Rather than continue to add per platform defaults, make the default a
likely common core count. 8 is also the default for x86.
Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

Currently there is no dsb between the tlbi in __cpu_setup and the write
to SCTLR_EL1 which enables the MMU in __turn_mmu_on. This means that the
TLB invalidation is not guaranteed to have completed at the point
address translation is enabled, leading to a number of possible issues
including incorrect translations and TLB conflict faults.

This patch moves the tlbi in __cpu_setup above an existing dsb used to
synchronise I-cache invalidation, ensuring that the TLBs have been
invalidated at the point the MMU is enabled.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

Pull ARM64 fixes from Catalin Marinas:
 - Remove preempt_count modifications in the arm64 IRQ handling code
   since that's already dealt with in generic irq_enter/irq_exit
 - PTE_PROT_NONE bit moved higher up to avoid overlapping with the
   hardware bits (for PROT_NONE mappings which are pte_present)
 - Big-endian fixes for ptrace support
 - Asynchronous aborts unmasking while in the kernel
 - pgprot_writecombine() change to create Normal NonCacheable memory
   rather than Device GRE

* tag 'arm64-stable' of git://git.kernel.org/pub/scm/linux/kernel/git/cmarinas/linux-aarch64:
  arm64: Move PTE_PROT_NONE higher up
  arm64: Use Normal NonCacheable memory for writecombine
  arm64: debug: make aarch32 bkpt checking endian clean
  arm64: ptrace: fix compat registes get/set to be endian clean
  arm64: Unmask asynchronous aborts when in kernel mode
  arm64: dts: Reserve the memory used for secondary CPU release address
  arm64: let the core code deal with preempt_count

Pull s390 updates from Martin Schwidefsky:
 "One performance improvement and a few bug fixes.  Two of the fixes
  deal with the clock related problems we have seen on recent kernels"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390/mm: handle asce-type exceptions as normal page fault
  s390,time: revert direct ktime path for s390 clockevent device
  s390/time,vdso: convert to the new update_vsyscall interface
  s390/uaccess: add missing page table walk range check
  s390/mm: optimize copy_page
  s390/dasd: validate request size before building CCW/TCW request
  s390/signal: always restore saved runtime instrumentation psw bit

Pull i2c fixes from Wolfram Sang:
 "Some easy but needed fixes for i2c drivers since rc1"

* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  i2c: bcm2835: Linking platform nodes to adapter nodes
  i2c: omap: raw read and write endian fix
  i2c: i2c-bcm-kona: Fix module build
  i2c: i2c-diolan-u2c: different usb endpoints for DLN-2-U2C
  i2c: bcm-kona: remove duplicated include
  i2c: davinci: raw read and write endian fix

Pull workqueue fixes from Tejun Heo:
 "This contains one important fix.  The NUMA support added a while back
  broke ordering guarantees on ordered workqueues.  It was enforced by
  having single frontend interface with @max_active == 1 but the NUMA
  support puts multiple interfaces on unbound workqueues on NUMA
  machines thus breaking the ordered guarantee.  This is fixed by
  disabling NUMA support on ordered workqueues.

  The above and a couple other patches were sitting in for-3.12-fixes
  but I forgot to push that out, so they ended up waiting a bit too
  long.  My aplogies.

  Other fixes are minor"

* 'for-3.13-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
  workqueue: fix pool ID allocation leakage and remove BUILD_BUG_ON() in init_workqueues
  workqueue: fix comment typo for __queue_work()
  workqueue: fix ordered workqueues in NUMA setups
  workqueue: swap set_cpus_allowed_ptr() and PF_NO_SETAFFINITY

Pull libata fixes from Tejun Heo:
 "libata device removal path was removing parent device node before its
  child, which is mostly harmless but triggers warning after recent
  sysfs changes.  Rafael's patch fixes the order.

  Other than that, minor controller-specific fixes and device ID
  additions"

* 'for-3.13-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/libata:
  ATA: Fix port removal ordering
  ahci: add Marvell 9230 to the AHCI PCI device list
  ata: fix acpi_bus_get_device() return value check
  pata_arasan_cf: add missing clk_disable_unprepare() on error path
  ahci: add support for IBM Akebono platform device

Pull cgroup fixes from Tejun Heo:
 "Fixes for three issues.

   - cgroup destruction path could swamp system_wq possibly leading to
     deadlock.  This actually seems to happen in the wild with memcg
     because memcg destruction path adds nested dependency on system_wq.

     Resolved by isolating cgroup destruction work items on its
     dedicated workqueue.

   - Possible locking context deadlock through seqcount reported by
     lockdep

   - Memory leak under certain conditions"

* 'for-3.13-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cgroup: fix cgroup_subsys_state leak for seq_files
  cpuset: Fix memory allocator deadlock
  cgroup: use a dedicated workqueue for cgroup destruction

Pull sound fixes from Takashi Iwai:
 "Quite a few HD-Audio fixes, a WUSB audio fix and a fix for FireWire
  audio.  The HD-audio part contains a couple of fixes for the generic
  parser, and these are the only intrusive fixes.  The rest are mostly
  device-specific fixes"

* tag 'sound-3.13-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
  ALSA: hda - Add LFE chmap to ASUS ET2700
  ALSA: hda - Initialize missing bass speaker pin for ASUS AIO ET2700
  ALSA: hda - limit mic boost on Asus UX31[A,E]
  ALSA: hda - Check leaf nodes to find aamix amps
  ALSA: hda - Fix hp-mic mode without VREF bits
  ALSA: hda - Create Headhpone Mic Jack Mode when really needed
  ALSA: usb: use multiple packets per urb for Wireless USB inbound audio
  ALSA: hda - Enable mute/mic-mute LEDs for more Thinkpads with Conexant codec
  ALSA: hda - Drop bus->avoid_link_reset flag
  ALSA: hda/realtek - Set pcbeep amp for ALC668
  ALSA: hda/realtek - Add support of ALC231 codec
  ALSA: firewire-lib: fix wrong value for FDF field as an empty packet

Pull vfs dentry reference count fix from Al Viro.

This fixes a possible inode_permission NULL pointer dereference (and
other problems) that were due to the root dentry count being decremented
too much.  In commit 48a066e7 ("RCU'd vfsmounts") the placement of
clearing the LOOKUP_RCU bit changed, and we then returned failure of
incrementing the lockref on the parent dentry with LOOKUP_RCU cleared.

But that meant we needed to go through the same cleanup routines that
the later failures did wrt LOOKUP_ROOT and nd->root.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  fix bogus path_put() of nd->root after some unlazy_walk() failures

Pull drm qxl leak fix from Dave Airlie:
 "As usual 5 mins after I send a trivial pull fix I find a real bug!

  This fixes a memory leak and I'd like to get it into stable queue
  asap"

* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux:
  drm/qxl: fix memory leak in release list handling

PTE_PROT_NONE means that a pte is present but does not have any
read/write attributes. However, setting the memory type like
pgprot_writecombine() is allowed and such bits overlap with
PTE_PROT_NONE. This causes mmap/munmap issues in drivers that change the
vma->vm_pg_prot on PROT_NONE mappings.

This patch reverts the PTE_FILE/PTE_PROT_NONE shift in commit
59911ca4 (ARM64: mm: Move PTE_PROT_NONE bit) and moves PTE_PROT_NONE
together with the other software bits.
Signed-off-by: Steve Capper <steve.capper@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Steve Capper <steve.capper@linaro.org>
Cc: <stable@vger.kernel.org> # 3.11+

This provides better performance compared to Device GRE and also allows
unaligned accesses. Such memory is intended to be used with standard RAM
(e.g. framebuffers) and not I/O.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

Failure to grab reference to parent dentry should go through the
same cleanup as nd->seq mismatch.  As it is, we might end up with
caller thinking it needs to path_put() nd->root, with obvious
nasty results once we'd hit that bug enough times to drive the
refcount of root dentry all the way to zero...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

wow no idea how I got this far without seeing this,
leaking the entries in the list makes kmalloc-64 slab grow.

References: https://bugzilla.kernel.org/show_bug.cgi?id=65121
Cc: stable@vger.kernel.org
Reported-by: Matthew Stapleton <matthew4196@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

The current breakpoint instruction checking code for A32 is not endian
clean. Fix this with appropriate byte-swapping when retrieving
instructions.
Signed-off-by: Matthew Leach <matthew.leach@arm.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

On a BE system the wrong half of the X registers is retrieved/written
when attempting to get/set the value of aarch32 registers through
ptrace.

Ensure that types are the correct width so that the relevant
casting occurs.
Signed-off-by: Matthew Leach <matthew.leach@arm.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

Pull GPIO fixes from Linus Walleij:
 "Here us a bunch of patches for the v3.13 series.  Most important stuff
  is related to fixes and documentation for the new GPIO descriptor API.
  If the diffstat is scary you'll notice most of it is to
  Documentation/*:

   - A big slew of documentation for the gpiod transition that happened
     in the merge window, no semantic effect, but we should provide
     proper documentation with the new API.

   - Fix flags related to the new API.

   - Fix to the find_chip_by_name() lookup function related to the new
     API.

   - Fix of_find_gpio() when not using device tree.

   - Bug fix for the TB10x direction setting.

   - Error path fixes from Dan Carpenter.

   - Nasty IRQdomain bug relating to taking an unitialized spinlock.

   - Minor fixes here and there"

* tag 'gpio-v3.13-2' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio:
  gpio: bcm281xx: Fix return value of bcm_kona_gpio_get()
  gpio: pl061: move irqdomain initialization
  gpio: ucb1400: Add MODULE_ALIAS
  gpiolib: fix of_find_gpio() when OF not defined
  gpio: fix memory leak in error path
  gpio: rcar: NULL dereference on error in probe()
  gpio: msm: make msm_gpio.summary_irq signed for error handling
  gpio: mvebu: make mvchip->irqbase signed for error handling
  gpiolib: use dedicated flags for GPIO properties
  gpiolib: fix find_chip_by_name()
  Documentation: gpiolib: document new interface
  gpio: tb10x: Set output value before setting direction to output

Pull md fixes from Neil Brown:
 "Three bug fixes for md in 3.13-rc

  All recent regressions, one in 3.12 so marked for -stable"

* tag 'md/3.13-fixes' of git://neil.brown.name/md:
  md/raid5: fix newly-broken locking in get_active_stripe.
  md: test mddev->flags more safely in md_check_recovery.
  md/raid5: fix new memory-reference bug in alloc_thread_groups.

Pull cifs fixes from Steve French:
 "SMB3 "validate negotiate" is needed to prevent certain types of
  downgrade attacks.

  Also changes SMB2/SMB3 copy offload from using the BTRFS copy ioctl
  (BTRFS_IOC_CLONE) to a cifs specific ioctl (CIFS_IOC_COPYCHUNK_FILE)
  to address Christoph's comment that there are semantic differences
  between requesting copy offload in which copy-on-write is mandatory
  (as in the BTRFS ioctl) and optional in the SMB2/SMB3 case.  Also
  fixes SMB2/SMB3 copychunk for large files"

* 'for-next' of git://git.samba.org/sfrench/cifs-2.6:
  [CIFS] Do not use btrfs refcopy ioctl for SMB2 copy offload
  Check SMB3 dialects against downgrade attacks
  Removed duplicated (and unneeded) goto
  CIFS: Fix SMB2/SMB3 Copy offload support (refcopy) for large files

The init_kernel_text() and core_kernel_text() functions should not
include the labels _einittext and _etext when checking if an address is
inside the .text or .init sections.
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

As the previous commit 1f0bbf03 added the pin config for the bass
speaker, this patch adds the corresponding LFE-only channel map on
ASUS ET2700.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=65961Signed-off-by: Takashi Iwai <tiwai@suse.de>

Add a fixup entry for the missing bass speaker pin 0x16 on ASUS ET2700
AiO desktop.  The channel map will be added in the next patch, so that
this can be backported easily to stable kernels.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=65961
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

This both devices need limit for internal dmic.

[cosmetic change; renamed fixup name by tiwai]
Signed-off-by: Oleksij Rempel <linux@rempel-privat.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

The current generic parser assumes blindly that the volume and mute
amps are found in the aamix node itself.  But on some codecs,
typically Analog Devices ones, the aamix amps are separately
implemented in each leaf node of the aamix node, and the current
driver can't establish the correct amp controls.  This is a regression
compared with the previous static quirks.

This patch extends the search for the amps to the leaf nodes for
allowing the aamix controls again on such codecs.
In this implementation, I didn't code to loop through the whole paths,
since usually one depth should suffice, and we can't search too
deeply, as it may result in the conflicting control assignments.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=65641
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

In order to find I2C devices in the device tree, the platform nodes
have to be known by the I2C core. This requires setting the
dev.of_node parameter of the adapter.
Signed-off-by: Florian Meier <florian.meier@koalo.de>
Tested-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Pull drm fixes from Dave Airlie:
 "Just two minor fixes as people keep resending since they are so low
  hanging"

* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux:
  drm/nouveau/hwmon: fix compilation without CONFIG_HWMON
  drm/sysfs: fix OOM verification

Pull tty/serial fixes from Greg KH:
 "Here are some tty/serial driver fixes for reported issues in 3.13-rc2.

  The n_gsm "fix" was reverted as it was found to not be correct.
  Hopefully this will be resolved in a future pull request, but as
  there's really only one user of this line setting, it's not a big
  deal..."

* tag 'tty-3.13-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  Revert "n_gsm: race between ld close and gsmtty open"
  n_tty: Protect minimum_to_wake reset for concurrent readers
  tty: Reset hupped state on open
  TTY: amiserial, add missing platform check
  TTY: pmac_zilog, check existence of ports in pmz_console_init()
  n_gsm: race between ld close and gsmtty open
  tty/serial/8250: fix typo in help text
  n_tty: Fix 4096-byte canonical reads
  n_tty: Fix echo overrun tail computation
  n_tty: Ensure reader restarts worker for next reader

Pull staging fixes from Greg KH:
 "Here are a number of staging, and IIO driver, fixes for 3.13-rc2 that
  resolve issues that have been reported for 3.13-rc1.  All of these
  have been in linux-next for a bit this week"

* tag 'staging-3.13-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (25 commits)
  Staging: tidspbridge: disable driver
  staging: zsmalloc: Ensure handle is never 0 on success
  staging/lustre/ptlrpc: fix ptlrpc_stop_pinger logic
  staging: r8188eu: Fix AP mode
  Staging: btmtk_usb: Add hdev parameter to hdev->send driver callback
  Staging: go7007: fix up some remaining go->dev issues
  staging: imx-drm: Fix modular build of DRM_IMX_IPUV3
  staging: ft1000: fix use of potentially uninitialized variable
  Revert "staging:media: Use dev_dbg() instead of pr_debug()"
  Staging: zram: Fix memory leak by refcount mismatch
  staging: vt6656: [BUG] Fix for TX USB resets from vendors driver.
  staging: nvec: potential NULL dereference on error path
  Staging: vt6655-6: potential NULL dereference in hostap_disable_hostapd()
  staging: comedi: s626: fix value written by s626_set_dac()
  Staging: comedi: pcl730: fix some bitwise vs logical AND bugs
  staging: comedi: fix potentially uninitialised variable
  iio:accel:kxsd9 fix missing mutex unlock
  iio: adc: ti_am335x_adc: avoid double free of buffer.
  staging:iio: Fix hmc5843 Kconfig dependencies
  iio: Fix tcs3472 Kconfig dependencies
  ...

Merge tag 'driver-core-3.13-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core fixes from Greg KH:
 "Here are 3 patches for sysfs issues that have been reported.  Well, 1
  patch really, the first one is reverted as it's not really needed (the
  correct fix is coming in through the different driver subsystems
  instead)

  But that 1 sysfs fix is needed, so this is still a good thing to pull
  in now"
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

* tag 'driver-core-3.13-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  Revert "sysfs: handle duplicate removal attempts in sysfs_remove_group()"
  sysfs: use a separate locking class for open files depending on mmap
  sysfs: handle duplicate removal attempts in sysfs_remove_group()

Pull HID fixes from Jiri Kosina:
 - fix compat ioctl leak in uhid, by David Herrmann
 - fix scheduling in atomic context (causing actual lockups in real
   world) in hid-sony driver, by Sven Eckelmann
 - revert patch introducing VID/PID conflict, by Jiri Kosina
 - support from various new device IDs by Benjamin Tissoires and
   KaiChung Cheng

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid:
  HID: uhid: fix leak for 64/32 UHID_CREATE
  HID: kye: fix unresponsive keyboard
  HID: kye: Add report fixup for Genius Manticore Keyboard
  HID: multicouh: add PID VID to support 1 new Wistron optical touch device
  HID: appleir: force input to be set
  Revert "HID: wiimote: add LEGO-wiimote VID"
  HID: sony: Send FF commands in non-atomic context

Pull ACPI and power management fixes from Rafael Wysocki:

 - Fix for a recent regression in the Tegra cpufreq driver causing
   excess error messages to be printed from Stephen Warren

 - ACPI-based device hotplug fix to prevent conflicting notify handlers
   from being installed for PCI host bridge objects.  From Toshi Kani

 - ACPICA update to upstream version 20131115.  This contains bug fixes
   mostly (loop termination fix for the get AML length function, fixes
   related to namespace node removal and debug output).  From Bob Moore,
   Tomasz Nowicki and Lv Zheng

 - Removal of incorrect inclusions of internal ACPICA header files by
   non-ACPICA code from Lv Zheng

 - Fixes for the ACPI sysfs interface exposing tables to user space from
   Daisuke Hatayama and Jeremy Compostella

 - Assorted ACPI and cpufreq cleanups from Sachin Kamat and Al Stone

 - cpupower tool fix and man page from Thomas Renninger

* tag 'pm+acpi-3.13-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  ACPI: Clean up incorrect inclusions of ACPICA headers
  tools: cpupower: fix wrong err msg not supported vs not available
  tools: cpupower: Add cpupower-idle-set(1) manpage
  ACPI / sysfs: Fix incorrect ACPI tables walk in acpi_tables_sysfs_init()
  ACPI / sysfs: Set file size for each exposed ACPI table
  ACPICA: Update version to 20131115.
  ACPICA: Add support to delete all objects attached to the root namespace node.
  ACPICA: Delete all attached data objects during namespace node deletion.
  ACPICA: Resources: Fix loop termination for the get AML length function.
  ACPICA: Tests: Add CHECKSUM_ABORT protection for test utilities.
  ACPICA: Debug output: Do not emit function nesting level for kernel build.
  ACPI / sleep: clean up compiler warning about uninitialized field
  cpufreq: exynos: Remove unwanted EXPORT_SYMBOL
  cpufreq: tegra: don't error target() when suspended
  ACPI / hotplug: Fix conflicted PCI bridge notify handlers

Since commit 7a6354e2 ("sched: Move wait.c into kernel/sched/"), the
path of this file has changed.
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Andy Whitcroft <apw@canonical.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Reported-by: Jim Davis <jim.epost@gmail.com>
Tested-by: Jim Davis <jim.epost@gmail.com>
Signed-off-by: Ilia Mirkin <imirkin@alum.mit.edu>
Signed-off-by: Dave Airlie <airlied@redhat.com>

arch_mutex_cpu_relax is already conditionally defined in mutex.h, so
simply include that header rather than replicate the code here.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Copy/Paste typo.. we need to test for ->kdev instead of ->dev.
Reported-by: Juha Leppänen <juha_efku@dnainternet.net>
Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

This tool hasn't been maintained in over a decade, and is pretty much
useless these days.  Let's pretend it never happened.

Also remove a long-dead email address.
Signed-off-by: Dave Jones <davej@fedoraproject.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull powerpc fixes from Ben Herrenschmidt:
 "The main thing that caused problem was that CONFIG_CPU_LITTLE_ENDIAN
  got turned on with allyesconfig and such, which is not a very good
  idea especially since it requires a newer toolchain than what most
  people have.

  So we turned it into a choice instead that defaults to big endian"

* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc:
  powerpc/windfarm: Fix XServe G5 fan control Makefile issue
  arch/powerpc/kernel: Use %12.12s instead of %12s to avoid memory overflow
  powerpc/signals: Improved mark VSX not saved with small contexts fix
  powerpc/kdump: Adding symbols in vmcoreinfo to facilitate dump filtering
  powerpc: allyesconfig should not select CONFIG_CPU_LITTLE_ENDIAN
  powerpc: Fix error when cross building TAGS & cscope
  powerpc/booke: Only check for hugetlb in flush if vma != NULL
  powerpc/85xx: typo in dts: "interupt" (four devices)
  powerpc/8xx: mfspr SPRN_TBRx in lieu of mftb/mftbu is not supported
  powerpc/corenet64: compile with CONFIG_E{5,6}500_CPU well

commit 566c09c5 raid5: relieve lock contention in get_active_stripe()

modified the locking in get_active_stripe() reducing the range
protected by the (highly contended) device_lock.
Unfortunately it reduced the range too much opening up some races.

One race can occur if get_priority_stripe runs between the
test on sh->count and device_lock being taken.
This will mean that sh->lru is not empty while get_active_stripe
thinks ->count is zero resulting in a 'BUG' firing.

Another race happens if __release_stripe is called immediately
after sh->count is tested and found to be non-zero.  If STRIPE_HANDLE
is not set, get_active_stripe should increment ->active_stripes
when it increments ->count from 0, but as it didn't think it was 0,
it doesn't.

Extending device_lock to cover the test on sh->count close these
races.

While we are here, fix the two BUG tests:
 -If count is zero, then lru really must not be empty, or we've
  lock the stripe_head somehow - no other tests are relevant.
 -STRIPE_ON_RELEASE_LIST is completely independent of ->lru so
  testing it is pointless.
Reported-and-tested-by: Brassow Jonathan <jbrassow@redhat.com>
Reviewed-by: Shaohua Li <shli@kernel.org>
Fixes: 566c09c5Signed-off-by: NeilBrown <neilb@suse.de>