1. 12 11月, 2014 1 次提交
  2. 16 9月, 2014 1 次提交
    • S
      scsi: balance out autopm get/put calls in scsi_sysfs_add_sdev() · 6fe8c1db
      Subhash Jadavani 提交于
      SCSI Well-known logical units generally don't have any scsi driver
      associated with it which means no one will call scsi_autopm_put_device()
      on these wlun scsi devices and this would result in keeping the
      corresponding scsi device always active (hence LLD can't be suspended as
      well). Same exact problem can be seen for other scsi device representing
      normal logical unit whose driver is yet to be loaded. This patch fixes
      the above problem with this approach:
      
      - make the scsi_autopm_put_device call at the end of scsi_sysfs_add_sdev
        to make it balance out the get earlier in the function.
      - let drivers do paired get/put calls in their probe methods.
      Signed-off-by: NSubhash Jadavani <subhashj@codeaurora.org>
      Signed-off-by: NDolev Raviv <draviv@codeaurora.org>
      Signed-off-by: NChristoph Hellwig <hch@lst.de>
      6fe8c1db
  3. 26 7月, 2014 1 次提交
  4. 18 7月, 2014 3 次提交
  5. 19 5月, 2014 1 次提交
  6. 17 12月, 2013 1 次提交
  7. 07 5月, 2013 1 次提交
  8. 26 1月, 2013 2 次提交
  9. 22 7月, 2011 1 次提交
    • K
      [SCSI] sr: check_events() ignore GET_EVENT when TUR says otherwise · 79b9677d
      Kay Sievers 提交于
      Some broken devices indicates that media has changed on every
      GET_EVENT_STATUS_NOTIFICATION.  This translates into MEDIA_CHANGE
      uevent on every open() which lets udev run into a loop.
      
      Verify GET_EVENT result against TUR and if it generates spurious
      events for several times in a row, ignore the GET_EVENT events, and
      trust only the TUR status.
      
      This is the log of a USB stick with a (broken) fake CDROM drive:
      
       scsi 5:0:0:0: Direct-Access     SanDisk  U3 Cruzer Micro  8.02 PQ: 0 ANSI: 0 CCS
       sd 5:0:0:0: Attached scsi generic sg3 type 0
       scsi 5:0:0:1: CD-ROM            SanDisk  U3 Cruzer Micro  8.02 PQ: 0 ANSI: 0
       sd 5:0:0:0: [sdb] Attached SCSI removable disk
       sr2: scsi3-mmc drive: 48x/48x tray
       sr 5:0:0:1: Attached scsi CD-ROM sr2
       sr 5:0:0:1: Attached scsi generic sg4 type 5
       sr2: GET_EVENT and TUR disagree continuously, suppress GET_EVENT events
       sd 5:0:0:0: [sdb] 31777279 512-byte logical blocks: (16.2 GB/15.1 GiB)
       sd 5:0:0:0: [sdb] No Caching mode page present
       sd 5:0:0:0: [sdb] Assuming drive cache: write through
       sd 5:0:0:0: [sdb] No Caching mode page present
       sd 5:0:0:0: [sdb] Assuming drive cache: write through
       sdb: sdb1
      
      -tj: Updated to consider only spurious GET_EVENT events among
           different types of disagreement and allow using TUR for kernel
           event polling after GET_EVENT is ignored.
      
      Reported-By: Markus Rathgeb maggu2810@googlemail.com
      Signed-off-by: NKay Sievers <kay.sievers@vrfy.org>
      Signed-off-by: NTejun Heo <tj@kernel.org>
      Cc: stable@kernel.org	# >= v2.6.38, fixes udev busy looping w/ certain devices
      Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>
      79b9677d
  10. 22 4月, 2011 1 次提交
  11. 31 3月, 2011 1 次提交
  12. 14 1月, 2011 1 次提交
    • T
      [SCSI] sd,sr: kill compat SDEV_MEDIA_CHANGE event · f4013c38
      Tejun Heo 提交于
      SDEV_MEDIA_CHANGE event was first added by commit a341cd0f (SCSI: add
      asynchronous event notification API) for SATA AN support and then
      extended to cover generic media change events by commit 285e9670
      ([SCSI] sr,sd: send media state change modification events).
      
      This event was mapped to block device in userland with all properties
      stripped to simulate CHANGE event on the block device, which, in turn,
      was used to trigger further userspace action on media change.
      
      The recent addition of disk event framework kept this event for
      backward compatibility but it turns out to be unnecessary and causes
      erratic and inefficient behavior.  The new disk event generates proper
      events on the block devices and the compat events are mapped to block
      device with all properties stripped, so the block device ends up
      generating multiple duplicate events for single actual event.
      
      This patch removes the compat event generation from both sr and sd as
      suggested by Kay Sievers.  Both existing and newer versions of udev
      and the associated tools will behave better with the removal of these
      events as they from the beginning were expecting events on the block
      devices.
      Signed-off-by: NTejun Heo <tj@kernel.org>
      Acked-by: NKay Sievers <kay.sievers@vrfy.org>
      Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>
      f4013c38
  13. 05 1月, 2011 1 次提交
    • T
      [SCSI] sd,sr: kill compat SDEV_MEDIA_CHANGE event · 140e3008
      Tejun Heo 提交于
      SDEV_MEDIA_CHANGE event was first added by commit a341cd0f (SCSI: add
      asynchronous event notification API) for SATA AN support and then
      extended to cover generic media change events by commit 285e9670
      ([SCSI] sr,sd: send media state change modification events).
      
      This event was mapped to block device in userland with all properties
      stripped to simulate CHANGE event on the block device, which, in turn,
      was used to trigger further userspace action on media change.
      
      The recent addition of disk event framework kept this event for
      backward compatibility but it turns out to be unnecessary and causes
      erratic and inefficient behavior.  The new disk event generates proper
      events on the block devices and the compat events are mapped to block
      device with all properties stripped, so the block device ends up
      generating multiple duplicate events for single actual event.
      
      This patch removes the compat event generation from both sr and sd as
      suggested by Kay Sievers.  Both existing and newer versions of udev
      and the associated tools will behave better with the removal of these
      events as they from the beginning were expecting events on the block
      devices.
      Signed-off-by: NTejun Heo <tj@kernel.org>
      Acked-by: NKay Sievers <kay.sievers@vrfy.org>
      Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>
      140e3008
  14. 17 12月, 2010 3 次提交
    • T
      sr: implement sr_check_events() · 93aae17a
      Tejun Heo 提交于
      Replace sr_media_change() with sr_check_events().  It normally only
      uses GET_EVENT_STATUS_NOTIFICATION to check both media change and
      eject request.  If @clearing includes DISK_EVENT_MEDIA_CHANGE, it
      issues TUR and compares whether media presence has changed.  The SCSI
      specific media change uevent is kept for compatibility.
      
      sr_media_change() was doing both media change check and revalidation.
      The revalidation part is split into sr_block_revalidate_disk().
      Signed-off-by: NTejun Heo <tj@kernel.org>
      Cc: Kay Sievers <kay.sievers@vrfy.org>
      Signed-off-by: NJens Axboe <jaxboe@fusionio.com>
      93aae17a
    • T
      scsi: replace sr_test_unit_ready() with scsi_test_unit_ready() · 9f8a2c23
      Tejun Heo 提交于
      The usage of TUR has been confusing involving several different
      commits updating different parts over time.  Currently, the only
      differences between scsi_test_unit_ready() and sr_test_unit_ready()
      are,
      
      * scsi_test_unit_ready() also sets sdev->changed on NOT_READY.
      
      * scsi_test_unit_ready() returns 0 if TUR ended with UNIT_ATTENTION or
        NOT_READY.
      
      Due to the above two differences, sr is using its own
      sr_test_unit_ready(), but sd - the sole user of the above extra
      handling - doesn't even need them.
      
      Where scsi_test_unit_ready() is used in sd_media_changed(), the code
      is looking for device ready w/ media present state which is true iff
      TUR succeeds w/o sense data or UA, and when the device is not ready
      for whatever reason sd_media_changed() explicitly marks media as
      missing so there's no reason to set sdev->changed automatically from
      scsi_test_unit_ready() on NOT_READY.
      
      Drop both special handlings from scsi_test_unit_ready(), which makes
      it equivalant to sr_test_unit_ready(), and replace
      sr_test_unit_ready() with scsi_test_unit_ready().  Also, drop the
      unnecessary explicit NOT_READY check from sd_media_changed().
      Checking return value is enough for testing device readiness.
      Signed-off-by: NTejun Heo <tj@kernel.org>
      Signed-off-by: NJens Axboe <jaxboe@fusionio.com>
      9f8a2c23
    • T
      scsi: fix TUR error handling in sr_media_change() · 638428ec
      Tejun Heo 提交于
      sr_test_unit_ready() returns 0 iff TUR succeeded - IOW, when media is
      present and the device is actually ready, so the return value wouldn't
      be zero when TUR ends with sense data. sr_media_change() incorrectly
      tests (retval || (scsi_sense_valid(sshdr)...)) when it tries to test
      whether TUR failed without sense data or with sense data indicating
      media-not-present.
      
      Fix the test using scsi_status_is_good() and update comments.
      
      - Fixed a comment typo spotted by Eike.
      Signed-off-by: NTejun Heo <tj@kernel.org>
      Cc: Rolf Eike Beer <eike-kernel@sf-tec.de>
      Signed-off-by: NJens Axboe <jaxboe@fusionio.com>
      638428ec
  15. 23 10月, 2010 1 次提交
    • H
      scsi/sr: add no_read_disc_info scsi_device flag · 8e04d805
      Hans de Goede 提交于
      Some USB devices emulate a usb-mass-storage attached (scsi) cdrom device,
      usually this fake cdrom contains the windows software for the device.
      While working on supporting Appotech ax3003 based photoframes, which do
      this I discovered that they will go of into lala land when ever they see a
      READ_DISC_INFO scsi command.
      
      Thus this patch adds a scsi_device flag (which can then be set by the
      usb-storage driver through an unsual-devs entry), to indicate this, and
      makes the sr driver honor this flag.
      
      I know this sucks, but as discussed on linux-scsi list there is no other
      way to make this device work properly.
      
      Looking at usb traces made under windows, windows never sends a
      READ_DISC_INFO during normal interactions with a usb cdrom device.  So as
      this cdrom emulation thingie becomes more common we might see more of this
      problem.
      Signed-off-by: NHans de Goede <hdegoede@redhat.com>
      Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
      Cc: Alan Stern <stern@rowland.harvard.edu>
      Cc: Matthew Dharm <mdharm-usb@one-eyed-alien.net>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
      8e04d805
  16. 05 10月, 2010 1 次提交
    • A
      block: autoconvert trivial BKL users to private mutex · 2a48fc0a
      Arnd Bergmann 提交于
      The block device drivers have all gained new lock_kernel
      calls from a recent pushdown, and some of the drivers
      were already using the BKL before.
      
      This turns the BKL into a set of per-driver mutexes.
      Still need to check whether this is safe to do.
      
      file=$1
      name=$2
      if grep -q lock_kernel ${file} ; then
          if grep -q 'include.*linux.mutex.h' ${file} ; then
                  sed -i '/include.*<linux\/smp_lock.h>/d' ${file}
          else
                  sed -i 's/include.*<linux\/smp_lock.h>.*$/include <linux\/mutex.h>/g' ${file}
          fi
          sed -i ${file} \
              -e "/^#include.*linux.mutex.h/,$ {
                      1,/^\(static\|int\|long\)/ {
                           /^\(static\|int\|long\)/istatic DEFINE_MUTEX(${name}_mutex);
      
      } }"  \
          -e "s/\(un\)*lock_kernel\>[ ]*()/mutex_\1lock(\&${name}_mutex)/g" \
          -e '/[      ]*cycle_kernel_lock();/d'
      else
          sed -i -e '/include.*\<smp_lock.h\>/d' ${file}  \
                      -e '/cycle_kernel_lock()/d'
      fi
      Signed-off-by: NArnd Bergmann <arnd@arndb.de>
      2a48fc0a
  17. 08 8月, 2010 2 次提交
    • A
      block: push down BKL into .open and .release · 6e9624b8
      Arnd Bergmann 提交于
      The open and release block_device_operations are currently
      called with the BKL held. In order to change that, we must
      first make sure that all drivers that currently rely
      on this have no regressions.
      
      This blindly pushes the BKL into all .open and .release
      operations for all block drivers to prepare for the
      next step. The drivers can subsequently replace the BKL
      with their own locks or remove it completely when it can
      be shown that it is not needed.
      
      The functions blkdev_get and blkdev_put are the only
      remaining users of the big kernel lock in the block
      layer, besides a few uses in the ioctl code, none
      of which need to serialize with blkdev_{get,put}.
      
      Most of these two functions is also under the protection
      of bdev->bd_mutex, including the actual calls to
      ->open and ->release, and the common code does not
      access any global data structures that need the BKL.
      Signed-off-by: NArnd Bergmann <arnd@arndb.de>
      Acked-by: NChristoph Hellwig <hch@infradead.org>
      Signed-off-by: NJens Axboe <jaxboe@fusionio.com>
      6e9624b8
    • A
      block: push down BKL into .locked_ioctl · 8a6cfeb6
      Arnd Bergmann 提交于
      As a preparation for the removal of the big kernel
      lock in the block layer, this removes the BKL
      from the common ioctl handling code, moving it
      into every single driver still using it.
      Signed-off-by: NArnd Bergmann <arnd@arndb.de>
      Acked-by: NChristoph Hellwig <hch@infradead.org>
      Signed-off-by: NJens Axboe <jaxboe@fusionio.com>
      8a6cfeb6
  18. 30 3月, 2010 1 次提交
    • T
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking... · 5a0e3ad6
      Tejun Heo 提交于
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
      
      percpu.h is included by sched.h and module.h and thus ends up being
      included when building most .c files.  percpu.h includes slab.h which
      in turn includes gfp.h making everything defined by the two files
      universally available and complicating inclusion dependencies.
      
      percpu.h -> slab.h dependency is about to be removed.  Prepare for
      this change by updating users of gfp and slab facilities include those
      headers directly instead of assuming availability.  As this conversion
      needs to touch large number of source files, the following script is
      used as the basis of conversion.
      
        http://userweb.kernel.org/~tj/misc/slabh-sweep.py
      
      The script does the followings.
      
      * Scan files for gfp and slab usages and update includes such that
        only the necessary includes are there.  ie. if only gfp is used,
        gfp.h, if slab is used, slab.h.
      
      * When the script inserts a new include, it looks at the include
        blocks and try to put the new include such that its order conforms
        to its surrounding.  It's put in the include block which contains
        core kernel includes, in the same order that the rest are ordered -
        alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
        doesn't seem to be any matching order.
      
      * If the script can't find a place to put a new include (mostly
        because the file doesn't have fitting include block), it prints out
        an error message indicating which .h file needs to be added to the
        file.
      
      The conversion was done in the following steps.
      
      1. The initial automatic conversion of all .c files updated slightly
         over 4000 files, deleting around 700 includes and adding ~480 gfp.h
         and ~3000 slab.h inclusions.  The script emitted errors for ~400
         files.
      
      2. Each error was manually checked.  Some didn't need the inclusion,
         some needed manual addition while adding it to implementation .h or
         embedding .c file was more appropriate for others.  This step added
         inclusions to around 150 files.
      
      3. The script was run again and the output was compared to the edits
         from #2 to make sure no file was left behind.
      
      4. Several build tests were done and a couple of problems were fixed.
         e.g. lib/decompress_*.c used malloc/free() wrappers around slab
         APIs requiring slab.h to be added manually.
      
      5. The script was run on all .h files but without automatically
         editing them as sprinkling gfp.h and slab.h inclusions around .h
         files could easily lead to inclusion dependency hell.  Most gfp.h
         inclusion directives were ignored as stuff from gfp.h was usually
         wildly available and often used in preprocessor macros.  Each
         slab.h inclusion directive was examined and added manually as
         necessary.
      
      6. percpu.h was updated not to include slab.h.
      
      7. Build test were done on the following configurations and failures
         were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
         distributed build env didn't work with gcov compiles) and a few
         more options had to be turned off depending on archs to make things
         build (like ipr on powerpc/64 which failed due to missing writeq).
      
         * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
         * powerpc and powerpc64 SMP allmodconfig
         * sparc and sparc64 SMP allmodconfig
         * ia64 SMP allmodconfig
         * s390 SMP allmodconfig
         * alpha SMP allmodconfig
         * um on x86_64 SMP allmodconfig
      
      8. percpu.h modifications were reverted so that it could be applied as
         a separate patch and serve as bisection point.
      
      Given the fact that I had only a couple of failures from tests on step
      6, I'm fairly confident about the coverage of this conversion patch.
      If there is a breakage, it's likely to be something in one of the arch
      headers which should be easily discoverable easily on most builds of
      the specific arch.
      Signed-off-by: NTejun Heo <tj@kernel.org>
      Guess-its-ok-by: NChristoph Lameter <cl@linux-foundation.org>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
      5a0e3ad6
  19. 02 10月, 2009 1 次提交
  20. 22 9月, 2009 1 次提交
  21. 22 6月, 2009 1 次提交
  22. 23 5月, 2009 1 次提交
  23. 11 5月, 2009 1 次提交
    • T
      block: convert to pos and nr_sectors accessors · 83096ebf
      Tejun Heo 提交于
      With recent cleanups, there is no place where low level driver
      directly manipulates request fields.  This means that the 'hard'
      request fields always equal the !hard fields.  Convert all
      rq->sectors, nr_sectors and current_nr_sectors references to
      accessors.
      
      While at it, drop superflous blk_rq_pos() < 0 test in swim.c.
      
      [ Impact: use pos and nr_sectors accessors ]
      Signed-off-by: NTejun Heo <tj@kernel.org>
      Acked-by: NGeert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
      Tested-by: NGrant Likely <grant.likely@secretlab.ca>
      Acked-by: NGrant Likely <grant.likely@secretlab.ca>
      Tested-by: NAdrian McMenamin <adrian@mcmen.demon.co.uk>
      Acked-by: NAdrian McMenamin <adrian@mcmen.demon.co.uk>
      Acked-by: NMike Miller <mike.miller@hp.com>
      Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
      Cc: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
      Cc: Borislav Petkov <petkovbb@googlemail.com>
      Cc: Sergei Shtylyov <sshtylyov@ru.mvista.com>
      Cc: Eric Moore <Eric.Moore@lsi.com>
      Cc: Alan Stern <stern@rowland.harvard.edu>
      Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
      Cc: Pete Zaitcev <zaitcev@redhat.com>
      Cc: Stephen Rothwell <sfr@canb.auug.org.au>
      Cc: Paul Clements <paul.clements@steeleye.com>
      Cc: Tim Waugh <tim@cyberelk.net>
      Cc: Jeff Garzik <jgarzik@pobox.com>
      Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
      Cc: Alex Dubov <oakad@yahoo.com>
      Cc: David Woodhouse <dwmw2@infradead.org>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Dario Ballabio <ballabio_dario@emc.com>
      Cc: David S. Miller <davem@davemloft.net>
      Cc: Rusty Russell <rusty@rustcorp.com.au>
      Cc: unsik Kim <donari75@gmail.com>
      Cc: Laurent Vivier <Laurent@lvivier.info>
      Signed-off-by: NJens Axboe <jens.axboe@oracle.com>
      83096ebf
  24. 03 4月, 2009 1 次提交
    • J
      [SCSI] fix recovered error handling · a9bddd74
      James Bottomley 提交于
      We have a problem with recovered error handling in that any command
      which goes down as BLOCK_PC but which returns a sense code of RECOVERED
      ERROR gets completed with -EIO.  For actual SG_IO commands, this doesn't
      matter at all, since the error return code gets dropped in favour of
      req->errors which contain the SCSI completion code.
      
      However, if this command is part of the block system, then it will pay
      attention to the returned error code.  In particularly if a SYNCHRONIZE
      CACHE from a barrier command completes with RECOVERED ERROR, the
      resulting -EIO on the barrier causes block to error the request and
      return it to the filesystem.  Fix this by converting the -EIO for
      recovered error to zero, plus remove the printing of this from sd and sr
      so the message isn't double printed.
      Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>
      a9bddd74
  25. 30 12月, 2008 1 次提交
  26. 04 12月, 2008 1 次提交
  27. 21 10月, 2008 4 次提交
  28. 09 10月, 2008 2 次提交
    • J
      block: unify request timeout handling · 242f9dcb
      Jens Axboe 提交于
      Right now SCSI and others do their own command timeout handling.
      Move those bits to the block layer.
      
      Instead of having a timer per command, we try to be a bit more clever
      and simply have one per-queue. This avoids the overhead of having to
      tear down and setup a timer for each command, so it will result in a lot
      less timer fiddling.
      Signed-off-by: NMike Anderson <andmike@linux.vnet.ibm.com>
      Signed-off-by: NJens Axboe <jens.axboe@oracle.com>
      242f9dcb
    • T
      block: don't depend on consecutive minor space · f331c029
      Tejun Heo 提交于
      * Implement disk_devt() and part_devt() and use them to directly
        access devt instead of computing it from ->major and ->first_minor.
      
        Note that all references to ->major and ->first_minor outside of
        block layer is used to determine devt of the disk (the part0) and as
        ->major and ->first_minor will continue to represent devt for the
        disk, converting these users aren't strictly necessary.  However,
        convert them for consistency.
      
      * Implement disk_max_parts() to avoid directly deferencing
        genhd->minors.
      
      * Update bdget_disk() such that it doesn't assume consecutive minor
        space.
      
      * Move devt computation from register_disk() to add_disk() and make it
        the only one (all other usages use the initially determined value).
      
      These changes clean up the code and will help disk->part dereference
      fix and extended block device numbers.
      Signed-off-by: NTejun Heo <tj@kernel.org>
      Signed-off-by: NJens Axboe <jens.axboe@oracle.com>
      f331c029
  29. 11 9月, 2008 1 次提交
  30. 29 8月, 2008 1 次提交
    • F
      remove blk_register_filter and blk_unregister_filter in gendisk · bb23b431
      FUJITA Tomonori 提交于
      This patch remove blk_register_filter and blk_unregister_filter in
      gendisk, and adds them to sd.c, sr.c. and ide-cd.c
      
      The commit abf54393 moved cmdfilter
      from gendisk to request_queue. It turned out that in some subsystems
      multiple gendisks share a single request_queue. So we get:
      
      Using physmap partition information
      Creating 3 MTD partitions on "physmap-flash":
      0x00000000-0x01c00000 : "User FS"
      0x01c00000-0x01c40000 : "booter"
      kobject (8511c410): tried to init an initialized object, something is seriously wrong.
      Call Trace:
      [<8036644c>] dump_stack+0x8/0x34
      [<8021f050>] kobject_init+0x50/0xcc
      [<8021fa18>] kobject_init_and_add+0x24/0x58
      [<8021d20c>] blk_register_filter+0x4c/0x64
      [<8021c194>] add_disk+0x78/0xe0
      [<8027d14c>] add_mtd_blktrans_dev+0x254/0x278
      [<8027c8f0>] blktrans_notify_add+0x40/0x78
      [<80279c00>] add_mtd_device+0xd0/0x150
      [<8027b090>] add_mtd_partitions+0x568/0x5d8
      [<80285458>] physmap_flash_probe+0x2ac/0x334
      [<802644f8>] driver_probe_device+0x12c/0x244
      [<8026465c>] __driver_attach+0x4c/0x84
      [<80263c64>] bus_for_each_dev+0x58/0xac
      [<802633ec>] bus_add_driver+0xc4/0x24c
      [<802648e0>] driver_register+0xcc/0x184
      [<80100460>] _stext+0x60/0x1bc
      
      In the long term, we need to fix such subsystems but we need a quick
      fix now. This patch add the command filter support to only sd and sr
      though it might be useful for other SG_IO users (such as cciss).
      Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
      Reported-by: NManuel Lauss <mano@roarinelk.homelinux.net>
      Signed-off-by: NJens Axboe <jens.axboe@oracle.com>
      bb23b431