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  1. Mar 11, 2014
  3. May 07, 2013
  5. May 06, 2013
  7. Nov 21, 2012
  9. Mar 26, 2012
  11. Jan 09, 2012
    • Brian Norris's avatar
      mtd: mtd_blkdevs: don't increase 'open' count on error path · 342ff28f
      Brian Norris authored 
      
Some error paths in mtd_blkdevs were fixed in the following commit:

    commit 94735ec4
    mtd: mtd_blkdevs: fix error path in blktrans_open

But on these error paths, the block device's `dev->open' count is
already incremented before we check for errors. This meant that, while
the error path was handled correctly on the first time through
blktrans_open(), the device is erroneously considered already open on
the second time through.

This problem can be seen, for instance, when a UBI volume is
simultaneously mounted as a UBIFS partition and read through its
corresponding gluebi mtdblockX device. This results in blktrans_open()
passing its error checks (with `dev->open > 0') without actually having
a handle on the device. Here's a summarized log of the actions and
results with nandsim:

    # modprobe nandsim
    # modprobe mtdblock
    # modprobe gluebi
    # modprobe ubifs
    # ubiattach /dev/ubi_ctrl -m 0
    ...
    # ubimkvol /dev/ubi0 -N test -s 16MiB
    ...
    # mount -t ubifs ubi0:test /mnt
    # ls /dev/mtdblock*
    /dev/mtdblock0  /dev/mtdblock1
    # cat /dev/mtdblock1 > /dev/null
    cat: can't open '/dev/mtdblock4': Device or resource busy
    # cat /dev/mtdblock1 > /dev/null

    CPU 0 Unable to handle kernel paging request at virtual address
    fffffff0, epc == 8031536c, ra == 8031f280
    Oops[#1]:
    ...
    Call Trace:
    [<8031536c>] ubi_leb_read+0x14/0x164
    [<8031f280>] gluebi_read+0xf0/0x148
    [<802edba8>] mtdblock_readsect+0x64/0x198
    [<802ecfe4>] mtd_blktrans_thread+0x330/0x3f4
    [<8005be98>] kthread+0x88/0x90
    [<8000bc04>] kernel_thread_helper+0x10/0x18

Cc: stable@kernel.org [3.0+]
Signed-off-by: default avatarBrian Norris <computersforpeace@gmail.com>
Signed-off-by: default avatarArtem Bityutskiy <Artem.Bityutskiy@linux.intel.com>
Signed-off-by: default avatarDavid Woodhouse <David.Woodhouse@intel.com>
      342ff28f
  13. Oct 14, 2011
  15. May 25, 2011
  17. Mar 11, 2011
  19. Oct 30, 2010
  21. Oct 25, 2010
  23. Oct 05, 2010
    • Arnd Bergmann's avatar
      block: autoconvert trivial BKL users to private mutex · 2a48fc0a
      Arnd Bergmann authored 
      
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: default avatarArnd Bergmann <arnd@arndb.de>
      2a48fc0a
  25. Aug 08, 2010
  27. Aug 07, 2010
  29. Aug 06, 2010
  31. Aug 02, 2010
  33. Mar 09, 2010
  35. Feb 26, 2010
  37. Feb 25, 2010
  39. Nov 30, 2009
  41. Nov 26, 2009
    • Ilya Loginov's avatar
      block: add helpers to run flush_dcache_page() against a bio and a request's pages · 2d4dc890
      Ilya Loginov authored 
      
Mtdblock driver doesn't call flush_dcache_page for pages in request.  So,
this causes problems on architectures where the icache doesn't fill from
the dcache or with dcache aliases.  The patch fixes this.

The ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE symbol was introduced to avoid
pointless empty cache-thrashing loops on architectures for which
flush_dcache_page() is a no-op.  Every architecture was provided with this
flush pages on architectires where ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE is
equal 1 or do nothing otherwise.

See "fix mtd_blkdevs problem with caches on some architectures" discussion
on LKML for more information.

Signed-off-by: default avatarIlya Loginov <isloginov@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Peter Horton <phorton@bitbox.co.uk>
Cc: "Ed L. Cashin" <ecashin@coraid.com>
Signed-off-by: default avatarJens Axboe <jens.axboe@oracle.com>
      2d4dc890
  43. Oct 20, 2009
  45. Oct 01, 2009
    • Christoph Hellwig's avatar
      block: use normal I/O path for discard requests · c15227de
      Christoph Hellwig authored 
      
prepare_discard_fn() was being called in a place where memory allocation
was effectively impossible.  This makes it inappropriate for all but
the most trivial translations of Linux's DISCARD operation to the block
command set.  Additionally adding a payload there makes the ownership
of the bio backing unclear as it's now allocated by the device driver
and not the submitter as usual.

It is replaced with QUEUE_FLAG_DISCARD which is used to indicate whether
the queue supports discard operations or not.  blkdev_issue_discard now
allocates a one-page, sector-length payload which is the right thing
for the common ATA and SCSI implementations.

The mtd implementation of prepare_discard_fn() is replaced with simply
checking for the request being a discard.

Largely based on a previous patch from Matthew Wilcox <matthew@wil.cx>
which did the prepare_discard_fn but not the different payload allocation
yet.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarJens Axboe <jens.axboe@oracle.com>
      c15227de
    • Christoph Hellwig's avatar
      block: use normal I/O path for discard requests · 1122a26f
      Christoph Hellwig authored 
      
prepare_discard_fn() was being called in a place where memory allocation
was effectively impossible.  This makes it inappropriate for all but
the most trivial translations of Linux's DISCARD operation to the block
command set.  Additionally adding a payload there makes the ownership
of the bio backing unclear as it's now allocated by the device driver
and not the submitter as usual.

It is replaced with QUEUE_FLAG_DISCARD which is used to indicate whether
the queue supports discard operations or not.  blkdev_issue_discard now
allocates a one-page, sector-length payload which is the right thing
for the common ATA and SCSI implementations.

The mtd implementation of prepare_discard_fn() is replaced with simply
checking for the request being a discard.

Largely based on a previous patch from Matthew Wilcox <matthew@wil.cx>
which did the prepare_discard_fn but not the different payload allocation
yet.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
      1122a26f
  47. Sep 22, 2009
  49. Aug 03, 2009
  51. May 26, 2009