Pull timer fix from Thomas Gleixner:
 "A single bug fix for a long standing issue:

   - Updating the expiry value of a relative timer _after_ letting the
     idle logic select a target cpu for the timer based on its stale
     expiry value is outright stupid.  Thanks to Viresh for spotting the
     brainfart"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  hrtimer: Set expiry time before switch_hrtimer_base()

Pull irq fixes from Thomas Gleixner:
 "Two small updates from the irq departement:

   - Provide missing inline stub for a SMP only function

   - Add sub-maintainer for the drivers/irqchip/ part of the irq
     subsystem.  YAY!"

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  MAINTAINERS: Add co-maintainer for drivers/irqchip
  genirq: Provide irq_force_affinity fallback for non-SMP

Thomas Gleixner has asked me to assist with the review and merging of
patches for the irqchip subsystem.
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
Link: http://lkml.kernel.org/r/1400006821-32145-1-git-send-email-jason@lakedaemon.netSigned-off-by: Thomas Gleixner <tglx@linutronix.de>

Pull file locking fix from Jeff Layton:
 "Fix for regression in handling of F_GETLK commands"

* tag 'locks-v3.15-4' of git://git.samba.org/jlayton/linux:
  locks: only validate the lock vs. f_mode in F_SETLK codepaths

Pull hwmon fixes from Guenter Roeck:
 "Fix resource leak as well as broken store function in emc1403 driver,
  and add support for additional chip revisions"

* tag 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging:
  hwmon: (emc1403) Support full range of known chip revision numbers
  hwmon: (emc1403) Fix resource leak on module unload
  hwmon: (emc1403) fix inverted store_hyst()

Pull a percpu fix from Tejun Heo:
 "Fix for a percpu allocator bug where it could try to kfree() a memory
  region allocated using vmalloc().  The bug has been there for years
  now and is unlikely to have ever triggered given the size of struct
  pcpu_chunk.  It's still theoretically possible and the fix is simple
  and safe enough, so the patch is marked with -stable"

* 'for-3.15-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu:
  percpu: make pcpu_alloc_chunk() use pcpu_mem_free() instead of kfree()

Pull workqueue fixes from Tejun Heo:
 "Fixes for two bugs in workqueue.

  One is exiting with internal mutex held in a failure path of
  wq_update_unbound_numa().  The other is a subtle and unlikely
  use-after-possible-last-put in the rescuer logic.  Both have been
  around for quite some time now and are unlikely to have triggered
  noticeably often.  All patches are marked for -stable backport"

* 'for-3.15-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
  workqueue: fix a possible race condition between rescuer and pwq-release
  workqueue: make rescuer_thread() empty wq->maydays list before exiting
  workqueue: fix bugs in wq_update_unbound_numa() failure path

Pull cgroup fixes from Tejun Heo:
 "During recent restructuring, device_cgroup unified config input check
  and enforcement logic; unfortunately, it turned out to share too much.
  Aristeu's patches fix the breakage and marked for -stable backport.

  The other two patches are fallouts from kernfs conversion.  The blkcg
  change is temporary and will go away once kernfs internal locking gets
  simplified (patches pending)"

* 'for-3.15-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  blkcg: use trylock on blkcg_pol_mutex in blkcg_reset_stats()
  device_cgroup: check if exception removal is allowed
  device_cgroup: fix the comment format for recently added functions
  device_cgroup: rework device access check and exception checking
  cgroup: fix the retry path of cgroup_mount()

Pull xen bug fixes from David Vrabel:
 - Fix arm64 crash on boot.
 - Quiet a noisy arm build warning (virt_to_pfn() redefined).

* tag 'stable/for-linus-3.15-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  arm64: introduce virt_to_pfn
  xen/events/fifo: correctly align bitops
  arm/xen: Remove definiition of virt_to_pfn in asm/xen/page.h

Pull cifs fix from Steve French:
 "Small cifs fix for metadata caching"

* 'for-linus' of git://git.samba.org/sfrench/cifs-2.6:
  cifs: fix actimeo=0 corner case when cifs_i->time == jiffies

Pull md bugfixes from Neil Brown:
 "Two bugfixes for md in 3.15

  Both tagged for -stable"

* tag 'md/3.15-fixes' of git://neil.brown.name/md:
  md: avoid possible spinning md thread at shutdown.
  md/raid10: call wait_barrier() for each request submitted.

Pull ARM SoC fixes from Olof Johansson:
 "Seems like we've had more fixes than usual this release cycle, but
  there's nothing in particular that we're doing differently.  Perhaps
  it's just one of those cycles where more people are finding more
  regressions (and/or that the latency of when people actually test
  what's been in the tree for a while is catching up so that we get the
  bug reports now).

  The bigger changes here are are for TI and Marvell platforms:
   * Timing changes for GPMC (generic localbus) on OMAP causing some
     largeish DTS deltas.
   * Fixes to window allocation on PCI for mvebu touching drivers/
     stuff.  Patches have acks from subsystem maintainers where needed.
   * A fix from Thomas for a botched DT conversion in drivers/edma.

  There's a handful of other fixes for the above platforms as well as
  sunxi, at91, i.MX.  I also included a MAINTAINER update for Broadcom,
  and a trivial move of a binding doc.

  I know you said you'd be offline this week, but I might as well post
  it for when you return.  :)"

I'm not quite offline yet.  Doing a few pulls in the last hour before my
internet goes away..

* tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (31 commits)
  MAINTAINERS: update Broadcom ARM tree location and add an SoC family
  ARM: dts: i.MX53: Fix ipu register space size
  ARM: dts: kirkwood: fix mislocated pcie-controller nodes
  ARM: sunxi: Enable GMAC in sunxi_defconfig
  ARM: common: edma: Fix xbar mapping
  ARM: sun7i: Fix i2c4 base address
  ARM: Kirkwood: T5325: Fix double probe of Codec
  ARM: mvebu: enable the SATA interface on Armada 375 DB
  ARM: mvebu: specify I2C bus frequency on Armada 370 DB
  ARM: mvebu: use qsgmii phy-mode for Armada XP GP interfaces
  ARM: mvebu: fix NOR bus-width in Armada XP OpenBlocks AX3 Device Tree
  ARM: mvebu: fix NOR bus-width in Armada XP DB Device Tree
  ARM: mvebu: fix NOR bus-width in Armada XP GP Device Tree
  ARM: dts: AM3517: Disable absent IPs inherited from OMAP3
  ARM: dts: OMAP2: Fix interrupts for OMAP2420 mailbox
  ARM: dts: OMAP5: Add mailbox dt node to fix boot warning
  ARM: OMAP5: Switch to THUMB mode if needed on secondary CPU
  ARM: dts: am437x-gp-evm: Do not reset gpio5
  ARM: dts: omap3-igep0020: use SMSC9221 timings
  PCI: mvebu: split PCIe BARs into multiple MBus windows when needed
  ...

The datasheet for EMC1413/EMC1414, which is fully compatible to
EMC1403/1404 and uses the same chip identification, references revision
numbers 0x01, 0x03, and 0x04. Accept the full range of revision numbers
from 0x01 to 0x04 to make sure none are missed.
Signed-off-by: Josef Gajdusek <atx@atx.name>
Cc: stable@vger.kernel.org
[Guenter Roeck: Updated headline and description]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

Commit 454aee17 claims to convert driver emc1403 to use
devm_hwmon_device_register_with_groups, however the patch itself makes
use of hwmon_device_register_with_groups instead. As the driver remove
function was still dropped, the hwmon device is no longer unregistered
on driver removal, leading to a resource leak.
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Fixes: 454aee17 hwmon: (emc1403) Convert to use devm_hwmon_device_register_with_groups
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: stable@vger.kernel.org [3.13+]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

Attempts to set the hysteresis value to a temperature below the target
limit fails with "write error: Numerical result out of range" due to
an inverted comparison.
Signed-off-by: Josef Gajdusek <atx@atx.name>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Cc: stable@vger.kernel.org
[Guenter Roeck: Updated headline and description]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

virt_to_pfn has been defined in arch/arm/include/asm/memory.h by commit
e26a9e00 "ARM: Better virt_to_page() handling" and Xen has come to rely
on it.  Introduce virt_to_pfn on arm64 too.
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>

switch_hrtimer_base() calls hrtimer_check_target() which ensures that
we do not migrate a timer to a remote cpu if the timer expires before
the current programmed expiry time on that remote cpu.

But __hrtimer_start_range_ns() calls switch_hrtimer_base() before the
new expiry time is set. So the sanity check in hrtimer_check_target()
is operating on stale or even uninitialized data.

Update expiry time before calling switch_hrtimer_base().

[ tglx: Rewrote changelog once again ]
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: linaro-kernel@lists.linaro.org
Cc: linaro-networking@linaro.org
Cc: fweisbec@gmail.com
Cc: arvind.chauhan@arm.com
Link: http://lkml.kernel.org/r/81999e148745fc51bbcd0615823fbab9b2e87e23.1399882253.git.viresh.kumar@linaro.org
Cc: stable@vger.kernel.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

Pull nfsd fixes from Bruce Fields.

* 'for-3.15' of git://linux-nfs.org/~bfields/linux:
  NFSD: Call ->set_acl with a NULL ACL structure if no entries
  NFSd: call rpc_destroy_wait_queue() from free_client()
  NFSd: Move default initialisers from create_client() to alloc_client()

Merge misc fixes from Andrew Morton:
 "4 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  mm, thp: close race between mremap() and split_huge_page()
  mm: postpone the disabling of kmemleak early logging
  MAINTAINERS: update maintainership of LTP
  drivers/rtc/rtc-hym8563.c: set uie_unsupported

It's critical for split_huge_page() (and migration) to catch and freeze
all PMDs on rmap walk.  It gets tricky if there's concurrent fork() or
mremap() since usually we copy/move page table entries on dup_mm() or
move_page_tables() without rmap lock taken.  To get it work we rely on
rmap walk order to not miss any entry.  We expect to see destination VMA
after source one to work correctly.

But after switching rmap implementation to interval tree it's not always
possible to preserve expected walk order.

It works fine for dup_mm() since new VMA has the same vma_start_pgoff()
/ vma_last_pgoff() and explicitly insert dst VMA after src one with
vma_interval_tree_insert_after().

But on move_vma() destination VMA can be merged into adjacent one and as
result shifted left in interval tree.  Fortunately, we can detect the
situation and prevent race with rmap walk by moving page table entries
under rmap lock.  See commit 38a76013.

Problem is that we miss the lock when we move transhuge PMD.  Most
likely this bug caused the crash[1].

[1] http://thread.gmane.org/gmane.linux.kernel.mm/96473

Fixes: 108d6642 ("mm anon rmap: remove anon_vma_moveto_tail")
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Acked-by: Michel Lespinasse <walken@google.com>
Cc: Dave Jones <davej@redhat.com>
Cc: David Miller <davem@davemloft.net>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: <stable@vger.kernel.org>        [3.7+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Commit 8910ae89 ("kmemleak: change some global variables to int"),
in addition to the atomic -> int conversion, moved the disabling of
kmemleak_early_log to the beginning of the kmemleak_init() function,
before the full kmemleak tracing is actually enabled.  In this small
window, kmem_cache_create() is called by kmemleak which triggers
additional memory allocation that are not traced.  This patch restores
the original logic with kmemleak_early_log disabling when kmemleak is
fully functional.

Fixes: 8910ae89 (kmemleak: change some global variables to int)
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Li Zefan <lizefan@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Also remove sf.net git repo which is no longer available and update link
to LTP web pages.
Signed-off-by: Cyril Hrubis <chrubis@suse.cz>
Signed-off-by: Caspar Zhang <caspar@casparzhang.com>
Signed-off-by: Wanlong Gao <gaowanlong@cn.fujitsu.com>
Signed-off-by: Jan Stancek <jstancek@redhat.com>
Signed-off-by: Alexey Kodanev <alexey.kodanev@oracle.com>
Signed-off-by: Stanislav Kholmanskikh <stanislav.kholmanskikh@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The alarm of the hym8563 only supports a minute accuracy, while the uie
wants an alarm one second in the future.  Therefore things like the
select() syscall will fail with a timeout, because the next alarm will
happen in a worst case of 60 seconds.
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Merge tag 'davinci-fixes-for-v3.15-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/nsekhar/linux-davinci into fixes

Pull "DaVinci fixes for v3.15" from Sekhar Nori:

The patch fixes EDMA crossbar mapping to actually
make it work. The patch has been tagged for stable.

* tag 'davinci-fixes-for-v3.15-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/nsekhar/linux-davinci:
  ARM: common: edma: Fix xbar mapping
Signed-off-by: Olof Johansson <olof@lixom.net>

Merge 'Allwinner fixes for 3.15' from Maxime Ripard:

Set of fixes for the Allwinner support for 3.15

Some minor things, the major thing being the enabling of the GMAC driver in
sunxi_defconfig that will un-break Olof's autobooters.

* tag 'sunxi-fixes-for-3.15' of https://github.com/mripard/linux:
  ARM: sunxi: Enable GMAC in sunxi_defconfig
  ARM: sun7i: Fix i2c4 base address
  ARM: sun7i: fix PLL4 clock and add PLL8
Signed-off-by: Olof Johansson <olof@lixom.net>

Merge 'ARM: mvebu: DT fixes for v3.15 (incr #2)' from Jason Cooper:

mvebu DT fixes for v3.15 (incremental #2)

 - kirkwood: fix mis-located pcie controller nodes

* tag 'mvebu-dt-fixes-3.15-2' of git://git.infradead.org/linux-mvebu:
  ARM: dts: kirkwood: fix mislocated pcie-controller nodes
Signed-off-by: Olof Johansson <olof@lixom.net>

The Broadcom ARM tree location has changed names to reflect other SoC
families that are queued here. Also add the 216xx family as maintained.
Signed-off-by: Matt Porter <mporter@linaro.org>
Signed-off-by: Olof Johansson <olof@lixom.net>

The IPU register space is 128MB, not 2GB.

Fixes: abed9a6b 'ARM i.MX53: Add IPU support'
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Acked-by: Shawn Guo <shawn.guo@freescale.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Olof Johansson <olof@lixom.net>

Pull x86 fixes from Peter Anvin:
 "A somewhat unpleasantly large collection of small fixes.  The big ones
  are the __visible tree sweep and a fix for 'earlyprintk=efi,keep'.  It
  was using __init functions with predictably suboptimal results.

  Another key fix is a build fix which would produce output that simply
  would not decompress correctly in some configuration, due to the
  existing Makefiles picking up an unfortunate local label and mistaking
  it for the global symbol _end.

  Additional fixes include the handling of 64-bit numbers when setting
  the vdso data page (a latent bug which became manifest when i386
  started exporting a vdso with time functions), a fix to the new MSR
  manipulation accessors which would cause features to not get properly
  unblocked, a build fix for 32-bit userland, and a few new platform
  quirks"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86, vdso, time: Cast tv_nsec to u64 for proper shifting in update_vsyscall()
  x86: Fix typo in MSR_IA32_MISC_ENABLE_LIMIT_CPUID macro
  x86: Fix typo preventing msr_set/clear_bit from having an effect
  x86/intel: Add quirk to disable HPET for the Baytrail platform
  x86/hpet: Make boot_hpet_disable extern
  x86-64, build: Fix stack protector Makefile breakage with 32-bit userland
  x86/reboot: Add reboot quirk for Certec BPC600
  asmlinkage: Add explicit __visible to drivers/*, lib/*, kernel/*
  asmlinkage, x86: Add explicit __visible to arch/x86/*
  asmlinkage: Revert "lto: Make asmlinkage __visible"
  x86, build: Don't get confused by local symbols
  x86/efi: earlyprintk=efi,keep fix

With tk->wall_to_monotonic.tv_nsec being a 32-bit value on 32-bit
systems, (tk->wall_to_monotonic.tv_nsec << tk->shift) in update_vsyscall()
may lose upper bits or, worse, add them since compiler will do this:
	(u64)(tk->wall_to_monotonic.tv_nsec << tk->shift)
instead of
	((u64)tk->wall_to_monotonic.tv_nsec << tk->shift)

So if, for example, tv_nsec is 0x800000 and shift is 8 we will end up
with 0xffffffff80000000 instead of 0x80000000. And then we are stuck in
the subsequent 'while' loop.

We need an explicit cast.
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Link: http://lkml.kernel.org/r/1399648287-15178-1-git-send-email-boris.ostrovsky@oracle.comAcked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: <stable@vger.kernel.org> # v3.14
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

The spuriously added semicolon didn't have any effect because the
macro isn't currently in use.

c0a639adSigned-off-by: Andres Freund <andres@anarazel.de>
Link: http://lkml.kernel.org/r/1399598957-7011-3-git-send-email-andres@anarazel.de
Cc: Borislav Petkov <bp@suse.de>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

Due to a typo the msr accessor function introduced in
22085a66 didn't have any lasting
effects because they accidentally wrote the old value back.

After c0a639ad this at the very least
this causes cpuid limits not to be lifted on some cpus leading to
missing capabilities for those.
Signed-off-by: Andres Freund <andres@anarazel.de>
Link: http://lkml.kernel.org/r/1399598957-7011-2-git-send-email-andres@anarazel.de
Cc: Borislav Petkov <bp@suse.de>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

v2: replace missing break in switch statement (as pointed out by Dave
    Jones)

commit bce7560d (locks: consolidate checks for compatible
filp->f_mode values in setlk handlers) introduced a regression in the
F_GETLK handler.

flock64_to_posix_lock is a shared codepath between F_GETLK and F_SETLK,
but the f_mode checks should only be applicable to the F_SETLK codepaths
according to POSIX.

Instead of just reverting the patch, add a new function to do this
checking and have the F_SETLK handlers call it.

Cc: Dave Jones <davej@redhat.com>
Reported-and-Tested-by: Reuben Farrelly <reuben@reub.net>
Signed-off-by: Jeff Layton <jlayton@poochiereds.net>

Pull xfs fixes from Dave Chinner:
 "The main fix is adding support for default ACLs on O_TMPFILE opened
  inodes to bring XFS into line with other filesystems.  Metadata CRCs
  are now also considered well enough tested to be fully supported, so
  we're removing the shouty warnings issued at mount time for
  filesystems with that format.  And there's transaction block
  reservation overrun fix.

  Summary:
   - fix a remote attribute size calculation bug that leads to a
     transaction overrun
   - add default ACLs to O_TMPFILE files
   - Remove the EXPERIMENTAL tag from filesystems with metadata CRC
     support"

* tag 'xfs-for-linus-3.15-rc5' of git://oss.sgi.com/xfs/xfs:
  xfs: remote attribute overwrite causes transaction overrun
  xfs: initialize default acls for ->tmpfile()
  xfs: fully support v5 format filesystems

Merge tag 'trace-fixes-v3.15-rc4-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fixes from Steven Rostedt:
 "This contains two fixes.

  The first is a long standing bug that causes bogus data to show up in
  the refcnt field of the module_refcnt tracepoint.  It was introduced
  by a merge conflict resolution back in 2.6.35-rc days.

  The result should be 'refcnt = incs - decs', but instead it did
  'refcnt = incs + decs'.

  The second fix is to a bug that was introduced in this merge window
  that allowed for a tracepoint funcs pointer to be used after it was
  freed.  Moving the location of where the probes are released solved
  the problem"

* tag 'trace-fixes-v3.15-rc4-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracepoint: Fix use of tracepoint funcs after rcu free
  trace: module: Maintain a valid user count

Pull input subsystem fixes from Dmitry Torokhov:
 "Just a few fixups to various drivers"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
  Input: elantech - fix touchpad initialization on Gigabyte U2442
  Input: tca8418 - fix loading this driver as a module from a device tree
  Input: bma150 - extend chip detection for bma180
  Input: atkbd - fix keyboard not working on some LG laptops
  Input: synaptics - add min/max quirk for ThinkPad Edge E431

Pull sound fixes from Takashi Iwai:
 "A bunch of small fixes for USB-audio and HD-audio, where most of them
  are for regressions: USB-audio PM fixes, ratelimit annoyance fix, HDMI
  offline state fix, and a couple of device-specific quirks"

* tag 'sound-3.15-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
  ALSA: hda - hdmi: Set converter channel count even without sink
  ALSA: usb-audio: work around corrupted TEAC UD-H01 feedback data
  ALSA: usb-audio: Fix deadlocks at resuming
  ALSA: usb-audio: Save mixer status only once at suspend
  ALSA: usb-audio: Prevent printk ratelimiting from spamming kernel log while DEBUG not defined
  ALSA: hda - add headset mic detect quirk for a Dell laptop

Pull mmc/rtsx revert from Lee Jones.

* tag 'mfd-mmc-fixes-3.15-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/mfd:
  mmc: rtsx: Revert "mmc: rtsx: add support for pre_req and post_req"

After setting ACL for directory, I got two problems that caused
by the cached zero-length default posix acl.

This patch make sure nfsd4_set_nfs4_acl calls ->set_acl
with a NULL ACL structure if there are no entries.

Thanks for Christoph Hellwig's advice.

First problem:
............ hang ...........

Second problem:
[ 1610.167668] ------------[ cut here ]------------
[ 1610.168320] kernel BUG at /root/nfs/linux/fs/nfsd/nfs4acl.c:239!
[ 1610.168320] invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC
[ 1610.168320] Modules linked in: nfsv4(OE) nfs(OE) nfsd(OE)
rpcsec_gss_krb5 fscache ip6t_rpfilter ip6t_REJECT cfg80211 xt_conntrack
rfkill ebtable_nat ebtable_broute bridge stp llc ebtable_filter ebtables
ip6table_nat nf_conntrack_ipv6 nf_defrag_ipv6 nf_nat_ipv6
ip6table_mangle ip6table_security ip6table_raw ip6table_filter
ip6_tables iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4
nf_nat nf_conntrack iptable_mangle iptable_security iptable_raw
auth_rpcgss nfs_acl snd_intel8x0 ppdev lockd snd_ac97_codec ac97_bus
snd_pcm snd_timer e1000 pcspkr parport_pc snd parport serio_raw joydev
i2c_piix4 sunrpc(OE) microcode soundcore i2c_core ata_generic pata_acpi
[last unloaded: nfsd]
[ 1610.168320] CPU: 0 PID: 27397 Comm: nfsd Tainted: G           OE
3.15.0-rc1+ #15
[ 1610.168320] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS
VirtualBox 12/01/2006
[ 1610.168320] task: ffff88005ab653d0 ti: ffff88005a944000 task.ti:
ffff88005a944000
[ 1610.168320] RIP: 0010:[<ffffffffa034d5ed>]  [<ffffffffa034d5ed>]
_posix_to_nfsv4_one+0x3cd/0x3d0 [nfsd]
[ 1610.168320] RSP: 0018:ffff88005a945b00  EFLAGS: 00010293
[ 1610.168320] RAX: 0000000000000001 RBX: ffff88006700bac0 RCX:
0000000000000000
[ 1610.168320] RDX: 0000000000000000 RSI: ffff880067c83f00 RDI:
ffff880068233300
[ 1610.168320] RBP: ffff88005a945b48 R08: ffffffff81c64830 R09:
0000000000000000
[ 1610.168320] R10: ffff88004ea85be0 R11: 000000000000f475 R12:
ffff880068233300
[ 1610.168320] R13: 0000000000000003 R14: 0000000000000002 R15:
ffff880068233300
[ 1610.168320] FS:  0000000000000000(0000) GS:ffff880077800000(0000)
knlGS:0000000000000000
[ 1610.168320] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[ 1610.168320] CR2: 00007f5bcbd3b0b9 CR3: 0000000001c0f000 CR4:
00000000000006f0
[ 1610.168320] DR0: 0000000000000000 DR1: 0000000000000000 DR2:
0000000000000000
[ 1610.168320] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7:
0000000000000400
[ 1610.168320] Stack:
[ 1610.168320]  ffffffff00000000 0000000b67c83500 000000076700bac0
0000000000000000
[ 1610.168320]  ffff88006700bac0 ffff880068233300 ffff88005a945c08
0000000000000002
[ 1610.168320]  0000000000000000 ffff88005a945b88 ffffffffa034e2d5
000000065a945b68
[ 1610.168320] Call Trace:
[ 1610.168320]  [<ffffffffa034e2d5>] nfsd4_get_nfs4_acl+0x95/0x150 [nfsd]
[ 1610.168320]  [<ffffffffa03400d6>] nfsd4_encode_fattr+0x646/0x1e70 [nfsd]
[ 1610.168320]  [<ffffffff816a6e6e>] ? kmemleak_alloc+0x4e/0xb0
[ 1610.168320]  [<ffffffffa0327962>] ?
nfsd_setuser_and_check_port+0x52/0x80 [nfsd]
[ 1610.168320]  [<ffffffff812cd4bb>] ? selinux_cred_prepare+0x1b/0x30
[ 1610.168320]  [<ffffffffa0341caa>] nfsd4_encode_getattr+0x5a/0x60 [nfsd]
[ 1610.168320]  [<ffffffffa0341e07>] nfsd4_encode_operation+0x67/0x110
[nfsd]
[ 1610.168320]  [<ffffffffa033844d>] nfsd4_proc_compound+0x21d/0x810 [nfsd]
[ 1610.168320]  [<ffffffffa0324d9b>] nfsd_dispatch+0xbb/0x200 [nfsd]
[ 1610.168320]  [<ffffffffa00850cd>] svc_process_common+0x46d/0x6d0 [sunrpc]
[ 1610.168320]  [<ffffffffa0085433>] svc_process+0x103/0x170 [sunrpc]
[ 1610.168320]  [<ffffffffa032472f>] nfsd+0xbf/0x130 [nfsd]
[ 1610.168320]  [<ffffffffa0324670>] ? nfsd_destroy+0x80/0x80 [nfsd]
[ 1610.168320]  [<ffffffff810a5202>] kthread+0xd2/0xf0
[ 1610.168320]  [<ffffffff810a5130>] ? insert_kthread_work+0x40/0x40
[ 1610.168320]  [<ffffffff816c1ebc>] ret_from_fork+0x7c/0xb0
[ 1610.168320]  [<ffffffff810a5130>] ? insert_kthread_work+0x40/0x40
[ 1610.168320] Code: 78 02 e9 e7 fc ff ff 31 c0 31 d2 31 c9 66 89 45 ce
41 8b 04 24 66 89 55 d0 66 89 4d d2 48 8d 04 80 49 8d 5c 84 04 e9 37 fd
ff ff <0f> 0b 90 0f 1f 44 00 00 55 8b 56 08 c7 07 00 00 00 00 8b 46 0c
[ 1610.168320] RIP  [<ffffffffa034d5ed>] _posix_to_nfsv4_one+0x3cd/0x3d0
[nfsd]
[ 1610.168320]  RSP <ffff88005a945b00>
[ 1610.257313] ---[ end trace 838254e3e352285b ]---
Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>