linux-stable.git/drivers/block, branch v3.2.40

nbd: fsync and kill block device on shutdown

2013-03-06T03:24:17+00:00

commit 3a2d63f87989e01437ba994df5f297528c353d7d upstream.

There are two problems with shutdown in the NBD driver.

1: Receiving the NBD_DISCONNECT ioctl does not sync the filesystem.

   This patch adds the sync operation into __nbd_ioctl()'s
   NBD_DISCONNECT handler.  This is useful because BLKFLSBUF is restricted
   to processes that have CAP_SYS_ADMIN, and the NBD client may not
   possess it (fsync of the block device does not sync the filesystem,
   either).

2: Once we clear the socket we have no guarantee that later reads will
   come from the same backing storage.

   The patch adds calls to kill_bdev() in __nbd_ioctl()'s socket
   clearing code so the page cache is cleaned, lest reads that hit on the
   page cache will return stale data from the previously-accessible disk.

Example:

    # qemu-nbd -r -c/dev/nbd0 /dev/sr0
    # file -s /dev/nbd0
    /dev/stdin: # UDF filesystem data (version 1.5) etc.
    # qemu-nbd -d /dev/nbd0
    # qemu-nbd -r -c/dev/nbd0 /dev/sda
    # file -s /dev/nbd0
    /dev/stdin: # UDF filesystem data (version 1.5) etc.

While /dev/sda has:

    # file -s /dev/sda
    /dev/sda: x86 boot sector; etc.

Signed-off-by: Paolo Bonzini 
Acked-by: Paul Clements 
Cc: Alex Bligh 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
[bwh: Backported to 3.2:
 - Adjusted context
 - s/\bnbd\b/lo/
 - Incorporate export of kill_bdev() from commit ff01bb483265
   ('fs: move code out of buffer.c')]
Signed-off-by: Ben Hutchings

xen-blkback: do not leak mode property

2013-03-06T03:24:05+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: Ben Hutchings

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

2013-03-06T03:22:33+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: Ben Hutchings

drbd: add missing part_round_stats to _drbd_start_io_acct

2013-02-06T04:33:56+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 
Signed-off-by: Ben Hutchings

virtio-blk: Don't free ida when disk is in use

2013-02-06T04:33:19+00:00

commit f4953fe6c4aeada2d5cafd78aa97587a46d2d8f9 upstream.

When a file system is mounted on a virtio-blk disk, we then remove it
and then reattach it, the reattached disk gets the same disk name and
ids as the hot removed one.

This leads to very nasty effects - mostly rendering the newly attached
device completely unusable.

Trying what happens when I do the same thing with a USB device, I saw
that the sd node simply doesn't get free'd when a device gets forcefully
removed.

Imitate the same behavior for vd devices. This way broken vd devices
simply are never free'd and newly attached ones keep working just fine.

Signed-off-by: Alexander Graf 
Signed-off-by: Rusty Russell 
Signed-off-by: Ben Hutchings

aoe: do not call bdi_init after blk_alloc_queue

2013-01-16T01:13:29+00:00

commit 0a41409c518083133e79015092585d68915865be upstream.

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: Ben Hutchings

floppy: properly handle failure on add_disk loop

2012-11-16T16:47:00+00:00

commit d60e7ec18c3fb2cbf90969ccd42889eb2d03aef9 upstream.

On floppy initialization, if something failed inside the loop we call
add_disk, there was no cleanup of previous iterations in the error
handling.

Signed-off-by: Herton Ronaldo Krzesinski 
Signed-off-by: Jiri Kosina 
Signed-off-by: Jens Axboe 
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings

floppy: do put_disk on current dr if blk_init_queue fails

2012-11-16T16:46:59+00:00

commit 238ab78469c6ab7845b43d5061cd3c92331b2452 upstream.

If blk_init_queue fails, we do not call put_disk on the current dr
(dr is decremented first in the error handling loop).

Reviewed-by: Ben Hutchings 
Signed-off-by: Herton Ronaldo Krzesinski 
Signed-off-by: Jiri Kosina 
Signed-off-by: Jens Axboe 
Signed-off-by: Ben Hutchings

x86: Remove the ancient and deprecated disable_hlt() and enable_hlt() facility

2012-11-16T16:46:46+00:00

commit f6365201d8a21fb347260f89d6e9b3e718d63c70 upstream.

The X86_32-only disable_hlt/enable_hlt mechanism was used by the
32-bit floppy driver. Its effect was to replace the use of the
HLT instruction inside default_idle() with cpu_relax() - essentially
it turned off the use of HLT.

This workaround was commented in the code as:

 "disable hlt during certain critical i/o operations"

 "This halt magic was a workaround for ancient floppy DMA
  wreckage. It should be safe to remove."

H. Peter Anvin additionally adds:

 "To the best of my knowledge, no-hlt only existed because of
  flaky power distributions on 386/486 systems which were sold to
  run DOS.  Since DOS did no power management of any kind,
  including HLT, the power draw was fairly uniform; when exposed
  to the much hhigher noise levels you got when Linux used HLT
  caused some of these systems to fail.

  They were by far in the minority even back then."

Alan Cox further says:

 "Also for the Cyrix 5510 which tended to go castors up if a HLT
  occurred during a DMA cycle and on a few other boxes HLT during
  DMA tended to go astray.

  Do we care ? I doubt it. The 5510 was pretty obscure, the 5520
  fixed it, the 5530 is probably the oldest still in any kind of
  use."

So, let's finally drop this.

Signed-off-by: Len Brown 
Signed-off-by: Josh Boyer 
Signed-off-by: Andrew Morton 
Acked-by: "H. Peter Anvin" 
Acked-by: Alan Cox 
Cc: Stephen Hemminger 
Link: http://lkml.kernel.org/n/tip-3rhk9bzf0x9rljkv488tloib@git.kernel.org
[ If anyone cares then alternative instruction patching could be
  used to replace HLT with a one-byte NOP instruction. Much simpler. ]
Signed-off-by: Ingo Molnar 
[bwh: Backported to 3.2: adjust filename, context]
Signed-off-by: Ben Hutchings

aoe: assert AoE packets marked as requiring no checksum

2012-10-10T02:31:34+00:00

[ Upstream commit 8babe8cc6570ed896b7b596337eb8fe730c3ff45 ]

In order for the network layer to see that AoE requires
no checksumming in a generic way, the packets must be
marked as requiring no checksum, so we make this requirement
explicit with the assertion.

Signed-off-by: Ed Cashin 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings