It's an enum, not a #define, you can't use it in asm files.

Introduced in commit 5fa10196 ("x86: Ignore NMIs that come in during
early boot"), and sadly I didn't compile-test things like I should have
before pushing out.

My weak excuse is that the x86 tree generally doesn't introduce stupid
things like this (and the ARM pull afterwards doesn't cause me to do a
compile-test either, since I don't cross-compile).

Cc: Don Zickus <dzickus@redhat.com>
Cc: H. Peter Anvin <hpa@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull ARM fixes from Russell King:
 "A number of ARM updates for -rc, covering mostly ARM specific code,
  but with one change to modpost.c to allow Thumb section mismatches to
  be detected.

  ARM changes include reporting when an attempt is made to boot a LPAE
  kernel on hardware which does not support LPAE, rather than just being
  silent about it.

  A number of other minor fixes are included too"

* 'fixes' of git://ftp.arm.linux.org.uk/~rmk/linux-arm:
  ARM: 7992/1: boot: compressed: ignore bswapsdi2.S
  ARM: 7991/1: sa1100: fix compile problem on Collie
  ARM: fix noMMU kallsyms symbol filtering
  ARM: 7980/1: kernel: improve error message when LPAE config doesn't match CPU
  ARM: 7964/1: Detect section mismatches in thumb relocations
  ARM: 7963/1: mm: report both sections from PMD

Pull x86 fixes from Peter Anvin:
 "A small collection of minor fixes.  The FPU stuff is still pending, I
  fear.  I haven't heard anything from Suresh so I suspect I'm going to
  have to dig into the init specifics myself and fix up the patchset"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86: Ignore NMIs that come in during early boot
  x86, trace: Further robustify CR2 handling vs tracing
  x86, trace: Fix CR2 corruption when tracing page faults
  x86/efi: Quirk out SGI UV

Pull power fixes from Ben Herrenschmidt:
 "Here are a couple of powerpc fixes for 3.14.

  One is (another!) nasty TM problem, we can crash the kernel by forking
  inside a transaction.  The other one is a simple fix for an alignment
  issue which can hurt in LE mode"

* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc:
  powerpc: Align p_dyn, p_rela and p_st symbols
  powerpc/tm: Fix crash when forking inside a transaction

Merge tag 'trace-fixes-v3.14-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fix from Steven Rostedt:
 "In the past, I've had lots of reports about trace events not working.
  Developers would say they put a trace_printk() before and after the
  trace event but when they enable it (and the trace event said it was
  enabled) they would see the trace_printks but not the trace event.

  I was not able to reproduce this, but that's because I wasn't looking
  at the right location.  Recently, another bug came up that showed the
  issue.

  If your kernel supports signed modules but allows for non-signed
  modules to be loaded, then when one is, the kernel will silently set
  the MODULE_FORCED taint on the module.  Although, this taint happens
  without the need for insmod --force or anything of the kind, it labels
  the module with that taint anyway.

  If this tainted module has tracepoints, the tracepoints will be
  ignored because of the MODULE_FORCED taint.  But no error message will
  be displayed.  Worse yet, the event infrastructure will still be
  created letting users enable the trace event represented by the
  tracepoint, although that event will never actually be enabled.  This
  is because the tracepoint infrastructure allows for non-existing
  tracepoints to be enabled for new modules to arrive and have their
  tracepoints set.

  Although there are several things wrong with the above, this change
  only addresses the creation of the trace event files for tracepoints
  that are not created when a module is loaded and is tainted.  This
  change will print an error message about the module being tainted and
  not the trace events will not be created, and it does not create the
  trace event infrastructure"

* tag 'trace-fixes-v3.14-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Do not add event files for modules that fail tracepoints

Pull irq fixes from Thomas Gleixner:
 - a bugfix for a long standing waitqueue race
 - a trivial fix for a missing include

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  genirq: Include missing header file in irqdomain.c
  genirq: Remove racy waitqueue_active check

Pull device mapper fixes from Mike Snitzer:

 - dm-cache memory allocation failure fix
 - fix DM's Kconfig identation
 - dm-snapshot metadata corruption fix for bug introduced in 3.14-rc1
 - important refcount < 0 fix for the DM persistent data library's space
   map metadata interface which fixes corruption reported by a few
   dm-thinp users

and last but not least:

 - more extensive fixes than ideal for dm-thinp's data resize capability
   (which has had growing pain much like we've seen from -ENOSPC
   handling of filesystems that mature).

   The end result is dm-thinp now handles metadata operation failure and
   no data space error conditions much better than before.

* tag 'dm-3.14-fixes-3' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm space map metadata: fix refcount decrement below 0 which caused corruption
  dm thin: fix Documentation for held metadata root feature
  dm thin: fix noflush suspend IO queueing
  dm thin: fix deadlock in __requeue_bio_list
  dm thin: fix out of data space handling
  dm thin: ensure user takes action to validate data and metadata consistency
  dm thin: synchronize the pool mode during suspend
  dm snapshot: fix metadata corruption
  dm: fix Kconfig indentation
  dm cache mq: fix memory allocation failure for large cache devices

Don Zickus reports:

A customer generated an external NMI using their iLO to test kdump
worked.  Unfortunately, the machine hung.  Disabling the nmi_watchdog
made things work.

I speculated the external NMI fired, caused the machine to panic (as
expected) and the perf NMI from the watchdog came in and was latched.
My guess was this somehow caused the hang.

   ----

It appears that the latched NMI stays latched until the early page
table generation on 64 bits, which causes exceptions to happen which
end in IRET, which re-enable NMI.  Therefore, ignore NMIs that come in
during early execution, until we have proper exception handling.
Reported-and-tested-by: Don Zickus <dzickus@redhat.com>
Link: http://lkml.kernel.org/r/1394221143-29713-1-git-send-email-dzickus@redhat.comSigned-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: <stable@vger.kernel.org> # v3.5+, older with some backport effort

Commit 017f161a (ARM: 7877/1: use built-in byte swap function) added
bswapsdi2.{o,S} to arch/arm/boot/compressed/Makefile, but didn't update
the .gitignore. Thus after a a build git status shows bswapsdi2.S as a
new file, which is a little annoying.

This patch updates arch/arm/boot/compressed/.gitignore to ignore
bswapsdi2.S, as we already do for ashldi3.S and others.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Kim Phillips <kim.phillips@freescale.com>
Cc: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Due to a problem in the MFD Kconfig it was not possible to
compile the UCB battery driver for the Collie SA1100 system,
in turn making it impossible to compile in the battery driver.
(See patch "mfd: include all drivers in subsystem menu".)

After fixing the MFD Kconfig (separate patch) a compile error
appears in the Collie battery driver due to the <mach/collie.h>
implicitly requiring <mach/hardware.h> through <linux/gpio.h>
via <mach/gpio.h> prior to commit
40ca061b "ARM: 7841/1: sa1100: remove complex GPIO interface".

Fix this up by including the required header into
<mach/collie.h>.

Cc: stable@vger.kernel.org
Cc: Andrea Adami <andrea.adami@gmail.com>
Cc: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

With noMMU, CONFIG_PAGE_OFFSET was not being set correctly.  As there's
no MMU, PAGE_OFFSET should be equal to PHYS_OFFSET in all cases.  This
commit makes that explicit.

Since we do this, we don't need to mess around in asm/memory.h with
ifdefs to sort this out, so let's get rid of that, and there's no point
offering the "Memory split" option for noMMU as that's meaningless
there.

Fixes: b9b32bf7 ("ARM: use linker magic for vectors and vector stubs")
Cc: <stable@vger.kernel.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

This fixes a subtle issue with cache flush which could potentially cause
random userspace crashes because of stale icache lines.

This error crept in when consolidating the cache flush code

Fixes: bd12976c (ARC: cacheflush refactor #3: Unify the {d,i}cache)
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: linux-kernel@vger.kernel.org
Cc: stable@vger.kernel.org  # 3.13
Cc: arc-linux-dev@synopsys.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull sound fixes from Takashi Iwai:
 "Just a few device-specific quirks for HD-audio and USB-audio, most of
  which are one-liners"

* tag 'sound-3.14-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
  ALSA: usb-audio: Add quirk for Logitech Webcam C500
  ALSA: hda - Use analog beep for Thinkpads with AD1984 codecs
  ALSA: hda - Add missing loopback merge path for AD1884/1984 codecs
  ALSA: hda - add automute fix for another dell AIO model
  ALSA: hda - Added inverted digital-mic handling for Acer TravelMate 8371

Pull drm fixes from Dave Airlie:
 "Mostly intel and radeon fixes, one tda998x, one kconfig dep fix and
  two more MAINTAINERS updates,

  All pretty run of the mill for this stage"

* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux:
  drm/radeon/atom: select the proper number of lanes in transmitter setup
  MAINTAINERS: add maintainer entry for TDA998x driver
  drm: fix bochs kconfig dependencies
  drm/radeon/dpm: fix typo in EVERGREEN_SMC_FIRMWARE_HEADER_softRegisters
  drm/radeon/cik: fix typo in documentation
  drm/radeon: silence GCC warning on 32 bit
  drm/radeon: resume old pm late
  drm/radeon: TTM must be init with cpu-visible VRAM, v2
  DRM: armada: fix use of kfifo_put()
  drm/i915: Reject >165MHz modes w/ DVI monitors
  drm/i915: fix assert_cursor on BDW
  drm/i915: vlv: reserve GT power context early
  drm/i915: fix pch pci device enumeration
  drm/i915: Resolving the memory region conflict for Stolen area
  drm/i915: use backlight legacy combination mode also for i915gm/i945gm
  MAINTAINERS: update AGP tree to point at drm tree

Pull block fixes from Jens Axboe:
 "Small collection of fixes for 3.14-rc. It contains:

   - Three minor update to blk-mq from Christoph.

   - Reduce number of unaligned (< 4kb) in-flight writes on mtip32xx to
     two.  From Micron.

   - Make the blk-mq CPU notify spinlock raw, since it can't be a
     sleeper spinlock on RT.  From Mike Galbraith.

   - Drop now bogus BUG_ON() for bio iteration with blk integrity.  From
     Nic Bellinger.

   - Properly propagate the SYNC flag on requests. From Shaohua"

* 'for-linus' of git://git.kernel.dk/linux-block:
  blk-mq: add REQ_SYNC early
  rt,blk,mq: Make blk_mq_cpu_notify_lock a raw spinlock
  bio-integrity: Drop bio_integrity_verify BUG_ON in post bip->bip_iter world
  blk-mq: support partial I/O completions
  blk-mq: merge blk_mq_insert_request and blk_mq_run_request
  blk-mq: remove blk_mq_alloc_rq
  mtip32xx: Reduce the number of unaligned writes to 2

Pull pin control fixes from Linus Walleij:
 "This is a set of pin control fixes I have collected over the last few
  days.  Some have rotated more than others in linux-next, but they were
  rebased on v3.14-rc5 due to sloppy commit messages.  I am quite
  convinced that they are all good fixes that only hit this or that
  individual driver and not the entire subsystem.

   - Fix chained interrupts, interrupt masking and register offset
     calculation for the sunxi driver

   - Make MSM a bool rather than a tristate to stop build problems to
     happen - chained interrupt controllers cannot currently be defined
     in modules

   - Fix a clock in the PFC driver

   - Fix a kernel panic in the sirf driver"

* tag 'pinctrl-v3.14-3' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl:
  pinctrl: sirf: fix kernel panic in gpio_lock_as_irq
  pinctrl: sh-pfc: r8a7791: SD1_CLK fix
  pinctrl: msm: make PINCTRL_MSM bool instead of tristate
  pinctrl: sunxi: Fix interrupt register offset calculation
  pinctrl: sunxi: Fix masking when setting irq type
  pinctrl: sunxi: use chained_irq_{enter, exit} for GIC compatibility

Pull Xen fix from Konrad Rzeszutek Wilk:
 "This has exactly one patch for Xen ARM.  It sets the dependency to
  compile the kernel with MMU enabled - otherwise - the guest won't work
  very well"

* tag 'stable/for-linus-3.14-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  ARM: XEN depends on having a MMU

Pull c6x build fix from Mark Salter:
 "Build fix for c6x"

* tag 'for-linus' of git://linux-c6x.org/git/projects/linux-c6x-upstreaming:
  c6x: fix build failure caused by cache.h

This has been a relatively long-standing issue that wasn't nailed down
until Teng-Feng Yang's meticulous bug report to dm-devel on 3/7/2014,
see: http://www.redhat.com/archives/dm-devel/2014-March/msg00021.html

From that report:
  "When decreasing the reference count of a metadata block with its
  reference count equals 3, we will call dm_btree_remove() to remove
  this enrty from the B+tree which keeps the reference count info in
  metadata device.

  The B+tree will try to rebalance the entry of the child nodes in each
  node it traversed, and the rebalance process contains the following
  steps.

  (1) Finding the corresponding children in current node (shadow_current(s))
  (2) Shadow the children block (issue BOP_INC)
  (3) redistribute keys among children, and free children if necessary (issue BOP_DEC)

  Since the update of a metadata block's reference count could be
  recursive, we will stash these reference count update operations in
  smm->uncommitted and then process them in a FILO fashion.

  The problem is that step(3) could free the children which is created
  in step(2), so the BOP_DEC issued in step(3) will be carried out
  before the BOP_INC issued in step(2) since these BOPs will be
  processed in FILO fashion. Once the BOP_DEC from step(3) tries to
  decrease the reference count of newly shadow block, it will report
  failure for its reference equals 0 before decreasing. It looks like we
  can solve this issue by processing these BOPs in a FIFO fashion
  instead of FILO."

Commit 5b564d80 ("dm space map: disallow decrementing a reference count
below zero") changed the code to report an error for this temporary
refcount decrement below zero.  So what was previously a harmless
invalid refcount became a hard failure due to the new error path:

 device-mapper: space map common: unable to decrement a reference count below 0
 device-mapper: thin: 253:6: dm_thin_insert_block() failed: error = -22
 device-mapper: thin: 253:6: switching pool to read-only mode

This bug is in dm persistent-data code that is common to the DM thin and
cache targets.  So any users of those targets should apply this fix.

Fix this by applying recursive space map operations in FIFO order rather
than FILO.

Resolves: https://bugzilla.kernel.org/show_bug.cgi?id=68801Reported-by: Apollon Oikonomopoulos <apoikos@debian.org>
Reported-by: edwillam1007@gmail.com
Reported-by: Teng-Feng Yang <shinrairis@gmail.com>
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # 3.13+

Add REQ_SYNC early, so rq_dispatched[] in blk_mq_rq_ctx_init
is set correctly.

Signed-off-by: Shaohua Li<shli@fusionio.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

The 64bit relocation code places a few symbols in the text segment.
These symbols are only 4 byte aligned where they need to be 8 byte
aligned. Add an explicit alignment.
Signed-off-by: Anton Blanchard <anton@samba.org>
Cc: stable@vger.kernel.org
Tested-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

When we fork/clone we currently don't copy any of the TM state to the new
thread.  This results in a TM bad thing (program check) when the new process is
switched in as the kernel does a tmrechkpt with TEXASR FS not set.  Also, since
R1 is from userspace, we trigger the bad kernel stack pointer detection.  So we
end up with something like this:

   Bad kernel stack pointer 0 at c0000000000404fc
   cpu 0x2: Vector: 700 (Program Check) at [c00000003ffefd40]
       pc: c0000000000404fc: restore_gprs+0xc0/0x148
       lr: 0000000000000000
       sp: 0
      msr: 9000000100201030
     current = 0xc000001dd1417c30
     paca    = 0xc00000000fe00800   softe: 0        irq_happened: 0x01
       pid   = 0, comm = swapper/2
   WARNING: exception is not recoverable, can't continue

The below fixes this by flushing the TM state before we copy the task_struct to
the clone.  To do this we go through the tmreclaim patch, which removes the
checkpointed registers from the CPU and transitions the CPU out of TM suspend
mode.  Hence we need to call tmrechkpt after to restore the checkpointed state
and the TM mode for the current task.

To make this fail from userspace is simply:
	tbegin
	li	r0, 2
	sc
	<boom>

Kudos to Adhemerval Zanella Neto for finding this.
Signed-off-by: Michael Neuling <mikey@neuling.org>
cc: Adhemerval Zanella Neto <azanella@br.ibm.com>
cc: stable@vger.kernel.org
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

one more radeon fix.

* 'drm-fixes-3.14' of git://people.freedesktop.org/~agd5f/linux:
  drm/radeon/atom: select the proper number of lanes in transmitter setup

We need to check for DVI vs. HDMI when setting up duallink since
HDMI is single link only.  Fixes 4k modes on newer asics.

bug:
https://bugs.freedesktop.org/show_bug.cgi?id=75223Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org

Add a maintainers entry for the TDA998x driver.  Rob Clark has handed
this driver over to me to look after.
Acked-by: Rob Clark <robdclark@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Dave Airlie <airlied@redhat.com>

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

fix for kfifo api change.
* 'drm-armada-fixes' of git://ftp.arm.linux.org.uk/~rmk/linux-cubox:
  DRM: armada: fix use of kfifo_put()

a few more radeon fixes.

* 'drm-fixes-3.14' of git://people.freedesktop.org/~agd5f/linux:
  drm/radeon/dpm: fix typo in EVERGREEN_SMC_FIRMWARE_HEADER_softRegisters
  drm/radeon/cik: fix typo in documentation
  drm/radeon: silence GCC warning on 32 bit
  drm/radeon: resume old pm late
  drm/radeon: TTM must be init with cpu-visible VRAM, v2

Should be at 0x8 rather than 0.

fixes:
https://bugzilla.kernel.org/show_bug.cgi?id=60523

Noticed by ArtForz on #radeon
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org

Copy-paste typo.
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

Building radeon_ttm.o on 32 bit x86 triggers a warning:
    In file included from include/asm-generic/bug.h:13:0,
                     from [...]/arch/x86/include/asm/bug.h:38,
                     from include/linux/bug.h:4,
                     from include/drm/drm_mm.h:39,
                     from include/drm/drm_vma_manager.h:26,
                     from include/drm/ttm/ttm_bo_api.h:35,
                     from drivers/gpu/drm/radeon/radeon_ttm.c:32:
    drivers/gpu/drm/radeon/radeon_ttm.c: In function 'radeon_ttm_gtt_read':
    include/linux/kernel.h:712:17: warning: comparison of distinct pointer types lacks a cast [enabled by default]
      (void) (&_min1 == &_min2);  \
                     ^
    drivers/gpu/drm/radeon/radeon_ttm.c:938:22: note: in expansion of macro 'min'
       ssize_t cur_size = min(size, PAGE_SIZE - off);
                          ^

Silence this warning by using min_t(). Since cur_size will never be
negative and its upper bound is PAGE_SIZE, we can change its type to
size_t and use min_t(size_t, [...]) here.
Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>

Moving the pm resume up in the init order to fix
dpm seems to have regressed somes cases with the old
pm code.  Move it back to late resume.
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

Without this, a bo may get created in the cpu-inaccessible vram.
Before the CP engines get setup, all copies are done via cpu memcpy.

This means that the cpu tries to read from inaccessible memory, fails,
and the radeon module proceeds to disable acceleration.

Doing this has no downsides, as the real VRAM size gets set as soon as the
CP engines get init.

This is a candidate for 3.14 fixes.

v2: Add comment on why the function is used
Signed-off-by: Lauri Kasanen <cand@gmx.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Cc: stable@vger.kernel.org

The Documentation for the thin provisioning target's held metadata root
feature was incorrect.  It is now available and the value for the held
metadata root is in block units (not 512b sectors).
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

Building on commit 0ac09f9f ("x86, trace: Fix CR2 corruption when
tracing page faults") this patch addresses another few issues:

 - Now that read_cr2() is lifted into trace_do_page_fault(), we should
   pass the address to trace_page_fault_entries() to avoid it
   re-reading a potentially changed cr2.

 - Put both trace_do_page_fault() and trace_page_fault_entries() under
   CONFIG_TRACING.

 - Mark both fault entry functions {,trace_}do_page_fault() as notrace
   to avoid getting __mcount or other function entry trace callbacks
   before we've observed CR2.

 - Mark __do_page_fault() as noinline to guarantee the function tracer
   does get to see the fault.

Cc: <jolsa@redhat.com>
Cc: <vincent.weaver@maine.edu>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20140306145300.GO9987@twins.programming.kicks-ass.netSigned-off-by: H. Peter Anvin <hpa@linux.intel.com>

i) by the time DM core calls the postsuspend hook the dm_noflush flag
has been cleared.  So the old thin_postsuspend did nothing.  We need to
use the presuspend hook instead.

ii) There was a race between bios leaving DM core and arriving in the
deferred queue.

thin_presuspend now sets a 'requeue' flag causing all bios destined for
that thin to be requeued back to DM core.  Then it requeues all held IO,
and all IO on the deferred queue (destined for that thin).  Finally
postsuspend clears the 'requeue' flag.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

The spin lock in requeue_io() was held for too long, allowing deadlock.
Don't worry, due to other issues addressed in the following "dm thin:
fix noflush suspend IO queueing" commit, this code was never called.

Fix this by taking the spin lock for a much shorter period of time.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

Ideally a thin pool would never run out of data space; the low water
mark would trigger userland to extend the pool before we completely run
out of space.  However, many small random IOs to unprovisioned space can
consume data space at an alarming rate.  Adjust your low water mark if
you're frequently seeing "out-of-data-space" mode.

Before this fix, if data space ran out the pool would be put in
PM_READ_ONLY mode which also aborted the pool's current metadata
transaction (data loss for any changes in the transaction).  This had a
side-effect of needlessly compromising data consistency.  And retry of
queued unserviceable bios, once the data pool was resized, could
initiate changes to potentially inconsistent pool metadata.

Now when the pool's data space is exhausted transition to a new pool
mode (PM_OUT_OF_DATA_SPACE) that allows metadata to be changed but data
may not be allocated.  This allows users to remove thin volumes or
discard data to recover data space.

The pool is no longer put in PM_READ_ONLY mode in response to the pool
running out of data space.  And PM_READ_ONLY mode no longer aborts the
pool's current metadata transaction.  Also, set_pool_mode() will now
notify userspace when the pool mode is changed.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

If a thin metadata operation fails the current transaction will abort,
whereby causing potential for IO layers up the stack (e.g. filesystems)
to have data loss.  As such, set THIN_METADATA_NEEDS_CHECK_FLAG in the
thin metadata's superblock which:
1) requires the user verify the thin metadata is consistent (e.g. use
   thin_check, etc)
2) suggests the user verify the thin data is consistent (e.g. use fsck)

The only way to clear the superblock's THIN_METADATA_NEEDS_CHECK_FLAG is
to run thin_repair.

On metadata operation failure: abort current metadata transaction, set
pool in read-only mode, and now set the needs_check flag.

As part of this change, constraints are introduced or relaxed:
* don't allow a pool to transition to write mode if needs_check is set
* don't allow data or metadata space to be resized if needs_check is set
* if a thin pool's metadata space is exhausted: the kernel will now
  force the user to take the pool offline for repair before the kernel
  will allow the metadata space to be extended.

Also, update Documentation to include information about when the thin
provisioning target commits metadata, how it handles metadata failures
and running out of space.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Joe Thornber <ejt@redhat.com>

Logitech C500 (046d:0807) needs the same workaround like other
Logitech Webcams.

Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>