size an UBI volume */ +#define UBI_IOCRSVOL _IOW(UBI_IOC_MAGIC, 2, struct ubi_rsvol_req) + +/* IOCTL commands of UBI volume character devices */ + +#define UBI_VOL_IOC_MAGIC 'O' + +/* Start UBI volume update */ +#define UBI_IOCVOLUP _IOW(UBI_VOL_IOC_MAGIC, 0, int64_t) +/* An eraseblock erasure command, used for debugging, disabled by default */ +#define UBI_IOCEBER _IOW(UBI_VOL_IOC_MAGIC, 1, int32_t) + +/* + * UBI volume type constants. + * + * @UBI_DYNAMIC_VOLUME: dynamic volume + * @UBI_STATIC_VOLUME: static volume + */ +enum { + UBI_DYNAMIC_VOLUME = 3, + UBI_STATIC_VOLUME = 4 +}; + +/** + * struct ubi_mkvol_req - volume description data structure used in + * volume creation requests. + * @vol_id: volume number + * @alignment: volume alignment + * @bytes: volume size in bytes + * @vol_type: volume type (%UBI_DYNAMIC_VOLUME or %UBI_STATIC_VOLUME) + * @padding1: reserved for future, not used + * @name_len: volume name length + * @padding2: reserved for future, not used + * @name: volume name + * + * This structure is used by userspace programs when creating new volumes. The + * @used_bytes field is only necessary when creating static volumes. + * + * The @alignment field specifies the required alignment of the volume logical + * eraseblock. This means, that the size of logical eraseblocks will be aligned + * to this number, i.e., + * (UBI device logical eraseblock size) mod (@alignment) = 0. + * + * To put it differently, the logical eraseblock of this volume may be slightly + * shortened in order to make it properly aligned. The alignment has to be + * multiple of the flash minimal input/output unit, or %1 to utilize the entire + * available space of logical eraseblocks. + * + * The @alignment field may be useful, for example, when one wants to maintain + * a block device on top of an UBI volume. In this case, it is desirable to fit + * an integer number of blocks in logical eraseblocks of this UBI volume. With + * alignment it is possible to update this volume using plane UBI volume image + * BLOBs, without caring about how to properly align them. + */ +struct ubi_mkvol_req { + int32_t vol_id; + int32_t alignment; + int64_t bytes; + int8_t vol_type; + int8_t padding1; + int16_t name_len; + int8_t padding2[4]; + char name[UBI_MAX_VOLUME_NAME+1]; +} __attribute__ ((packed)); + +/** + * struct ubi_rsvol_req - a data structure used in volume re-size requests. + * @vol_id: ID of the volume to re-size + * @bytes: new size of the volume in bytes + * + * Re-sizing is possible for both dynamic and static volumes. But while dynamic + * volumes may be re-sized arbitrarily, static volumes cannot be made to be + * smaller then the number of bytes they bear. To arbitrarily shrink a static + * volume, it must be wiped out first (by means of volume update operation with + * zero number of bytes). + */ +struct ubi_rsvol_req { + int64_t bytes; + int32_t vol_id; +} __attribute__ ((packed)); + +#endif /* __UBI_USER_H__ */ |
