Pull drm radeon and nouveau fixes from Dave Airlie:
 "Fixes for the other big two.

  The radeon VCE one is large but it fixes some userspace triggerable
  issues, otherwise its blackscreens and oopses.

  Nouveau fixes a bleeding laptop panel issue when displayport is used
  sometimes"

* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux:
  drm/radeon/pm: don't allow debugfs/sysfs access when PX card is off (v2)
  drm/radeon: avoid segfault on device open when accel is not working.
  drm/radeon: fix typo in finding PLL params
  drm/radeon: fix register typo on si
  drm/radeon: fix buffer placement under memory pressure v2
  drm/radeon: fix page directory update size estimation
  drm/radeon: handle non-VGA class pci devices with ATRM
  drm/radeon: fix DCE83 check for mullins
  drm/radeon: check VCE relocation buffer range v3
  drm/radeon: also try GART for CPU accessed buffers
  drm/gf119-/disp: fix nasty bug which can clobber SOR0's clock setup
  drm/nvd9/therm: handle another kind of PWM fan

Merge misc fixes from Andrew Morton:
 "9 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  MAINTAINERS: add closing angle bracket to Vince Bridgers' email address
  Documentation: fix DOCBOOKS=... building
  ocfs2: fix double kmem_cache_destroy in dlm_init
  mm/memory-failure.c: fix memory leak by race between poison and unpoison
  wait: swap EXIT_ZOMBIE(Z) and EXIT_DEAD(X) chars in TASK_STATE_TO_CHAR_STR
  memcg: fix swapcache charge from kernel thread context
  mm: madvise: fix MADV_WILLNEED on shmem swapouts
  mm/filemap.c: avoid always dirtying mapping->flags on O_DIRECT
  hwpoison, hugetlb: lock_page/unlock_page does not match for handling a free hugepage

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Cc: Vince Bridgers <vbridgers2013@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Prior to commit 42661299 ("[media] DocBook: Move all media docbook
stuff into its own directory") it was possible to build only a single
(or more) book(s) by calling, for example

    make htmldocs DOCBOOKS=80211.xml

This now fails:

    cp: target `.../Documentation/DocBook//media_api' is not a directory

Ignore errors from that copy to make this possible again.

Fixes: 42661299 ("[media] DocBook: Move all media docbook stuff into its own directory")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-by: Randy Dunlap <rdunlap@xenotime.net>
Cc: Mauro Carvalho Chehab <mchehab@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

In dlm_init, if create dlm_lockname_cache failed in
dlm_init_master_caches, it will destroy dlm_lockres_cache which created
before twice.  And this will cause system die when loading modules.
Signed-off-by: Joseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

When a memory error happens on an in-use page or (free and in-use)
hugepage, the victim page is isolated with its refcount set to one.

When you try to unpoison it later, unpoison_memory() calls put_page()
for it twice in order to bring the page back to free page pool (buddy or
free hugepage list).  However, if another memory error occurs on the
page which we are unpoisoning, memory_failure() returns without
releasing the refcount which was incremented in the same call at first,
which results in memory leak and unconsistent num_poisoned_pages
statistics.  This patch fixes it.
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: <stable@vger.kernel.org>    [2.6.32+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

In commit ad86622b ("wait: swap EXIT_ZOMBIE and EXIT_DEAD to hide
EXIT_TRACE from user-space") the order of task state definitions were
changed: EXIT_DEAD and EXIT_ZOMBIE were swapped.  Though the charterers
for the states in TASK_STATE_TO_CHAR_STR string were not updated.  This
patch synchronizes the string to the order of definitions.
Signed-off-by: Masatake YAMATO <yamato@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Commit 284f39af ("mm: memcg: push !mm handling out to page cache
charge function") explicitly checks for page cache charges without any
mm context (from kernel thread context[1]).

This seemed to be the only possible case where memory could be charged
without mm context so commit 03583f1a ("memcg: remove unnecessary
!mm check from try_get_mem_cgroup_from_mm()") removed the mm check from
get_mem_cgroup_from_mm().  This however caused another NULL ptr
dereference during early boot when loopback kernel thread splices to
tmpfs as reported by Stephan Kulow:

  BUG: unable to handle kernel NULL pointer dereference at 0000000000000360
  IP: get_mem_cgroup_from_mm.isra.42+0x2b/0x60
  Oops: 0000 [#1] SMP
  Modules linked in: btrfs dm_multipath dm_mod scsi_dh multipath raid10 raid456 async_raid6_recov async_memcpy async_pq raid6_pq async_xor xor async_tx raid1 raid0 md_mod parport_pc parport nls_utf8 isofs usb_storage iscsi_ibft iscsi_boot_sysfs arc4 ecb fan thermal nfs lockd fscache nls_iso8859_1 nls_cp437 sg st hid_generic usbhid af_packet sunrpc sr_mod cdrom ata_generic uhci_hcd virtio_net virtio_blk ehci_hcd usbcore ata_piix floppy processor button usb_common virtio_pci virtio_ring virtio edd squashfs loop ppa]
  CPU: 0 PID: 97 Comm: loop1 Not tainted 3.15.0-rc5-5-default #1
  Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
  Call Trace:
    __mem_cgroup_try_charge_swapin+0x40/0xe0
    mem_cgroup_charge_file+0x8b/0xd0
    shmem_getpage_gfp+0x66b/0x7b0
    shmem_file_splice_read+0x18f/0x430
    splice_direct_to_actor+0xa2/0x1c0
    do_lo_receive+0x5a/0x60 [loop]
    loop_thread+0x298/0x720 [loop]
    kthread+0xc6/0xe0
    ret_from_fork+0x7c/0xb0

Also Branimir Maksimovic reported the following oops which is tiggered
for the swapcache charge path from the accounting code for kernel threads:

  CPU: 1 PID: 160 Comm: kworker/u8:5 Tainted: P           OE 3.15.0-rc5-core2-custom #159
  Hardware name: System manufacturer System Product Name/MAXIMUSV GENE, BIOS 1903 08/19/2013
  task: ffff880404e349b0 ti: ffff88040486a000 task.ti: ffff88040486a000
  RIP: get_mem_cgroup_from_mm.isra.42+0x2b/0x60
  Call Trace:
    __mem_cgroup_try_charge_swapin+0x45/0xf0
    mem_cgroup_charge_file+0x9c/0xe0
    shmem_getpage_gfp+0x62c/0x770
    shmem_write_begin+0x38/0x40
    generic_perform_write+0xc5/0x1c0
    __generic_file_aio_write+0x1d1/0x3f0
    generic_file_aio_write+0x4f/0xc0
    do_sync_write+0x5a/0x90
    do_acct_process+0x4b1/0x550
    acct_process+0x6d/0xa0
    do_exit+0x827/0xa70
    kthread+0xc3/0xf0

This patch fixes the issue by reintroducing mm check into
get_mem_cgroup_from_mm.  We could do the same trick in
__mem_cgroup_try_charge_swapin as we do for the regular page cache path
but it is not worth troubles.  The check is not that expensive and it is
better to have get_mem_cgroup_from_mm more robust.

[1] - http://marc.info/?l=linux-mm&m=139463617808941&w=2

Fixes: 03583f1a ("memcg: remove unnecessary !mm check from try_get_mem_cgroup_from_mm()")
Reported-and-tested-by: Stephan Kulow <coolo@suse.com>
Reported-by: Branimir Maksimovic <branimir.maksimovic@gmail.com>
Signed-off-by: Michal Hocko <mhocko@suse.cz>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

MADV_WILLNEED currently does not read swapped out shmem pages back in.

Commit 0cd6144a ("mm + fs: prepare for non-page entries in page
cache radix trees") made find_get_page() filter exceptional radix tree
entries but failed to convert all find_get_page() callers that WANT
exceptional entries over to find_get_entry().  One of them is shmem swap
readahead in madvise, which now skips over any swap-out records.

Convert it to find_get_entry().

Fixes: 0cd6144a ("mm + fs: prepare for non-page entries in page cache radix trees")
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reported-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

In some testing I ran today (some fio jobs that spread over two nodes),
we end up spending 40% of the time in filemap_check_errors().  That
smells fishy.  Looking further, this is basically what happens:

blkdev_aio_read()
    generic_file_aio_read()
        filemap_write_and_wait_range()
            if (!mapping->nr_pages)
                filemap_check_errors()

and filemap_check_errors() always attempts two test_and_clear_bit() on
the mapping flags, thus dirtying it for every single invocation.  The
patch below tests each of these bits before clearing them, avoiding this
issue.  In my test case (4-socket box), performance went from 1.7M IOPS
to 4.0M IOPS.
Signed-off-by: Jens Axboe <axboe@fb.com>
Acked-by: Jeff Moyer <jmoyer@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

For handling a free hugepage in memory failure, the race will happen if
another thread hwpoisoned this hugepage concurrently.  So we need to
check PageHWPoison instead of !PageHWPoison.

If hwpoison_filter(p) returns true or a race happens, then we need to
unlock_page(hpage).
Signed-off-by: Chen Yucong <slaoub@gmail.com>
Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Tested-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Cc: <stable@vger.kernel.org>	[2.6.36+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The 'renameat2()' system call was incorrectly added as a ENTRY_COMP() in
the parisc system call table by commit 18e480aa ("parisc: add
renameat2 syscall").  That causes a link-time error due to there not
being any compat version of that system call:

  arch/parisc/kernel/built-in.o: In function `sys_call_table':
  (.rodata+0xad0): undefined reference to `compat_sys_renameat2'
  make: *** [vmlinux] Error 1

Easily fixed by marking the system call as being the same for compat as
for native by using ENTRY_SAME() instead of ENTRY_COMP().
Reported-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Miklos Szeredi <miklos@szeredi.hu>
Acked-by: Helge Deller <deller@gmx.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

radeon fixes, VCE one is big but does fix a userspace crash.

* 'drm-fixes-3.15' of git://people.freedesktop.org/~deathsimple/linux:
  drm/radeon/pm: don't allow debugfs/sysfs access when PX card is off (v2)
  drm/radeon: avoid segfault on device open when accel is not working.
  drm/radeon: fix typo in finding PLL params
  drm/radeon: fix register typo on si
  drm/radeon: fix buffer placement under memory pressure v2
  drm/radeon: fix page directory update size estimation
  drm/radeon: handle non-VGA class pci devices with ATRM
  drm/radeon: fix DCE83 check for mullins
  drm/radeon: check VCE relocation buffer range v3
  drm/radeon: also try GART for CPU accessed buffers

Merge branch 'drm-nouveau-next' of git://anongit.freedesktop.org/git/nouveau/linux-2.6 into drm-fixes

fixes nasty panel bleeding bug.

* 'drm-nouveau-next' of git://anongit.freedesktop.org/git/nouveau/linux-2.6:
  drm/gf119-/disp: fix nasty bug which can clobber SOR0's clock setup
  drm/nvd9/therm: handle another kind of PWM fan

Pull two powerpc fixes from Ben Herrenschmidt:
 "Here are a couple of fixes for 3.15.  One from Anton fixes a nasty
  regression I introduced when trying to fix a loss of irq_work whose
  consequences is that we can completely lose timer interrupts on a
  CPU... not pretty.

  The other one is a change to our PCIe reset hook to use a firmware
  call instead of direct config space accesses to trigger a fundamental
  reset on the root port.  This is necessary so that the FW gets a
  chance to disable the link down error monitoring, which would
  otherwise trip and cause subsequent fatal EEH error"

* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc:
  powerpc: irq work racing with timer interrupt can result in timer interrupt hang
  powerpc/powernv: Reset root port in firmware

Pull two btrfs fixes from Chris Mason:
 "This has two fixes that we've been testing for 3.16, but since both
  are safe and fix real bugs, it makes sense to send for 3.15 instead"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: send, fix incorrect ref access when using extrefs
  Btrfs: fix EIO on reading file after ioctl clone works on it

Pull two ceph fixes from Sage Weil:
 "The first patch fixes a problem when we have a page count of 0 for
  sendpage which is triggered by zfs.  The second fixes a bug in CRUSH
  that was resolved in the userland code a while back but fell through
  the cracks on the kernel side"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client:
  crush: decode and initialize chooseleaf_vary_r
  libceph: fix corruption when using page_count 0 page in rbd

Pull xfs fixes from Dave Chinner:
 "Code inspection of the XFS error number sign translations found a
  bunch of issues, including returning incorrectly signed errors for
  some data integrity operations.

  These leak to userspace and result in applications not getting the
  errors correctly reported.  Hence they need fixing sooner rather than
  later.

  A couple of the bugs are in data integrity operations, a couple more
  are in the new COLLAPSE_RANGE code.  One of these came in through a
  recent ext4 merge and so I had to update the base tree to 3.15-rc5
  before fixing the issues"

* tag 'xfs-for-linus-3.15-rc6' of git://oss.sgi.com/xfs/xfs:
  xfs: list_lru_init returns a negative error
  xfs: negate xfs_icsb_init_counters error value
  xfs: negate mount workqueue init error value
  xfs: fix wrong err sign on xfs_set_acl()
  xfs: fix wrong errno from xfs_initxattrs
  xfs: correct error sign on COLLAPSE_RANGE errors
  xfs: xfs_commit_metadata returns wrong errno
  xfs: fix incorrect error sign in xfs_file_aio_read
  xfs: xfs_dir_fsync() returns positive errno

Pull renameat2 arch support from Miklos Szeredi:
 "I've collected architecture patches for the renameat2 syscall that
  maintainers acked and/or asked me to queue.

  This adds architecture support for the renameat2 syscall to m68k,
  parisc, ia64 and through asm-generic to arc, arm64, c6x, hexagon,
  metag, openrisc, score, tile, unicore32"

* 'renameat2' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs:
  scripts/checksyscalls.sh: Make renameat optional
  asm-generic: Add renameat2 syscall
  ia64: add renameat2 syscall
  parisc: add renameat2 syscall
  m68k: add renameat2 syscall

Pull iommu fixes from Joerg Roedel:
 "Three fixes for the AMD IOMMU driver:
   - fix a locking issue around get_user_pages()
   - fix two issues with device aliasing and exclusion range handling"

* tag 'iommu-fixes-v3.15-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu:
  iommu/amd: fix enabling exclusion range for an exact device
  iommu/amd: Take mmap_sem when calling get_user_pages
  iommu/amd: Fix interrupt remapping for aliased devices

Merge tag 'stable/for-linus-3.15-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/ibft

Pull iscsi_ibft fix from Konrad Rzeszutek Wilk:
 "Fix iBFT regression on Broadcom NICs introduced in 3.2"

* tag 'stable/for-linus-3.15-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/ibft:
  iscsi_ibft: Fix finding Broadcom specific ibft sign

Merge tag 'renesas-sh-drivers-for-v3.15' of git://git.kernel.org/pub/scm/linux/kernel/git/horms/renesas

Pull SH driver fix from Simon Horman:
 "Compile drivers/sh/pm_runtime.c if ARCH_SHMOBILE_MULTI

  This resolves a regression introduced in v3.14 by commit bf98c1ea
  ("ARM: Rename ARCH_SHMOBILE to ARCH_SHMOBILE_LEGACY")"

* tag 'renesas-sh-drivers-for-v3.15' of git://git.kernel.org/pub/scm/linux/kernel/git/horms/renesas:
  drivers: sh: compile drivers/sh/pm_runtime.c if ARCH_SHMOBILE_MULTI

Pull media fixes from Mauro Carvalho Chehab:
 "Most of the changes are drivers fixes (rtl28xuu, fc2580, ov7670,
  davinci, gspca, s5p-fimc and s5c73m3).

  There is also a compat32 fix and one infoleak fixup at the media
  controller"

* 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media:
  [media] V4L2: fix VIDIOC_CREATE_BUFS in 64- / 32-bit compatibility mode
  [media] V4L2: ov7670: fix a wrong index, potentially Oopsing the kernel from user-space
  [media] media-device: fix infoleak in ioctl media_enum_entities()
  [media] fc2580: fix tuning failure on 32-bit arch
  [media] Prefer gspca_sonixb over sn9c102 for all devices
  [media] media: davinci: vpfe: make sure all the buffers unmapped and released
  [media] staging: media: davinci: vpfe: make sure all the buffers are released
  [media] media: davinci: vpbe_display: fix releasing of active buffers
  [media] media: davinci: vpif_display: fix releasing of active buffers
  [media] media: davinci: vpif_capture: fix releasing of active buffers
  [media] s5p-fimc: Fix YUV422P depth
  [media] s5c73m3: Add missing rename of v4l2_of_get_next_endpoint() function
  [media] rtl28xxu: silence error log about disabled rtl2832_sdr module
  [media] rtl28xxu: do not hard depend on staging SDR module

Pull staging driver fixes from Greg KH:
 "Here are five staging driver fixes for 3.15-rc6 that resolve some
  reported issues.  They are for the imx and rtl8723au drivers"

* tag 'staging-3.15-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
  staging: rtl8723au: Do not reset wdev->iftype in netdev_close()
  staging: rtl8723au: Use correct pipe type for USB interrupts
  imx-drm: imx-tve: correct DDC property name to 'ddc-i2c-bus'
  imx-drm: imx-drm-core: skip components whose parent device is disabled
  imx-drm: imx-drm-core: fix imx_drm_encoder_get_mux_id

Merge tag 'driver-core-3.15-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core fixes from Greg KH:
 "Here are two driver core (well, sysfs) fixes for 3.15-rc6 that resolve
  some reported issues and a regression from 3.13"

* tag 'driver-core-3.15-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  sysfs: make sure read buffer is zeroed
  kernfs, sysfs, cgroup: restrict extra perm check on open to sysfs

Pull PCI fixes from Bjorn Helgaas:
 "These are fixes for an SHPCHP hotplug regression, a "wait for pending
  transaction" problem (used in device reset paths), and an email
  address update.

  PCI device hotplug:
    - Fix SHPCHP bus speed mismatch issue (Marcel Apfelbaum)

  Miscellaneous:
    - Fix pci_wait_for_pending_transaction() (Gavin Shan)
    - Update email address (Ben Hutchings)"

* tag 'pci-v3.15-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci:
  PCI: Wrong register used to check pending traffic
  PCI: shpchp: Check bridge's secondary (not primary) bus speed
  PCI: Update my email address

Pull /dev/random fix from Ted Ts'o:
 "This fixes a BUG_ON-causing regression that was introduced during the
  last merge window"

* tag 'random_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random:
  random: fix BUG_ON caused by accounting simplification

Pull clock framework fixes from Mike Turquette:
 "Clock framework and driver fixes, all of which fix user-visible
  regressions.

  As usual most fixes are for platform-specific clock drivers, but there
  are also two fixes to the clk core after recent changes to the way
  that clock unregistration is handled"

* tag 'clk-fixes-for-linus' of git://git.linaro.org/people/mike.turquette/linux:
  clk: tegra: Fix wrong value written to PLLE_AUX
  clk: shmobile: clk-mstp: change to using clock-indices
  clk: Fix slab corruption in clk_unregister()
  clk: Fix double free due to devm_clk_register()
  clk: socfpga: fix clock driver for 3.15
  clk: divider: Fix best div calculation for power-of-two and table dividers
  clk: bcm281xx: don't use unnamed structs or unions

Pull spi fixes from Mark Brown:
 "A few core fixes around outlying cases here, nothing that should
  affect most users but useful fixes.  The diffstat is rather larger
  than one might hope due some simple code motion in the fix for
  !CONFIG_DMA, the actual meaningful change is much smaller.

   - Fix handling of unsupported dual and quad mode support on slave
     registration so that drivers that can degrade gracefully do so,
     preventing regressions for drivers this is added.
   - Fix build in !CONFIG_DMA cases following addition of generic DMA
     mapping support.
   - Fix error handling for queue creation which due to wider kernel
     changes can be triggered more easily.
   - A couple of driver specific fixes"

* tag 'spi-v3.15-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi:
  spi/pxa2xx: Prevent DMA from transferring too many bytes
  spi: core: Don't destroy master queue if we fail to create it
  spi: qup: Fix return value checking for pm_runtime_get_sync()
  spi: core: Protect DMA code by #ifdef CONFIG_HAS_DMA
  spi: core: Ignore unsupported Dual/Quad Transfer Mode bits

Pull GPIO fixes from Linus Walleij:
 - fix a null pointer bug in the ICH6 chipset driver
 - fix device tree registration for the mcp23s08 driver

* tag 'gpio-v3.15-3' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio:
  gpio: mcp23s08: Bug fix of SPI device tree registration.
  gpio: ich: set regs and reglen for i3100 and ich6 chipset

Pull more cgroup fixes from Tejun Heo:
 "Three more patches to fix cgroup_freezer breakage due to the recent
  cgroup internal locking changes - an operation cgroup_freezer was
  using now requires sleepable context and cgroup_freezer was invoking
  that while holding a spin lock.  cgroup_freezer was using an overly
  elaborate hierarchical locking scheme.

  While it's possible to convert the hierarchical spinlocks directly to
  mutexes, this patch simplifies the overall locking so that it uses a
  global mutex.  This has the added benefit of avoiding iterating
  potentially huge number of tasks under a spinlock.  While the patch is
  on the larger side in the devel cycle, the changes made are mostly
  straight-forward and the locking logic is a lot simpler afterwards"

* 'for-3.15-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cgroup: fix rcu_read_lock() leak in update_if_frozen()
  cgroup_freezer: replace freezer->lock with freezer_mutex
  cgroup: introduce task_css_is_root()

Pull libata fixes from Tejun Heo:
 "Mostly device-specific fixes.  The only thing which isn't is the fix
  for zpodd oops-on-detach bug"

* 'for-3.15-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/libata:
  ahci: imx: PLL clock needs 100us to settle down
  ata: pata_at91 only works on sam9
  libata: clean up ZPODD when a port is detached
  ahci: imx: software workaround for phy reset issue in resume
  ahci: imx: add namespace for register enums
  ahci: disable DEVSLP for Intel Valleyview

Pull crypto fixes from Herbert Xu:
 "This fixes a NULL pointer dereference on allocation failure in caam,
  as well as a regression in the ctr mode on s390 that was added with
  the recent concurrency fixes"

* git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  crypto: s390 - fix aes,des ctr mode concurrency finding.
  crypto: caam - add allocation failure handling in SPRINTFCAT macro

Pull scsi target fixes from Nicholas Bellinger:
 "This series include:

   - Close race between iser-target network portal shutdown + accepting
     new connection logins (sagi)
   - Fix free-after-use regression in tcm_fc post conversion to
     percpu-ida pre-allocation (nab)
   - Explicitly disable Immediate + Unsolicited Data for iser-target
     connections when T10-PI is enabled (sagi + nab)
   - Allow pi_prot_type + emulate_write_cache attributes to be set to
     zero regardless of backend support (andy)
   - memory leak fix (mikulas)"

* git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending:
  target: fix memory leak on XCOPY
  target: Don't allow setting WC emulation if device doesn't support
  iscsi-target: Disable Immediate + Unsolicited Data with ISER Protection
  tcm_fc: Fix free-after-use regression in ft_free_cmd
  iscsi-target: Change BUG_ON to REJECT in iscsit_process_nop_out
  Target/iscsi,iser: Avoid accepting transport connections during stop stage
  Target/iser: Fix iscsit_accept_np and rdma_cm racy flow
  Target/iser: Fix wrong connection requests list addition
  target: Allow non-supporting backends to set pi_prot_type to 0

Pull i2c fixes from Wolfram Sang:
 "Some I2C bugfixes for 3.15.  Typical stuff, I'd say"

* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  i2c: rcar: bail out on zero length transfers
  i2c: qup: Fix pm_runtime_get_sync usage
  i2c: s3c2410: resume race fix
  i2c: nomadik: Don't use IS_ERR for devm_ioremap
  i2c: designware: Mask all interrupts during i2c controller enable

Pull ACPI and power management fixes from Rafael Wysocki:
 "Still fixing regressions (partly by reverting commits that broke
  things for people), fixing other stable-candidate bugs and adding some
  blacklist entries for ACPI video and _OSI.

  Two ACPICA regression fixes (one recent and one for a 3.14 commit), a
  fix for an ACPI-related regression in TPM (introduced in 3.14), a
  revert of the ACPI AC driver conversion in 3.13 that went wrong for an
  unknown reason, two reverts of commits that attempted to remove an old
  user space interface in /proc and broke some utilities, in 3.13 too, a
  fix for a CPU hotplug bug in the ACPI processor driver (stable
  material), two (stable candidate) fixes for intel_pstate and a few new
  blacklist entries, mostly for systems that shipped with Windows 8.

  Specifics:

   - ACPICA fix for a stale pointer access introduced by a recent commit
     in the XSDT validation code from Lv Zheng.

   - ACPICA fix for the default value of the command line switch to
     favor 32-bit FADT addresses (in case there's a conflict between a
     64-bit and a 32-bit address).  The previous default was that the
     32-bit version would take precedence and we tried to change it to
     the other way around and it didn't work.  From Lv Zheng.

   - A TPM commit related to ACPI _DSM in 3.14 caused the driver to
     refuse to load if a specific _DSM was missing and that broke resume
     from system suspend on Chromebooks that require the TPM hardware to
     be restored to a working state during resume by the OS.  Restore
     the old behavior to load the driver if the _DSM in question is not
     present, but prevent it from using the feature the _DSM is for.

   - ACPI AC driver conversion in 3.13 broke thermal management on at
     least one machine and has to be reverted.  From Guenter Roeck.

   - Two reverts of 3.13 commits that attempted to remove the old ACPI
     battery interface in /proc, but turned out to break some utilities
     still using that interface.  From Lan Tianyu.

   - ACPI processor driver fix to prevent acpi_processor_add() from
     modifying the CPU device's .offline field which leads to breakage
     if the initial online of the CPU fails.  From Igor Mammedov.

   - Two intel_pstate fixes, one to take a BayTrail documentation update
     into account and one to avoid forcing the maximum P-state on init
     which causes CPU PM trouble on systems with P-states coordination
     when one of the CPU cores is initialized after an offline/online
     cycle triggered by user space.  Both stable candidates, from Dirk
     Brandewie.

   - Fix for the ACPI video DMI blacklist entry for Dell Inspiron 7520
     from Aaron Lu.

   - Two new ACPI video blacklist entries for machines shipping with
     Win8 that need to use native backlight so that it can be controlled
     in a usual way (which doesn't work otherwise due bugs in the ACPI
     tables) from Hans de Goede.

   - Two ACPI _OSI quirks for systems that need them to work correctly
     with Linux from Edward Lin and Hans de Goede"

* tag 'pm+acpi-3.15-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  ACPI / video: Revert native brightness quirk for ThinkPad T530
  intel_pstate: remove setting P state to MAX on init
  ACPICA: Tables: Restore old behavor to favor 32-bit FADT addresses.
  ACPI / video: correct DMI tag for Dell Inspiron 7520
  intel_pstate: Set turbo VID for BayTrail
  ACPI / TPM: Fix resume regression on Chromebooks
  ACPI / proc: Do not say when /proc interfaces will be deleted in Kconfig
  ACPI / processor: do not mark present at boot but not onlined CPU as onlined
  ACPI: Revert "ACPI / AC: convert ACPI ac driver to platform bus"
  ACPI / blacklist: Add dmi_enable_osi_linux quirk for Asus EEE PC 1015PX
  ACPI: blacklist win8 OSI for Dell Inspiron 7737
  ACPI / video: Add use_native_backlight quirks for more systems
  ACPI: Revert "ACPI / Battery: Remove battery's proc directory"
  ACPI: Revert "ACPI: Remove CONFIG_ACPI_PROCFS_POWER and cm_sbsc.c"
  ACPICA: Tables: Fix invalid pointer accesses in acpi_tb_parse_root_table().

Pull device mapper fixes from Mike Snitzer:
 "A dm-crypt fix for a cpu hotplug crash that switches from using
  per-cpu data to a mempool allocation (which offers allocation with cpu
  locality, and there is no inter-cpu communication on slab allocation).

  A couple dm-thinp stable fixes to address "out-of-data-space" issues.

  A dm-multipath fix for a LOCKDEP warning introduced in 3.15-rc1"

* tag 'dm-3.15-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm mpath: fix lock order inconsistency in multipath_ioctl
  dm thin: add timeout to stop out-of-data-space mode holding IO forever
  dm thin: allow metadata commit if pool is in PM_OUT_OF_DATA_SPACE mode
  dm crypt: fix cpu hotplug crash by removing per-cpu structure

Pull device tree fixes from Grant Likely:
 "Drivercore bugfixes for v3.15

  This branch contains bug fixes important to get into v3.15.  There is
  a fix for modifying properties seen during early boot, a fix for an
  incorrect prototype when CONFIG_OF=n, and a couple of corrections to
  device tree memory nodes on a few platforms"

* tag 'dt-for-linus' of git://git.secretlab.ca/git/linux:
  mips: dts: Fix missing device_type="memory" property in memory nodes
  arm: dts: Fix missing device_type="memory" for ste-ccu8540
  of: fix CONFIG_OF=n prototype of of_node_full_name()
  of: make of_update_property() usable earlier in the boot process

When running send, if an inode only has extended reference items
associated to it and no regular references, send.c:get_first_ref()
was incorrectly assuming the reference it found was of type
BTRFS_INODE_REF_KEY due to use of the wrong key variable.
This caused weird behaviour when using the found item has a regular
reference, such as weird path string, and occasionally (when lucky)
a crash:

[  190.600652] general protection fault: 0000 [#1] SMP DEBUG_PAGEALLOC
[  190.600994] Modules linked in: btrfs xor raid6_pq binfmt_misc nfsd auth_rpcgss oid_registry nfs_acl nfs lockd fscache sunrpc psmouse serio_raw evbug pcspkr i2c_piix4 e1000 floppy
[  190.602565] CPU: 2 PID: 14520 Comm: btrfs Not tainted 3.13.0-fdm-btrfs-next-26+ #1
[  190.602728] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[  190.602868] task: ffff8800d447c920 ti: ffff8801fa79e000 task.ti: ffff8801fa79e000
[  190.603030] RIP: 0010:[<ffffffff813266b4>]  [<ffffffff813266b4>] memcpy+0x54/0x110
[  190.603262] RSP: 0018:ffff8801fa79f880  EFLAGS: 00010202
[  190.603395] RAX: ffff8800d4326e3f RBX: 000000000000036a RCX: ffff880000000000
[  190.603553] RDX: 000000000000032a RSI: ffe708844042936a RDI: ffff8800d43271a9
[  190.603710] RBP: ffff8801fa79f8c8 R08: 00000000003a4ef0 R09: 0000000000000000
[  190.603867] R10: 793a4ef09f000000 R11: 9f0000000053726f R12: ffff8800d43271a9
[  190.604020] R13: 0000160000000000 R14: ffff8802110134f0 R15: 000000000000036a
[  190.604020] FS:  00007fb423d09b80(0000) GS:ffff880216200000(0000) knlGS:0000000000000000
[  190.604020] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[  190.604020] CR2: 00007fb4229d4b78 CR3: 00000001f5d76000 CR4: 00000000000006e0
[  190.604020] Stack:
[  190.604020]  ffffffffa01f4d49 ffff8801fa79f8f0 00000000000009f9 ffff8801fa79f8c8
[  190.604020]  00000000000009f9 ffff880211013260 000000000000f971 ffff88021147dba8
[  190.604020]  00000000000009f9 ffff8801fa79f918 ffffffffa02367f5 ffff8801fa79f928
[  190.604020] Call Trace:
[  190.604020]  [<ffffffffa01f4d49>] ? read_extent_buffer+0xb9/0x120 [btrfs]
[  190.604020]  [<ffffffffa02367f5>] fs_path_add_from_extent_buffer+0x45/0x60 [btrfs]
[  190.604020]  [<ffffffffa0238806>] get_first_ref+0x1f6/0x210 [btrfs]
[  190.604020]  [<ffffffffa0238994>] __get_cur_name_and_parent+0x174/0x3a0 [btrfs]
[  190.604020]  [<ffffffff8118df3d>] ? kmem_cache_alloc_trace+0x11d/0x1e0
[  190.604020]  [<ffffffffa0236674>] ? fs_path_alloc+0x24/0x60 [btrfs]
[  190.604020]  [<ffffffffa0238c91>] get_cur_path+0xd1/0x240 [btrfs]
(...)

Steps to reproduce (either crash or some weirdness like an odd path string):

    mkfs.btrfs -f -O extref /dev/sdd
    mount /dev/sdd /mnt

    mkdir /mnt/testdir
    touch /mnt/testdir/foobar

    for i in `seq 1 2550`; do
        ln /mnt/testdir/foobar /mnt/testdir/foobar_link_`printf "%04d" $i`
    done

    ln /mnt/testdir/foobar /mnt/testdir/final_foobar_name

    rm -f /mnt/testdir/foobar
    for i in `seq 1 2550`; do
        rm -f /mnt/testdir/foobar_link_`printf "%04d" $i`
    done

    btrfs subvolume snapshot -r /mnt /mnt/mysnap
    btrfs send /mnt/mysnap -f /tmp/mysnap.send
Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>