cgroup: delay the clearing of cgrp->kn->priv

Run these two scripts concurrently:

    for ((; ;))
    {
        mkdir /cgroup/sub
        rmdir /cgroup/sub
    }

    for ((; ;))
    {
        echo $$ > /cgroup/sub/cgroup.procs
        echo $$ > /cgroup/cgroup.procs
    }

A kernel bug will be triggered:

BUG: unable to handle kernel NULL pointer dereference at 00000038
IP: [<c10bbd69>] cgroup_put+0x9/0x80
...
Call Trace:
 [<c10bbe19>] cgroup_kn_unlock+0x39/0x50
 [<c10bbe91>] cgroup_kn_lock_live+0x61/0x70
 [<c10be3c1>] __cgroup_procs_write.isra.26+0x51/0x230
 [<c10be5b2>] cgroup_tasks_write+0x12/0x20
 [<c10bb7b0>] cgroup_file_write+0x40/0x130
 [<c11aee71>] kernfs_fop_write+0xd1/0x160
 [<c1148e58>] vfs_write+0x98/0x1e0
 [<c114934d>] SyS_write+0x4d/0xa0
 [<c16f656b>] sysenter_do_call+0x12/0x12

We clear cgrp->kn->priv in the end of cgroup_rmdir(), but another
concurrent thread can access kn->priv after the clearing.

We should move the clearing to css_release_work_fn(). At that time
no one is holding reference to the cgroup and no one can gain a new
reference to access it.

v2:
- move RCU_INIT_POINTER() into the else block. (Tejun)
- remove the cgroup_parent() check. (Tejun)
- update the comment in css_tryget_online_from_dir().

Cc: <stable@vger.kernel.org> # 3.15+
Reported-by: Toralf Förster <toralf.foerster@gmx.de>
Signed-off-by: Zefan Li <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
cgroup: check cgroup liveliness before unbreaking kernfs

When cgroup_kn_lock_live() is called through some kernfs operation and
another thread is calling cgroup_rmdir(), we'll trigger the warning in
cgroup_get().

------------[ cut here ]------------
WARNING: CPU: 1 PID: 1228 at kernel/cgroup.c:1034 cgroup_get+0x89/0xa0()
...
Call Trace:
 [<c16ee73d>] dump_stack+0x41/0x52
 [<c10468ef>] warn_slowpath_common+0x7f/0xa0
 [<c104692d>] warn_slowpath_null+0x1d/0x20
 [<c10bb999>] cgroup_get+0x89/0xa0
 [<c10bbe58>] cgroup_kn_lock_live+0x28/0x70
 [<c10be3c1>] __cgroup_procs_write.isra.26+0x51/0x230
 [<c10be5b2>] cgroup_tasks_write+0x12/0x20
 [<c10bb7b0>] cgroup_file_write+0x40/0x130
 [<c11aee71>] kernfs_fop_write+0xd1/0x160
 [<c1148e58>] vfs_write+0x98/0x1e0
 [<c114934d>] SyS_write+0x4d/0xa0
 [<c16f656b>] sysenter_do_call+0x12/0x12
---[ end trace 6f2e0c38c2108a74 ]---

Fix this by calling css_tryget() instead of cgroup_get().

v2:
- move cgroup_tryget() right below cgroup_get() definition. (Tejun)

Cc: <stable@vger.kernel.org> # 3.15+
Reported-by: Toralf Förster <toralf.foerster@gmx.de>
Signed-off-by: Zefan Li <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Merge tag 'platform-drivers-x86-v3.17-1' of git://git.infradead.org/users/dvhart/linux-platform-drivers-x86

Pull x86 platform drivers fixes from Darren Hart:
 "This is my first pull request since taking on maintenance for the
  platform-drivers-x86 tree from Matthew Garrett.  These have passed my
  build testing and been run through Fengguang's LKP tests.  Due to
  timing this round, these have not spent any time in linux-next.  I
  have asked Stephen to include my for-next branch in linux-next going
  forward, once he's back from vacation.

  Details from tag:

   - toshiba_acpi: re-enable hotkeys and cleanups
   - ideapad-laptop: revert touchpad disable, and cleanup static/const
     usage
   - MAINTAINERS: update platform-drivers-x86 maintainer and tree"

* tag 'platform-drivers-x86-v3.17-1' of git://git.infradead.org/users/dvhart/linux-platform-drivers-x86:
  toshiba_acpi: fix and cleanup toshiba_kbd_bl_mode_store()
  platform/x86: toshiba: re-enable acpi hotkeys after suspend to disk
  ideapad-laptop: Constify DMI table for real!
  Revert "ideapad-laptop: Disable touchpad interface on Yoga models"
  MAINTAINERS: Update platform-drivers-x86 maintainer and tree
Merge tag 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging

Pull hwmon bugfix from Guenter Roeck:
 "Fix a bug in the ds1621 driver"

* tag 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging:
  hwmon: (ds1621) Update zbits after conversion rate change
Merge tag 'mac80211-for-john-2014-08-29' of git://git.kernel.org/pub/scm/linux/kernel/git/jberg/mac80211

Johannes Berg <johannes@sipsolutions.net> says:

"Here are a few fixes for mac80211. One has been discussed for a while
and adds a terminating NUL-byte to the alpha2 sent to userspace, which
shouldn't be necessary but since many places treat it as a string we
couldn't move to just sending two bytes.

In addition to that, we have two VLAN fixes from Felix, a mesh fix, a
fix for the recently introduced RX aggregation offload, a revert for
a broken patch (that luckily didn't really cause any harm) and a small
fix for alignment in debugfs."

Signed-off-by: John W. Linville <linville@redhat.com>
Merge branch 'for-john' of git://git.kernel.org/pub/scm/linux/kernel/git/iwlwifi/iwlwifi-fixes
Revert "i2c: rcar: remove spinlock"

This reverts commit 150b8be3cda54412ad7b54f5392b513b25c0aaa7.

The I2C core's per-adapter locks can't protect from IRQs, so the driver still
needs a spinlock to protect the register accesses.

Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Cc: stable@vger.kernel.org # 3.16+
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Merge branch 'topic/component' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound into asoc-suspend
ASoC: Set card->instantiated to false when removing the card

Set card->instantiated to false when the card is removed to make sure that
operations that expect the card to be fully instantiated do not run anymore
during card removal.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
ASoC: Shutdown DAPM contexts when removing a card

Currently when a ASoC sound card is unregistered we leave the individual
components in their current state, just call the remove() callback and leave
it to the drivers to do the proper shutdown/cleanup.

This patch introduces a call to snd_soc_dapm_shutdown() when removing the
card.  This will make sure that all DAPM widgets are properly powered down
and all DAPM contexts are put at the SND_SOC_BIAS_OFF level. This will
ensure that all components are properly powered down when the card is
removed.

Since a lot of drivers manually go to SND_SOC_BIAS_OFF in their remove
callback this will also allow us to remove a bit of duplicated code.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
ASoC: Add support for automatically going to BIAS_OFF on suspend

There is a substantial amount of drivers that in go to SND_SOC_BIAS_OFF on
suspend and go back to SND_SOC_BIAS_SUSPEND on resume (Often this is even
the only thing done in the suspend and resume handlers). This patch
introduces a new suspend_bias_off flag, which when set by a driver will let
the ASoC core automatically put the device's DAPM context at the
SND_SOC_BIAS_OFF level during suspend. Once the device is resumed the DAPM
context will go back to SND_SOC_BIAS_STANDBY (if the context is idle,
otherwise to SND_SOC_BIAS_ON).

This will allow us to remove a fair bit of duplicated code from the drivers.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
ASoC: Always run default suspend/resume code

We do a bit more than just running the callbacks during suspend and resume
these days (e.g. call regcache_mark_dirty() during suspend). But this is
only when suspend and resume callbacks are specified for the driver,
otherwise nothing is done. This means that drivers which don't want to do
anything special during suspend and resume, but still want the standard
operations to run, need to provide empty suspend and resume callback
functions (rather than no callbacks). This patch updates the suspend and
resume code to always run standard sequence regardless of whether suspend
and resume handlers are provided.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
ASoC: adau1373: Cleanup manual bias level transitions

The ASoC core now takes care of setting the bias level to SND_SOC_BIAS_OFF
when removing the CODEC, no need to do it manually anymore.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
ASoC: adau17x1: Cleanup manual bias level transitions

Set the CODEC driver's suspend_bias_off flag rather than manually going to
SND_SOC_BIAS_OFF in suspend and SND_SOC_BIAS_STANDBY in resume. This makes
the code a bit shorter and cleaner.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
ASoC: adav80x: Cleanup manual bias level transitions

Set the CODEC driver's suspend_bias_off flag rather than manually going to
SND_SOC_BIAS_OFF in suspend and SND_SOC_BIAS_STANDBY in resume. This makes
the code a bit shorter and cleaner. While we are at it also remove the
regcache_cache_only() calls from suspend/resume as there shouldn't be any IO
between suspend and resume.

Since the ASoC core now takes care of setting the bias level to
SND_SOC_BIAS_OFF when removing the CODEC there is no need to do it manually
anymore either.

The manual transition to SND_SOC_BIAS_STANDBY at the end of CODEC probe()
can also be removed as the core will automatically do this after the CODEC
has been probed.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
ASoC: ssm2518: Cleanup manual bias level transitions

Since the ASoC core now takes care of setting the bias level to
SND_SOC_BIAS_OFF when removing the CODEC there is no need to do it manually
anymore either.

The manual transition to SND_SOC_BIAS_OFF at the end of CODEC probe()
can also be removed as the CODEC is already in OFF state at this point.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
ASoC: ssm2602: Cleanup manual bias level transitions

Set the CODEC driver's suspend_bias_off flag rather than manually going to
SND_SOC_BIAS_OFF in suspend and SND_SOC_BIAS_STANDBY in resume. This makes
the code a bit shorter and cleaner. While we are at it also remove the
regcache_cache_only() calls from suspend/resume as there shouldn't be any IO
between suspend and resume.

Since the ASoC core now takes care of setting the bias level to
SND_SOC_BIAS_OFF when removing the CODEC there is no need to do it manually
anymore either.

The manual transition to SND_SOC_BIAS_STANDBY at the end of CODEC probe()
can also be removed as the core will automatically do this after the CODEC
has been probed.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
spi: sirf: enable RX_IO_DMA_INT interrupt

in spi interrupt handler, we need check RX_IO_DMA status to ensure
rx fifo have received the specify count data.

if not set, the while statement in spi isr function will keep loop,
at last, make the kernel hang.

[The code is actually there in the interrupt handler but apparently it
needs the interrupt unmasking so the handler sees the status -- broonie]

Signed-off-by: Qipan Li <Qipan.Li@csr.com>
Signed-off-by: Barry Song <Baohua.Song@csr.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org
udf: Make udf_read_inode() and udf_iget() return error

Currently __udf_read_inode() wasn't returning anything and we found out
whether we succeeded reading inode by checking whether inode is bad or
not. udf_iget() returned NULL on failure and inode pointer otherwise.
Make these two functions properly propagate errors up the call stack and
use the return value in callers.

Signed-off-by: Jan Kara <jack@suse.cz>
udf: Properly detect stale inodes

NFS can easily ask for inodes that are already deleted. Currently UDF
happily returns such inodes which is a bug. Return -ESTALE if
udf_read_inode() is asked to read deleted inode.

Signed-off-by: Jan Kara <jack@suse.cz>