This patch is intentionally incomplete to simplify the review.
It ignores ep_unregister_pollwait() which plays with the same wqh.
See the next change.

epoll assumes that the EPOLL_CTL_ADD'ed file controls everything
f_op->poll() needs. In particular it assumes that the wait queue
can't go away until eventpoll_release(). This is not true in case
of signalfd, the task which does EPOLL_CTL_ADD uses its ->sighand
which is not connected to the file.

This patch adds the special event, POLLFREE, currently only for
epoll. It expects that init_poll_funcptr()'ed hook should do the
necessary cleanup. Perhaps it should be defined as EPOLLFREE in
eventpoll.

__cleanup_sighand() is changed to do wake_up_poll(POLLFREE) if
->signalfd_wqh is not empty, we add the new signalfd_cleanup()
helper.

ep_poll_callback(POLLFREE) simply does list_del_init(task_list).
This make this poll entry inconsistent, but we don't care. If you
share epoll fd which contains our sigfd with another process you
should blame yourself. signalfd is "really special". I simply do
not know how we can define the "right" semantics if it used with
epoll.

The main problem is, epoll calls signalfd_poll() once to establish
the connection with the wait queue, after that signalfd_poll(NULL)
returns the different/inconsistent results depending on who does
EPOLL_CTL_MOD/signalfd_read/etc. IOW: apart from sigmask, signalfd
has nothing to do with the file, it works with the current thread.

In short: this patch is the hack which tries to fix the symptoms.
It also assumes that nobody can take tasklist_lock under epoll
locks, this seems to be true.

Note:

	- we do not have wake_up_all_poll() but wake_up_poll()
	  is fine, poll/epoll doesn't use WQ_FLAG_EXCLUSIVE.

	- signalfd_cleanup() uses POLLHUP along with POLLFREE,
	  we need a couple of simple changes in eventpoll.c to
	  make sure it can't be "lost".
Reported-by: Maxime Bizon <mbizon@freebox.fr>
Cc: <stable@kernel.org>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Quoth Chris:
 "This is later than I wanted because I got backed up running through
  btrfs bugs from the Oracle QA teams.  But they are all bug fixes that
  we've queued and tested since rc1.

  Nothing in particular stands out, this just reflects bug fixing and QA
  done in parallel by all the btrfs developers.  The most user visible
  of these is:

    Btrfs: clear the extent uptodate bits during parent transid failures

  Because that helps deal with out of date drives (say an iscsi disk
  that has gone away and come back).  The old code wasn't always
  properly retrying the other mirror for this type of failure."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (24 commits)
  Btrfs: fix compiler warnings on 32 bit systems
  Btrfs: increase the global block reserve estimates
  Btrfs: clear the extent uptodate bits during parent transid failures
  Btrfs: add extra sanity checks on the path names in btrfs_mksubvol
  Btrfs: make sure we update latest_bdev
  Btrfs: improve error handling for btrfs_insert_dir_item callers
  Btrfs: be less strict on finding next node in clear_extent_bit
  Btrfs: fix a bug on overcommit stuff
  Btrfs: kick out redundant stuff in convert_extent_bit
  Btrfs: skip states when they does not contain bits to clear
  Btrfs: check return value of lookup_extent_mapping() correctly
  Btrfs: fix deadlock on page lock when doing auto-defragment
  Btrfs: fix return value check of extent_io_ops
  btrfs: honor umask when creating subvol root
  btrfs: silence warning in raid array setup
  btrfs: fix structs where bitfields and spinlock/atomic share 8B word
  btrfs: delalloc for page dirtied out-of-band in fixup worker
  Btrfs: fix memory leak in load_free_space_cache()
  btrfs: don't check DUP chunks twice
  Btrfs: fix trim 0 bytes after a device delete
  ...

This is the arch/c6x part of commit 7c431851 ("Kbuild: Use dtc's -d
(dependency) option") which was dropped because c6x had not yet been
merged at the time.

* tag 'for-linus' of git://linux-c6x.org/git/projects/linux-c6x-upstreaming:
  Kbuild: Use dtc's -d (dependency) option

I don't even live in the same country as any of my PA-RISC hardware
these days, so the odds of me touching the code are pretty low.
(Also re-order things to ensure jejb gets CC'd since he's been the
primary maintainer for the last few years.)
Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Don't clear vm_mm in a deleted VMA as it's unnecessary and might
conceivably break the filesystem or driver VMA close routine.
Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Lock i_mmap_mutex for access to the VMA prio list to prevent concurrent
access.  Currently, certain parts of the mmap handling are protected by
the region mutex, but not all.
Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

SH/R-Mobile fixes for 3.3-rc5

* tag 'rmobile-for-linus' of git://github.com/pmundt/linux-sh:
  arch/arm/mach-shmobile/board-ag5evm.c: included linux/dma-mapping.h twice
  ARM: mach-shmobile: r8a7779 PFC IPSR4 fix
  ARM: mach-shmobile: sh73a0 PSTR 32-bit access fix
  ARM: mach-shmobile: add GPIO-to-IRQ translation to sh7372
  ARM: mach-shmobile: clock-sh73a0: add DSIxPHY clock support
  arm: fix compile failure in mach-shmobile/board-ag5evm.c
  ARM: mach-shmobile: mackerel: add ak4642 amixer settings on comment
  ARM: mach-shmobile: mackerel: use renesas_usbhs instead of r8a66597_hcd
  ARM: mach-shmobile: simplify MMCIF DMA configuration
  ARM: mach-shmobile: IRQ driven GPIO key support for Kota2
  ARM: mach-shmobile: sh73a0 IRQ sparse alloc fix
  ARM: mach-shmobile: sh73a0 PINT IRQ base fix

SuperH fixes for 3.3-rc5

* tag 'sh-for-linus' of git://github.com/pmundt/linux-sh:
  sh: Fix sh2a build error for CONFIG_CACHE_WRITETHROUGH
  sh: modify a resource of sh_eth_giga1_resources in board-sh7757lcr
  arch/sh: remove references to cpu_*_map.
  sh: Fix typo in pci-sh7780.c
  sh: add platform_device for SPI1 in setup-sh7757
  sh: modify resource for SPI0 in setup-sh7757
  sh: se7724: fix compile breakage
  sh: clkfwk: bugfix: use clk_reparent() for div6 clocks
  sh: clock-sh7724: fixup sh_fsi clock settings
  sh: sh7757lcr: update to the new MMCIF DMA configuration
  sh: fix the sh_mmcif_plat_data in board-sh7757lcr
  video: pvr2fb: Fix up spurious section mismatch warnings.
  sh: Defer to asm-generic/device.h.

There is an issue when memcg unregisters events that were attached to
the same eventfd:

- On the first call mem_cgroup_usage_unregister_event() removes all
  events attached to a given eventfd, and if there were no events left,
  thresholds->primary would become NULL;

- Since there were several events registered, cgroups core will call
  mem_cgroup_usage_unregister_event() again, but now kernel will oops,
  as the function doesn't expect that threshold->primary may be NULL.

That's a good question whether mem_cgroup_usage_unregister_event()
should actually remove all events in one go, but nowadays it can't
do any better as cftype->unregister_event callback doesn't pass
any private event-associated cookie. So, let's fix the issue by
simply checking for threshold->primary.

FWIW, w/o the patch the following oops may be observed:

 BUG: unable to handle kernel NULL pointer dereference at 0000000000000004
 IP: [<ffffffff810be32c>] mem_cgroup_usage_unregister_event+0x9c/0x1f0
 Pid: 574, comm: kworker/0:2 Not tainted 3.3.0-rc4+ #9 Bochs Bochs
 RIP: 0010:[<ffffffff810be32c>]  [<ffffffff810be32c>] mem_cgroup_usage_unregister_event+0x9c/0x1f0
 RSP: 0018:ffff88001d0b9d60  EFLAGS: 00010246
 Process kworker/0:2 (pid: 574, threadinfo ffff88001d0b8000, task ffff88001de91cc0)
 Call Trace:
  [<ffffffff8107092b>] cgroup_event_remove+0x2b/0x60
  [<ffffffff8103db94>] process_one_work+0x174/0x450
  [<ffffffff8103e413>] worker_thread+0x123/0x2d0

Cc: stable <stable@vger.kernel.org>
Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The enospc tracing code added some interesting uses of
u64 pointer casts.
Signed-off-by: Chris Mason <chris.mason@oracle.com>

arch/arm/mach-shmobile/board-ag5evm.c: included 'linux/dma-mapping.h'
twice, remove the duplicate.
Signed-off-by: Danny Kukawka <danny.kukawka@bisect.de>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

Fix the bit field width information for the IPSR4 register
in the r8a7779 pin function controller (PFC).

Without this fix the Marzen board fails to receive data
over the serial console due to misconfigured pin function
for the RX pin.
Signed-off-by: Magnus Damm <damm@opensource.se>
Tested-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Tested-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

Convert the sh73a0 SMP code to use 32-bit PSTR access.

This fixes wakeup from deep sleep for sh73a0 secondary CPUs.
Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

Signed-off-by: Phil Edworthy <phil.edworthy@renesas.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

The latest sh_eth driver needs a resource of TSU in the channel 1,
if the controller has TSU registers. So, this patch adds the resource.
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

This has been obsolescent for a while; time for the final push.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: linux-sh@vger.kernel.org
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

Correct spelling "erorr" to "error" in
arch/sh/drivers/pci/pci-sh7780.c
Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

With kernel 3.1, Christoph removed i_alloc_sem and replaced it with
calls (namely inode_dio_wait() and inode_dio_done()) which are
EXPORT_SYMBOL_GPL() thus they cannot be used by non-GPL file systems and
further inode_dio_wait() was pushed from notify_change() into the file
system ->setattr() method but no non-GPL file system can make this call.

That means non-GPL file systems cannot exist any more unless they do not
use any VFS functionality related to reading/writing as far as I can
tell or at least as long as they want to implement direct i/o.

Both Linus and Al (and others) have said on LKML that this breakage of
the VFS API should not have happened and that the change was simply
missed as it was not documented in the change logs of the patches that
did those changes.

This patch changes the two function exports in question to be
EXPORT_SYMBOL() thus restoring the VFS API as it used to be - accessible
for all modules.

Christoph, who introduced the two functions and exported them GPL-only
is CC-ed on this patch to give him the opportunity to object to the
symbols being changed in this manner if he did indeed intend them to be
GPL-only and does not want them to become available to all modules.
Signed-off-by: Anton Altaparmakov <anton@tuxera.com>
CC: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

A fix from Jesper Juhl removes an assignment in an ASSERT when a compare
is intended.  Two fixes from Mitsuo Hayasaka address off-by-ones in XFS
quota enforcement.

* 'for-linus' of git://oss.sgi.com/xfs/xfs:
  xfs: make inode quota check more general
  xfs: change available ranges of softlimit and hardlimit in quota check
  XFS: xfs_trans_add_item() - don't assign in ASSERT() when compare is intended

BenH says:
 'Here are a few more powerpc bits for you.  A stupid regression I
  introduced with my previous commit to "fix" program check exceptions
  (brown paper bag for me), fix the cpuidle default, a bug fix for
  something that isn't strictly speaking a regression but some upstream
  changes causes it to show in lockdep now while it didn't before, and
  finally a trivial one for rusty to make his life easier later on
  removing the old cpumask cruft. '

* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc:
  powerpc: Fix various issues with return to userspace
  cpuidle: Default y on powerpc pSeries
  powerpc: Fix program check handling when lockdep is enabled
  powerpc: Remove references to cpu_*_map

sound fixes for 3.3-rc5

Just a collection of boring small fixes for ASoC, HD-audio Realtek
and USB-audio drivers.

* tag 'sound-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
  ALSA: snd-usb-caiaq: Fix the return of XRUN
  ASoC: ak4642: fixup HeadPhone L/R dapm settings
  ALSA: hda/realtek - Fix surround output regression on Acer Aspire 5935
  ALSA: hda/realtek - Fix overflow of vol/sw check bitmap
  ALSA: usb-audio: avoid integer overflow in create_fixed_stream_quirk()
  ASoC: wm8962: Fix sidetone enumeration texts

When doing IO with large amounts of data fragmentation, the global block
reserve calulations are too low.  This increases them to avoid
ENOSPC crashes.
Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>

If btrfs reads a block and finds a parent transid mismatch, it clears
the uptodate flags on the extent buffer, and the pages inside it.  But
we only clear the uptodate bits in the state tree if the block straddles
more than one page.

This is from an old optimization from to reduce contention on the extent
state tree.  But it is buggy because the code that retries a read from
a different copy of the block is going to find the uptodate state bits
set and skip the IO.

The end result of the bug is that we'll never actually read the good
copy (if there is one).

The fix here is to always clear the uptodate state bits, which is safe
because this code is only called when the parent transid fails.
Signed-off-by: Chris Mason <chris.mason@oracle.com>

Signed-off-by: Chris Mason <chris.mason@oracle.com>

When we are setting up the mount, we close all the
devices that were not actually part of the metadata we found.

But, we don't make sure that one of those devices wasn't
fs_devices->latest_bdev, which means we can do a use after free
on the one we closed.

This updates latest_bdev as it goes.
Signed-off-by: Chris Mason <chris.mason@oracle.com>

This allows us to gracefully continue if we aren't able to insert
directory items, both for normal files/dirs and snapshots.
Signed-off-by: Chris Mason <chris.mason@oracle.com>

USB bugfixes for 3.3-rc4

A number of new device ids, and a cleanup/fix for some of the option
device ids that shouldn't have been added in the first place.

There's also a few USB 3 fixes for problems that people have reported,
and a usb-storage bugfix to round it out.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

* tag 'usb-3.3-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
  USB: Added Kamstrup VID/PIDs to cp210x serial driver.
  USB: Serial: ti_usb_3410_5052: Add Abbot Diabetes Care cable id
  usb-storage: fix freezing of the scanning thread
  xhci: Fix encoding for HS bulk/control NAK rate.
  USB: Set hub depth after USB3 hub reset
  USB: Fix handoff when BIOS disables host PCI device.
  USB: option: cleanup zte 3g-dongle's pid in option.c
  USB: Don't fail USB3 probe on missing legacy PCI IRQ.
  xhci: Fix oops caused by more USB2 ports than USB3 ports.
  USB: Remove duplicate USB 3.0 hub feature #defines.

Intel, radeon, exynos fixes.

Intel: fixes a few Ivybridge hangs, along with fixing RC6 on SNB (still
not on, but at least allows for distros to patch it on easily).

radeon: oops reading some files in debugfs that weren't meant to appear,
a fix that touches a lot of files, so looks worse than it is, it fixes
an oops if a GPU reset fails and userspace keeps submitting more data,
along with a minor BIOS fix for newer boards.

exynos: a group of fixes for exynos, they've sent me a few more but
these were all I got through, and its no hw vanilla kernel users see a
lot off yet.

* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux:
  drm/radeon/kms/atom: dpms bios scratch reg updates
  drm/radeon/kms: properly set accel working flag and bailout when false
  drm/radeon: Only create additional ring debugfs files on Cayman or newer.
  drm/exynos: added postclose to release resource.
  drm/exynos: removed exynos_drm_fbdev_recreate function.
  drm/exynos: fixed page flip issue.
  drm/exynos: added possible_clones setup function.
  drm/exynos: removed pageflip_event_list init code when closed.
  drm/exynos: changed priority of mixer layers.
  drm/exynos: Fix typo in exynos_mixer.c
  drm/i915: do not enable RC6p on Sandy Bridge
  drm/i915: gen7: Disable the RHWO optimization as it can cause GPU hangs.
  drm/i915: gen7: work around a system hang on IVB
  drm/i915: gen7: Implement an L3 caching workaround.
  drm/i915: gen7: implement rczunit workaround

It contains 3 important fixes for ColdFire based machines:
 - fix processes getting stuck when running from strace
 - fix kernel vmalloced pages not being visible in all kernel contexts
 - fix shared user pages sometimes being visible in another process
   context

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gerg/m68knommu:
  m68k: Do not set global share for non-kernel shared pages
  m68k: Add shared bit to Coldfire kernel page entries
  m68knommu: fix syscall tracing stuck process

Bugfixes for the NFS client.

Fix a nasty Oops in the NFSv4 getacl code, another source of infinite
loops in the NFSv4 state recovery code, and a regression in NFSv4.1
session initialisation.

Also deal with an NFSv4.1 memory leak.

* tag 'nfs-for-3.3-4' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
  NFSv4: fix server_scope memory leak
  NFSv4.1: Fix a NFSv4.1 session initialisation regression
  NFSv4: Ensure we throw out bad delegation stateids on NFS4ERR_BAD_STATEID
  NFSv4: Fix an Oops in the NFSv4 getacl code

dpms bits not used on DCE4+
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

If accel is not working many subsystem such as the ib pool might not be
initialized properly that can lead to segfault inside kernel when cs
ioctl is call with non working acceleration. To avoid this make sure
the accel working flag is false when an error in GPU startup happen and
return EBUSY from cs ioctl if accel is not working.
Signed-off-by: Jerome Glisse <jglisse@redhat.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=46274

Tested with a Cayman card in a Llano system: The additional files are created
and working for the Cayman card but not created for the CPU's built-in GPU.
Signed-off-by: Michel Dänzer <michel.daenzer@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

Merge branch 'drm-intel-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/drm-intel into drm-fixes

* 'drm-intel-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/drm-intel:
  drm/i915: do not enable RC6p on Sandy Bridge
  drm/i915: gen7: Disable the RHWO optimization as it can cause GPU hangs.
  drm/i915: gen7: work around a system hang on IVB
  drm/i915: gen7: Implement an L3 caching workaround.
  drm/i915: gen7: implement rczunit workaround

Commit 3702b082 added a lock, but did not account for the case of
SNDRV_PCM_POS_XRUN, which would get immediately overwritten.

This could be bundled into one if-else-if statement, but the goto
helps to clarify the 'exceptional' case.

Thanks to Andreas Pape for spotting this.
Signed-off-by: Mark Hills <mark@pogo.org.uk>
Acked-by: Daniel Mack <zonque@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

We have a few problems when returning to userspace. This is a
quick set of fixes for 3.3, I'll look into a more comprehensive
rework for 3.4. This fixes:

 - We kept interrupts soft-disabled when schedule'ing or calling
do_signal when returning to userspace as a result of a hardware
interrupt.

 - Rename do_signal to do_notify_resume like all other archs (and
do_signal_pending back to do_signal, which it was before Roland
changed it).

 - Add the missing call to key_replace_session_keyring() to
do_notify_resume().
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
---

We moved all our pSeries idle loops to the cpu idle framework
so we really want it to come up by default.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

In commit 54321242 ("Disable interrupts early in Program Check"), we
switched from enabling to disabling interrupts in program_check_common.

Whereas ENABLE_INTS leaves r3 untouched, if lockdep is enabled DISABLE_INTS
calls into lockdep code and will clobber r3. That means we pass a bogus
struct pt_regs* into program_check_exception() and all hell breaks loose.

So load our regs pointer into r3 after we call DISABLE_INTS.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

This has been obsolescent for a while; time for the final push.

In adjacent context, replaced old cpus_* with cpumask_*.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>