diff options
Diffstat (limited to 'drivers/scsi/sd.c')
| -rw-r--r-- | drivers/scsi/sd.c | 1740 |
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); |
