We will need some of these values in mce.c. Move them to the
appropriate header file so they are available.
Acked-by: NBorislav Petkov <bp@amd64.org>
Signed-off-by: NTony Luck <tony.luck@intel.com>
Cc: Chen Gong <gong.chen@linux.intel.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Link: http://lkml.kernel.org/r/0ccfb1af5fe35e537b7cd8e4d448bf7d851dbfb9.1343078495.git.tony.luck@intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

In the current kernel, percpu variable `vector_irq' is not always
cleared when a CPU is offlined. If the CPU that has the disabled
irqs in vector_irq is hotplugged again, __setup_vector_irq()
hits invalid irq vector and may crash.

This bug can be reproduced as following;

 # echo 0 > /sys/devices/system/cpu/cpu7/online
 # modprobe -r some_driver_using_interrupts     # vector_irq@cpu7 uncleared
 # echo 1 > /sys/devices/system/cpu/cpu7/online # kernel may crash

To fix this problem, this patch clears vector_irq in
__fixup_irqs() when the CPU is offlined.

This also reverts commit f6175f5b, which partially fixes
this bug by clearing vector in __clear_irq_vector(). But in
environments with IOMMU IRQ remapper, it could fail because
cfg->domain doesn't contain offlined CPUs. With this patch, the
fix in __clear_irq_vector() can be reverted because every
vector_irq is already cleared in __fixup_irqs() on offlined CPUs.
Signed-off-by: NTomoki Sekiyama <tomoki.sekiyama.qu@hitachi.com>
Acked-by: NSuresh Siddha <suresh.b.siddha@intel.com>
Cc: yrl.pp-manager.tt@hitachi.com
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Alexander Gordeev <agordeev@redhat.com>
Link: http://lkml.kernel.org/r/20120726104732.2889.19144.stgit@kvmdevSigned-off-by: NIngo Molnar <mingo@kernel.org>

Merge in Linus's tree to avoid a conflict.
Signed-off-by: NIngo Molnar <mingo@kernel.org>

The Intel case falls through into the generic case which then changes
the values.  For cases like the P6 it doesn't do the right thing so
this seems to be a screwup.
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Link: http://lkml.kernel.org/n/tip-lww2uirad4skzjlmrm0vru8o@git.kernel.orgSigned-off-by: NH. Peter Anvin <hpa@zytor.com>
Cc: <stable@vger.kernel.org>

Pull a x86/build change from Ingo Molnar.

This makes the default stack alignment on x86-64 be just 8, allowing for
improved code generation (it can avoid some unnecessary extra alignment
logic and use just pure push/pop sequences) and smaller stack frames.

We can't generally do SSE with 16-byte alignment issues in the kernel anyway.

* 'x86-build-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86-64, gcc: Use -mpreferred-stack-boundary=3 if supported

Pull x86/uv changes from Ingo Molnar:
 "UV2 BAU productization fixes.

  The BAU (Broadcast Assist Unit) is SGI's fancy out of line way on UV
  hardware to do TLB flushes, instead of the normal APIC IPI methods.
  The commits here fix / work around hangs in their latest hardware
  iteration (UV2).

  My understanding is that the main purpose of the out of line
  signalling channel is to improve scalability: the UV APIC hardware
  glue does not handle broadcasting to many CPUs very well, and this
  matters most for TLB shootdowns.

  [ I don't agree with all aspects of the current approach: in hindsight
    it would have been better to link the BAU at the IPI/APIC driver
    level instead of the TLB shootdown level, where TLB flushes are
    really just one of the uses of broadcast SMP messages.  Doing that
    would improve scalability in some other ways and it would also
    remove a few uglies from the TLB path.  It would also be nice to
    push more is_uv_system() tests into proper x86_init or x86_platform
    callbacks.  Cliff? ]"

* 'x86-uv-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/uv: Work around UV2 BAU hangs
  x86/uv: Implement UV BAU runtime enable and disable control via /proc/sgi_uv/
  x86/uv: Fix the UV BAU destination timeout period

Pull x86/reboot changes from Ingo Molnar:
 "Now that the revampted x86 real-mode trampoline code is upstream and
  seems to be working well, we can extend the 64-bit reboot code to be
  as capable as the 32-bit one."

* 'x86-reboot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86-64, reboot: Be more paranoid in 64-bit reboot=bios
  x86, reboot: Drop redundant write of reboot_mode
  x86-64, reboot: Allow reboot=bios and reboot-cpu override on x86-64

Pull x86 platform changes from Ingo Molnar:
 "This tree mostly involves various APIC driver cleanups/robustization,
  and vSMP motivated platform callback improvements/cleanups"

Fix up trivial conflict due to printk cleanup right next to return value
change.

* 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (29 commits)
  Revert "x86/early_printk: Replace obsolete simple_strtoul() usage with kstrtoint()"
  x86/apic/x2apic: Use multiple cluster members for the irq destination only with the explicit affinity
  x86/apic/x2apic: Limit the vector reservation to the user specified mask
  x86/apic: Optimize cpu traversal in __assign_irq_vector() using domain membership
  x86/vsmp: Fix vector_allocation_domain's return value
  irq/apic: Use config_enabled(CONFIG_SMP) checks to clean up irq_set_affinity() for UP
  x86/vsmp: Fix linker error when CONFIG_PROC_FS is not set
  x86/apic/es7000: Make apicid of a cluster (not CPU) from a cpumask
  x86/apic/es7000+summit: Always make valid apicid from a cpumask
  x86/apic/es7000+summit: Fix compile warning in cpu_mask_to_apicid()
  x86/apic: Fix ugly casting and branching in cpu_mask_to_apicid_and()
  x86/apic: Eliminate cpu_mask_to_apicid() operation
  x86/x2apic/cluster: Vector_allocation_domain() should return a value
  x86/apic/irq_remap: Silence a bogus pr_err()
  x86/vsmp: Ignore IOAPIC IRQ affinity if possible
  x86/apic: Make cpu_mask_to_apicid() operations check cpu_online_mask
  x86/apic: Make cpu_mask_to_apicid() operations return error code
  x86/apic: Avoid useless scanning thru a cpumask in assign_irq_vector()
  x86/apic: Try to spread IRQ vectors to different priority levels
  x86/apic: Factor out default vector_allocation_domain() operation
  ...

Pull debug-for-linus git tree from Ingo Molnar.

Fix up trivial conflict in arch/x86/kernel/cpu/perf_event_intel.c due to
a printk() having changed to a pr_info() differently in the two branches.

* 'x86-debug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86: Move call to print_modules() out of show_regs()
  x86/mm: Mark free_initrd_mem() as __init
  x86/microcode: Mark microcode_id[] as __initconst
  x86/nmi: Clean up register_nmi_handler() usage
  x86: Save cr2 in NMI in case NMIs take a page fault (for i386)
  x86: Remove cmpxchg from i386 NMI nesting code
  x86: Save cr2 in NMI in case NMIs take a page fault
  x86/debug: Add KERN_<LEVEL> to bare printks, convert printks to pr_<level>

Pull x86/asm changes from Ingo Molnar:
 "Assorted single-commit improvements, as usual"

* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mm/mtrr: Slightly simplify print_mtrr_state()
  x86/mm/mtrr: Fix alignment determination in range_to_mtrr()
  x86/copy_user_generic: Optimize copy_user_generic with CPU erms feature
  x86/alternatives: Use atomic_xchg() instead atomic_dec_and_test() for stop_machine_text_poke()

Pull timer core changes from Ingo Molnar:
 "Continued cleanups of the core time and NTP code, plus more nohz work
  preparing for tick-less userspace execution."

* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  time: Rework timekeeping functions to take timekeeper ptr as argument
  time: Move xtime_nsec adjustment underflow handling timekeeping_adjust
  time: Move arch_gettimeoffset() usage into timekeeping_get_ns()
  time: Refactor accumulation of nsecs to secs
  time: Condense timekeeper.xtime into xtime_sec
  time: Explicitly use u32 instead of int for shift values
  time: Whitespace cleanups per Ingo%27s requests
  nohz: Move next idle expiry time record into idle logic area
  nohz: Move ts->idle_calls incrementation into strict idle logic
  nohz: Rename ts->idle_tick to ts->last_tick
  nohz: Make nohz API agnostic against idle ticks cputime accounting
  nohz: Separate idle sleeping time accounting from nohz logic
  timers: Improve get_next_timer_interrupt()
  timers: Add accounting of non deferrable timers
  timers: Consolidate base->next_timer update
  timers: Create detach_if_pending() and use it

Pull smp/hotplug changes from Ingo Molnar:
 "Various cleanups to the SMP hotplug code - a continuing effort of
  Thomas et al"

* 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  smpboot: Remove leftover declaration
  smp: Remove num_booting_cpus()
  smp: Remove ipi_call_lock[_irq]()/ipi_call_unlock[_irq]()
  POWERPC: Smp: remove call to ipi_call_lock()/ipi_call_unlock()
  SPARC: SMP: Remove call to ipi_call_lock_irq()/ipi_call_unlock_irq()
  ia64: SMP: Remove call to ipi_call_lock_irq()/ipi_call_unlock_irq()
  x86-smp-remove-call-to-ipi_call_lock-ipi_call_unlock
  tile: SMP: Remove call to ipi_call_lock()/ipi_call_unlock()
  S390: Smp: remove call to ipi_call_lock()/ipi_call_unlock()
  parisc: Smp: remove call to ipi_call_lock()/ipi_call_unlock()
  mn10300: SMP: Remove call to ipi_call_lock()/ipi_call_unlock()
  hexagon: SMP: Remove call to ipi_call_lock()/ipi_call_unlock()

Pull perf events changes from Ingo Molnar:

 "- kernel side:

   - Intel uncore PMU support for Nehalem and Sandy Bridge CPUs, we
     support both the events available via the MSR and via the PCI
     access space.

   - various uprobes cleanups and restructurings

   - PMU driver quirks by microcode version and required x86 microcode
     loader cleanups/robustization

   - various tracing robustness updates

   - static keys: remove obsolete static_branch()

  - tooling side:

   - GTK browser improvements

   - perf report browser: support screenshots to file

   - more automated tests

   - perf kvm improvements

   - perf bench refinements

   - build environment improvements

   - pipe mode improvements

   - libtraceevent updates, we have now hopefully merged most bits with
     the out of tree forked code base

  ... and many other goodies."

* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (138 commits)
  tracing: Check for allocation failure in __tracing_open()
  perf/x86: Fix intel_perfmon_event_mapformatting
  jump label: Remove static_branch()
  tracepoint: Use static_key_false(), since static_branch() is deprecated
  perf/x86: Uncore filter support for SandyBridge-EP
  perf/x86: Detect number of instances of uncore CBox
  perf/x86: Fix event constraint for SandyBridge-EP C-Box
  perf/x86: Use 0xff as pseudo code for fixed uncore event
  perf/x86: Save a few bytes in 'struct x86_pmu'
  perf/x86: Add a microcode revision check for SNB-PEBS
  perf/x86: Improve debug output in check_hw_exists()
  perf/x86/amd: Unify AMD's generic and family 15h pmus
  perf/x86: Move Intel specific code to intel_pmu_init()
  perf/x86: Rename Intel specific macros
  perf/x86: Fix USER/KERNEL tagging of samples
  perf tools: Split event symbols arrays to hw and sw parts
  perf tools: Split out PE_VALUE_SYM parsing token to SW and HW tokens
  perf tools: Add empty rule for new line in event syntax parsing
  perf test: Use ARRAY_SIZE in parse events tests
  tools lib traceevent: Cleanup realloc use
  ...

Pull RCU changes from Ingo Molnar:
 "Quoting from Paul, the major features of this series are:

  1. Preventing latency spikes of more than 200 microseconds for
     kernels built with NR_CPUS=4096, which is reportedly becoming the
     default for some distros.  This is a first step, as it does not
     help with systems that actually -have- 4096 CPUs (work on this case
     is in progress, but is not yet ready for mainline).

     This category also includes improving concurrency of rcu_barrier(),
     placed here due to conflicts.  Posted to LKML at:

      https://lkml.org/lkml/2012/6/22/381

     Note that patches 18-22 of that series have been defered to 3.7, as
     they have not yet proven themselves to be mainline-ready (and yes,
     these are the ones intended to get rid of RCU's latency spikes for
     systems that actually have 4096 CPUs).

  2. Updates to documentation and rcutorture fixes, the latter category
     including improvements to rcu_barrier() testing.  Posted to LKML at

      http://lkml.indiana.edu/hypermail/linux/kernel/1206.1/04094.html.

  3. Miscellaneous fixes posted to LKML at:

      https://lkml.org/lkml/2012/6/22/500

     with the exception of the last commit, which was posted here:

      http://www.gossamer-threads.com/lists/linux/kernel/1561830

  4. RCU_FAST_NO_HZ fixes and improvements.  Posted to LKML at:

      http://lkml.indiana.edu/hypermail/linux/kernel/1206.1/00006.html
      http://www.gossamer-threads.com/lists/linux/kernel/1561833

     The first four patches of the first series went into 3.5 to fix a
     regression.

  5. Code-style fixes.  These were posted to LKML at

      http://lkml.indiana.edu/hypermail/linux/kernel/1205.2/01180.html
      http://lkml.indiana.edu/hypermail/linux/kernel/1205.2/01181.html"

* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (48 commits)
  rcu: Fix broken strings in RCU's source code.
  rcu: Fix code-style issues involving "else"
  rcu: Introduce check for callback list/count mismatch
  rcu: Make RCU_FAST_NO_HZ respect nohz= boot parameter
  rcu: Fix qlen_lazy breakage
  rcu: Round FAST_NO_HZ lazy timeout to nearest second
  rcu: The rcu_needs_cpu() function is not a quiescent state
  rcu: Dump only the current CPU's buffers for idle-entry/exit warnings
  rcu: Add check for CPUs going offline with callbacks queued
  rcu: Disable preemption in rcu_blocking_is_gp()
  rcu: Prevent uninitialized string in RCU CPU stall info
  rcu: Fix rcu_is_cpu_idle() #ifdef in TINY_RCU
  rcu: Split RCU core processing out of __call_rcu()
  rcu: Prevent __call_rcu() from invoking RCU core on offline CPUs
  rcu: Make __call_rcu() handle invocation from idle
  rcu: Remove function versions of __kfree_rcu and __is_kfree_rcu_offset
  rcu: Consolidate tree/tiny __rcu_read_{,un}lock() implementations
  rcu: Remove return value from rcu_assign_pointer()
  key: Remove extraneous parentheses from rcu_assign_keypointer()
  rcu: Remove return value from RCU_INIT_POINTER()
  ...

Pull core/iommu changes from Ingo Molnar.

* 'core-iommu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  iommu/dmar: Use pr_format() instead of PREFIX to tidy up pr_*() calls
  iommu/dmar: Reserve mmio space used by the IOMMU, if the BIOS forgets to
  iommu/dmar: Replace printks with appropriate pr_*()

This reverts commit fbd24153.

This commit is subtly buggy: kstrto*int() can return an error but
it's not checked in every path. simple_strtoul() on the other hand
could not fail, so this patch subtly intruduces new failure modes.
Signed-off-by: NShuah Khan <shuahkhan@gmail.com>
Link: http://lkml.kernel.org/r/1338424803.3569.5.camel@lorien2Signed-off-by: NIngo Molnar <mingo@kernel.org>

The SYSTEM_SUSPEND_DISK system state is never used, so drop it.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Merge emailed kgdb dmesg fixups patches from Anton Vorontsov:
 "The dmesg command appears to be broken after the printk rework.  The
  old logic in the kdb code makes no sense in terms of current
  printk/logging storage format, and KDB simply hangs forever upon
  entering 'dmesg' command.

  The first patch revives the command by switching to kmsg_dumper
  iterator.  As a side-effect, the code is now much more simpler.

  A few changes were needed in the printk.c: we needed unlocked variant
  of the kmsg_dumper iterator, but these can surely wait for 3.6.

  It's probably too late even for the first patch to go to 3.5, but I'll
  try to convince otherwise.  :-) Here we go:

   - The current code is broken for sure, and has no hope to work at
     all.  It is a regression
   - The new code works for me, and probably works for everyone else;
   - If it compiles (and I urge everyone to compile-test it on your
     setup), it hardly can make things worse."

* Merge emailed patches from Anton Vorontsov: (4 commits)
  kdb: Switch to nolock variants of kmsg_dump functions
  printk: Implement some unlocked kmsg_dump functions
  printk: Remove kdb_syslog_data
  kdb: Revive dmesg command

The locked variants are prone to deadlocks (suppose we got to the
debugger w/ the logbuf lock held), so let's switch to nolock variants.
Signed-off-by: NAnton Vorontsov <anton.vorontsov@linaro.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

If used from KDB, the locked variants are prone to deadlocks (suppose we
got to the debugger w/ the logbuf lock held).

So, we have to implement a few routines that grab no logbuf lock.

Yet we don't need these functions in modules, so we don't export them.
Signed-off-by: NAnton Vorontsov <anton.vorontsov@linaro.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The function is no longer needed, so remove it.
Signed-off-by: NAnton Vorontsov <anton.vorontsov@linaro.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The kgdb dmesg command is broken after the printk rework.  The old logic
in kdb code makes no sense in terms of current printk/logging storage
format, and KDB simply hangs forever.

This patch revives the command by switching to kmsg_dumper iterator.

The code is now much more simpler and shorter.
Signed-off-by: NAnton Vorontsov <anton.vorontsov@linaro.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Pull late MIPS fixes from Ralf Baechle:
 "This fixes a number of lose ends in the MIPS code and various bug
  fixes.

  Aside of dropping some patch that should not be in this pull request
  everything has sat in -next for quite a while and there are no known
  issues.

  The biggest patch in this patch set moves the allocation of an array
  that is aliased to a function (for runtime generated code) to
  assembler code.  This avoids an issue with certain toolchains when
  building for microMIPS."

* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (35 commits)
  MIPS: PCI: Move fixups from __init to __devinit.
  MIPS: Fix bug.h MIPS build regression
  MIPS: sync-r4k: remove redundant irq operation
  MIPS: smp: Warn on too early irq enable
  MIPS: call set_cpu_online() on cpu being brought up with irq disabled
  MIPS: call ->smp_finish() a little late
  MIPS: Yosemite: delay irq enable to ->smp_finish()
  MIPS: SMTC: delay irq enable to ->smp_finish()
  MIPS: BMIPS: delay irq enable to ->smp_finish()
  MIPS: Octeon: delay enable irq to ->smp_finish()
  MIPS: Oprofile: Fix build as a module.
  MIPS: BCM63XX: Fix BCM6368 IPSec clock bit
  MIPS: perf: Fix build error caused by unused counters_per_cpu_to_total()
  MIPS: Fix Magic SysRq L kernel crash.
  MIPS: BMIPS: Fix duplicate header inclusion.
  mips: mark const init data with __initconst instead of __initdata
  MIPS: cmpxchg.h: Add missing include
  MIPS: Malta may also be equipped with MIPS64 R2 processors.
  MIPS: Fix typo multipy -> multiply
  MIPS: Cavium: Fix duplicate ARCH_SPARSEMEM_ENABLE in kconfig.
  ...

Pull device-mapper discard fixes from Alasdair G Kergon:
  - avoid a crash in dm-raid1 when discards coincide with mirror
    recovery;
  - avoid discarding shared data that's still needed in dm-thin;
  - don't guarantee that discarded blocks will be wiped in dm-raid1.

* tag 'dm-3.5-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-dm:
  dm raid1: set discard_zeroes_data_unsupported
  dm thin: do not send discards to shared blocks
  dm raid1: fix crash with mirror recovery and discard

Pull pnfs/ore fixes from Boaz Harrosh:
 "These are catastrophic fixes to the pnfs objects-layout that were just
  discovered.  They are also destined for @stable.

  I have found these and worked on them at around RC1 time but
  unfortunately went to the hospital for kidney stones and had a very
  slow recovery.  I refrained from sending them as is, before proper
  testing, and surly I have found a bug just yesterday.

  So now they are all well tested, and have my sign-off.  Other then
  fixing the problem at hand, and assuming there are no bugs at the new
  code, there is low risk to any surrounding code.  And in anyway they
  affect only these paths that are now broken.  That is RAID5 in pnfs
  objects-layout code.  It does also affect exofs (which was not broken)
  but I have tested exofs and it is lower priority then objects-layout
  because no one is using exofs, but objects-layout has lots of users."

* 'for-linus' of git://git.open-osd.org/linux-open-osd:
  pnfs-obj: Fix __r4w_get_page when offset is beyond i_size
  pnfs-obj: don't leak objio_state if ore_write/read fails
  ore: Unlock r4w pages in exact reverse order of locking
  ore: Remove support of partial IO request (NFS crash)
  ore: Fix NFS crash by supporting any unaligned RAID IO

Pull UBIFS free space fix-up bugfix from Artem Bityutskiy:
 "It's been reported already twice recently:

    http://lists.infradead.org/pipermail/linux-mtd/2012-May/041408.html
    http://lists.infradead.org/pipermail/linux-mtd/2012-June/042422.html

  and we finally have the fix.  I am quite confident the fix is correct
  because I could reproduce the problem with nandsim and verify the fix.
  It was also verified by Iwo (the reporter).

  I am also confident that this is OK to merge the fix so late because
  this patch affects only the fixup functionality, which is not used by
  most users."

* tag 'upstream-3.5-rc8' of git://git.infradead.org/linux-ubifs:
  UBIFS: fix a bug in empty space fix-up

We can't guarantee that REQ_DISCARD on dm-mirror zeroes the data even if
the underlying disks support zero on discard.  So this patch sets
ti->discard_zeroes_data_unsupported.

For example, if the mirror is in the process of resynchronizing, it may
happen that kcopyd reads a piece of data, then discard is sent on the
same area and then kcopyd writes the piece of data to another leg.
Consequently, the data is not zeroed.

The flag was made available by commit 983c7db3
(dm crypt: always disable discard_zeroes_data).
Signed-off-by: NMikulas Patocka <mpatocka@redhat.com>
Cc: stable@kernel.org
Signed-off-by: NAlasdair G Kergon <agk@redhat.com>

When process_discard receives a partial discard that doesn't cover a
full block, it sends this discard down to that block. Unfortunately, the
block can be shared and the discard would corrupt the other snapshots
sharing this block.

This patch detects block sharing and ends the discard with success when
sending it to the shared block.

The above change means that if the device supports discard it can't be
guaranteed that a discard request zeroes data. Therefore, we set
ti->discard_zeroes_data_unsupported.

Thin target discard support with this bug arrived in commit
104655fd (dm thin: support discards).
Signed-off-by: NMikulas Patocka <mpatocka@redhat.com>
Cc: stable@kernel.org
Signed-off-by: NMike Snitzer <snitzer@redhat.com>
Signed-off-by: NAlasdair G Kergon <agk@redhat.com>

This patch fixes a crash when a discard request is sent during mirror
recovery.

Firstly, some background.  Generally, the following sequence happens during
mirror synchronization:
- function do_recovery is called
- do_recovery calls dm_rh_recovery_prepare
- dm_rh_recovery_prepare uses a semaphore to limit the number
  simultaneously recovered regions (by default the semaphore value is 1,
  so only one region at a time is recovered)
- dm_rh_recovery_prepare calls __rh_recovery_prepare,
  __rh_recovery_prepare asks the log driver for the next region to
  recover. Then, it sets the region state to DM_RH_RECOVERING. If there
  are no pending I/Os on this region, the region is added to
  quiesced_regions list. If there are pending I/Os, the region is not
  added to any list. It is added to the quiesced_regions list later (by
  dm_rh_dec function) when all I/Os finish.
- when the region is on quiesced_regions list, there are no I/Os in
  flight on this region. The region is popped from the list in
  dm_rh_recovery_start function. Then, a kcopyd job is started in the
  recover function.
- when the kcopyd job finishes, recovery_complete is called. It calls
  dm_rh_recovery_end. dm_rh_recovery_end adds the region to
  recovered_regions or failed_recovered_regions list (depending on
  whether the copy operation was successful or not).

The above mechanism assumes that if the region is in DM_RH_RECOVERING
state, no new I/Os are started on this region. When I/O is started,
dm_rh_inc_pending is called, which increases reg->pending count. When
I/O is finished, dm_rh_dec is called. It decreases reg->pending count.
If the count is zero and the region was in DM_RH_RECOVERING state,
dm_rh_dec adds it to the quiesced_regions list.

Consequently, if we call dm_rh_inc_pending/dm_rh_dec while the region is
in DM_RH_RECOVERING state, it could be added to quiesced_regions list
multiple times or it could be added to this list when kcopyd is copying
data (it is assumed that the region is not on any list while kcopyd does
its jobs). This results in memory corruption and crash.

There already exist bypasses for REQ_FLUSH requests: REQ_FLUSH requests
do not belong to any region, so they are always added to the sync list
in do_writes. dm_rh_inc_pending does not increase count for REQ_FLUSH
requests. In mirror_end_io, dm_rh_dec is never called for REQ_FLUSH
requests. These bypasses avoid the crash possibility described above.

These bypasses were improperly implemented for REQ_DISCARD when
the mirror target gained discard support in commit
5fc2ffea (dm raid1: support discard).

In do_writes, REQ_DISCARD requests is always added to the sync queue and
immediately dispatched (even if the region is in DM_RH_RECOVERING).  However,
dm_rh_inc and dm_rh_dec is called for REQ_DISCARD resusts.  So it violates the
rule that no I/Os are started on DM_RH_RECOVERING regions, and causes the list
corruption described above.

This patch changes it so that REQ_DISCARD requests follow the same path
as REQ_FLUSH. This avoids the crash.

Reference: https://bugzilla.redhat.com/837607Signed-off-by: NMikulas Patocka <mpatocka@redhat.com>
Cc: stable@kernel.org
Signed-off-by: NAlasdair G Kergon <agk@redhat.com>

It is very common for the end of the file to be unaligned on
stripe size. But since we know it's beyond file's end then
the XOR should be preformed with all zeros.

Old code used to just read zeros out of the OSD devices, which is a great
waist. But what scares me more about this situation is that, we now have
pages attached to the file's mapping that are beyond i_size. I don't
like the kind of bugs this calls for.

Fix both birds, by returning a global zero_page, if offset is beyond
i_size.

TODO:
	Change the API to ->__r4w_get_page() so a NULL can be
	returned without being considered as error, since XOR API
	treats NULL entries as zero_pages.

[Bug since 3.2. Should apply the same way to all Kernels since]
CC: Stable Tree <stable@kernel.org>
Signed-off-by: NBoaz Harrosh <bharrosh@panasas.com>

[Bug since 3.2 Kernel]
CC: Stable Tree <stable@kernel.org>
Signed-off-by: NBoaz Harrosh <bharrosh@panasas.com>

The read-4-write pages are locked in address ascending order.
But where unlocked in a way easiest for coding. Fix that,
locks should be released in opposite order of locking, .i.e
descending address order.

I have not hit this dead-lock. It was found by inspecting the
dbug print-outs. I suspect there is an higher lock at caller that
protects us, but fix it regardless.
Signed-off-by: NBoaz Harrosh <bharrosh@panasas.com>

Do to OOM situations the ore might fail to allocate all resources
needed for IO of the full request. If some progress was possible
it would proceed with a partial/short request, for the sake of
forward progress.

Since this crashes NFS-core and exofs is just fine without it just
remove this contraption, and fail.

TODO:
	Support real forward progress with some reserved allocations
	of resources, such as mem pools and/or bio_sets

[Bug since 3.2 Kernel]
CC: Stable Tree <stable@kernel.org>
CC: Benny Halevy <bhalevy@tonian.com>
Signed-off-by: NBoaz Harrosh <bharrosh@panasas.com>

In RAID_5/6 We used to not permit an IO that it's end
byte is not stripe_size aligned and spans more than one stripe.
.i.e the caller must check if after submission the actual
transferred bytes is shorter, and would need to resubmit
a new IO with the remainder.

Exofs supports this, and NFS was supposed to support this
as well with it's short write mechanism. But late testing has
exposed a CRASH when this is used with none-RPC layout-drivers.

The change at NFS is deep and risky, in it's place the fix
at ORE to lift the limitation is actually clean and simple.
So here it is below.

The principal here is that in the case of unaligned IO on
both ends, beginning and end, we will send two read requests
one like old code, before the calculation of the first stripe,
and also a new site, before the calculation of the last stripe.
If any "boundary" is aligned or the complete IO is within a single
stripe. we do a single read like before.

The code is clean and simple by splitting the old _read_4_write
into 3 even parts:
1._read_4_write_first_stripe
2. _read_4_write_last_stripe
3. _read_4_write_execute

And calling 1+3 at the same place as before. 2+3 before last
stripe, and in the case of all in a single stripe then 1+2+3
is preformed additively.

Why did I not think of it before. Well I had a strike of
genius because I have stared at this code for 2 years, and did
not find this simple solution, til today. Not that I did not try.

This solution is much better for NFS than the previous supposedly
solution because the short write was dealt  with out-of-band after
IO_done, which would cause for a seeky IO pattern where as in here
we execute in order. At both solutions we do 2 separate reads, only
here we do it within a single IO request. (And actually combine two
writes into a single submission)

NFS/exofs code need not change since the ORE API communicates the new
shorter length on return, what will happen is that this case would not
occur anymore.

hurray!!

[Stable this is an NFS bug since 3.2 Kernel should apply cleanly]
CC: Stable Tree <stable@kernel.org>
Signed-off-by: NBoaz Harrosh <bharrosh@panasas.com>

UBIFS has a feature called "empty space fix-up" which is a quirk to work-around
limitations of dumb flasher programs. Namely, of those flashers that are unable
to skip NAND pages full of 0xFFs while flashing, resulting in empty space at
the end of half-filled eraseblocks to be unusable for UBIFS. This feature is
relatively new (introduced in v3.0).

The fix-up routine (fixup_free_space()) is executed only once at the very first
mount if the superblock has the 'space_fixup' flag set (can be done with -F
option of mkfs.ubifs). It basically reads all the UBIFS data and metadata and
writes it back to the same LEB. The routine assumes the image is pristine and
does not have anything in the journal.

There was a bug in 'fixup_free_space()' where it fixed up the log incorrectly.
All but one LEB of the log of a pristine file-system are empty. And one
contains just a commit start node. And 'fixup_free_space()' just unmapped this
LEB, which resulted in wiping the commit start node. As a result, some users
were unable to mount the file-system next time with the following symptom:

UBIFS error (pid 1): replay_log_leb: first log node at LEB 3:0 is not CS node
UBIFS error (pid 1): replay_log_leb: log error detected while replaying the log at LEB 3:0

The root-cause of this bug was that 'fixup_free_space()' wrongly assumed
that the beginning of empty space in the log head (c->lhead_offs) was known
on mount. However, it is not the case - it was always 0. UBIFS does not store
in it the master node and finds out by scanning the log on every mount.

The fix is simple - just pass commit start node size instead of 0 to
'fixup_leb()'.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@linux.intel.com>
Cc: stable@vger.kernel.org [v3.0+]
Reported-by: NIwo Mergler <Iwo.Mergler@netcommwireless.com>
Tested-by: NIwo Mergler <Iwo.Mergler@netcommwireless.com>
Reported-by: NJames Nute <newten82@gmail.com>

Pull last minute Ceph fixes from Sage Weil:
 "The important one fixes a bug in the socket failure handling behavior
  that was turned up in some recent failure injection testing.  The
  other two are minor bug fixes."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client:
  rbd: endian bug in rbd_req_cb()
  rbd: Fix ceph_snap_context size calculation
  libceph: fix messenger retry

Pull three md bugfixes from NeilBrown:
 "One of the bugs was introduced in 3.5-rc1.  Others have been there for
  longer."

* tag 'md-3.5-fixes' of git://neil.brown.name/md:
  md/raid1: close some possible races on write errors during resync
  md: avoid crash when stopping md array races with closing other open fds.
  md: fix bug in handling of new_data_offset

Pull networking changes from David Miller:
 "Ok, we should be good to go now"

1) We have to statically initialize the init_net device list head rather
   than do so in an initcall, otherwise netprio_cgroup crashes if it's
   built statically rather than modular (Mark D.  Rustad)

2) Fix SKB null oopser in CIPSO ipv4 option processing (Paul Moore)

3) Qlogic maintainers update (Anirban Chakraborty)

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net:
  net: Statically initialize init_net.dev_base_head
  MAINTAINERS: Changes in qlcnic and qlge maintainers list
  cipso: don't follow a NULL pointer when setsockopt() is called

Pull HID update from Jiri Kosina:
 "A final round of changes for HID for 3.5: just device ID additions."

* 'upstream-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid:
  HID: hid-multitouch: add support for Zytronic panels
  HID: add Sennheiser BTD500USB device support
  HID: add battery quirk for Apple Wireless ANSI