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-rw-r--r--drivers/scsi/sd.c1740
1 files changed, 1740 insertions, 0 deletions
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
new file mode 100644
index 0000000..19afb25
--- /dev/null
+++ b/drivers/scsi/sd.c
@@ -0,0 +1,1740 @@
+/*
+ * sd.c Copyright (C) 1992 Drew Eckhardt
+ * Copyright (C) 1993, 1994, 1995, 1999 Eric Youngdale
+ *
+ * Linux scsi disk driver
+ * Initial versions: Drew Eckhardt
+ * Subsequent revisions: Eric Youngdale
+ * Modification history:
+ * - Drew Eckhardt <drew@colorado.edu> original
+ * - Eric Youngdale <eric@andante.org> add scatter-gather, multiple
+ * outstanding request, and other enhancements.
+ * Support loadable low-level scsi drivers.
+ * - Jirka Hanika <geo@ff.cuni.cz> support more scsi disks using
+ * eight major numbers.
+ * - Richard Gooch <rgooch@atnf.csiro.au> support devfs.
+ * - Torben Mathiasen <tmm@image.dk> Resource allocation fixes in
+ * sd_init and cleanups.
+ * - Alex Davis <letmein@erols.com> Fix problem where partition info
+ * not being read in sd_open. Fix problem where removable media
+ * could be ejected after sd_open.
+ * - Douglas Gilbert <dgilbert@interlog.com> cleanup for lk 2.5.x
+ * - Badari Pulavarty <pbadari@us.ibm.com>, Matthew Wilcox
+ * <willy@debian.org>, Kurt Garloff <garloff@suse.de>:
+ * Support 32k/1M disks.
+ *
+ * Logging policy (needs CONFIG_SCSI_LOGGING defined):
+ * - setting up transfer: SCSI_LOG_HLQUEUE levels 1 and 2
+ * - end of transfer (bh + scsi_lib): SCSI_LOG_HLCOMPLETE level 1
+ * - entering sd_ioctl: SCSI_LOG_IOCTL level 1
+ * - entering other commands: SCSI_LOG_HLQUEUE level 3
+ * Note: when the logging level is set by the user, it must be greater
+ * than the level indicated above to trigger output.
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/mm.h>
+#include <linux/bio.h>
+#include <linux/genhd.h>
+#include <linux/hdreg.h>
+#include <linux/errno.h>
+#include <linux/idr.h>
+#include <linux/interrupt.h>
+#include <linux/init.h>
+#include <linux/blkdev.h>
+#include <linux/blkpg.h>
+#include <linux/kref.h>
+#include <linux/delay.h>
+#include <asm/uaccess.h>
+
+#include <scsi/scsi.h>
+#include <scsi/scsi_cmnd.h>
+#include <scsi/scsi_dbg.h>
+#include <scsi/scsi_device.h>
+#include <scsi/scsi_driver.h>
+#include <scsi/scsi_eh.h>
+#include <scsi/scsi_host.h>
+#include <scsi/scsi_ioctl.h>
+#include <scsi/scsi_request.h>
+#include <scsi/scsicam.h>
+
+#include "scsi_logging.h"
+
+/*
+ * More than enough for everybody ;) The huge number of majors
+ * is a leftover from 16bit dev_t days, we don't really need that
+ * much numberspace.
+ */
+#define SD_MAJORS 16
+
+/*
+ * This is limited by the naming scheme enforced in sd_probe,
+ * add another character to it if you really need more disks.
+ */
+#define SD_MAX_DISKS (((26 * 26) + 26 + 1) * 26)
+
+/*
+ * Time out in seconds for disks and Magneto-opticals (which are slower).
+ */
+#define SD_TIMEOUT (30 * HZ)
+#define SD_MOD_TIMEOUT (75 * HZ)
+
+/*
+ * Number of allowed retries
+ */
+#define SD_MAX_RETRIES 5
+#define SD_PASSTHROUGH_RETRIES 1
+
+static void scsi_disk_release(struct kref *kref);
+
+struct scsi_disk {
+ struct scsi_driver *driver; /* always &sd_template */
+ struct scsi_device *device;
+ struct kref kref;
+ struct gendisk *disk;
+ unsigned int openers; /* protected by BKL for now, yuck */
+ sector_t capacity; /* size in 512-byte sectors */
+ u32 index;
+ u8 media_present;
+ u8 write_prot;
+ unsigned WCE : 1; /* state of disk WCE bit */
+ unsigned RCD : 1; /* state of disk RCD bit, unused */
+};
+
+static DEFINE_IDR(sd_index_idr);
+static DEFINE_SPINLOCK(sd_index_lock);
+
+/* This semaphore is used to mediate the 0->1 reference get in the
+ * face of object destruction (i.e. we can't allow a get on an
+ * object after last put) */
+static DECLARE_MUTEX(sd_ref_sem);
+
+static int sd_revalidate_disk(struct gendisk *disk);
+static void sd_rw_intr(struct scsi_cmnd * SCpnt);
+
+static int sd_probe(struct device *);
+static int sd_remove(struct device *);
+static void sd_shutdown(struct device *dev);
+static void sd_rescan(struct device *);
+static int sd_init_command(struct scsi_cmnd *);
+static int sd_issue_flush(struct device *, sector_t *);
+static void sd_end_flush(request_queue_t *, struct request *);
+static int sd_prepare_flush(request_queue_t *, struct request *);
+static void sd_read_capacity(struct scsi_disk *sdkp, char *diskname,
+ struct scsi_request *SRpnt, unsigned char *buffer);
+
+static struct scsi_driver sd_template = {
+ .owner = THIS_MODULE,
+ .gendrv = {
+ .name = "sd",
+ .probe = sd_probe,
+ .remove = sd_remove,
+ .shutdown = sd_shutdown,
+ },
+ .rescan = sd_rescan,
+ .init_command = sd_init_command,
+ .issue_flush = sd_issue_flush,
+ .prepare_flush = sd_prepare_flush,
+ .end_flush = sd_end_flush,
+};
+
+/*
+ * Device no to disk mapping:
+ *
+ * major disc2 disc p1
+ * |............|.............|....|....| <- dev_t
+ * 31 20 19 8 7 4 3 0
+ *
+ * Inside a major, we have 16k disks, however mapped non-
+ * contiguously. The first 16 disks are for major0, the next
+ * ones with major1, ... Disk 256 is for major0 again, disk 272
+ * for major1, ...
+ * As we stay compatible with our numbering scheme, we can reuse
+ * the well-know SCSI majors 8, 65--71, 136--143.
+ */
+static int sd_major(int major_idx)
+{
+ switch (major_idx) {
+ case 0:
+ return SCSI_DISK0_MAJOR;
+ case 1 ... 7:
+ return SCSI_DISK1_MAJOR + major_idx - 1;
+ case 8 ... 15:
+ return SCSI_DISK8_MAJOR + major_idx - 8;
+ default:
+ BUG();
+ return 0; /* shut up gcc */
+ }
+}
+
+#define to_scsi_disk(obj) container_of(obj,struct scsi_disk,kref)
+
+static inline struct scsi_disk *scsi_disk(struct gendisk *disk)
+{
+ return container_of(disk->private_data, struct scsi_disk, driver);
+}
+
+static struct scsi_disk *scsi_disk_get(struct gendisk *disk)
+{
+ struct scsi_disk *sdkp = NULL;
+
+ down(&sd_ref_sem);
+ if (disk->private_data == NULL)
+ goto out;
+ sdkp = scsi_disk(disk);
+ kref_get(&sdkp->kref);
+ if (scsi_device_get(sdkp->device))
+ goto out_put;
+ up(&sd_ref_sem);
+ return sdkp;
+
+ out_put:
+ kref_put(&sdkp->kref, scsi_disk_release);
+ sdkp = NULL;
+ out:
+ up(&sd_ref_sem);
+ return sdkp;
+}
+
+static void scsi_disk_put(struct scsi_disk *sdkp)
+{
+ struct scsi_device *sdev = sdkp->device;
+
+ down(&sd_ref_sem);
+ kref_put(&sdkp->kref, scsi_disk_release);
+ scsi_device_put(sdev);
+ up(&sd_ref_sem);
+}
+
+/**
+ * sd_init_command - build a scsi (read or write) command from
+ * information in the request structure.
+ * @SCpnt: pointer to mid-level's per scsi command structure that
+ * contains request and into which the scsi command is written
+ *
+ * Returns 1 if successful and 0 if error (or cannot be done now).
+ **/
+static int sd_init_command(struct scsi_cmnd * SCpnt)
+{
+ unsigned int this_count, timeout;
+ struct gendisk *disk;
+ sector_t block;
+ struct scsi_device *sdp = SCpnt->device;
+ struct request *rq = SCpnt->request;
+
+ timeout = sdp->timeout;
+
+ /*
+ * SG_IO from block layer already setup, just copy cdb basically
+ */
+ if (blk_pc_request(rq)) {
+ if (sizeof(rq->cmd) > sizeof(SCpnt->cmnd))
+ return 0;
+
+ memcpy(SCpnt->cmnd, rq->cmd, sizeof(SCpnt->cmnd));
+ if (rq_data_dir(rq) == WRITE)
+ SCpnt->sc_data_direction = DMA_TO_DEVICE;
+ else if (rq->data_len)
+ SCpnt->sc_data_direction = DMA_FROM_DEVICE;
+ else
+ SCpnt->sc_data_direction = DMA_NONE;
+
+ this_count = rq->data_len;
+ if (rq->timeout)
+ timeout = rq->timeout;
+
+ SCpnt->transfersize = rq->data_len;
+ SCpnt->allowed = SD_PASSTHROUGH_RETRIES;
+ goto queue;
+ }
+
+ /*
+ * we only do REQ_CMD and REQ_BLOCK_PC
+ */
+ if (!blk_fs_request(rq))
+ return 0;
+
+ disk = rq->rq_disk;
+ block = rq->sector;
+ this_count = SCpnt->request_bufflen >> 9;
+
+ SCSI_LOG_HLQUEUE(1, printk("sd_init_command: disk=%s, block=%llu, "
+ "count=%d\n", disk->disk_name,
+ (unsigned long long)block, this_count));
+
+ if (!sdp || !scsi_device_online(sdp) ||
+ block + rq->nr_sectors > get_capacity(disk)) {
+ SCSI_LOG_HLQUEUE(2, printk("Finishing %ld sectors\n",
+ rq->nr_sectors));
+ SCSI_LOG_HLQUEUE(2, printk("Retry with 0x%p\n", SCpnt));
+ return 0;
+ }
+
+ if (sdp->changed) {
+ /*
+ * quietly refuse to do anything to a changed disc until
+ * the changed bit has been reset
+ */
+ /* printk("SCSI disk has been changed. Prohibiting further I/O.\n"); */
+ return 0;
+ }
+ SCSI_LOG_HLQUEUE(2, printk("%s : block=%llu\n",
+ disk->disk_name, (unsigned long long)block));
+
+ /*
+ * If we have a 1K hardware sectorsize, prevent access to single
+ * 512 byte sectors. In theory we could handle this - in fact
+ * the scsi cdrom driver must be able to handle this because
+ * we typically use 1K blocksizes, and cdroms typically have
+ * 2K hardware sectorsizes. Of course, things are simpler
+ * with the cdrom, since it is read-only. For performance
+ * reasons, the filesystems should be able to handle this
+ * and not force the scsi disk driver to use bounce buffers
+ * for this.
+ */
+ if (sdp->sector_size == 1024) {
+ if ((block & 1) || (rq->nr_sectors & 1)) {
+ printk(KERN_ERR "sd: Bad block number requested");
+ return 0;
+ } else {
+ block = block >> 1;
+ this_count = this_count >> 1;
+ }
+ }
+ if (sdp->sector_size == 2048) {
+ if ((block & 3) || (rq->nr_sectors & 3)) {
+ printk(KERN_ERR "sd: Bad block number requested");
+ return 0;
+ } else {
+ block = block >> 2;
+ this_count = this_count >> 2;
+ }
+ }
+ if (sdp->sector_size == 4096) {
+ if ((block & 7) || (rq->nr_sectors & 7)) {
+ printk(KERN_ERR "sd: Bad block number requested");
+ return 0;
+ } else {
+ block = block >> 3;
+ this_count = this_count >> 3;
+ }
+ }
+ if (rq_data_dir(rq) == WRITE) {
+ if (!sdp->writeable) {
+ return 0;
+ }
+ SCpnt->cmnd[0] = WRITE_6;
+ SCpnt->sc_data_direction = DMA_TO_DEVICE;
+ } else if (rq_data_dir(rq) == READ) {
+ SCpnt->cmnd[0] = READ_6;
+ SCpnt->sc_data_direction = DMA_FROM_DEVICE;
+ } else {
+ printk(KERN_ERR "sd: Unknown command %lx\n", rq->flags);
+/* overkill panic("Unknown sd command %lx\n", rq->flags); */
+ return 0;
+ }
+
+ SCSI_LOG_HLQUEUE(2, printk("%s : %s %d/%ld 512 byte blocks.\n",
+ disk->disk_name, (rq_data_dir(rq) == WRITE) ?
+ "writing" : "reading", this_count, rq->nr_sectors));
+
+ SCpnt->cmnd[1] = 0;
+
+ if (block > 0xffffffff) {
+ SCpnt->cmnd[0] += READ_16 - READ_6;
+ SCpnt->cmnd[2] = sizeof(block) > 4 ? (unsigned char) (block >> 56) & 0xff : 0;
+ SCpnt->cmnd[3] = sizeof(block) > 4 ? (unsigned char) (block >> 48) & 0xff : 0;
+ SCpnt->cmnd[4] = sizeof(block) > 4 ? (unsigned char) (block >> 40) & 0xff : 0;
+ SCpnt->cmnd[5] = sizeof(block) > 4 ? (unsigned char) (block >> 32) & 0xff : 0;
+ SCpnt->cmnd[6] = (unsigned char) (block >> 24) & 0xff;
+ SCpnt->cmnd[7] = (unsigned char) (block >> 16) & 0xff;
+ SCpnt->cmnd[8] = (unsigned char) (block >> 8) & 0xff;
+ SCpnt->cmnd[9] = (unsigned char) block & 0xff;
+ SCpnt->cmnd[10] = (unsigned char) (this_count >> 24) & 0xff;
+ SCpnt->cmnd[11] = (unsigned char) (this_count >> 16) & 0xff;
+ SCpnt->cmnd[12] = (unsigned char) (this_count >> 8) & 0xff;
+ SCpnt->cmnd[13] = (unsigned char) this_count & 0xff;
+ SCpnt->cmnd[14] = SCpnt->cmnd[15] = 0;
+ } else if ((this_count > 0xff) || (block > 0x1fffff) ||
+ SCpnt->device->use_10_for_rw) {
+ if (this_count > 0xffff)
+ this_count = 0xffff;
+
+ SCpnt->cmnd[0] += READ_10 - READ_6;
+ SCpnt->cmnd[2] = (unsigned char) (block >> 24) & 0xff;
+ SCpnt->cmnd[3] = (unsigned char) (block >> 16) & 0xff;
+ SCpnt->cmnd[4] = (unsigned char) (block >> 8) & 0xff;
+ SCpnt->cmnd[5] = (unsigned char) block & 0xff;
+ SCpnt->cmnd[6] = SCpnt->cmnd[9] = 0;
+ SCpnt->cmnd[7] = (unsigned char) (this_count >> 8) & 0xff;
+ SCpnt->cmnd[8] = (unsigned char) this_count & 0xff;
+ } else {
+ if (this_count > 0xff)
+ this_count = 0xff;
+
+ SCpnt->cmnd[1] |= (unsigned char) ((block >> 16) & 0x1f);
+ SCpnt->cmnd[2] = (unsigned char) ((block >> 8) & 0xff);
+ SCpnt->cmnd[3] = (unsigned char) block & 0xff;
+ SCpnt->cmnd[4] = (unsigned char) this_count;
+ SCpnt->cmnd[5] = 0;
+ }
+ SCpnt->request_bufflen = SCpnt->bufflen =
+ this_count * sdp->sector_size;
+
+ /*
+ * We shouldn't disconnect in the middle of a sector, so with a dumb
+ * host adapter, it's safe to assume that we can at least transfer
+ * this many bytes between each connect / disconnect.
+ */
+ SCpnt->transfersize = sdp->sector_size;
+ SCpnt->underflow = this_count << 9;
+ SCpnt->allowed = SD_MAX_RETRIES;
+
+queue:
+ SCpnt->timeout_per_command = timeout;
+
+ /*
+ * This is the completion routine we use. This is matched in terms
+ * of capability to this function.
+ */
+ SCpnt->done = sd_rw_intr;
+
+ /*
+ * This indicates that the command is ready from our end to be
+ * queued.
+ */
+ return 1;
+}
+
+/**
+ * sd_open - open a scsi disk device
+ * @inode: only i_rdev member may be used
+ * @filp: only f_mode and f_flags may be used
+ *
+ * Returns 0 if successful. Returns a negated errno value in case
+ * of error.
+ *
+ * Note: This can be called from a user context (e.g. fsck(1) )
+ * or from within the kernel (e.g. as a result of a mount(1) ).
+ * In the latter case @inode and @filp carry an abridged amount
+ * of information as noted above.
+ **/
+static int sd_open(struct inode *inode, struct file *filp)
+{
+ struct gendisk *disk = inode->i_bdev->bd_disk;
+ struct scsi_disk *sdkp;
+ struct scsi_device *sdev;
+ int retval;
+
+ if (!(sdkp = scsi_disk_get(disk)))
+ return -ENXIO;
+
+
+ SCSI_LOG_HLQUEUE(3, printk("sd_open: disk=%s\n", disk->disk_name));
+
+ sdev = sdkp->device;
+
+ /*
+ * If the device is in error recovery, wait until it is done.
+ * If the device is offline, then disallow any access to it.
+ */
+ retval = -ENXIO;
+ if (!scsi_block_when_processing_errors(sdev))
+ goto error_out;
+
+ if (sdev->removable || sdkp->write_prot)
+ check_disk_change(inode->i_bdev);
+
+ /*
+ * If the drive is empty, just let the open fail.
+ */
+ retval = -ENOMEDIUM;
+ if (sdev->removable && !sdkp->media_present &&
+ !(filp->f_flags & O_NDELAY))
+ goto error_out;
+
+ /*
+ * If the device has the write protect tab set, have the open fail
+ * if the user expects to be able to write to the thing.
+ */
+ retval = -EROFS;
+ if (sdkp->write_prot && (filp->f_mode & FMODE_WRITE))
+ goto error_out;
+
+ /*
+ * It is possible that the disk changing stuff resulted in
+ * the device being taken offline. If this is the case,
+ * report this to the user, and don't pretend that the
+ * open actually succeeded.
+ */
+ retval = -ENXIO;
+ if (!scsi_device_online(sdev))
+ goto error_out;
+
+ if (!sdkp->openers++ && sdev->removable) {
+ if (scsi_block_when_processing_errors(sdev))
+ scsi_set_medium_removal(sdev, SCSI_REMOVAL_PREVENT);
+ }
+
+ return 0;
+
+error_out:
+ scsi_disk_put(sdkp);
+ return retval;
+}
+
+/**
+ * sd_release - invoked when the (last) close(2) is called on this
+ * scsi disk.
+ * @inode: only i_rdev member may be used
+ * @filp: only f_mode and f_flags may be used
+ *
+ * Returns 0.
+ *
+ * Note: may block (uninterruptible) if error recovery is underway
+ * on this disk.
+ **/
+static int sd_release(struct inode *inode, struct file *filp)
+{
+ struct gendisk *disk = inode->i_bdev->bd_disk;
+ struct scsi_disk *sdkp = scsi_disk(disk);
+ struct scsi_device *sdev = sdkp->device;
+
+ SCSI_LOG_HLQUEUE(3, printk("sd_release: disk=%s\n", disk->disk_name));
+
+ if (!--sdkp->openers && sdev->removable) {
+ if (scsi_block_when_processing_errors(sdev))
+ scsi_set_medium_removal(sdev, SCSI_REMOVAL_ALLOW);
+ }
+
+ /*
+ * XXX and what if there are packets in flight and this close()
+ * XXX is followed by a "rmmod sd_mod"?
+ */
+ scsi_disk_put(sdkp);
+ return 0;
+}
+
+static int sd_hdio_getgeo(struct block_device *bdev, struct hd_geometry __user *loc)
+{
+ struct scsi_disk *sdkp = scsi_disk(bdev->bd_disk);
+ struct scsi_device *sdp = sdkp->device;
+ struct Scsi_Host *host = sdp->host;
+ int diskinfo[4];
+
+ /* default to most commonly used values */
+ diskinfo[0] = 0x40; /* 1 << 6 */
+ diskinfo[1] = 0x20; /* 1 << 5 */
+ diskinfo[2] = sdkp->capacity >> 11;
+
+ /* override with calculated, extended default, or driver values */
+ if (host->hostt->bios_param)
+ host->hostt->bios_param(sdp, bdev, sdkp->capacity, diskinfo);
+ else
+ scsicam_bios_param(bdev, sdkp->capacity, diskinfo);
+
+ if (put_user(diskinfo[0], &loc->heads))
+ return -EFAULT;
+ if (put_user(diskinfo[1], &loc->sectors))
+ return -EFAULT;
+ if (put_user(diskinfo[2], &loc->cylinders))
+ return -EFAULT;
+ if (put_user((unsigned)get_start_sect(bdev),
+ (unsigned long __user *)&loc->start))
+ return -EFAULT;
+ return 0;
+}
+
+/**
+ * sd_ioctl - process an ioctl
+ * @inode: only i_rdev/i_bdev members may be used
+ * @filp: only f_mode and f_flags may be used
+ * @cmd: ioctl command number
+ * @arg: this is third argument given to ioctl(2) system call.
+ * Often contains a pointer.
+ *
+ * Returns 0 if successful (some ioctls return postive numbers on
+ * success as well). Returns a negated errno value in case of error.
+ *
+ * Note: most ioctls are forward onto the block subsystem or further
+ * down in the scsi subsytem.
+ **/
+static int sd_ioctl(struct inode * inode, struct file * filp,
+ unsigned int cmd, unsigned long arg)
+{
+ struct block_device *bdev = inode->i_bdev;
+ struct gendisk *disk = bdev->bd_disk;
+ struct scsi_device *sdp = scsi_disk(disk)->device;
+ void __user *p = (void __user *)arg;
+ int error;
+
+ SCSI_LOG_IOCTL(1, printk("sd_ioctl: disk=%s, cmd=0x%x\n",
+ disk->disk_name, cmd));
+
+ /*
+ * If we are in the middle of error recovery, don't let anyone
+ * else try and use this device. Also, if error recovery fails, it
+ * may try and take the device offline, in which case all further
+ * access to the device is prohibited.
+ */
+ error = scsi_nonblockable_ioctl(sdp, cmd, p, filp);
+ if (!scsi_block_when_processing_errors(sdp) || !error)
+ return error;
+
+ if (cmd == HDIO_GETGEO) {
+ if (!arg)
+ return -EINVAL;
+ return sd_hdio_getgeo(bdev, p);
+ }
+
+ /*
+ * Send SCSI addressing ioctls directly to mid level, send other
+ * ioctls to block level and then onto mid level if they can't be
+ * resolved.
+ */
+ switch (cmd) {
+ case SCSI_IOCTL_GET_IDLUN:
+ case SCSI_IOCTL_GET_BUS_NUMBER:
+ return scsi_ioctl(sdp, cmd, p);
+ default:
+ error = scsi_cmd_ioctl(filp, disk, cmd, p);
+ if (error != -ENOTTY)
+ return error;
+ }
+ return scsi_ioctl(sdp, cmd, p);
+}
+
+static void set_media_not_present(struct scsi_disk *sdkp)
+{
+ sdkp->media_present = 0;
+ sdkp->capacity = 0;
+ sdkp->device->changed = 1;
+}
+
+/**
+ * sd_media_changed - check if our medium changed
+ * @disk: kernel device descriptor
+ *
+ * Returns 0 if not applicable or no change; 1 if change
+ *
+ * Note: this function is invoked from the block subsystem.
+ **/
+static int sd_media_changed(struct gendisk *disk)
+{
+ struct scsi_disk *sdkp = scsi_disk(disk);
+ struct scsi_device *sdp = sdkp->device;
+ int retval;
+
+ SCSI_LOG_HLQUEUE(3, printk("sd_media_changed: disk=%s\n",
+ disk->disk_name));
+
+ if (!sdp->removable)
+ return 0;
+
+ /*
+ * If the device is offline, don't send any commands - just pretend as
+ * if the command failed. If the device ever comes back online, we
+ * can deal with it then. It is only because of unrecoverable errors
+ * that we would ever take a device offline in the first place.
+ */
+ if (!scsi_device_online(sdp))
+ goto not_present;
+
+ /*
+ * Using TEST_UNIT_READY enables differentiation between drive with
+ * no cartridge loaded - NOT READY, drive with changed cartridge -
+ * UNIT ATTENTION, or with same cartridge - GOOD STATUS.
+ *
+ * Drives that auto spin down. eg iomega jaz 1G, will be started
+ * by sd_spinup_disk() from sd_revalidate_disk(), which happens whenever
+ * sd_revalidate() is called.
+ */
+ retval = -ENODEV;
+ if (scsi_block_when_processing_errors(sdp))
+ retval = scsi_test_unit_ready(sdp, SD_TIMEOUT, SD_MAX_RETRIES);
+
+ /*
+ * Unable to test, unit probably not ready. This usually
+ * means there is no disc in the drive. Mark as changed,
+ * and we will figure it out later once the drive is
+ * available again.
+ */
+ if (retval)
+ goto not_present;
+
+ /*
+ * For removable scsi disk we have to recognise the presence
+ * of a disk in the drive. This is kept in the struct scsi_disk
+ * struct and tested at open ! Daniel Roche (dan@lectra.fr)
+ */
+ sdkp->media_present = 1;
+
+ retval = sdp->changed;
+ sdp->changed = 0;
+
+ return retval;
+
+not_present:
+ set_media_not_present(sdkp);
+ return 1;
+}
+
+static int sd_sync_cache(struct scsi_device *sdp)
+{
+ struct scsi_request *sreq;
+ int retries, res;
+
+ if (!scsi_device_online(sdp))
+ return -ENODEV;
+
+ sreq = scsi_allocate_request(sdp, GFP_KERNEL);
+ if (!sreq) {
+ printk("FAILED\n No memory for request\n");
+ return -ENOMEM;
+ }
+
+ sreq->sr_data_direction = DMA_NONE;
+ for (retries = 3; retries > 0; --retries) {
+ unsigned char cmd[10] = { 0 };
+
+ cmd[0] = SYNCHRONIZE_CACHE;
+ /*
+ * Leave the rest of the command zero to indicate
+ * flush everything.
+ */
+ scsi_wait_req(sreq, cmd, NULL, 0, SD_TIMEOUT, SD_MAX_RETRIES);
+ if (sreq->sr_result == 0)
+ break;
+ }
+
+ res = sreq->sr_result;
+ if (res) {
+ printk(KERN_WARNING "FAILED\n status = %x, message = %02x, "
+ "host = %d, driver = %02x\n ",
+ status_byte(res), msg_byte(res),
+ host_byte(res), driver_byte(res));
+ if (driver_byte(res) & DRIVER_SENSE)
+ scsi_print_req_sense("sd", sreq);
+ }
+
+ scsi_release_request(sreq);
+ return res;
+}
+
+static int sd_issue_flush(struct device *dev, sector_t *error_sector)
+{
+ struct scsi_device *sdp = to_scsi_device(dev);
+ struct scsi_disk *sdkp = dev_get_drvdata(dev);
+
+ if (!sdkp)
+ return -ENODEV;
+
+ if (!sdkp->WCE)
+ return 0;
+
+ return sd_sync_cache(sdp);
+}
+
+static void sd_end_flush(request_queue_t *q, struct request *flush_rq)
+{
+ struct request *rq = flush_rq->end_io_data;
+ struct scsi_cmnd *cmd = rq->special;
+ unsigned int bytes = rq->hard_nr_sectors << 9;
+
+ if (!flush_rq->errors) {
+ spin_unlock(q->queue_lock);
+ scsi_io_completion(cmd, bytes, 0);
+ spin_lock(q->queue_lock);
+ } else if (blk_barrier_postflush(rq)) {
+ spin_unlock(q->queue_lock);
+ scsi_io_completion(cmd, 0, bytes);
+ spin_lock(q->queue_lock);
+ } else {
+ /*
+ * force journal abort of barriers
+ */
+ end_that_request_first(rq, -EOPNOTSUPP, rq->hard_nr_sectors);
+ end_that_request_last(rq);
+ }
+}
+
+static int sd_prepare_flush(request_queue_t *q, struct request *rq)
+{
+ struct scsi_device *sdev = q->queuedata;
+ struct scsi_disk *sdkp = dev_get_drvdata(&sdev->sdev_gendev);
+
+ if (sdkp->WCE) {
+ memset(rq->cmd, 0, sizeof(rq->cmd));
+ rq->flags |= REQ_BLOCK_PC | REQ_SOFTBARRIER;
+ rq->timeout = SD_TIMEOUT;
+ rq->cmd[0] = SYNCHRONIZE_CACHE;
+ return 1;
+ }
+
+ return 0;
+}
+
+static void sd_rescan(struct device *dev)
+{
+ struct scsi_disk *sdkp = dev_get_drvdata(dev);
+ sd_revalidate_disk(sdkp->disk);
+}
+
+
+#ifdef CONFIG_COMPAT
+/*
+ * This gets directly called from VFS. When the ioctl
+ * is not recognized we go back to the other translation paths.
+ */
+static long sd_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+ struct block_device *bdev = file->f_dentry->d_inode->i_bdev;
+ struct gendisk *disk = bdev->bd_disk;
+ struct scsi_device *sdev = scsi_disk(disk)->device;
+
+ /*
+ * If we are in the middle of error recovery, don't let anyone
+ * else try and use this device. Also, if error recovery fails, it
+ * may try and take the device offline, in which case all further
+ * access to the device is prohibited.
+ */
+ if (!scsi_block_when_processing_errors(sdev))
+ return -ENODEV;
+
+ if (sdev->host->hostt->compat_ioctl) {
+ int ret;
+
+ ret = sdev->host->hostt->compat_ioctl(sdev, cmd, (void __user *)arg);
+
+ return ret;
+ }
+
+ /*
+ * Let the static ioctl translation table take care of it.
+ */
+ return -ENOIOCTLCMD;
+}
+#endif
+
+static struct block_device_operations sd_fops = {
+ .owner = THIS_MODULE,
+ .open = sd_open,
+ .release = sd_release,
+ .ioctl = sd_ioctl,
+#ifdef CONFIG_COMPAT
+ .compat_ioctl = sd_compat_ioctl,
+#endif
+ .media_changed = sd_media_changed,
+ .revalidate_disk = sd_revalidate_disk,
+};
+
+/**
+ * sd_rw_intr - bottom half handler: called when the lower level
+ * driver has completed (successfully or otherwise) a scsi command.
+ * @SCpnt: mid-level's per command structure.
+ *
+ * Note: potentially run from within an ISR. Must not block.
+ **/
+static void sd_rw_intr(struct scsi_cmnd * SCpnt)
+{
+ int result = SCpnt->result;
+ int this_count = SCpnt->bufflen;
+ int good_bytes = (result == 0 ? this_count : 0);
+ sector_t block_sectors = 1;
+ u64 first_err_block;
+ sector_t error_sector;
+ struct scsi_sense_hdr sshdr;
+ int sense_valid = 0;
+ int sense_deferred = 0;
+ int info_valid;
+
+ if (result) {
+ sense_valid = scsi_command_normalize_sense(SCpnt, &sshdr);
+ if (sense_valid)
+ sense_deferred = scsi_sense_is_deferred(&sshdr);
+ }
+
+#ifdef CONFIG_SCSI_LOGGING
+ SCSI_LOG_HLCOMPLETE(1, printk("sd_rw_intr: %s: res=0x%x\n",
+ SCpnt->request->rq_disk->disk_name, result));
+ if (sense_valid) {
+ SCSI_LOG_HLCOMPLETE(1, printk("sd_rw_intr: sb[respc,sk,asc,"
+ "ascq]=%x,%x,%x,%x\n", sshdr.response_code,
+ sshdr.sense_key, sshdr.asc, sshdr.ascq));
+ }
+#endif
+ /*
+ Handle MEDIUM ERRORs that indicate partial success. Since this is a
+ relatively rare error condition, no care is taken to avoid
+ unnecessary additional work such as memcpy's that could be avoided.
+ */
+
+ /*
+ * If SG_IO from block layer then set good_bytes to stop retries;
+ * else if errors, check them, and if necessary prepare for
+ * (partial) retries.
+ */
+ if (blk_pc_request(SCpnt->request))
+ good_bytes = this_count;
+ else if (driver_byte(result) != 0 &&
+ sense_valid && !sense_deferred) {
+ switch (sshdr.sense_key) {
+ case MEDIUM_ERROR:
+ if (!blk_fs_request(SCpnt->request))
+ break;
+ info_valid = scsi_get_sense_info_fld(
+ SCpnt->sense_buffer, SCSI_SENSE_BUFFERSIZE,
+ &first_err_block);
+ /*
+ * May want to warn and skip if following cast results
+ * in actual truncation (if sector_t < 64 bits)
+ */
+ error_sector = (sector_t)first_err_block;
+ if (SCpnt->request->bio != NULL)
+ block_sectors = bio_sectors(SCpnt->request->bio);
+ switch (SCpnt->device->sector_size) {
+ case 1024:
+ error_sector <<= 1;
+ if (block_sectors < 2)
+ block_sectors = 2;
+ break;
+ case 2048:
+ error_sector <<= 2;
+ if (block_sectors < 4)
+ block_sectors = 4;
+ break;
+ case 4096:
+ error_sector <<=3;
+ if (block_sectors < 8)
+ block_sectors = 8;
+ break;
+ case 256:
+ error_sector >>= 1;
+ break;
+ default:
+ break;
+ }
+
+ error_sector &= ~(block_sectors - 1);
+ good_bytes = (error_sector - SCpnt->request->sector) << 9;
+ if (good_bytes < 0 || good_bytes >= this_count)
+ good_bytes = 0;
+ break;
+
+ case RECOVERED_ERROR: /* an error occurred, but it recovered */
+ case NO_SENSE: /* LLDD got sense data */
+ /*
+ * Inform the user, but make sure that it's not treated
+ * as a hard error.
+ */
+ scsi_print_sense("sd", SCpnt);
+ SCpnt->result = 0;
+ memset(SCpnt->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE);
+ good_bytes = this_count;
+ break;
+
+ case ILLEGAL_REQUEST:
+ if (SCpnt->device->use_10_for_rw &&
+ (SCpnt->cmnd[0] == READ_10 ||
+ SCpnt->cmnd[0] == WRITE_10))
+ SCpnt->device->use_10_for_rw = 0;
+ if (SCpnt->device->use_10_for_ms &&
+ (SCpnt->cmnd[0] == MODE_SENSE_10 ||
+ SCpnt->cmnd[0] == MODE_SELECT_10))
+ SCpnt->device->use_10_for_ms = 0;
+ break;
+
+ default:
+ break;
+ }
+ }
+ /*
+ * This calls the generic completion function, now that we know
+ * how many actual sectors finished, and how many sectors we need
+ * to say have failed.
+ */
+ scsi_io_completion(SCpnt, good_bytes, block_sectors << 9);
+}
+
+static int media_not_present(struct scsi_disk *sdkp, struct scsi_request *srp)
+{
+ struct scsi_sense_hdr sshdr;
+
+ if (!srp->sr_result)
+ return 0;
+ if (!(driver_byte(srp->sr_result) & DRIVER_SENSE))
+ return 0;
+ /* not invoked for commands that could return deferred errors */
+ if (scsi_request_normalize_sense(srp, &sshdr)) {
+ if (sshdr.sense_key != NOT_READY &&
+ sshdr.sense_key != UNIT_ATTENTION)
+ return 0;
+ if (sshdr.asc != 0x3A) /* medium not present */
+ return 0;
+ }
+ set_media_not_present(sdkp);
+ return 1;
+}
+
+/*
+ * spinup disk - called only in sd_revalidate_disk()
+ */
+static void
+sd_spinup_disk(struct scsi_disk *sdkp, char *diskname,
+ struct scsi_request *SRpnt, unsigned char *buffer) {
+ unsigned char cmd[10];
+ unsigned long spintime_value = 0;
+ int retries, spintime;
+ unsigned int the_result;
+ struct scsi_sense_hdr sshdr;
+ int sense_valid = 0;
+
+ spintime = 0;
+
+ /* Spin up drives, as required. Only do this at boot time */
+ /* Spinup needs to be done for module loads too. */
+ do {
+ retries = 0;
+
+ do {
+ cmd[0] = TEST_UNIT_READY;
+ memset((void *) &cmd[1], 0, 9);
+
+ SRpnt->sr_cmd_len = 0;
+ memset(SRpnt->sr_sense_buffer, 0,
+ SCSI_SENSE_BUFFERSIZE);
+ SRpnt->sr_data_direction = DMA_NONE;
+
+ scsi_wait_req (SRpnt, (void *) cmd, (void *) buffer,
+ 0/*512*/, SD_TIMEOUT, SD_MAX_RETRIES);
+
+ the_result = SRpnt->sr_result;
+ if (the_result)
+ sense_valid = scsi_request_normalize_sense(
+ SRpnt, &sshdr);
+ retries++;
+ } while (retries < 3 &&
+ (!scsi_status_is_good(the_result) ||
+ ((driver_byte(the_result) & DRIVER_SENSE) &&
+ sense_valid && sshdr.sense_key == UNIT_ATTENTION)));
+
+ /*
+ * If the drive has indicated to us that it doesn't have
+ * any media in it, don't bother with any of the rest of
+ * this crap.
+ */
+ if (media_not_present(sdkp, SRpnt))
+ return;
+
+ if ((driver_byte(the_result) & DRIVER_SENSE) == 0) {
+ /* no sense, TUR either succeeded or failed
+ * with a status error */
+ if(!spintime && !scsi_status_is_good(the_result))
+ printk(KERN_NOTICE "%s: Unit Not Ready, "
+ "error = 0x%x\n", diskname, the_result);
+ break;
+ }
+
+ /*
+ * The device does not want the automatic start to be issued.
+ */
+ if (sdkp->device->no_start_on_add) {
+ break;
+ }
+
+ /*
+ * If manual intervention is required, or this is an
+ * absent USB storage device, a spinup is meaningless.
+ */
+ if (sense_valid &&
+ sshdr.sense_key == NOT_READY &&
+ sshdr.asc == 4 && sshdr.ascq == 3) {
+ break; /* manual intervention required */
+
+ /*
+ * Issue command to spin up drive when not ready
+ */
+ } else if (sense_valid && sshdr.sense_key == NOT_READY) {
+ if (!spintime) {
+ printk(KERN_NOTICE "%s: Spinning up disk...",
+ diskname);
+ cmd[0] = START_STOP;
+ cmd[1] = 1; /* Return immediately */
+ memset((void *) &cmd[2], 0, 8);
+ cmd[4] = 1; /* Start spin cycle */
+ SRpnt->sr_cmd_len = 0;
+ memset(SRpnt->sr_sense_buffer, 0,
+ SCSI_SENSE_BUFFERSIZE);
+
+ SRpnt->sr_data_direction = DMA_NONE;
+ scsi_wait_req(SRpnt, (void *)cmd,
+ (void *) buffer, 0/*512*/,
+ SD_TIMEOUT, SD_MAX_RETRIES);
+ spintime_value = jiffies;
+ }
+ spintime = 1;
+ /* Wait 1 second for next try */
+ msleep(1000);
+ printk(".");
+ } else {
+ /* we don't understand the sense code, so it's
+ * probably pointless to loop */
+ if(!spintime) {
+ printk(KERN_NOTICE "%s: Unit Not Ready, "
+ "sense:\n", diskname);
+ scsi_print_req_sense("", SRpnt);
+ }
+ break;
+ }
+
+ } while (spintime &&
+ time_after(spintime_value + 100 * HZ, jiffies));
+
+ if (spintime) {
+ if (scsi_status_is_good(the_result))
+ printk("ready\n");
+ else
+ printk("not responding...\n");
+ }
+}
+
+/*
+ * read disk capacity
+ */
+static void
+sd_read_capacity(struct scsi_disk *sdkp, char *diskname,
+ struct scsi_request *SRpnt, unsigned char *buffer) {
+ unsigned char cmd[16];
+ struct scsi_device *sdp = sdkp->device;
+ int the_result, retries;
+ int sector_size = 0;
+ int longrc = 0;
+ struct scsi_sense_hdr sshdr;
+ int sense_valid = 0;
+
+repeat:
+ retries = 3;
+ do {
+ if (longrc) {
+ memset((void *) cmd, 0, 16);
+ cmd[0] = SERVICE_ACTION_IN;
+ cmd[1] = SAI_READ_CAPACITY_16;
+ cmd[13] = 12;
+ memset((void *) buffer, 0, 12);
+ } else {
+ cmd[0] = READ_CAPACITY;
+ memset((void *) &cmd[1], 0, 9);
+ memset((void *) buffer, 0, 8);
+ }
+
+ SRpnt->sr_cmd_len = 0;
+ memset(SRpnt->sr_sense_buffer, 0, SCSI_SENSE_BUFFERSIZE);
+ SRpnt->sr_data_direction = DMA_FROM_DEVICE;
+
+ scsi_wait_req(SRpnt, (void *) cmd, (void *) buffer,
+ longrc ? 12 : 8, SD_TIMEOUT, SD_MAX_RETRIES);
+
+ if (media_not_present(sdkp, SRpnt))
+ return;
+
+ the_result = SRpnt->sr_result;
+ if (the_result)
+ sense_valid = scsi_request_normalize_sense(SRpnt,
+ &sshdr);
+ retries--;
+
+ } while (the_result && retries);
+
+ if (the_result && !longrc) {
+ printk(KERN_NOTICE "%s : READ CAPACITY failed.\n"
+ "%s : status=%x, message=%02x, host=%d, driver=%02x \n",
+ diskname, diskname,
+ status_byte(the_result),
+ msg_byte(the_result),
+ host_byte(the_result),
+ driver_byte(the_result));
+
+ if (driver_byte(the_result) & DRIVER_SENSE)
+ scsi_print_req_sense("sd", SRpnt);
+ else
+ printk("%s : sense not available. \n", diskname);
+
+ /* Set dirty bit for removable devices if not ready -
+ * sometimes drives will not report this properly. */
+ if (sdp->removable &&
+ sense_valid && sshdr.sense_key == NOT_READY)
+ sdp->changed = 1;
+
+ /* Either no media are present but the drive didn't tell us,
+ or they are present but the read capacity command fails */
+ /* sdkp->media_present = 0; -- not always correct */
+ sdkp->capacity = 0x200000; /* 1 GB - random */
+
+ return;
+ } else if (the_result && longrc) {
+ /* READ CAPACITY(16) has been failed */
+ printk(KERN_NOTICE "%s : READ CAPACITY(16) failed.\n"
+ "%s : status=%x, message=%02x, host=%d, driver=%02x \n",
+ diskname, diskname,
+ status_byte(the_result),
+ msg_byte(the_result),
+ host_byte(the_result),
+ driver_byte(the_result));
+ printk(KERN_NOTICE "%s : use 0xffffffff as device size\n",
+ diskname);
+
+ sdkp->capacity = 1 + (sector_t) 0xffffffff;
+ goto got_data;
+ }
+
+ if (!longrc) {
+ sector_size = (buffer[4] << 24) |
+ (buffer[5] << 16) | (buffer[6] << 8) | buffer[7];
+ if (buffer[0] == 0xff && buffer[1] == 0xff &&
+ buffer[2] == 0xff && buffer[3] == 0xff) {
+ if(sizeof(sdkp->capacity) > 4) {
+ printk(KERN_NOTICE "%s : very big device. try to use"
+ " READ CAPACITY(16).\n", diskname);
+ longrc = 1;
+ goto repeat;
+ }
+ printk(KERN_ERR "%s: too big for this kernel. Use a "
+ "kernel compiled with support for large block "
+ "devices.\n", diskname);
+ sdkp->capacity = 0;
+ goto got_data;
+ }
+ sdkp->capacity = 1 + (((sector_t)buffer[0] << 24) |
+ (buffer[1] << 16) |
+ (buffer[2] << 8) |
+ buffer[3]);
+ } else {
+ sdkp->capacity = 1 + (((u64)buffer[0] << 56) |
+ ((u64)buffer[1] << 48) |
+ ((u64)buffer[2] << 40) |
+ ((u64)buffer[3] << 32) |
+ ((sector_t)buffer[4] << 24) |
+ ((sector_t)buffer[5] << 16) |
+ ((sector_t)buffer[6] << 8) |
+ (sector_t)buffer[7]);
+
+ sector_size = (buffer[8] << 24) |
+ (buffer[9] << 16) | (buffer[10] << 8) | buffer[11];
+ }
+
+ /* Some devices return the total number of sectors, not the
+ * highest sector number. Make the necessary adjustment. */
+ if (sdp->fix_capacity)
+ --sdkp->capacity;
+
+got_data:
+ if (sector_size == 0) {
+ sector_size = 512;
+ printk(KERN_NOTICE "%s : sector size 0 reported, "
+ "assuming 512.\n", diskname);
+ }
+
+ if (sector_size != 512 &&
+ sector_size != 1024 &&
+ sector_size != 2048 &&
+ sector_size != 4096 &&
+ sector_size != 256) {
+ printk(KERN_NOTICE "%s : unsupported sector size "
+ "%d.\n", diskname, sector_size);
+ /*
+ * The user might want to re-format the drive with
+ * a supported sectorsize. Once this happens, it
+ * would be relatively trivial to set the thing up.
+ * For this reason, we leave the thing in the table.
+ */
+ sdkp->capacity = 0;
+ /*
+ * set a bogus sector size so the normal read/write
+ * logic in the block layer will eventually refuse any
+ * request on this device without tripping over power
+ * of two sector size assumptions
+ */
+ sector_size = 512;
+ }
+ {
+ /*
+ * The msdos fs needs to know the hardware sector size
+ * So I have created this table. See ll_rw_blk.c
+ * Jacques Gelinas (Jacques@solucorp.qc.ca)
+ */
+ int hard_sector = sector_size;
+ sector_t sz = sdkp->capacity * (hard_sector/256);
+ request_queue_t *queue = sdp->request_queue;
+ sector_t mb;
+
+ blk_queue_hardsect_size(queue, hard_sector);
+ /* avoid 64-bit division on 32-bit platforms */
+ mb = sz >> 1;
+ sector_div(sz, 1250);
+ mb -= sz - 974;
+ sector_div(mb, 1950);
+
+ printk(KERN_NOTICE "SCSI device %s: "
+ "%llu %d-byte hdwr sectors (%llu MB)\n",
+ diskname, (unsigned long long)sdkp->capacity,
+ hard_sector, (unsigned long long)mb);
+ }
+
+ /* Rescale capacity to 512-byte units */
+ if (sector_size == 4096)
+ sdkp->capacity <<= 3;
+ else if (sector_size == 2048)
+ sdkp->capacity <<= 2;
+ else if (sector_size == 1024)
+ sdkp->capacity <<= 1;
+ else if (sector_size == 256)
+ sdkp->capacity >>= 1;
+
+ sdkp->device->sector_size = sector_size;
+}
+
+/* called with buffer of length 512 */
+static inline int
+sd_do_mode_sense(struct scsi_request *SRpnt, int dbd, int modepage,
+ unsigned char *buffer, int len, struct scsi_mode_data *data)
+{
+ return __scsi_mode_sense(SRpnt, dbd, modepage, buffer, len,
+ SD_TIMEOUT, SD_MAX_RETRIES, data);
+}
+
+/*
+ * read write protect setting, if possible - called only in sd_revalidate_disk()
+ * called with buffer of length 512
+ */
+static void
+sd_read_write_protect_flag(struct scsi_disk *sdkp, char *diskname,
+ struct scsi_request *SRpnt, unsigned char *buffer) {
+ int res;
+ struct scsi_mode_data data;
+
+ set_disk_ro(sdkp->disk, 0);
+ if (sdkp->device->skip_ms_page_3f) {
+ printk(KERN_NOTICE "%s: assuming Write Enabled\n", diskname);
+ return;
+ }
+
+ if (sdkp->device->use_192_bytes_for_3f) {
+ res = sd_do_mode_sense(SRpnt, 0, 0x3F, buffer, 192, &data);
+ } else {
+ /*
+ * First attempt: ask for all pages (0x3F), but only 4 bytes.
+ * We have to start carefully: some devices hang if we ask
+ * for more than is available.
+ */
+ res = sd_do_mode_sense(SRpnt, 0, 0x3F, buffer, 4, &data);
+
+ /*
+ * Second attempt: ask for page 0 When only page 0 is
+ * implemented, a request for page 3F may return Sense Key
+ * 5: Illegal Request, Sense Code 24: Invalid field in
+ * CDB.
+ */
+ if (!scsi_status_is_good(res))
+ res = sd_do_mode_sense(SRpnt, 0, 0, buffer, 4, &data);
+
+ /*
+ * Third attempt: ask 255 bytes, as we did earlier.
+ */
+ if (!scsi_status_is_good(res))
+ res = sd_do_mode_sense(SRpnt, 0, 0x3F, buffer, 255,
+ &data);
+ }
+
+ if (!scsi_status_is_good(res)) {
+ printk(KERN_WARNING
+ "%s: test WP failed, assume Write Enabled\n", diskname);
+ } else {
+ sdkp->write_prot = ((data.device_specific & 0x80) != 0);
+ set_disk_ro(sdkp->disk, sdkp->write_prot);
+ printk(KERN_NOTICE "%s: Write Protect is %s\n", diskname,
+ sdkp->write_prot ? "on" : "off");
+ printk(KERN_DEBUG "%s: Mode Sense: %02x %02x %02x %02x\n",
+ diskname, buffer[0], buffer[1], buffer[2], buffer[3]);
+ }
+}
+
+/*
+ * sd_read_cache_type - called only from sd_revalidate_disk()
+ * called with buffer of length 512
+ */
+static void
+sd_read_cache_type(struct scsi_disk *sdkp, char *diskname,
+ struct scsi_request *SRpnt, unsigned char *buffer) {
+ int len = 0, res;
+
+ const int dbd = 0; /* DBD */
+ const int modepage = 0x08; /* current values, cache page */
+ struct scsi_mode_data data;
+ struct scsi_sense_hdr sshdr;
+
+ if (sdkp->device->skip_ms_page_8)
+ goto defaults;
+
+ /* cautiously ask */
+ res = sd_do_mode_sense(SRpnt, dbd, modepage, buffer, 4, &data);
+
+ if (!scsi_status_is_good(res))
+ goto bad_sense;
+
+ /* that went OK, now ask for the proper length */
+ len = data.length;
+
+ /*
+ * We're only interested in the first three bytes, actually.
+ * But the data cache page is defined for the first 20.
+ */
+ if (len < 3)
+ goto bad_sense;
+ if (len > 20)
+ len = 20;
+
+ /* Take headers and block descriptors into account */
+ len += data.header_length + data.block_descriptor_length;
+
+ /* Get the data */
+ res = sd_do_mode_sense(SRpnt, dbd, modepage, buffer, len, &data);
+
+ if (scsi_status_is_good(res)) {
+ const char *types[] = {
+ "write through", "none", "write back",
+ "write back, no read (daft)"
+ };
+ int ct = 0;
+ int offset = data.header_length +
+ data.block_descriptor_length + 2;
+
+ sdkp->WCE = ((buffer[offset] & 0x04) != 0);
+ sdkp->RCD = ((buffer[offset] & 0x01) != 0);
+
+ ct = sdkp->RCD + 2*sdkp->WCE;
+
+ printk(KERN_NOTICE "SCSI device %s: drive cache: %s\n",
+ diskname, types[ct]);
+
+ return;
+ }
+
+bad_sense:
+ if (scsi_request_normalize_sense(SRpnt, &sshdr) &&
+ sshdr.sense_key == ILLEGAL_REQUEST &&
+ sshdr.asc == 0x24 && sshdr.ascq == 0x0)
+ printk(KERN_NOTICE "%s: cache data unavailable\n",
+ diskname); /* Invalid field in CDB */
+ else
+ printk(KERN_ERR "%s: asking for cache data failed\n",
+ diskname);
+
+defaults:
+ printk(KERN_ERR "%s: assuming drive cache: write through\n",
+ diskname);
+ sdkp->WCE = 0;
+ sdkp->RCD = 0;
+}
+
+/**
+ * sd_revalidate_disk - called the first time a new disk is seen,
+ * performs disk spin up, read_capacity, etc.
+ * @disk: struct gendisk we care about
+ **/
+static int sd_revalidate_disk(struct gendisk *disk)
+{
+ struct scsi_disk *sdkp = scsi_disk(disk);
+ struct scsi_device *sdp = sdkp->device;
+ struct scsi_request *sreq;
+ unsigned char *buffer;
+
+ SCSI_LOG_HLQUEUE(3, printk("sd_revalidate_disk: disk=%s\n", disk->disk_name));
+
+ /*
+ * If the device is offline, don't try and read capacity or any
+ * of the other niceties.
+ */
+ if (!scsi_device_online(sdp))
+ goto out;
+
+ sreq = scsi_allocate_request(sdp, GFP_KERNEL);
+ if (!sreq) {
+ printk(KERN_WARNING "(sd_revalidate_disk:) Request allocation "
+ "failure.\n");
+ goto out;
+ }
+
+ buffer = kmalloc(512, GFP_KERNEL | __GFP_DMA);
+ if (!buffer) {
+ printk(KERN_WARNING "(sd_revalidate_disk:) Memory allocation "
+ "failure.\n");
+ goto out_release_request;
+ }
+
+ /* defaults, until the device tells us otherwise */
+ sdp->sector_size = 512;
+ sdkp->capacity = 0;
+ sdkp->media_present = 1;
+ sdkp->write_prot = 0;
+ sdkp->WCE = 0;
+ sdkp->RCD = 0;
+
+ sd_spinup_disk(sdkp, disk->disk_name, sreq, buffer);
+
+ /*
+ * Without media there is no reason to ask; moreover, some devices
+ * react badly if we do.
+ */
+ if (sdkp->media_present) {
+ sd_read_capacity(sdkp, disk->disk_name, sreq, buffer);
+ if (sdp->removable)
+ sd_read_write_protect_flag(sdkp, disk->disk_name,
+ sreq, buffer);
+ sd_read_cache_type(sdkp, disk->disk_name, sreq, buffer);
+ }
+
+ set_capacity(disk, sdkp->capacity);
+ kfree(buffer);
+
+ out_release_request:
+ scsi_release_request(sreq);
+ out:
+ return 0;
+}
+
+/**
+ * sd_probe - called during driver initialization and whenever a
+ * new scsi device is attached to the system. It is called once
+ * for each scsi device (not just disks) present.
+ * @dev: pointer to device object
+ *
+ * Returns 0 if successful (or not interested in this scsi device
+ * (e.g. scanner)); 1 when there is an error.
+ *
+ * Note: this function is invoked from the scsi mid-level.
+ * This function sets up the mapping between a given
+ * <host,channel,id,lun> (found in sdp) and new device name
+ * (e.g. /dev/sda). More precisely it is the block device major
+ * and minor number that is chosen here.
+ *
+ * Assume sd_attach is not re-entrant (for time being)
+ * Also think about sd_attach() and sd_remove() running coincidentally.
+ **/
+static int sd_probe(struct device *dev)
+{
+ struct scsi_device *sdp = to_scsi_device(dev);
+ struct scsi_disk *sdkp;
+ struct gendisk *gd;
+ u32 index;
+ int error;
+
+ error = -ENODEV;
+ if ((sdp->type != TYPE_DISK) && (sdp->type != TYPE_MOD))
+ goto out;
+
+ SCSI_LOG_HLQUEUE(3, printk("sd_attach: scsi device: <%d,%d,%d,%d>\n",
+ sdp->host->host_no, sdp->channel, sdp->id, sdp->lun));
+
+ error = -ENOMEM;
+ sdkp = kmalloc(sizeof(*sdkp), GFP_KERNEL);
+ if (!sdkp)
+ goto out;
+
+ memset (sdkp, 0, sizeof(*sdkp));
+ kref_init(&sdkp->kref);
+
+ gd = alloc_disk(16);
+ if (!gd)
+ goto out_free;
+
+ if (!idr_pre_get(&sd_index_idr, GFP_KERNEL))
+ goto out_put;
+
+ spin_lock(&sd_index_lock);
+ error = idr_get_new(&sd_index_idr, NULL, &index);
+ spin_unlock(&sd_index_lock);
+
+ if (index >= SD_MAX_DISKS)
+ error = -EBUSY;
+ if (error)
+ goto out_put;
+
+ sdkp->device = sdp;
+ sdkp->driver = &sd_template;
+ sdkp->disk = gd;
+ sdkp->index = index;
+ sdkp->openers = 0;
+
+ if (!sdp->timeout) {
+ if (sdp->type == TYPE_DISK)
+ sdp->timeout = SD_TIMEOUT;
+ else
+ sdp->timeout = SD_MOD_TIMEOUT;
+ }
+
+ gd->major = sd_major((index & 0xf0) >> 4);
+ gd->first_minor = ((index & 0xf) << 4) | (index & 0xfff00);
+ gd->minors = 16;
+ gd->fops = &sd_fops;
+
+ if (index < 26) {
+ sprintf(gd->disk_name, "sd%c", 'a' + index % 26);
+ } else if (index < (26 + 1) * 26) {
+ sprintf(gd->disk_name, "sd%c%c",
+ 'a' + index / 26 - 1,'a' + index % 26);
+ } else {
+ const unsigned int m1 = (index / 26 - 1) / 26 - 1;
+ const unsigned int m2 = (index / 26 - 1) % 26;
+ const unsigned int m3 = index % 26;
+ sprintf(gd->disk_name, "sd%c%c%c",
+ 'a' + m1, 'a' + m2, 'a' + m3);
+ }
+
+ strcpy(gd->devfs_name, sdp->devfs_name);
+
+ gd->private_data = &sdkp->driver;
+
+ sd_revalidate_disk(gd);
+
+ gd->driverfs_dev = &sdp->sdev_gendev;
+ gd->flags = GENHD_FL_DRIVERFS;
+ if (sdp->removable)
+ gd->flags |= GENHD_FL_REMOVABLE;
+ gd->queue = sdkp->device->request_queue;
+
+ dev_set_drvdata(dev, sdkp);
+ add_disk(gd);
+
+ printk(KERN_NOTICE "Attached scsi %sdisk %s at scsi%d, channel %d, "
+ "id %d, lun %d\n", sdp->removable ? "removable " : "",
+ gd->disk_name, sdp->host->host_no, sdp->channel,
+ sdp->id, sdp->lun);
+
+ return 0;
+
+out_put:
+ put_disk(gd);
+out_free:
+ kfree(sdkp);
+out:
+ return error;
+}
+
+/**
+ * sd_remove - called whenever a scsi disk (previously recognized by
+ * sd_probe) is detached from the system. It is called (potentially
+ * multiple times) during sd module unload.
+ * @sdp: pointer to mid level scsi device object
+ *
+ * Note: this function is invoked from the scsi mid-level.
+ * This function potentially frees up a device name (e.g. /dev/sdc)
+ * that could be re-used by a subsequent sd_probe().
+ * This function is not called when the built-in sd driver is "exit-ed".
+ **/
+static int sd_remove(struct device *dev)
+{
+ struct scsi_disk *sdkp = dev_get_drvdata(dev);
+
+ del_gendisk(sdkp->disk);
+ sd_shutdown(dev);
+ down(&sd_ref_sem);
+ kref_put(&sdkp->kref, scsi_disk_release);
+ up(&sd_ref_sem);
+
+ return 0;
+}
+
+/**
+ * scsi_disk_release - Called to free the scsi_disk structure
+ * @kref: pointer to embedded kref
+ *
+ * sd_ref_sem must be held entering this routine. Because it is
+ * called on last put, you should always use the scsi_disk_get()
+ * scsi_disk_put() helpers which manipulate the semaphore directly
+ * and never do a direct kref_put().
+ **/
+static void scsi_disk_release(struct kref *kref)
+{
+ struct scsi_disk *sdkp = to_scsi_disk(kref);
+ struct gendisk *disk = sdkp->disk;
+
+ spin_lock(&sd_index_lock);
+ idr_remove(&sd_index_idr, sdkp->index);
+ spin_unlock(&sd_index_lock);
+
+ disk->private_data = NULL;
+
+ put_disk(disk);
+
+ kfree(sdkp);
+}
+
+/*
+ * Send a SYNCHRONIZE CACHE instruction down to the device through
+ * the normal SCSI command structure. Wait for the command to
+ * complete.
+ */
+static void sd_shutdown(struct device *dev)
+{
+ struct scsi_device *sdp = to_scsi_device(dev);
+ struct scsi_disk *sdkp = dev_get_drvdata(dev);
+
+ if (!sdkp)
+ return; /* this can happen */
+
+ if (!sdkp->WCE)
+ return;
+
+ printk(KERN_NOTICE "Synchronizing SCSI cache for disk %s: \n",
+ sdkp->disk->disk_name);
+ sd_sync_cache(sdp);
+}
+
+/**
+ * init_sd - entry point for this driver (both when built in or when
+ * a module).
+ *
+ * Note: this function registers this driver with the scsi mid-level.
+ **/
+static int __init init_sd(void)
+{
+ int majors = 0, i;
+
+ SCSI_LOG_HLQUEUE(3, printk("init_sd: sd driver entry point\n"));
+
+ for (i = 0; i < SD_MAJORS; i++)
+ if (register_blkdev(sd_major(i), "sd") == 0)
+ majors++;
+
+ if (!majors)
+ return -ENODEV;
+
+ return scsi_register_driver(&sd_template.gendrv);
+}
+
+/**
+ * exit_sd - exit point for this driver (when it is a module).
+ *
+ * Note: this function unregisters this driver from the scsi mid-level.
+ **/
+static void __exit exit_sd(void)
+{
+ int i;
+
+ SCSI_LOG_HLQUEUE(3, printk("exit_sd: exiting sd driver\n"));
+
+ scsi_unregister_driver(&sd_template.gendrv);
+ for (i = 0; i < SD_MAJORS; i++)
+ unregister_blkdev(sd_major(i), "sd");
+}
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Eric Youngdale");
+MODULE_DESCRIPTION("SCSI disk (sd) driver");
+
+module_init(init_sd);
+module_exit(exit_sd);
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