linux-stable.git/drivers/block/loop.c, branch linux-2.6.37.y

block: kill loop_mutex

2011-03-07T23:05:24+00:00

commit fd51469fb68b987032e46297e0a4fe9020063c20 upstream.

Following steps lead to deadlock in kernel:

dd if=/dev/zero of=img bs=512 count=1000
losetup -f img
mkfs.ext2 /dev/loop0
mount -t ext2 -o loop /dev/loop0 mnt
umount mnt/

Stacktrace:
[] irq_exit+0x36/0x59
[] smp_apic_timer_interrupt+0x6b/0x75
[] apic_timer_interrupt+0x31/0x38
[] mutex_spin_on_owner+0x54/0x5b
[] lo_release+0x12/0x67 [loop]
[] __blkdev_put+0x7c/0x10c
[] fput+0xd5/0x1aa
[] loop_clr_fd+0x1a9/0x1b1 [loop]
[] lo_release+0x39/0x67 [loop]
[] __blkdev_put+0x7c/0x10c
[] deactivate_locked_super+0x17/0x36
[] sys_umount+0x27e/0x2a5
[] sys_oldumount+0xb/0xe
[] sysenter_do_call+0x12/0x26
[] 0xffffffff

Regression since 2a48fc0ab24241755dc9, which introduced the private
loop_mutex as part of the BKL removal process.

As per [1], the mutex can be safely removed.

[1] http://www.gossamer-threads.com/lists/linux/kernel/1341930

Addresses: https://bugzilla.novell.com/show_bug.cgi?id=669394
Addresses: https://bugzilla.kernel.org/show_bug.cgi?id=29172

Signed-off-by: Petr Uzel 
Reviewed-by: Nikanth Karthikesan 
Acked-by: Arnd Bergmann 
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

block: remove REQ_HARDBARRIER

2010-11-10T13:54:09+00:00

REQ_HARDBARRIER is dead now, so remove the leftovers.  What's left
at this point is:

 - various checks inside the block layer.
 - sanity checks in bio based drivers.
 - now unused bio_empty_barrier helper.
 - Xen blockfront use of BLKIF_OP_WRITE_BARRIER - it's dead for a while,
   but Xen really needs to sort out it's barrier situaton.
 - setting of ordered tags in uas - dead code copied from old scsi
   drivers.
 - scsi different retry for barriers - it's dead and should have been
   removed when flushes were converted to FS requests.
 - blktrace handling of barriers - removed.  Someone who knows blktrace
   better should add support for REQ_FLUSH and REQ_FUA, though.

Signed-off-by: Christoph Hellwig 
Signed-off-by: Jens Axboe

loop: Properly clear sysfs in autoclear mode

2010-10-28T01:51:30+00:00

In autoclear mode bdev is NULL but the sysfs
entry should be destroyed otherwise this warning appears:

WARNING: at fs/sysfs/dir.c:451 sysfs_add_one+0x82/0x95()
sysfs: cannot create duplicate filename '/devices/virtual/block/loop0/loop'

Fixes commit ee86273062cbb310665fe49e1f1937d2cf85b0b9

Signed-off-by: Milan Broz 
Signed-off-by: Jens Axboe

mm: strictly nested kmap_atomic()

2010-10-26T23:52:08+00:00

Ensure kmap_atomic() usage is strictly nested

Signed-off-by: Peter Zijlstra 
Reviewed-by: Rik van Riel 
Acked-by: Chris Metcalf 
Cc: David Howells 
Cc: Hugh Dickins 
Cc: Ingo Molnar 
Cc: Thomas Gleixner 
Cc: "H. Peter Anvin" 
Cc: Steven Rostedt 
Cc: Russell King 
Cc: Ralf Baechle 
Cc: David Miller 
Cc: Paul Mackerras 
Cc: Benjamin Herrenschmidt 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge branch 'for-2.6.37/barrier' of git://git.kernel.dk/linux-2.6-block

2010-10-23T00:07:18+00:00

* 'for-2.6.37/barrier' of git://git.kernel.dk/linux-2.6-block: (46 commits)
  xen-blkfront: disable barrier/flush write support
  Added blk-lib.c and blk-barrier.c was renamed to blk-flush.c
  block: remove BLKDEV_IFL_WAIT
  aic7xxx_old: removed unused 'req' variable
  block: remove the BH_Eopnotsupp flag
  block: remove the BLKDEV_IFL_BARRIER flag
  block: remove the WRITE_BARRIER flag
  swap: do not send discards as barriers
  fat: do not send discards as barriers
  ext4: do not send discards as barriers
  jbd2: replace barriers with explicit flush / FUA usage
  jbd2: Modify ASYNC_COMMIT code to not rely on queue draining on barrier
  jbd: replace barriers with explicit flush / FUA usage
  nilfs2: replace barriers with explicit flush / FUA usage
  reiserfs: replace barriers with explicit flush / FUA usage
  gfs2: replace barriers with explicit flush / FUA usage
  btrfs: replace barriers with explicit flush / FUA usage
  xfs: replace barriers with explicit flush / FUA usage
  block: pass gfp_mask and flags to sb_issue_discard
  dm: convey that all flushes are processed as empty
  ...

Merge branch 'for-2.6.37/drivers' of git://git.kernel.dk/linux-2.6-block

2010-10-23T00:03:12+00:00

* 'for-2.6.37/drivers' of git://git.kernel.dk/linux-2.6-block: (95 commits)
  cciss: fix PCI IDs for new Smart Array controllers
  drbd: add race-breaker to drbd_go_diskless
  drbd: use dynamic_dev_dbg to optionally log uuid changes
  dynamic_debug.h: Fix dynamic_dev_dbg() macro if CONFIG_DYNAMIC_DEBUG not set
  drbd: cleanup: change "<= 0" to "== 0"
  drbd: relax the grace period of the md_sync timer again
  drbd: add some more explicit drbd_md_sync
  drbd: drop wrong debug asserts, fix recently introduced race
  drbd: cleanup useless leftover warn/error printk's
  drbd: add explicit drbd_md_sync to drbd_resync_finished
  drbd: Do not log an ASSERT for P_OV_REQUEST packets while C_CONNECTED
  drbd: fix for possible deadlock on IO error during resync
  drbd: fix unlikely access after free and list corruption
  drbd: fix for spurious fullsync (uuids rotated too fast)
  drbd: allow for explicit resync-finished notifications
  drbd: preparation commit, using full state in receive_state()
  drbd: drbd_send_ack_dp must not rely on header information
  drbd: Fix regression in recv_bm_rle_bits (compressed bitmap)
  drbd: Fixed a stupid copy and paste error
  drbd: Allow larger values for c-fill-target.
  ...

Fix up trivial conflict in drivers/block/ataflop.c due to BKL removal

block: autoconvert trivial BKL users to private mutex

2010-10-05T13:01:10+00:00

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.*/d' ${file}
    else
            sed -i 's/include.*.*$/include /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.*\/d' ${file}  \
                -e '/cycle_kernel_lock()/d'
fi

Signed-off-by: Arnd Bergmann

block/loop: implement REQ_FLUSH/FUA support

2010-09-10T10:35:37+00:00

Deprecate REQ_HARDBARRIER and implement REQ_FLUSH/FUA instead.  Also,
instead of checking file->f_op->fsync() directly, look at the value of
vfs_fsync() and ignore -EINVAL return.

Signed-off-by: Tejun Heo 
Signed-off-by: Jens Axboe

block: deprecate barrier and replace blk_queue_ordered() with blk_queue_flush()

2010-09-10T10:35:36+00:00

Barrier is deemed too heavy and will soon be replaced by FLUSH/FUA
requests.  Deprecate barrier.  All REQ_HARDBARRIERs are failed with
-EOPNOTSUPP and blk_queue_ordered() is replaced with simpler
blk_queue_flush().

blk_queue_flush() takes combinations of REQ_FLUSH and FUA.  If a
device has write cache and can flush it, it should set REQ_FLUSH.  If
the device can handle FUA writes, it should also set REQ_FUA.

All blk_queue_ordered() users are converted.

* ORDERED_DRAIN is mapped to 0 which is the default value.
* ORDERED_DRAIN_FLUSH is mapped to REQ_FLUSH.
* ORDERED_DRAIN_FLUSH_FUA is mapped to REQ_FLUSH | REQ_FUA.

Signed-off-by: Tejun Heo 
Acked-by: Boaz Harrosh 
Cc: Christoph Hellwig 
Cc: Nick Piggin 
Cc: Michael S. Tsirkin 
Cc: Jeremy Fitzhardinge 
Cc: Chris Wright 
Cc: FUJITA Tomonori 
Cc: Geert Uytterhoeven 
Cc: David S. Miller 
Cc: Alasdair G Kergon 
Cc: Pierre Ossman 
Cc: Stefan Weinhuber 
Signed-off-by: Jens Axboe

block/loop: queue ordered mode should be DRAIN_FLUSH

2010-09-10T10:35:36+00:00

loop implements FLUSH using fsync but was incorrectly setting its
ordered mode to DRAIN.  Change it to DRAIN_FLUSH.  In practice, this
doesn't change anything as loop doesn't make use of the block layer
ordered implementation.

Signed-off-by: Tejun Heo 
Signed-off-by: Jens Axboe