cgroup: make sure that decisions in __css_put are atomic

__css_put is using atomic_dec on the ref count, and then
looking at the ref count to make decisions.  This is prone
to races, as someone else may decrement ref count between
our decrement and our decision.  Instead, we should base our
decisions on the value that we decremented the ref count to.

(This results in an actual race on Google's kernel which I
haven't been able to reproduce on the upstream kernel.  Having
said that, it's still incorrect by inspection).

Signed-off-by: Salman Qazi <sqazi@google.com>
Acked-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: stable@vger.kernel.org
dmaengine: pl330: dont complete descriptor for cyclic dma

Commit eab215855803 ("dmaengine: pl330: dont complete descriptor for
cyclic dma") wrongly completes descriptor for cyclic dma, hence following
BUG_ON is still hit with cyclic DMA operations.

kernel BUG at drivers/dma/dmaengine.h:53!

Signed-off-by: Tushar Behera <tushar.behera@linaro.org>
Acked-by: Jassi Brar <jaswinder.singh@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
Cc: stable <stable@vger.kernel.org>
dma: imx-sdma: buf_tail should be initialize in prepare function

This fix audio underrun issue. When SNDRV_PCM_TRIGGER_STOP
and SNDRV_PCM_TRIGGER_START, it calls prepare again. buf_tail
should be reset to zero.
So move buf_tail initialization into prepare function.

Signed-off-by: Richard Zhao <richard.zhao@freescale.com>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
DMA: PL330: Add missing static storage class specifier

Fixes the following sparse warning:
drivers/dma/pl330.c:2542:5: warning: symbol 'add_desc' was not declared. Should it be static?

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
DMA: PL330: Fix racy mutex unlock

pl330_update() stores a pointer to the thrd->req that finished, which
contains a pointer to the corresponding pl330_req.  This is done with
the pl330_lock held.  Then, it iterates through the req_done list,
calling the callback for each of the requests that are done.  The
problem is that the driver releases the lock before calling the
callback for each of the callbacks.  pl330_submit_req() running in
another processor can then acquire the lock and insert another request
in one of the thrd->req that hasn't been processed yet, replacing the
pointer to pl330_req there.  When the callback returns in
pl330_update() and the next rqdone is popped from the list, it
dereferences the pl330_req pointer to the just scheduled pl330_req,
instead of the one that has finished, calling pl330 with the wrong r.

This patch fixes this by storing the pointer to pl330_req directly in
the list.

Signed-off-by: Javi Merino <javi.merino@arm.com>
Cc: Jassi Brar <jaswinder.singh@linaro.org>
Acked-by: Jassi Brar <jaswinder.singh@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
hwmon: (applesmc) Limit key length in warning messages

Key lookups may call read_smc() with a fixed-length key string,
and if the lookup fails, trailing stack content may appear in the
kernel log. Fixed with this patch.

Signed-off-by: Henrik Rydberg <rydberg@euromail.se>
Cc: stable@vger.kernel.org
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
hwmon: (emc2103) Fix use of an uninitilized variable in error case

Fix:

emc2103.c: In function set_pwm_enable:
emc2103.c:463:12: warning: conf_reg may be used uninitialized in this function

by checking the return value from read_u8_from_i2c(). This fixes a real problem,
as conf_reg is really uninitialized if read_u8_from_i2c returns an error.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Robert Coulson <robert.coulson@ericsson.com>
Acked-by: Jean Delvare <khali@linux-fr.org>
cgroups: Account for CSS_DEACT_BIAS in __css_put

When we fixed the race between atomic_dec and css_refcnt, we missed
the fact that css_refcnt internally subtracts CSS_DEACT_BIAS to get
the actual reference count.  This can potentially cause a refcount leak
if __css_put races with cgroup_clear_css_refs.

Signed-off-by: Salman Qazi <sqazi@google.com>
Acked-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
media: pms.c needs linux/slab.h

drivers/media/video/pms.c uses kzalloc() and kfree() so it should
include <linux/slab.h> to fix build errors and a warning.

  drivers/media/video/pms.c:1047:2: error: implicit declaration of function 'kzalloc'
  drivers/media/video/pms.c:1047:6: warning: assignment makes pointer from integer without a cast
  drivers/media/video/pms.c:1116:2: error: implicit declaration of function 'kfree'

Found in mmotm but applies to mainline.

Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Cc: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm, mempolicy: fix mbind() to do synchronous migration

If the range passed to mbind() is not allocated on nodes set in the
nodemask, it migrates the pages to respect the constraint.

The final formal of migrate_pages() is a mode of type enum migrate_mode,
not a boolean.  do_mbind() is currently passing "true" which is the
equivalent of MIGRATE_SYNC_LIGHT.  This should instead be MIGRATE_SYNC
for synchronous page migration.

Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Merge branch 'for-3.5-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup

Pull two cgroup fixes from Tejun Heo:
 "This containes two patches fixing a refcnt race bug during css_put().
  Decrementing and checking the value weren't atomic and two tasks could
  think that they both pushed the counter to zero."

* 'for-3.5-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cgroups: Account for CSS_DEACT_BIAS in __css_put
  cgroup: make sure that decisions in __css_put are atomic
Merge branch 'fixes' of git://git.infradead.org/users/vkoul/slave-dma

Pull slave-dmaengine fixes from Vinod Koul:
 "A few fixes in pl330 and imx-sdma drivers."

* 'fixes' of git://git.infradead.org/users/vkoul/slave-dma:
  DMA: PL330: Fix racy mutex unlock
  DMA: PL330: Add missing static storage class specifier
  dma: imx-sdma: buf_tail should be initialize in prepare function
  dmaengine: pl330: dont complete descriptor for cyclic dma
Btrfs: introduce btrfs_next_old_item

We introduce btrfs_next_old_item that uses btrfs_next_old_leaf instead
of btrfs_next_leaf.

btrfs_next_item is also changed to simply call btrfs_next_old_item with
time_seq being 0.

Signed-off-by: Alexander Block <ablock84@googlemail.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Btrfs: don't assume to be on the correct extent in add_all_parents

add_all_parents did assume that path is already at a correct extent data
item, which may not be true in case of data extents that were partly
rewritten and splitted.

We need to check if we're on a matching extent for every item and only
for the ones after the first. The loop is changed to do this now.

This patch also fixes a bug introduced with commit 3b127fd8 "Btrfs:
remove obsolete btrfs_next_leaf call from __resolve_indirect_ref".
The removal of next_leaf did sometimes result in slot==nritems when
the above described case happens, and thus resulting in invalid values
(e.g. wanted_obejctid) in add_all_parents (leading to missed backrefs
or even crashes).

Signed-off-by: Alexander Block <ablock84@googlemail.com>
Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Btrfs: add a missing spin_lock

When fixing up the locking in the delayed ref destruction work I accidently
broke the locking myself ;(.  Add back a spin_lock that should be there and
we are now all set.  Thanks,
Btrfs: add a missing spin_lock

When fixing up the locking in the delayed ref destruction work I accidently
broke the locking myself ;(.  Add back a spin_lock that should be there and
we are now all set.  Thanks,

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Btrfs: delay iput with async extents

There is some concern that these iput()'s could be the final iputs and could
induce lockups on people waiting on writeback.  This would happen in the
rare case that we don't create ordered extents because of an error, but it
is theoretically possible and we already have a mechanism to deal with this
so just make them delayed iputs to negate any worry.

Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Merge tag 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging

Pull hwmon fixes from Guenter Roeck:
 "Two minor fixes in emc2103 and applesmc drivers."

* tag 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging:
  hwmon: (emc2103) Fix use of an uninitilized variable in error case
  hwmon: (applesmc) Limit key length in warning messages
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs

Pull btrfs fixes from Chris Mason:
 "This is a small pull with btrfs fixes.  The biggest of the bunch is
  another fix for the new backref walking code.

  We're still hammering out one btrfs dio vs buffered reads problem, but
  that one will have to wait for the next rc."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: delay iput with async extents
  Btrfs: add a missing spin_lock
  Btrfs: don't assume to be on the correct extent in add_all_parents
  Btrfs: introduce btrfs_next_old_item