ClabureDB: Classified Bug-Reports Database

   /*
    *      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/module.h>
  #include <linux/fs.h>
  #include <linux/kernel.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/delay.h>
  #include <linux/mutex.h>
  #include <linux/string_helpers.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/scsicam.h>
  
  #include "sd.h"
  #include "scsi_logging.h"
  
  MODULE_AUTHOR("Eric Youngdale");
  MODULE_DESCRIPTION("SCSI disk (sd) driver");
  MODULE_LICENSE("GPL");
  
  MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK0_MAJOR);
  MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK1_MAJOR);
  MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK2_MAJOR);
  MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK3_MAJOR);
  MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK4_MAJOR);
  MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK5_MAJOR);
  MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK6_MAJOR);
  MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK7_MAJOR);
  MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK8_MAJOR);
  MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK9_MAJOR);
  MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK10_MAJOR);
  MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK11_MAJOR);
  MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK12_MAJOR);
  MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK13_MAJOR);
  MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK14_MAJOR);
  MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK15_MAJOR);
  MODULE_ALIAS_SCSI_DEVICE(TYPE_DISK);
  MODULE_ALIAS_SCSI_DEVICE(TYPE_MOD);
  MODULE_ALIAS_SCSI_DEVICE(TYPE_RBC);
  
  #if !defined(CONFIG_DEBUG_BLOCK_EXT_DEVT)
  #define SD_MINORS        16
  #else
  #define SD_MINORS        0
  #endif
  
  static int  sd_revalidate_disk(struct gendisk *);
  static int  sd_probe(struct device *);
  static int  sd_remove(struct device *);
  static void sd_shutdown(struct device *);
 static int sd_suspend(struct device *, pm_message_t state);
 static int sd_resume(struct device *);
 static void sd_rescan(struct device *);
 static int sd_done(struct scsi_cmnd *);
 static void sd_read_capacity(struct scsi_disk *sdkp, unsigned char *buffer);
 static void scsi_disk_release(struct device *cdev);
 static void sd_print_sense_hdr(struct scsi_disk *, struct scsi_sense_hdr *);
 static void sd_print_result(struct scsi_disk *, int);
 
 static DEFINE_IDA(sd_index_ida);
 
 /* 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 DEFINE_MUTEX(sd_ref_mutex);
 
 static const char *sd_cache_types[] = {
         "write through", "none", "write back",
         "write back, no read (daft)"
 };
 
 static ssize_t
 sd_store_cache_type(struct device *dev, struct device_attribute *attr,
                     const char *buf, size_t count)
 {
         int i, ct = -1, rcd, wce, sp;
         struct scsi_disk *sdkp = to_scsi_disk(dev);
         struct scsi_device *sdp = sdkp->device;
         char buffer[64];
         char *buffer_data;
         struct scsi_mode_data data;
         struct scsi_sense_hdr sshdr;
         int len;
 
         if (sdp->type != TYPE_DISK)
                 /* no cache control on RBC devices; theoretically they
                  * can do it, but there's probably so many exceptions
                  * it's not worth the risk */
                 return -EINVAL;
 
         for (i = 0; i < ARRAY_SIZE(sd_cache_types); i++) {
                 const int len = strlen(sd_cache_types[i]);
                 if (strncmp(sd_cache_types[i], buf, len) == 0 &&
                     buf[len] == '\n') {
                         ct = i;
                         break;
                 }
         }
         if (ct < 0)
                 return -EINVAL;
         rcd = ct & 0x01 ? 1 : 0;
         wce = ct & 0x02 ? 1 : 0;
         if (scsi_mode_sense(sdp, 0x08, 8, buffer, sizeof(buffer), SD_TIMEOUT,
                             SD_MAX_RETRIES, &data, NULL))
                 return -EINVAL;
         len = min_t(size_t, sizeof(buffer), data.length - data.header_length -
                   data.block_descriptor_length);
         buffer_data = buffer + data.header_length +
                 data.block_descriptor_length;
         buffer_data[2] &= ~0x05;
         buffer_data[2] |= wce << 2 | rcd;
         sp = buffer_data[0] & 0x80 ? 1 : 0;
 
         if (scsi_mode_select(sdp, 1, sp, 8, buffer_data, len, SD_TIMEOUT,
                              SD_MAX_RETRIES, &data, &sshdr)) {
                 if (scsi_sense_valid(&sshdr))
                         sd_print_sense_hdr(sdkp, &sshdr);
                 return -EINVAL;
         }
         revalidate_disk(sdkp->disk);
         return count;
 }
 
 static ssize_t
 sd_store_manage_start_stop(struct device *dev, struct device_attribute *attr,
                            const char *buf, size_t count)
 {
         struct scsi_disk *sdkp = to_scsi_disk(dev);
         struct scsi_device *sdp = sdkp->device;
 
         if (!capable(CAP_SYS_ADMIN))
                 return -EACCES;
 
         sdp->manage_start_stop = simple_strtoul(buf, NULL, 10);
 
         return count;
 }
 
 static ssize_t
 sd_store_allow_restart(struct device *dev, struct device_attribute *attr,
                        const char *buf, size_t count)
 {
         struct scsi_disk *sdkp = to_scsi_disk(dev);
         struct scsi_device *sdp = sdkp->device;
 
         if (!capable(CAP_SYS_ADMIN))
                 return -EACCES;
 
         if (sdp->type != TYPE_DISK)
                 return -EINVAL;
 
         sdp->allow_restart = simple_strtoul(buf, NULL, 10);
 
         return count;
 }
 
 static ssize_t
 sd_show_cache_type(struct device *dev, struct device_attribute *attr,
                    char *buf)
 {
         struct scsi_disk *sdkp = to_scsi_disk(dev);
         int ct = sdkp->RCD + 2*sdkp->WCE;
 
         return snprintf(buf, 40, "%s\n", sd_cache_types[ct]);
 }
 
 static ssize_t
 sd_show_fua(struct device *dev, struct device_attribute *attr, char *buf)
 {
         struct scsi_disk *sdkp = to_scsi_disk(dev);
 
         return snprintf(buf, 20, "%u\n", sdkp->DPOFUA);
 }
 
 static ssize_t
 sd_show_manage_start_stop(struct device *dev, struct device_attribute *attr,
                           char *buf)
 {
         struct scsi_disk *sdkp = to_scsi_disk(dev);
         struct scsi_device *sdp = sdkp->device;
 
         return snprintf(buf, 20, "%u\n", sdp->manage_start_stop);
 }
 
 static ssize_t
 sd_show_allow_restart(struct device *dev, struct device_attribute *attr,
                       char *buf)
 {
         struct scsi_disk *sdkp = to_scsi_disk(dev);
 
         return snprintf(buf, 40, "%d\n", sdkp->device->allow_restart);
 }
 
 static ssize_t
 sd_show_protection_type(struct device *dev, struct device_attribute *attr,
                         char *buf)
 {
         struct scsi_disk *sdkp = to_scsi_disk(dev);
 
         return snprintf(buf, 20, "%u\n", sdkp->protection_type);
 }
 
 static ssize_t
 sd_show_app_tag_own(struct device *dev, struct device_attribute *attr,
                     char *buf)
 {
         struct scsi_disk *sdkp = to_scsi_disk(dev);
 
         return snprintf(buf, 20, "%u\n", sdkp->ATO);
 }
 
 static struct device_attribute sd_disk_attrs[] = {
         __ATTR(cache_type, S_IRUGO|S_IWUSR, sd_show_cache_type,
                sd_store_cache_type),
         __ATTR(FUA, S_IRUGO, sd_show_fua, NULL),
         __ATTR(allow_restart, S_IRUGO|S_IWUSR, sd_show_allow_restart,
                sd_store_allow_restart),
         __ATTR(manage_start_stop, S_IRUGO|S_IWUSR, sd_show_manage_start_stop,
                sd_store_manage_start_stop),
         __ATTR(protection_type, S_IRUGO, sd_show_protection_type, NULL),
         __ATTR(app_tag_own, S_IRUGO, sd_show_app_tag_own, NULL),
         __ATTR_NULL,
 };
 
 static struct class sd_disk_class = {
         .name                = "scsi_disk",
         .owner                = THIS_MODULE,
         .dev_release        = scsi_disk_release,
         .dev_attrs        = sd_disk_attrs,
 };
 
 static struct scsi_driver sd_template = {
         .owner                        = THIS_MODULE,
         .gendrv = {
                 .name                = "sd",
                 .probe                = sd_probe,
                 .remove                = sd_remove,
                 .suspend        = sd_suspend,
                 .resume                = sd_resume,
                 .shutdown        = sd_shutdown,
         },
         .rescan                        = sd_rescan,
         .done                        = sd_done,
 };
 
 /*
  * 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 */
         }
 }
 
 static struct scsi_disk *__scsi_disk_get(struct gendisk *disk)
 {
         struct scsi_disk *sdkp = NULL;
 
         if (disk->private_data) {
                 sdkp = scsi_disk(disk);
                 if (scsi_device_get(sdkp->device) == 0)
                         get_device(&sdkp->dev);
                 else
                         sdkp = NULL;
         }
         return sdkp;
 }
 
 static struct scsi_disk *scsi_disk_get(struct gendisk *disk)
 {
         struct scsi_disk *sdkp;
 
         mutex_lock(&sd_ref_mutex);
         sdkp = __scsi_disk_get(disk);
         mutex_unlock(&sd_ref_mutex);
         return sdkp;
 }
 
 static struct scsi_disk *scsi_disk_get_from_dev(struct device *dev)
 {
         struct scsi_disk *sdkp;
 
         mutex_lock(&sd_ref_mutex);
         sdkp = dev_get_drvdata(dev);
         if (sdkp)
                 sdkp = __scsi_disk_get(sdkp->disk);
         mutex_unlock(&sd_ref_mutex);
         return sdkp;
 }
 
 static void scsi_disk_put(struct scsi_disk *sdkp)
 {
         struct scsi_device *sdev = sdkp->device;
 
         mutex_lock(&sd_ref_mutex);
         put_device(&sdkp->dev);
         scsi_device_put(sdev);
         mutex_unlock(&sd_ref_mutex);
 }
 
 /**
  *        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_prep_fn(struct request_queue *q, struct request *rq)
 {
         struct scsi_cmnd *SCpnt;
         struct scsi_device *sdp = q->queuedata;
         struct gendisk *disk = rq->rq_disk;
         struct scsi_disk *sdkp;
         sector_t block = rq->sector;
         sector_t threshold;
         unsigned int this_count = rq->nr_sectors;
         int ret, host_dif;
 
         if (rq->cmd_type == REQ_TYPE_BLOCK_PC) {
                 ret = scsi_setup_blk_pc_cmnd(sdp, rq);
                 goto out;
         } else if (rq->cmd_type != REQ_TYPE_FS) {
                 ret = BLKPREP_KILL;
                 goto out;
         }
         ret = scsi_setup_fs_cmnd(sdp, rq);
         if (ret != BLKPREP_OK)
                 goto out;
         SCpnt = rq->special;
         sdkp = scsi_disk(disk);
 
         /* from here on until we're complete, any goto out
          * is used for a killable error condition */
         ret = BLKPREP_KILL;
 
         SCSI_LOG_HLQUEUE(1, scmd_printk(KERN_INFO, SCpnt,
                                         "sd_init_command: block=%llu, "
                                         "count=%d\n",
                                         (unsigned long long)block,
                                         this_count));
 
         if (!sdp || !scsi_device_online(sdp) ||
              block + rq->nr_sectors > get_capacity(disk)) {
                 SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt,
                                                 "Finishing %ld sectors\n",
                                                 rq->nr_sectors));
                 SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt,
                                                 "Retry with 0x%p\n", SCpnt));
                 goto out;
         }
 
         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"); */
                 goto out;
         }
 
         /*
          * Some SD card readers can't handle multi-sector accesses which touch
          * the last one or two hardware sectors.  Split accesses as needed.
          */
         threshold = get_capacity(disk) - SD_LAST_BUGGY_SECTORS *
                 (sdp->sector_size / 512);
 
         if (unlikely(sdp->last_sector_bug && block + this_count > threshold)) {
                 if (block < threshold) {
                         /* Access up to the threshold but not beyond */
                         this_count = threshold - block;
                 } else {
                         /* Access only a single hardware sector */
                         this_count = sdp->sector_size / 512;
                 }
         }
 
         SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt, "block=%llu\n",
                                         (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)) {
                         scmd_printk(KERN_ERR, SCpnt,
                                     "Bad block number requested\n");
                         goto out;
                 } else {
                         block = block >> 1;
                         this_count = this_count >> 1;
                 }
         }
         if (sdp->sector_size == 2048) {
                 if ((block & 3) || (rq->nr_sectors & 3)) {
                         scmd_printk(KERN_ERR, SCpnt,
                                     "Bad block number requested\n");
                         goto out;
                 } else {
                         block = block >> 2;
                         this_count = this_count >> 2;
                 }
         }
         if (sdp->sector_size == 4096) {
                 if ((block & 7) || (rq->nr_sectors & 7)) {
                         scmd_printk(KERN_ERR, SCpnt,
                                     "Bad block number requested\n");
                         goto out;
                 } else {
                         block = block >> 3;
                         this_count = this_count >> 3;
                 }
         }
         if (rq_data_dir(rq) == WRITE) {
                 if (!sdp->writeable) {
                         goto out;
                 }
                 SCpnt->cmnd[0] = WRITE_6;
                 SCpnt->sc_data_direction = DMA_TO_DEVICE;
 
                 if (blk_integrity_rq(rq) &&
                     sd_dif_prepare(rq, block, sdp->sector_size) == -EIO)
                         goto out;
 
         } else if (rq_data_dir(rq) == READ) {
                 SCpnt->cmnd[0] = READ_6;
                 SCpnt->sc_data_direction = DMA_FROM_DEVICE;
         } else {
                 scmd_printk(KERN_ERR, SCpnt, "Unknown command %x\n", rq->cmd_flags);
                 goto out;
         }
 
         SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt,
                                         "%s %d/%ld 512 byte blocks.\n",
                                         (rq_data_dir(rq) == WRITE) ?
                                         "writing" : "reading", this_count,
                                         rq->nr_sectors));
 
         /* Set RDPROTECT/WRPROTECT if disk is formatted with DIF */
         host_dif = scsi_host_dif_capable(sdp->host, sdkp->protection_type);
         if (host_dif)
                 SCpnt->cmnd[1] = 1 << 5;
         else
                 SCpnt->cmnd[1] = 0;
 
         if (block > 0xffffffff) {
                 SCpnt->cmnd[0] += READ_16 - READ_6;
                 SCpnt->cmnd[1] |= blk_fua_rq(rq) ? 0x8 : 0;
                 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) ||
                    scsi_device_protection(SCpnt->device) ||
                    SCpnt->device->use_10_for_rw) {
                 if (this_count > 0xffff)
                         this_count = 0xffff;
 
                 SCpnt->cmnd[0] += READ_10 - READ_6;
                 SCpnt->cmnd[1] |= blk_fua_rq(rq) ? 0x8 : 0;
                 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 (unlikely(blk_fua_rq(rq))) {
                         /*
                          * This happens only if this drive failed
                          * 10byte rw command with ILLEGAL_REQUEST
                          * during operation and thus turned off
                          * use_10_for_rw.
                          */
                         scmd_printk(KERN_ERR, SCpnt,
                                     "FUA write on READ/WRITE(6) drive\n");
                         goto out;
                 }
 
                 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->sdb.length = this_count * sdp->sector_size;
 
         /* If DIF or DIX is enabled, tell HBA how to handle request */
         if (host_dif || scsi_prot_sg_count(SCpnt))
                 sd_dif_op(SCpnt, host_dif, scsi_prot_sg_count(SCpnt),
                           sdkp->protection_type);
 
         /*
          * 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;
 
         /*
          * This indicates that the command is ready from our end to be
          * queued.
          */
         ret = BLKPREP_OK;
  out:
         return scsi_prep_return(q, rq, ret);
 }
 
 /**
  *        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 block_device *bdev, fmode_t mode)
 {
         struct scsi_disk *sdkp = scsi_disk_get(bdev->bd_disk);
         struct scsi_device *sdev;
         int retval;
 
         if (!sdkp)
                 return -ENXIO;
 
         SCSI_LOG_HLQUEUE(3, sd_printk(KERN_INFO, sdkp, "sd_open\n"));
 
         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(bdev);
 
         /*
          * If the drive is empty, just let the open fail.
          */
         retval = -ENOMEDIUM;
         if (sdev->removable && !sdkp->media_present && !(mode & FMODE_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 && (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 gendisk *disk, fmode_t mode)
 {
         struct scsi_disk *sdkp = scsi_disk(disk);
         struct scsi_device *sdev = sdkp->device;
 
         SCSI_LOG_HLQUEUE(3, sd_printk(KERN_INFO, sdkp, "sd_release\n"));
 
         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_getgeo(struct block_device *bdev, struct hd_geometry *geo)
 {
         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);
 
         geo->heads = diskinfo[0];
         geo->sectors = diskinfo[1];
         geo->cylinders = diskinfo[2];
         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 subsystem.
  **/
 static int sd_ioctl(struct block_device *bdev, fmode_t mode,
                     unsigned int cmd, unsigned long arg)
 {
         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,
                                         (mode & FMODE_NDELAY) != 0);
         if (!scsi_block_when_processing_errors(sdp) || !error)
                 return error;
 
         /*
          * 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(disk->queue, disk, mode, 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;
         struct scsi_sense_hdr *sshdr = NULL;
         int retval;
 
         SCSI_LOG_HLQUEUE(3, sd_printk(KERN_INFO, sdkp, "sd_media_changed\n"));
 
         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)) {
                 set_media_not_present(sdkp);
                 retval = 1;
                 goto out;
         }
 
         /*
          * 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)) {
                 sshdr  = kzalloc(sizeof(*sshdr), GFP_KERNEL);
                 retval = scsi_test_unit_ready(sdp, SD_TIMEOUT, SD_MAX_RETRIES,
                                               sshdr);
         }
 
         /*
          * 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 || (scsi_sense_valid(sshdr) &&
                        /* 0x3a is medium not present */
                        sshdr->asc == 0x3a)) {
                 set_media_not_present(sdkp);
                 retval = 1;
                 goto out;
         }
 
         /*
          * 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;
 out:
         if (retval != sdkp->previous_state)
                 sdev_evt_send_simple(sdp, SDEV_EVT_MEDIA_CHANGE, GFP_KERNEL);
         sdkp->previous_state = retval;
         kfree(sshdr);
         return retval;
 }
 
 static int sd_sync_cache(struct scsi_disk *sdkp)
 {
         int retries, res;
         struct scsi_device *sdp = sdkp->device;
         struct scsi_sense_hdr sshdr;
 
         if (!scsi_device_online(sdp))
                 return -ENODEV;
 
 
         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.
                  */
                 res = scsi_execute_req(sdp, cmd, DMA_NONE, NULL, 0, &sshdr,
                                        SD_TIMEOUT, SD_MAX_RETRIES);
                 if (res == 0)
                         break;
         }
 
         if (res) {
                 sd_print_result(sdkp, res);
                 if (driver_byte(res) & DRIVER_SENSE)
                         sd_print_sense_hdr(sdkp, &sshdr);
         }
 
         if (res)
                 return -EIO;
         return 0;
 }
 
 static void sd_prepare_flush(struct request_queue *q, struct request *rq)
 {
         rq->cmd_type = REQ_TYPE_BLOCK_PC;
         rq->timeout = SD_TIMEOUT;
         rq->cmd[0] = SYNCHRONIZE_CACHE;
         rq->cmd_len = 10;
 }
 
 static void sd_rescan(struct device *dev)
 {
         struct scsi_disk *sdkp = scsi_disk_get_from_dev(dev);
 
         if (sdkp) {
                 revalidate_disk(sdkp->disk);
                 scsi_disk_put(sdkp);
         }
 }
 
 
 #ifdef CONFIG_COMPAT
 /* 
  * This gets directly called from VFS. When the ioctl 
  * is not recognized we go back to the other translation paths. 
  */
 static int sd_compat_ioctl(struct block_device *bdev, fmode_t mode,
                            unsigned int cmd, unsigned long arg)
 {
         struct scsi_device *sdev = scsi_disk(bdev->bd_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,
         .locked_ioctl                = sd_ioctl,
         .getgeo                        = sd_getgeo,
 #ifdef CONFIG_COMPAT
         .compat_ioctl                = sd_compat_ioctl,
 #endif
         .media_changed                = sd_media_changed,
         .revalidate_disk        = sd_revalidate_disk,
 };
 
 static unsigned int sd_completed_bytes(struct scsi_cmnd *scmd)
 {
         u64 start_lba = scmd->request->sector;
         u64 end_lba = scmd->request->sector + (scsi_bufflen(scmd) / 512);
         u64 bad_lba;
         int info_valid;
 
         if (!blk_fs_request(scmd->request))
                 return 0;
 
         info_valid = scsi_get_sense_info_fld(scmd->sense_buffer,
                                              SCSI_SENSE_BUFFERSIZE,
                                              &bad_lba);
         if (!info_valid)
                 return 0;
 
         if (scsi_bufflen(scmd) <= scmd->device->sector_size)
                 return 0;
 
         if (scmd->device->sector_size < 512) {
                 /* only legitimate sector_size here is 256 */
                 start_lba <<= 1;
                 end_lba <<= 1;
         } else {
                 /* be careful ... don't want any overflows */
                 u64 factor = scmd->device->sector_size / 512;
                 do_div(start_lba, factor);
                 do_div(end_lba, factor);
         }
 
         /* The bad lba was reported incorrectly, we have no idea where
         * the error is.
         */
        if (bad_lba < start_lba  || bad_lba >= end_lba)
                return 0;

        /* This computation should always be done in terms of
         * the resolution of the device's medium.
         */
        return (bad_lba - start_lba) * scmd->device->sector_size;
}

/**
 *        sd_done - 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 int sd_done(struct scsi_cmnd *SCpnt)
{
        int result = SCpnt->result;
        unsigned int good_bytes = result ? 0 : scsi_bufflen(SCpnt);
        struct scsi_sense_hdr sshdr;
        int sense_valid = 0;
        int sense_deferred = 0;

        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, scsi_print_result(SCpnt));
        if (sense_valid) {
                SCSI_LOG_HLCOMPLETE(1, scmd_printk(KERN_INFO, SCpnt,
                                                   "sd_done: sb[respc,sk,asc,"
                                                   "ascq]=%x,%x,%x,%x\n",
                                                   sshdr.response_code,
                                                   sshdr.sense_key, sshdr.asc,
                                                   sshdr.ascq));
        }
#endif
        if (driver_byte(result) != DRIVER_SENSE &&
            (!sense_valid || sense_deferred))
                goto out;

        switch (sshdr.sense_key) {
        case HARDWARE_ERROR:
        case MEDIUM_ERROR:
                good_bytes = sd_completed_bytes(SCpnt);
                break;
        case RECOVERED_ERROR:
                /* 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 = scsi_bufflen(SCpnt);
                break;
        case NO_SENSE:
                /* This indicates a false check condition, so ignore it.  An
                 * unknown amount of data was transferred so treat it as an
                 * error.
                 */
                scsi_print_sense("sd", SCpnt);
                SCpnt->result = 0;
                memset(SCpnt->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE);
                break;
        case ABORTED_COMMAND:
                if (sshdr.asc == 0x10) { /* DIF: Disk detected corruption */
                        scsi_print_result(SCpnt);
                        scsi_print_sense("sd", SCpnt);
                        good_bytes = sd_completed_bytes(SCpnt);
                }
                break;
        case ILLEGAL_REQUEST:
                if (sshdr.asc == 0x10) { /* DIX: HBA detected corruption */
                        scsi_print_result(SCpnt);
                        scsi_print_sense("sd", SCpnt);
                        good_bytes = sd_completed_bytes(SCpnt);
                }
                break;
        default:
                break;
        }
 out:
        if (rq_data_dir(SCpnt->request) == READ && scsi_prot_sg_count(SCpnt))
                sd_dif_complete(SCpnt, good_bytes);

        return good_bytes;
}

static int media_not_present(struct scsi_disk *sdkp,
                             struct scsi_sense_hdr *sshdr)
{

        if (!scsi_sense_valid(sshdr))
                return 0;
        /* not invoked for commands that could return deferred errors */
        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)
{
        unsigned char cmd[10];
        unsigned long spintime_expire = 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);

                        the_result = scsi_execute_req(sdkp->device, cmd,
                                                      DMA_NONE, NULL, 0,
                                                      &sshdr, SD_TIMEOUT,
                                                      SD_MAX_RETRIES);

                        /*
                         * If the drive has indicated to us that it
                         * doesn't have any media in it, don't bother
                         * with any more polling.
                         */
                        if (media_not_present(sdkp, &sshdr))
                                return;

                        if (the_result)
                                sense_valid = scsi_sense_valid(&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 ((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)) {
                                sd_printk(KERN_NOTICE, sdkp, "Unit Not Ready\n");
                                sd_print_result(sdkp, 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) {
                                sd_printk(KERN_NOTICE, sdkp, "Spinning up disk...");
                                cmd[0] = START_STOP;
                                cmd[1] = 1;        /* Return immediately */
                                memset((void *) &cmd[2], 0, 8);
                                cmd[4] = 1;        /* Start spin cycle */
                                if (sdkp->device->start_stop_pwr_cond)
                                        cmd[4] |= 1 << 4;
                                scsi_execute_req(sdkp->device, cmd, DMA_NONE,
                                                 NULL, 0, &sshdr,
                                                 SD_TIMEOUT, SD_MAX_RETRIES);
                                spintime_expire = jiffies + 100 * HZ;
                                spintime = 1;
                        }
                        /* Wait 1 second for next try */
                        msleep(1000);
                        printk(".");

                /*
                 * Wait for USB flash devices with slow firmware.
                 * Yes, this sense key/ASC combination shouldn't
                 * occur here.  It's characteristic of these devices.
                 */
                } else if (sense_valid &&
                                sshdr.sense_key == UNIT_ATTENTION &&
                                sshdr.asc == 0x28) {
                        if (!spintime) {
                                spintime_expire = jiffies + 5 * HZ;
                                spintime = 1;
                        }
                        /* Wait 1 second for next try */
                        msleep(1000);
                } else {
                        /* we don't understand the sense code, so it's
                         * probably pointless to loop */
                        if(!spintime) {
                                sd_printk(KERN_NOTICE, sdkp, "Unit Not Ready\n");
                                sd_print_sense_hdr(sdkp, &sshdr);
                        }
                        break;
                }
                                
        } while (spintime && time_before_eq(jiffies, spintime_expire));

        if (spintime) {
                if (scsi_status_is_good(the_result))
                        printk("ready\n");
                else
                        printk("not responding...\n");
        }
}


/*
 * Determine whether disk supports Data Integrity Field.
 */
void sd_read_protection_type(struct scsi_disk *sdkp, unsigned char *buffer)
{
        struct scsi_device *sdp = sdkp->device;
        u8 type;

        if (scsi_device_protection(sdp) == 0 || (buffer[12] & 1) == 0)
                type = 0;
        else
                type = ((buffer[12] >> 1) & 7) + 1; /* P_TYPE 0 = Type 1 */

        sdkp->protection_type = type;

        switch (type) {
        case SD_DIF_TYPE0_PROTECTION:
        case SD_DIF_TYPE1_PROTECTION:
        case SD_DIF_TYPE3_PROTECTION:
                break;

        case SD_DIF_TYPE2_PROTECTION:
                sd_printk(KERN_ERR, sdkp, "formatted with DIF Type 2 "        \
                          "protection which is currently unsupported. "        \
                          "Disabling disk!\n");
                goto disable;

        default:
                sd_printk(KERN_ERR, sdkp, "formatted with unknown "        \
                          "protection type %d. Disabling disk!\n", type);
                goto disable;
        }

        return;

disable:
        sdkp->capacity = 0;
}

/*
 * read disk capacity
 */
static void
sd_read_capacity(struct scsi_disk *sdkp, unsigned char *buffer)
{
        unsigned char cmd[16];
        int the_result, retries;
        int sector_size = 0;
        /* Force READ CAPACITY(16) when PROTECT=1 */
        int longrc = scsi_device_protection(sdkp->device) ? 1 : 0;
        struct scsi_sense_hdr sshdr;
        int sense_valid = 0;
        struct scsi_device *sdp = sdkp->device;

repeat:
        retries = 3;
        do {
                if (longrc) {
                        memset((void *) cmd, 0, 16);
                        cmd[0] = SERVICE_ACTION_IN;
                        cmd[1] = SAI_READ_CAPACITY_16;
                        cmd[13] = 13;
                        memset((void *) buffer, 0, 13);
                } else {
                        cmd[0] = READ_CAPACITY;
                        memset((void *) &cmd[1], 0, 9);
                        memset((void *) buffer, 0, 8);
                }
                
                the_result = scsi_execute_req(sdp, cmd, DMA_FROM_DEVICE,
                                              buffer, longrc ? 13 : 8, &sshdr,
                                              SD_TIMEOUT, SD_MAX_RETRIES);

                if (media_not_present(sdkp, &sshdr))
                        return;

                if (the_result)
                        sense_valid = scsi_sense_valid(&sshdr);
                retries--;

        } while (the_result && retries);

        if (the_result && !longrc) {
                sd_printk(KERN_NOTICE, sdkp, "READ CAPACITY failed\n");
                sd_print_result(sdkp, the_result);
                if (driver_byte(the_result) & DRIVER_SENSE)
                        sd_print_sense_hdr(sdkp, &sshdr);
                else
                        sd_printk(KERN_NOTICE, sdkp, "Sense not available.\n");

                /* 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 = 0; /* unknown mapped to zero - as usual */

                return;
        } else if (the_result && longrc) {
                /* READ CAPACITY(16) has been failed */
                sd_printk(KERN_NOTICE, sdkp, "READ CAPACITY(16) failed\n");
                sd_print_result(sdkp, the_result);
                sd_printk(KERN_NOTICE, sdkp, "Use 0xffffffff as device size\n");

                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) {
                                sd_printk(KERN_NOTICE, sdkp, "Very big device. "
                                          "Trying to use READ CAPACITY(16).\n");
                                longrc = 1;
                                goto repeat;
                        }
                        sd_printk(KERN_ERR, sdkp, "Too big for this kernel. Use "
                                  "a kernel compiled with support for large "
                                  "block devices.\n");
                        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];

                sd_read_protection_type(sdkp, buffer);
        }        

        /* Some devices return the total number of sectors, not the
         * highest sector number.  Make the necessary adjustment. */
        if (sdp->fix_capacity) {
                --sdkp->capacity;

        /* Some devices have version which report the correct sizes
         * and others which do not. We guess size according to a heuristic
         * and err on the side of lowering the capacity. */
        } else {
                if (sdp->guess_capacity)
                        if (sdkp->capacity & 0x01) /* odd sizes are odd */
                                --sdkp->capacity;
        }

got_data:
        if (sector_size == 0) {
                sector_size = 512;
                sd_printk(KERN_NOTICE, sdkp, "Sector size 0 reported, "
                          "assuming 512.\n");
        }

        if (sector_size != 512 &&
            sector_size != 1024 &&
            sector_size != 2048 &&
            sector_size != 4096 &&
            sector_size != 256) {
                sd_printk(KERN_NOTICE, sdkp, "Unsupported sector size %d.\n",
                          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;
        }
        blk_queue_hardsect_size(sdp->request_queue, sector_size);

        {
                char cap_str_2[10], cap_str_10[10];
                u64 sz = (u64)sdkp->capacity << ilog2(sector_size);

                string_get_size(sz, STRING_UNITS_2, cap_str_2,
                                sizeof(cap_str_2));
                string_get_size(sz, STRING_UNITS_10, cap_str_10,
                                sizeof(cap_str_10));

                sd_printk(KERN_NOTICE, sdkp,
                          "%llu %d-byte hardware sectors: (%s/%s)\n",
                          (unsigned long long)sdkp->capacity,
                          sector_size, cap_str_10, cap_str_2);
        }

        /* 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_device *sdp, int dbd, int modepage,
                 unsigned char *buffer, int len, struct scsi_mode_data *data,
                 struct scsi_sense_hdr *sshdr)
{
        return scsi_mode_sense(sdp, dbd, modepage, buffer, len,
                               SD_TIMEOUT, SD_MAX_RETRIES, data,
                               sshdr);
}

/*
 * read write protect setting, if possible - called only in sd_revalidate_disk()
 * called with buffer of length SD_BUF_SIZE
 */
static void
sd_read_write_protect_flag(struct scsi_disk *sdkp, unsigned char *buffer)
{
        int res;
        struct scsi_device *sdp = sdkp->device;
        struct scsi_mode_data data;

        set_disk_ro(sdkp->disk, 0);
        if (sdp->skip_ms_page_3f) {
                sd_printk(KERN_NOTICE, sdkp, "Assuming Write Enabled\n");
                return;
        }

        if (sdp->use_192_bytes_for_3f) {
                res = sd_do_mode_sense(sdp, 0, 0x3F, buffer, 192, &data, NULL);
        } 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(sdp, 0, 0x3F, buffer, 4, &data, NULL);

                /*
                 * 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(sdp, 0, 0, buffer, 4, &data, NULL);

                /*
                 * Third attempt: ask 255 bytes, as we did earlier.
                 */
                if (!scsi_status_is_good(res))
                        res = sd_do_mode_sense(sdp, 0, 0x3F, buffer, 255,
                                               &data, NULL);
        }

        if (!scsi_status_is_good(res)) {
                sd_printk(KERN_WARNING, sdkp,
                          "Test WP failed, assume Write Enabled\n");
        } else {
                sdkp->write_prot = ((data.device_specific & 0x80) != 0);
                set_disk_ro(sdkp->disk, sdkp->write_prot);
                sd_printk(KERN_NOTICE, sdkp, "Write Protect is %s\n",
                          sdkp->write_prot ? "on" : "off");
                sd_printk(KERN_DEBUG, sdkp,
                          "Mode Sense: %02x %02x %02x %02x\n",
                          buffer[0], buffer[1], buffer[2], buffer[3]);
        }
}

/*
 * sd_read_cache_type - called only from sd_revalidate_disk()
 * called with buffer of length SD_BUF_SIZE
 */
static void
sd_read_cache_type(struct scsi_disk *sdkp, unsigned char *buffer)
{
        int len = 0, res;
        struct scsi_device *sdp = sdkp->device;

        int dbd;
        int modepage;
        struct scsi_mode_data data;
        struct scsi_sense_hdr sshdr;

        if (sdp->skip_ms_page_8)
                goto defaults;

        if (sdp->type == TYPE_RBC) {
                modepage = 6;
                dbd = 8;
        } else {
                modepage = 8;
                dbd = 0;
        }

        /* cautiously ask */
        res = sd_do_mode_sense(sdp, dbd, modepage, buffer, 4, &data, &sshdr);

        if (!scsi_status_is_good(res))
                goto bad_sense;

        if (!data.header_length) {
                modepage = 6;
                sd_printk(KERN_ERR, sdkp, "Missing header in MODE_SENSE response\n");
        }

        /* 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;
        if (len > SD_BUF_SIZE)
                goto bad_sense;

        /* Get the data */
        res = sd_do_mode_sense(sdp, dbd, modepage, buffer, len, &data, &sshdr);

        if (scsi_status_is_good(res)) {
                int offset = data.header_length + data.block_descriptor_length;

                if (offset >= SD_BUF_SIZE - 2) {
                        sd_printk(KERN_ERR, sdkp, "Malformed MODE SENSE response\n");
                        goto defaults;
                }

                if ((buffer[offset] & 0x3f) != modepage) {
                        sd_printk(KERN_ERR, sdkp, "Got wrong page\n");
                        goto defaults;
                }

                if (modepage == 8) {
                        sdkp->WCE = ((buffer[offset + 2] & 0x04) != 0);
                        sdkp->RCD = ((buffer[offset + 2] & 0x01) != 0);
                } else {
                        sdkp->WCE = ((buffer[offset + 2] & 0x01) == 0);
                        sdkp->RCD = 0;
                }

                sdkp->DPOFUA = (data.device_specific & 0x10) != 0;
                if (sdkp->DPOFUA && !sdkp->device->use_10_for_rw) {
                        sd_printk(KERN_NOTICE, sdkp,
                                  "Uses READ/WRITE(6), disabling FUA\n");
                        sdkp->DPOFUA = 0;
                }

                sd_printk(KERN_NOTICE, sdkp,
                       "Write cache: %s, read cache: %s, %s\n",
                       sdkp->WCE ? "enabled" : "disabled",
                       sdkp->RCD ? "disabled" : "enabled",
                       sdkp->DPOFUA ? "supports DPO and FUA"
                       : "doesn't support DPO or FUA");

                return;
        }

bad_sense:
        if (scsi_sense_valid(&sshdr) &&
            sshdr.sense_key == ILLEGAL_REQUEST &&
            sshdr.asc == 0x24 && sshdr.ascq == 0x0)
                /* Invalid field in CDB */
                sd_printk(KERN_NOTICE, sdkp, "Cache data unavailable\n");
        else
                sd_printk(KERN_ERR, sdkp, "Asking for cache data failed\n");

defaults:
        sd_printk(KERN_ERR, sdkp, "Assuming drive cache: write through\n");
        sdkp->WCE = 0;
        sdkp->RCD = 0;
        sdkp->DPOFUA = 0;
}

/*
 * The ATO bit indicates whether the DIF application tag is available
 * for use by the operating system.
 */
void sd_read_app_tag_own(struct scsi_disk *sdkp, unsigned char *buffer)
{
        int res, offset;
        struct scsi_device *sdp = sdkp->device;
        struct scsi_mode_data data;
        struct scsi_sense_hdr sshdr;

        if (sdp->type != TYPE_DISK)
                return;

        if (sdkp->protection_type == 0)
                return;

        res = scsi_mode_sense(sdp, 1, 0x0a, buffer, 36, SD_TIMEOUT,
                              SD_MAX_RETRIES, &data, &sshdr);

        if (!scsi_status_is_good(res) || !data.header_length ||
            data.length < 6) {
                sd_printk(KERN_WARNING, sdkp,
                          "getting Control mode page failed, assume no ATO\n");

                if (scsi_sense_valid(&sshdr))
                        sd_print_sense_hdr(sdkp, &sshdr);

                return;
        }

        offset = data.header_length + data.block_descriptor_length;

        if ((buffer[offset] & 0x3f) != 0x0a) {
                sd_printk(KERN_ERR, sdkp, "ATO Got wrong page\n");
                return;
        }

        if ((buffer[offset + 5] & 0x80) == 0)
                return;

        sdkp->ATO = 1;

        return;
}

/**
 *        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;
        unsigned char *buffer;
        unsigned ordered;

        SCSI_LOG_HLQUEUE(3, sd_printk(KERN_INFO, sdkp,
                                      "sd_revalidate_disk\n"));

        /*
         * If the device is offline, don't try and read capacity or any
         * of the other niceties.
         */
        if (!scsi_device_online(sdp))
                goto out;

        buffer = kmalloc(SD_BUF_SIZE, GFP_KERNEL);
        if (!buffer) {
                sd_printk(KERN_WARNING, sdkp, "sd_revalidate_disk: Memory "
                          "allocation failure.\n");
                goto out;
        }

        /* 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;
        sdkp->ATO = 0;

        sd_spinup_disk(sdkp);

        /*
         * Without media there is no reason to ask; moreover, some devices
         * react badly if we do.
         */
        if (sdkp->media_present) {
                sd_read_capacity(sdkp, buffer);
                sd_read_write_protect_flag(sdkp, buffer);
                sd_read_cache_type(sdkp, buffer);
                sd_read_app_tag_own(sdkp, buffer);
        }

        /*
         * We now have all cache related info, determine how we deal
         * with ordered requests.  Note that as the current SCSI
         * dispatch function can alter request order, we cannot use
         * QUEUE_ORDERED_TAG_* even when ordered tag is supported.
         */
        if (sdkp->WCE)
                ordered = sdkp->DPOFUA
                        ? QUEUE_ORDERED_DRAIN_FUA : QUEUE_ORDERED_DRAIN_FLUSH;
        else
                ordered = QUEUE_ORDERED_DRAIN;

        blk_queue_ordered(sdkp->disk->queue, ordered, sd_prepare_flush);

        set_capacity(disk, sdkp->capacity);
        kfree(buffer);

 out:
        return 0;
}

/**
 *        sd_format_disk_name - format disk name
 *        @prefix: name prefix - ie. "sd" for SCSI disks
 *        @index: index of the disk to format name for
 *        @buf: output buffer
 *        @buflen: length of the output buffer
 *
 *        SCSI disk names starts at sda.  The 26th device is sdz and the
 *        27th is sdaa.  The last one for two lettered suffix is sdzz
 *        which is followed by sdaaa.
 *
 *        This is basically 26 base counting with one extra 'nil' entry
 *        at the beggining from the second digit on and can be
 *        determined using similar method as 26 base conversion with the
 *        index shifted -1 after each digit is computed.
 *
 *        CONTEXT:
 *        Don't care.
 *
 *        RETURNS:
 *        0 on success, -errno on failure.
 */
static int sd_format_disk_name(char *prefix, int index, char *buf, int buflen)
{
        const int base = 'z' - 'a' + 1;
        char *begin = buf + strlen(prefix);
        char *end = buf + buflen;
        char *p;
        int unit;

        p = end - 1;
        *p = '\0';
        unit = base;
        do {
                if (p == begin)
                        return -EINVAL;
                *--p = 'a' + (index % unit);
                index = (index / unit) - 1;
        } while (index >= 0);

        memmove(begin, p, end - p);
        memcpy(buf, prefix, strlen(prefix));

        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 && sdp->type != TYPE_RBC)
                goto out;

        SCSI_LOG_HLQUEUE(3, sdev_printk(KERN_INFO, sdp,
                                        "sd_attach\n"));

        error = -ENOMEM;
        sdkp = kzalloc(sizeof(*sdkp), GFP_KERNEL);
        if (!sdkp)
                goto out;

        gd = alloc_disk(SD_MINORS);
        if (!gd)
                goto out_free;

        do {
                if (!ida_pre_get(&sd_index_ida, GFP_KERNEL))
                        goto out_put;

                error = ida_get_new(&sd_index_ida, &index);
        } while (error == -EAGAIN);

        if (error)
                goto out_put;

        error = sd_format_disk_name("sd", index, gd->disk_name, DISK_NAME_LEN);
        if (error)
                goto out_free_index;

        sdkp->device = sdp;
        sdkp->driver = &sd_template;
        sdkp->disk = gd;
        sdkp->index = index;
        sdkp->openers = 0;
        sdkp->previous_state = 1;

        if (!sdp->request_queue->rq_timeout) {
                if (sdp->type != TYPE_MOD)
                        blk_queue_rq_timeout(sdp->request_queue, SD_TIMEOUT);
                else
                        blk_queue_rq_timeout(sdp->request_queue,
                                             SD_MOD_TIMEOUT);
        }

        device_initialize(&sdkp->dev);
        sdkp->dev.parent = &sdp->sdev_gendev;
        sdkp->dev.class = &sd_disk_class;
        strncpy(sdkp->dev.bus_id, sdp->sdev_gendev.bus_id, BUS_ID_SIZE);

        if (device_add(&sdkp->dev))
                goto out_free_index;

        get_device(&sdp->sdev_gendev);

        if (index < SD_MAX_DISKS) {
                gd->major = sd_major((index & 0xf0) >> 4);
                gd->first_minor = ((index & 0xf) << 4) | (index & 0xfff00);
                gd->minors = SD_MINORS;
        }
        gd->fops = &sd_fops;
        gd->private_data = &sdkp->driver;
        gd->queue = sdkp->device->request_queue;

        sd_revalidate_disk(gd);

        blk_queue_prep_rq(sdp->request_queue, sd_prep_fn);

        gd->driverfs_dev = &sdp->sdev_gendev;
        gd->flags = GENHD_FL_EXT_DEVT | GENHD_FL_DRIVERFS;
        if (sdp->removable)
                gd->flags |= GENHD_FL_REMOVABLE;

        dev_set_drvdata(dev, sdkp);
        add_disk(gd);
        sd_dif_config_host(sdkp);

        sd_printk(KERN_NOTICE, sdkp, "Attached SCSI %sdisk\n",
                  sdp->removable ? "removable " : "");

        return 0;

 out_free_index:
        ida_remove(&sd_index_ida, index);
 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);

        device_del(&sdkp->dev);
        del_gendisk(sdkp->disk);
        sd_shutdown(dev);

        mutex_lock(&sd_ref_mutex);
        dev_set_drvdata(dev, NULL);
        put_device(&sdkp->dev);
        mutex_unlock(&sd_ref_mutex);

        return 0;
}

/**
 *        scsi_disk_release - Called to free the scsi_disk structure
 *        @dev: pointer to embedded class device
 *
 *        sd_ref_mutex 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 put_device.
 **/
static void scsi_disk_release(struct device *dev)
{
        struct scsi_disk *sdkp = to_scsi_disk(dev);
        struct gendisk *disk = sdkp->disk;
        
        ida_remove(&sd_index_ida, sdkp->index);

        disk->private_data = NULL;
        put_disk(disk);
        put_device(&sdkp->device->sdev_gendev);

        kfree(sdkp);
}

static int sd_start_stop_device(struct scsi_disk *sdkp, int start)
{
        unsigned char cmd[6] = { START_STOP };        /* START_VALID */
        struct scsi_sense_hdr sshdr;
        struct scsi_device *sdp = sdkp->device;
        int res;

        if (start)
                cmd[4] |= 1;        /* START */

        if (sdp->start_stop_pwr_cond)
                cmd[4] |= start ? 1 << 4 : 3 << 4;        /* Active or Standby */

        if (!scsi_device_online(sdp))
                return -ENODEV;

        res = scsi_execute_req(sdp, cmd, DMA_NONE, NULL, 0, &sshdr,
                               SD_TIMEOUT, SD_MAX_RETRIES);
        if (res) {
                sd_printk(KERN_WARNING, sdkp, "START_STOP FAILED\n");
                sd_print_result(sdkp, res);
                if (driver_byte(res) & DRIVER_SENSE)
                        sd_print_sense_hdr(sdkp, &sshdr);
        }

        return res;
}

/*
 * 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_disk *sdkp = scsi_disk_get_from_dev(dev);

        if (!sdkp)
                return;         /* this can happen */

        if (sdkp->WCE) {
                sd_printk(KERN_NOTICE, sdkp, "Synchronizing SCSI cache\n");
                sd_sync_cache(sdkp);
        }

        if (system_state != SYSTEM_RESTART && sdkp->device->manage_start_stop) {
                sd_printk(KERN_NOTICE, sdkp, "Stopping disk\n");
                sd_start_stop_device(sdkp, 0);
        }

        scsi_disk_put(sdkp);
}

static int sd_suspend(struct device *dev, pm_message_t mesg)
{
        struct scsi_disk *sdkp = scsi_disk_get_from_dev(dev);
        int ret = 0;

        if (!sdkp)
                return 0;        /* this can happen */

        if (sdkp->WCE) {
                sd_printk(KERN_NOTICE, sdkp, "Synchronizing SCSI cache\n");
                ret = sd_sync_cache(sdkp);
                if (ret)
                        goto done;
        }

        if ((mesg.event & PM_EVENT_SLEEP) && sdkp->device->manage_start_stop) {
                sd_printk(KERN_NOTICE, sdkp, "Stopping disk\n");
                ret = sd_start_stop_device(sdkp, 0);
        }

done:
        scsi_disk_put(sdkp);
        return ret;
}

static int sd_resume(struct device *dev)
{
        struct scsi_disk *sdkp = scsi_disk_get_from_dev(dev);
        int ret = 0;

        if (!sdkp->device->manage_start_stop)
                goto done;

        sd_printk(KERN_NOTICE, sdkp, "Starting disk\n");
        ret = sd_start_stop_device(sdkp, 1);

done:
        scsi_disk_put(sdkp);
        return ret;
}

/**
 *        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, err;

        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;

        err = class_register(&sd_disk_class);
        if (err)
                goto err_out;

        err = scsi_register_driver(&sd_template.gendrv);
        if (err)
                goto err_out_class;

        return 0;

err_out_class:
        class_unregister(&sd_disk_class);
err_out:
        for (i = 0; i < SD_MAJORS; i++)
                unregister_blkdev(sd_major(i), "sd");
        return err;
}

/**
 *        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);
        class_unregister(&sd_disk_class);

        for (i = 0; i < SD_MAJORS; i++)
                unregister_blkdev(sd_major(i), "sd");
}

module_init(init_sd);
module_exit(exit_sd);

static void sd_print_sense_hdr(struct scsi_disk *sdkp,
                               struct scsi_sense_hdr *sshdr)
{
        sd_printk(KERN_INFO, sdkp, "");
        scsi_show_sense_hdr(sshdr);
        sd_printk(KERN_INFO, sdkp, "");
        scsi_show_extd_sense(sshdr->asc, sshdr->ascq);
}

static void sd_print_result(struct scsi_disk *sdkp, int result)
{
        sd_printk(KERN_INFO, sdkp, "");
        scsi_show_result(result);
}