linux-toradex.git/drivers/block, branch v3.0.79

drbd: fix for deadlock when using automatic split-brain-recovery

2013-05-19T17:04:48+00:00

commit 7c689e63a847316c1b2500f86891b0a574ce7e69 upstream.

With an automatic after split-brain recovery policy of
"after-sb-1pri call-pri-lost-after-sb",
when trying to drbd_set_role() to R_SECONDARY,
we run into a deadlock.

This was first recognized and supposedly fixed by
2009-06-10 "Fixed a deadlock when using automatic split brain recovery when both nodes are"
replacing drbd_set_role() with drbd_change_state() in that code-path,
but the first hunk of that patch forgets to remove the drbd_set_role().

We apparently only ever tested the "two primaries" case.

Signed-off-by: Philipp Reisner 
Signed-off-by: Lars Ellenberg 
Signed-off-by: Jens Axboe 
Signed-off-by: Jonghwan Choi 
Signed-off-by: Greg Kroah-Hartman

aoe: reserve enough headroom on skbs

2013-04-05T17:16:53+00:00

[ Upstream commit 91c5746425aed8f7188a351f1224a26aa232e4b3 ]

Some network drivers use a non default hard_header_len

Transmitted skb should take into account dev->hard_header_len, or risk
crashes or expensive reallocations.

In the case of aoe, lets reserve MAX_HEADER bytes.

David reported a crash in defxx driver, solved by this patch.

Reported-by: David Oostdyk 
Tested-by: David Oostdyk 
Signed-off-by: Eric Dumazet 
Cc: Ed Cashin 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

loop: prevent bdev freeing while device in use

2013-04-05T17:16:51+00:00

commit c1681bf8a7b1b98edee8b862a42c19c4e53205fd upstream.

struct block_device lifecycle is defined by its inode (see fs/block_dev.c) -
block_device allocated first time we access /dev/loopXX and deallocated on
bdev_destroy_inode. When we create the device "losetup /dev/loopXX afile"
we want that block_device stay alive until we destroy the loop device
with "losetup -d".

But because we do not hold /dev/loopXX inode its counter goes 0, and
inode/bdev can be destroyed at any moment. Usually it happens at memory
pressure or when user drops inode cache (like in the test below). When later in
loop_clr_fd() we want to use bdev we have use-after-free error with following
stack:

BUG: unable to handle kernel NULL pointer dereference at 0000000000000280
  bd_set_size+0x10/0xa0
  loop_clr_fd+0x1f8/0x420 [loop]
  lo_ioctl+0x200/0x7e0 [loop]
  lo_compat_ioctl+0x47/0xe0 [loop]
  compat_blkdev_ioctl+0x341/0x1290
  do_filp_open+0x42/0xa0
  compat_sys_ioctl+0xc1/0xf20
  do_sys_open+0x16e/0x1d0
  sysenter_dispatch+0x7/0x1a

To prevent use-after-free we need to grab the device in loop_set_fd()
and put it later in loop_clr_fd().

The issue is reprodusible on current Linus head and v3.3. Here is the test:

  dd if=/dev/zero of=loop.file bs=1M count=1
  while [ true ]; do
    losetup /dev/loop0 loop.file
    echo 2 > /proc/sys/vm/drop_caches
    losetup -d /dev/loop0
  done

[ Doing bdgrab/bput in loop_set_fd/loop_clr_fd is safe, because every
  time we call loop_set_fd() we check that loop_device->lo_state is
  Lo_unbound and set it to Lo_bound If somebody will try to set_fd again
  it will get EBUSY.  And if we try to loop_clr_fd() on unbound loop
  device we'll get ENXIO.

  loop_set_fd/loop_clr_fd (and any other loop ioctl) is called under
  loop_device->lo_ctl_mutex. ]

Signed-off-by: Anatol Pomozov 
Cc: Al Viro 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

xen-blkback: fix dispatch_rw_block_io() error path

2013-04-05T17:16:36+00:00

commit 0e5e098ac22dae38f957e951b70d3cf73beff0f7 upstream.

Commit 7708992 ("xen/blkback: Seperate the bio allocation and the bio
submission") consolidated the pendcnt updates to just a single write,
neglecting the fact that the error path relied on it getting set to 1
up front (such that the decrement in __end_block_io_op() would actually
drop the count to zero, triggering the necessary cleanup actions).

Also remove a misleading and a stale (after said commit) comment.

Signed-off-by: Jan Beulich 
Signed-off-by: Konrad Rzeszutek Wilk 
Signed-off-by: Greg Kroah-Hartman

loopdev: fix a deadlock

2013-03-20T19:58:53+00:00

commit 5370019dc2d2c2ff90e95d181468071362934f3a upstream.

bd_mutex and lo_ctl_mutex can be held in different order.

Path #1:

blkdev_open
 blkdev_get
  __blkdev_get (hold bd_mutex)
   lo_open (hold lo_ctl_mutex)

Path #2:

blkdev_ioctl
 lo_ioctl (hold lo_ctl_mutex)
  lo_set_capacity (hold bd_mutex)

Lockdep does not report it, because path #2 actually holds a subclass of
lo_ctl_mutex.  This subclass seems creep into the code by mistake.  The
patch author actually just mentioned it in the changelog, see commit
f028f3b2 ("loop: fix circular locking in loop_clr_fd()"), also see:

	http://marc.info/?l=linux-kernel&m=123806169129727&w=2

Path #2 hold bd_mutex to call bd_set_size(), I've protected it
with i_mutex in a previous patch, so drop bd_mutex at this site.

Signed-off-by: Guo Chao 
Cc: Alexander Viro 
Cc: Guo Chao 
Cc: M. Hindess 
Cc: Nikanth Karthikesan 
Cc: Jens Axboe 
Signed-off-by: Andrew Morton 
Signed-off-by: Jens Axboe 
Acked-by: Jeff Mahoney 
Signed-off-by: Greg Kroah-Hartman

xen-blkback: do not leak mode property

2013-03-03T22:09:04+00:00

commit 9d092603cc306ee6edfe917bf9ab8beb5f32d7bc upstream.

"be->mode" is obtained from xenbus_read(), which does a kmalloc() for
the message body. The short string is never released, so do it along
with freeing "be" itself, and make sure the string isn't kept when
backend_changed() doesn't complete successfully (which made it
desirable to slightly re-structure that function, so that the error
cleanup can be done in one place).

Reported-by: Olaf Hering 
Signed-off-by: Jan Beulich 
Signed-off-by: Konrad Rzeszutek Wilk 
Signed-off-by: Greg Kroah-Hartman

sunvdc: Fix off-by-one in generic_request().

2013-02-28T14:32:26+00:00

[ Upstream commit f4d9605434c0fd4cc8639bf25cfc043418c52362 ]

The 'operations' bitmap corresponds one-for-one with the operation
codes, no adjustment is necessary.

Reported-by: Mark Kettenis 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

drbd: add missing part_round_stats to _drbd_start_io_acct

2013-01-21T19:44:59+00:00

commit 72585d2428fa3a0daab02ebad1f41e5ef517dbaa upstream.

Without this, iostat frequently sees bogus svctime and >= 100% "utilization".

Signed-off-by: Philipp Reisner 
Signed-off-by: Lars Ellenberg 
Cc: Raoul Bhatia 
Signed-off-by: Greg Kroah-Hartman

aoe: do not call bdi_init after blk_alloc_queue

2013-01-17T16:43:57+00:00

commit 0a41409c518083133e79015092585d68915865be upstream, but doesn't
apply, so this version is different for older kernels than 3.7.x

blk_alloc_queue has already done a bdi_init, so do not bdi_init
again in aoeblk_gdalloc.  The extra call causes list corruption
in the per-CPU backing dev info stats lists.

Affected users see console WARNINGs about list_del corruption on
percpu_counter_destroy when doing "rmmod aoe" or "aoeflush -a"
when AoE targets have been detected and initialized by the
system.

The patch below applies to v3.6.11, with its v47 aoe driver.  It
is expected to apply to all currently maintained stable kernels
except 3.7.y.  A related but different fix has been posted for
3.7.y.

References:

  RedHat bugzilla ticket with original report
  https://bugzilla.redhat.com/show_bug.cgi?id=853064

  LKML discussion of bug and fix
  http://thread.gmane.org/gmane.linux.kernel/1416336/focus=1416497

Reported-by: Josh Boyer 
Signed-off-by: Ed Cashin 
Signed-off-by: Greg Kroah-Hartman

drivers/block/DAC960: fix -Wuninitialized warning

2012-12-03T20:59:12+00:00

commit cecd353a02fb1405c8a72a324b26b5acf97e7411 upstream.

Set CommandMailbox with memset before use it. Fix for:

drivers/block/DAC960.c: In function ‘DAC960_V1_EnableMemoryMailboxInterface’:
arch/x86/include/asm/io.h:61:1: warning: ‘CommandMailbox.Bytes[12]’
 may be used uninitialized in this function [-Wuninitialized]
drivers/block/DAC960.c:1175:30: note: ‘CommandMailbox.Bytes[12]’
 was declared here

Signed-off-by: Danny Kukawka 
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman