Using the current state of the page directory registers, we can
determine which of our address spaces was active when the hang occurred.
This allows us to scan through all the address spaces to identify the
"active" one during error capture.

v2: Rebased for BDW error detection. BDW error detection is similar
except instead of PP_DIR_BASE, we can use the PDP registers.
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
[danvet: Add FIXME about global gtt misuse.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The existing check was insufficient to determine whether we can use the
GTT mapping to read out the object during error capture.

The previous condition was, if the object has a GGTT mapping, and the
reloc is in the GTT range... the can happen with opjects mapped into
multiple vms (one of which being the GTT).

There are two solutions to this problem:
1. This patch, which avoid reading the io mapping
2. Use the GGTT offset with the io mapping.

Since error capture is about recording the most accurate possible error
state, and the error was caused by the object not in the GGTT - I opted
for the former.
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

formerly: drm/i915: Create VMAs (part 6) - finish error plumbing
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This came from a patch called, "drm/i915: Move active to vma"

When moving an object to the inactive list, we do it for all VMs for
which the object is bound.

The primary difference from that patch is this time around we don't not
track 'active' per vma, but rather by object. Therefore, we only need
one unref.
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This was found by code inspection. If the GTT setup fails then we are
left without properly tearing down the drm_mm.

Hopefully this never happens.
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

To be able to effectively use the GGTT object lookup function, we don't
want to warn when there is no GGTT mapping. Let the caller deal with it
instead.

Originally, I had intended to have this behavior, and has not
introduced the WARN. It was introduced during review with the addition
of the follow commit

commit 5c2abbea
Author: Ben Widawsky <benjamin.widawsky@intel.com>
Date:   Tue Sep 24 09:57:57 2013 -0700

    drm/i915: Provide a cheap ggtt vma lookup
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Since the beginning, the functions which try to properly reference the
aliasing PPGTT have deferences a potentially null aliasing_ppgtt member.
Since the accessors are meant to be global, this will not do.

Introduced originally in:
commit a70a3148
Author: Ben Widawsky <ben@bwidawsk.net>
Date:   Wed Jul 31 16:59:56 2013 -0700

    drm/i915: Make proper functions for VMs
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The initial implementation of this function used MMIO to write the PDPs.
Upon review it was determined (correctly) that the docs say to use LRI.
The issue is there are times where we want to do a synchronous write
(GPU reset).

I've tested this, and it works. I've verified with as many people as
possible that it should work.

This should fix the failing reset problems.
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Linux 3.13-rc3

I need a backmerge for two reasons:
- For merging the ppgtt patches from Ben I need to pull in the bdw
  support.
- We now have duplicated calls to intel_uncore_forcewake_reset in the
  setup code to due 2 different patches merged into -next and 3.13.
  The conflict is silen so I need the merge to be able to apply
  Deepak's fixup patch.

Conflicts:
	drivers/gpu/drm/i915/intel_display.c

Trivial conflict, it doesn't even show up in the merge diff.
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Currently, PC8 is enabled at modeset_global_resources, which is called
after intel_modeset_update_state. Due to this, there's a small race
condition on the case where we start enabling PC8, then do a modeset
while PC8 is still being enabled. The racing condition triggers a WARN
because intel_modeset_update_state will mark the CRTC as enabled, then
the thread that's still enabling PC8 might look at the data structure
and think that PC8 is being enabled while a pipe is enabled. Despite
the WARN, this is not really a bug since we'll wait for the
PC8-enabling thread to finish when we call modeset_global_resources.

The spec says the CRTC cannot be enabled when we disable LCPLL, so we
had a check for crtc->base.enabled. If we change to crtc->active we
will still prevent disabling LCPLL while the CRTC is enabled, and we
will also prevent the WARN above.

This is a replacement for the previous patch named
    "drm/i915: get/put PC8 when we get/put a CRTC"

Testcase: igt/pm_pc8/modeset-lpsp-stress-no-wait
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Merge tag 'trace-fixes-3.13-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fix from Steven Rostedt:
 "A regression showed up that there's a large delay when enabling all
  events.  This was prevalent when FTRACE_SELFTEST was enabled which
  enables all events several times, and caused the system bootup to
  pause for over a minute.

  This was tracked down to an addition of a synchronize_sched()
  performed when system call tracepoints are unregistered.

  The synchronize_sched() is needed between the unregistering of the
  system call tracepoint and a deletion of a tracing instance buffer.
  But placing the synchronize_sched() in the unreg of *every* system
  call tracepoint is a bit overboard.  A single synchronize_sched()
  before the deletion of the instance is sufficient"

* tag 'trace-fixes-3.13-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Only run synchronize_sched() at instance deletion time

Pull aio fix from Benjamin LaHaise:
 "AIO fix from Gu Zheng that fixes a GPF that Dave Jones uncovered with
  trinity"

* git://git.kvack.org/~bcrl/aio-next:
  aio: clean up aio ring in the fail path

Pull SCSI fixes from James Bottomley:
 "This is a set of nine fixes (and one author update).

  The libsas one should fix discovery in eSATA devices, the WRITE_SAME
  one is the largest, but it should fix a lot of problems we've been
  getting with the emulated RAID devices (they've been effectively lying
  about support and then firmware has been choking on the commands).

  The rest are various crash, hang or warn driver fixes"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  [SCSI] bfa: Fix crash when symb name set for offline vport
  [SCSI] enclosure: fix WARN_ON in dual path device removing
  [SCSI] pm80xx: Tasklets synchronization fix.
  [SCSI] pm80xx: Resetting the phy state.
  [SCSI] pm80xx: Fix for direct attached device.
  [SCSI] pm80xx: Module author addition
  [SCSI] hpsa: return 0 from driver probe function on success, not 1
  [SCSI] hpsa: do not discard scsi status on aborted commands
  [SCSI] Disable WRITE SAME for RAID and virtual host adapter drivers
  [SCSI] libsas: fix usage of ata_tf_to_fis

Pull IMA fixes from James Morris:
 "Here are two more fixes for IMA"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
  ima: properly free ima_template_entry structures
  ima: Do not free 'entry' before it is initialized

Pull devicetree fixes from Rob Herring:
 - Various DT binding documentation updates
 - Add Kumar Gala and remove Stephen Warren as DT binding maintainers

* tag 'dt-fixes-for-3.13' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux:
  dt: binding: reword PowerPC 8xxx GPIO documentation
  ARM: tegra: delete nvidia,tegra20-spi.txt binding
  hwmon: ntc_thermistor: Fix typo (pullup-uV -> pullup-uv)
  of: add vendor prefix for GMT
  clk: exynos: Fix typos in DT bindings documentation
  of: Add vendor prefix for LG Corporation
  Documentation: net: fsl-fec.txt: Add phy-supply entry
  ARM: dts: doc: Document missing binding for omap5-mpu
  dt-bindings: add ARMv8 PMU binding
  MAINTAINERS: remove swarren from DT bindings
  MAINTAINERS: Add Kumar to Device Tree Binding maintainers group

Clean up the aio ring file in the fail path of aio_setup_ring
and ioctx_alloc. And maybe it can fix the GPF issue reported by
Dave Jones:
https://lkml.org/lkml/2013/11/25/898Signed-off-by: NGu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: NBenjamin LaHaise <bcrl@kvack.org>

Merge branch 'free-memory' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity into for-linus

Pull power management fixes from Rafael Wysocki:

 - cpufreq regression fix from Bjørn Mork restoring the pre-3.12
   behavior of the framework during system suspend/hibernation to avoid
   garbage sysfs files from being left behind in case of a suspend error

 - PNP regression fix to restore the correct states of devices after
   resume from hibernation broken in 3.12.  From Dmitry Torokhov.

 - cpuidle fix to prevent cpuidle device unregistration from crashing
   due to a NULL pointer dereference if cpuidle has been disabled from
   the kernel command line.  From Konrad Rzeszutek Wilk.

 - intel_idle fix for the C6 state definition on Intel Avoton/Rangeley
   processors from Arne Bockholdt.

 - Power capping framework fix to make the energy_uj sysfs attribute
   work in accordance with the documentation.  From Srinivas Pandruvada.

 - epoll fix to make it ignore the EPOLLWAKEUP flag if the kernel has
   been compiled with CONFIG_PM_SLEEP unset (in which case that flag
   should not have any effect).  From Amit Pundir.

 - cpufreq fix to prevent governor sysfs files from being lost over
   system suspend/resume in some (arguably unusual) situations.  From
   Viresh Kumar.

* tag 'pm-3.13-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  PowerCap: Fix mode for energy counter
  PNP: fix restoring devices after hibernation
  cpuidle: Check for dev before deregistering it.
  epoll: drop EPOLLWAKEUP if PM_SLEEP is disabled
  cpufreq: fix garbage kobjects on errors during suspend/resume
  cpufreq: suspend governors on system suspend/hibernate
  intel_idle: Fixed C6 state on Avoton/Rangeley processors

* pm-epoll:
  epoll: drop EPOLLWAKEUP if PM_SLEEP is disabled

* pnp:
  PNP: fix restoring devices after hibernation

* powercap:
  PowerCap: Fix mode for energy counter

* pm-cpuidle:
  cpuidle: Check for dev before deregistering it.
  intel_idle: Fixed C6 state on Avoton/Rangeley processors

* pm-cpufreq:
  cpufreq: fix garbage kobjects on errors during suspend/resume
  cpufreq: suspend governors on system suspend/hibernate

Pull arch/tile ftrace bug fix from Chris Metcalf:
 "This fixes a build failure with allyesconfig reported by Fengguang Wu
  and fixed by Tony Lu"

* 'stable' of git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile:
  ftrace: default to tilegx if ARCH=tile is specified

Pull block layer fixes from Jens Axboe:
 "A small collection of fixes for the current series. It contains:

   - A fix for a use-after-free of a request in blk-mq.  From Ming Lei

   - A fix for a blk-mq bug that could attempt to dereference a NULL rq
     if allocation failed

   - Two xen-blkfront small fixes

   - Cleanup of submit_bio_wait() type uses in the kernel, unifying
     that.  From Kent

   - A fix for 32-bit blkg_rwstat reading.  I apologize for this one
     looking mangled in the shortlog, it's entirely my fault for missing
     an empty line between the description and body of the text"

* 'for-linus' of git://git.kernel.dk/linux-block:
  blk-mq: fix use-after-free of request
  blk-mq: fix dereference of rq->mq_ctx if allocation fails
  block: xen-blkfront: Fix possible NULL ptr dereference
  xen-blkfront: Silence pfn maybe-uninitialized warning
  block: submit_bio_wait() conversions
  Update of blkg_stat and blkg_rwstat may happen in bh context

Pull NFS client bugfixes from Trond Myklebust:
 - Stable fix for a NFSv4.1 delegation and state recovery deadlock
 - Stable fix for a loop on irrecoverable errors when returning
   delegations
 - Fix a 3-way deadlock between layoutreturn, open, and state recovery
 - Update the MAINTAINERS file with contact information for Trond
   Myklebust
 - Close needs to handle NFS4ERR_ADMIN_REVOKED
 - Enabling v4.2 should not recompile nfsd and lockd
 - Fix a couple of compile warnings

* tag 'nfs-for-3.13-3' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
  nfs: fix do_div() warning by instead using sector_div()
  MAINTAINERS: Update contact information for Trond Myklebust
  NFSv4.1: Prevent a 3-way deadlock between layoutreturn, open and state recovery
  SUNRPC: do not fail gss proc NULL calls with EACCES
  NFSv4: close needs to handle NFS4ERR_ADMIN_REVOKED
  NFSv4: Update list of irrecoverable errors on DELEGRETURN
  NFSv4 wait on recovery for async session errors
  NFS: Fix a warning in nfs_setsecurity
  NFS: Enabling v4.2 should not recompile nfsd and lockd

This matches the existing behavior in arch/tile/Makefile for defconfig.

Reported-by: fengguang.wu@intel.com
Acked-by: NSteven Rostedt <rostedt@goodmis.org>
Signed-off-by: NTony Lu <zlu@tilera.com>
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

It has been reported that boot up with FTRACE_SELFTEST enabled can take a
very long time. There can be stalls of over a minute.

This was tracked down to the synchronize_sched() called when a system call
event is disabled. As the self tests enable and disable thousands of events,
this makes the synchronize_sched() get called thousands of times.

The synchornize_sched() was added with d562aff9 "tracing: Add support
for SOFT_DISABLE to syscall events" which caused this regression (added
in 3.13-rc1).

The synchronize_sched() is to protect against the events being accessed
when a tracer instance is being deleted. When an instance is being deleted
all the events associated to it are unregistered. The synchronize_sched()
makes sure that no more users are running when it finishes.

Instead of calling synchronize_sched() for all syscall events, we only
need to call it once, after the events are unregistered and before the
instance is deleted. The event_mutex is held during this action to
prevent new users from enabling events.

Link: http://lkml.kernel.org/r/20131203124120.427b9661@gandalf.local.homeReported-by: NPetr Mladek <pmladek@suse.cz>
Acked-by: NTom Zanussi <tom.zanussi@linux.intel.com>
Acked-by: NPetr Mladek <pmladek@suse.cz>
Tested-by: NPetr Mladek <pmladek@suse.cz>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

Pull btrfs MAINTAINERS file update:
 "I'm still getting settled into new devel hardware etc, but I do have
  one commit for the next rc.

  This changes my email over to fb.com, and adds a MAINTAINERS entry for
  Josef as well"

* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: update the MAINTAINERS file

Pull minor fbdev fixes from Tomi Valkeinen.

* tag 'fbdev-fixes-3.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tomba/linux:
  video: vt8500: fix error handling in probe()
  atmel_lcdfb: fix module autoload
  fbdev: sh_mobile_meram: Fix defined but not used compiler warnings
  video: kyro: fix incorrect sizes when copying to userspace
  ARM: OMAPFB: panel-sony-acx565akm: fix bad unlock balance

Pull sound fixes from Takashi Iwai:
 "A usual pattern of half ASoC and half HD-audio fixes, although
  HD-audio fixups have more volumes, in addition to a couple of trivial
  fixes.  Nothing to worry much is found here.

  For ASoC side: a few fixes for PCM rate constraints calculations,
  regmap byte-order fix, the rest driver specific fixes (atmel, fsl,
  omap, kirkwood, wm codecs).

  For HD-audio: Dell headset and mono out fix, ELD update in polling
  mode, ALC283 Chromebook fixes, a few fixes for old AD codecs and
  MBA2, one regression fix"

* tag 'sound-3.13-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound: (30 commits)
  ALSA: hda - Fix silent output on MacBook Air 2,1
  ALSA: hda - Fix missing ELD info when using jackpoll_ms parameter
  ALSA: hda/realtek - remove hp_automute_hook from alc283_fixup_chromebook
  ASoC: wm8731: fix dsp mode configuration
  ALSA: hda/realtek - Independent of model for HP
  ALSA: hda - Fix headset mic input after muted internal mic (Dell/Realtek)
  ALSA: hda - Use always amps for auto-mute on AD1986A codec
  ALSA: hda/analog - Handle inverted EAPD properly in vmaster hook
  ALSA: hda - Another fixup for ASUS laptop with ALC660 codec
  ALSA: atmel: Fix possible array overflow
  ALSA: hda - Fix complete_all() timing in deferred probes
  ALSA: hda - Fix bad EAPD setup for HP machines with AD1984A
  ASoC: core: fix devres parameter in devm_snd_soc_register_card()
  ASoC: omap: n810: Convert to clk_prepare_enable/clk_disable_unprepare
  ASoC: fsl: set correct platform drvdata in pcm030_fabric_probe()
  ASoC: fsl: imx-pcm-fiq: Remove unused 'runtime' variable
  ASoC: fsl: imx-pcm-fiq: remove bogus period delta calculation
  ALSA: hda - Fix silent output on ASUS W7J laptop
  ASoC: core: Use consistent byte ordering in snd_soc_bytes_get
  ALSA: dice: fix array limits in dice_proc_read()
  ...

Pull pin control fixes from Linus Walleij:

 - Minor bug fixes for the Rockchip, ST-Ericsson abx500, Renesas PFC
   r8a7740 and sh7372.

 - Compilation warning fixes.

* tag 'pinctrl-v3.13-2' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl:
  sh-pfc: sh7372: Fix pin bias setup
  sh-pfc: r8a7740: Fix pin bias setup
  pinctrl: abx500: Fix header file include guard
  pinctrl: rockchip: missing unlock on error in rockchip_set_pull()
  pinctrl: abx500: fix some more bitwise AND tests
  pinctrl: rockchip: testing the wrong variable

If accounting is on, we will do the IO completion accounting after
we have freed the request. Fix that by moving it sooner instead.
Signed-off-by: NJens Axboe <axboe@kernel.dk>

If we force the hw to idle as our first step during unload, we can abort
the unload upon failure. Later we can probe whether the hardware remain
active even after we try to shut it down.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@gmail.com>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Pull x86 and EFI fixes from Peter Anvin:
 "Half of these are EFI-related:

  The by far biggest change is the change to hold off the deletion of a
  sysfs entry while a backend scan is in progress.  This is to avoid
  calling kmemdup() while under a spinlock.

  The other major change is for each entry in the EFI pstore backend to
  get a unique identifier, as required by the pstore filesystem proper.

  The other changes are:

  A fix to the recent consolidation and optimization of using "asm goto"
  with read-modify-write operation, which broke the bitops; specifically
  in such a way that we could end up generating invalid code.

  A build hack to make sure we compile with -mno-sse.  icc, and most
  likely future versions of gcc, can generate SSE instructions unless we
  tell it not to.

  A comment-only patch to a change the was due in part to an unpublished
  erratum; now when the erratum is published we want to add a comment
  explaining why"

* 'x86/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/apic, doc: Justification for disabling IO APIC before Local APIC
  x86, bitops: Correct the assembly constraints to testing bitops
  x86-64, build: Always pass in -mno-sse
  efi-pstore: Make efi-pstore return a unique id
  x86/efi: Fix earlyprintk off-by-one bug
  efivars, efi-pstore: Hold off deletion of sysfs entry until the scan is completed

Since erratum AVR31 in "Intel Atom Processor C2000 Product Family
Specification Update" is now published, I added a justification
comment for disabling IO APIC before Local APIC, as changed in commit:

522e6646 x86/apic: Disable I/O APIC before shutdown of the local APIC
Signed-off-by: NFenghua Yu <fenghua.yu@intel.com>
Link: http://lkml.kernel.org/r/1386202069-51515-1-git-send-email-fenghua.yu@intel.comSigned-off-by: NH. Peter Anvin <hpa@linux.intel.com>

As per the documentation of powercap sysfs, energy_uj field is read only,
if it can't be reset. Currently it always allows write but will fail,
if there is no reset callback.
Changing mode field, to read only if there is no reset callback.
Signed-off-by: NSrinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Reported-by: NDirk Brandewie <dirk.j.brandewie@intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

On returning from hibernation 'restore' callback is called,
not 'resume'.  Fix it.

Fixes: eaf140b6 (PNP: convert PNP driver bus legacy pm_ops to dev_pm_ops)
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: 3.12+ <stable@vger.kernel.org> # 3.12+
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

In checkin:

0c44c2d0 x86: Use asm goto to implement better modify_and_test() functions

the various functions which do modify and test were unified and
optimized using "asm goto".  However, this change missed the detail
that the bitops require an "Ir" constraint rather than an "er"
constraint ("I" = integer constant from 0-31, "e" = signed 32-bit
integer constant).  This would cause code to miscompile if these
functions were used on constant bit positions 32-255 and the build to
fail if used on constant bit positions above 255.

Add the constraints as a parameter to the GEN_BINARY_RMWcc() macro to
avoid this problem.
Reported-by: NJesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/529E8719.4070202@zytor.com

When compiling a 32bit kernel with CONFIG_LBDAF=n the compiler complains like
shown below.  Fix this warning by instead using sector_div() which is provided
by the kernel.h header file.

fs/nfs/blocklayout/extents.c: In function ‘normalize’:
include/asm-generic/div64.h:43:28: warning: comparison of distinct pointer types lacks a cast [enabled by default]
fs/nfs/blocklayout/extents.c:47:13: note: in expansion of macro ‘do_div’
nfs/blocklayout/extents.c:47:2: warning: right shift count >= width of type [enabled by default]
fs/nfs/blocklayout/extents.c:47:2: warning: passing argument 1 of ‘__div64_32’ from incompatible pointer type [enabled by default]
include/asm-generic/div64.h:35:17: note: expected ‘uint64_t *’ but argument is of type ‘sector_t *’
 extern uint32_t __div64_32(uint64_t *dividend, uint32_t divisor);
Signed-off-by: NHelge Deller <deller@gmx.de>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Andy Adamson reports:

The state manager is recovering expired state and recovery OPENs are being
processed. If kswapd is pruning inodes at the same time, a deadlock can occur
when kswapd calls evict_inode on an NFSv4.1 inode with a layout, and the
resultant layoutreturn gets an error that the state mangager is to handle,
causing the layoutreturn to wait on the (NFS client) cl_rpcwaitq.

At the same time an open is waiting for the inode deletion to complete in
__wait_on_freeing_inode.

If the open is either the open called by the state manager, or an open from
the same open owner that is holding the NFSv4 sequence id which causes the
OPEN from the state manager to wait for the sequence id on the Seqid_waitqueue,
then the state is deadlocked with kswapd.

The fix is simply to have layoutreturn ignore all errors except NFS4ERR_DELAY.
We already know that layouts are dropped on all server reboots, and that
it has to be coded to deal with the "forgetful client model" that doesn't
send layoutreturns.
Reported-by: NAndy Adamson <andros@netapp.com>
Link: http://lkml.kernel.org/r/1385402270-14284-1-git-send-email-andros@netapp.comSigned-off-by: NTrond Myklebust <Trond.Myklebust@primarydata.com>