There is nothing gained by holding a lock while we check if a pointer
is NULL or not.  If there could be a race, then it could become NULL
immediately after the unlock - but there is no race here.

So just remove the locking.
Signed-off-by: NeilBrown <neilb@suse.de>

The use of a goto makes the control flow more obscure here.

So make it a normal:
  if (x) {
     Y;
  }

No functional change.
Signed-off-by: NeilBrown <neilb@suse.de>

The part of /proc/mdstat which describes the bitmap should really
be generated by code in bitmap.c.  So move it there.
Signed-off-by: NeilBrown <neilb@suse.de>

Signed-off-by: NeilBrown <neilb@suse.de>

'resizing' an array in this context means making use of extra
space that has become available in component devices, not adding new
devices.
It also includes shrinking the array to take up less space of
component devices.

This is not supported for array with a 'far' layout.  However
for 'near' and 'offset' layout arrays, adding and removing space at
the end of the devices is easy to support, and this patch provides
that support.
Signed-off-by: NeilBrown <neilb@suse.de>

Currently we don't honour merge_bvec_fn in member devices so if there
is one, we force all requests to be single-page at most.
This is not ideal.

So create a raid1 merge_bvec_fn to check that function in children
as well.

This introduces a small problem.  There is no locking around calls
the ->merge_bvec_fn and subsequent calls to ->make_request.  So a
device added between these could end up getting a request which
violates its merge_bvec_fn.

Currently the best we can do is synchronize_sched().  This will work
providing no preemption happens.  If there is is preemption, we just
have to hope that new devices are largely consistent with old devices.
Signed-off-by: NeilBrown <neilb@suse.de>

Currently we don't honour merge_bvec_fn in member devices so if there
is one, we force all requests to be single-page at most.
This is not ideal.

So enhance the raid10 merge_bvec_fn to check that function in children
as well.

This introduces a small problem.  There is no locking around calls
the ->merge_bvec_fn and subsequent calls to ->make_request.  So a
device added between these could end up getting a request which
violates its merge_bvec_fn.

Currently the best we can do is synchronize_sched().  This will work
providing no preemption happens.  If there is preemption, we just
have to hope that new devices are largely consistent with old devices.
Signed-off-by: NeilBrown <neilb@suse.de>

These personalities currently set a max request size of one page
when any member device has a merge_bvec_fn because they don't
bother to call that function.

This causes extra works in splitting and combining requests.

So make the extra effort to call the merge_bvec_fn when it exists
so that we end up with larger requests out the bottom.
Signed-off-by: NeilBrown <neilb@suse.de>

md.h has an 'rdev_for_each()' macro for iterating the rdevs in an
mddev.  However it uses the 'safe' version of list_for_each_entry,
and so requires the extra variable, but doesn't include 'safe' in the
name, which is useful documentation.

Consequently some places use this safe version without needing it, and
many use an explicity list_for_each entry.

So:
 - rename rdev_for_each to rdev_for_each_safe
 - create a new rdev_for_each which uses the plain
   list_for_each_entry,
 - use the 'safe' version only where needed, and convert all other
   list_for_each_entry calls to use rdev_for_each.
Signed-off-by: NeilBrown <neilb@suse.de>

If RAID1 or RAID10 is used under LVM or some other stacking
block device, it is possible to enter a deadlock during
resync or recovery.
This can happen if the upper level block device creates
two requests to the RAID1 or RAID10.  The first request gets
processed, blocks recovery and queue requests for underlying
requests in current->bio_list.  A resync request then starts
which will wait for those requests and block new IO.

But then the second request to the RAID1/10 will be attempted
and it cannot progress until the resync request completes,
which cannot progress until the underlying device requests complete,
which are on a queue behind that second request.

So allow that second request to proceed even though there is
a resync request about to start.

This is suitable for any -stable kernel.

Cc: stable@vger.kernel.org
Reported-by: Ray Morris <support@bettercgi.com>
Tested-by: Ray Morris <support@bettercgi.com>
Signed-off-by: NeilBrown <neilb@suse.de>

When commit 69e51b44 (md/bitmap:  separate out loading a bitmap...)
created bitmap_load, it missed calling it after bitmap_create when a
bitmap is created through the sysfs interface.
So if a bitmap is added this way, we don't allocate memory properly
and can crash.

This is suitable for any -stable release since 2.6.35.
Cc: stable@vger.kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>

It seems that with recent kernel, writeback can still be happening
while shutdown is happening, and consequently data can be written
after the md reboot notifier switches all arrays to read-only.
This causes a BUG.

So don't switch them to read-only - just mark them clean and
set 'safemode' to '2' which mean that immediately after any
write the array will be switch back to 'clean'.

This could result in the shutdown happening when array is marked
dirty, thus forcing a resync on reboot.  However if you reboot
without performing a "sync" first, you get to keep both halves.

This is suitable for any stable kernel (though there might be some
conflicts with obvious fixes in earlier kernels).

Cc: stable@vger.kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>

When an array is failed (some data inaccessible) then there is no
point attempting to add a spare as it could not possibly be recovered.

However that may be value in re-adding a recently removed device.
e.g. if there is a write-intent-bitmap and it is clear, then access
to the data could be restored by this action.

So don't reject a re-add to a failed array for RAID10 and RAID5 (the
only arrays  types that check for a failed array).
Signed-off-by: NeilBrown <neilb@suse.de>

Signed-off-by: majianpeng <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>

Signed-off-by: majianpeng <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>

commit 908f4fbd removed the last user of this variable,
so we should discard it completely.
Signed-off-by: NeilBrown <neilb@suse.de>

Recent commit 4ca40c2c (md/raid10: Allow replacement device ...)
added an smp_mb in end_sync_write.
This was to close a possible race with raid10_remove_disk.
However there is no such race as it is never attempted to remove a
disk while resync (or recovery) is happening.
so the smp_mb is just noise.
Signed-off-by: NeilBrown <neilb@suse.de>

Leaving a valid reshape_position value in place could be confusing.
Signed-off-by: NeilBrown <neilb@suse.de>

Current code has put_ioctx() called asynchronously from aio_fput_routine();
that's done *after* we have killed the request that used to pin ioctx,
so there's nothing to stop io_destroy() waiting in wait_for_all_aios()
from progressing.  As the result, we can end up with async call of
put_ioctx() being the last one and possibly happening during exit_mmap()
or elf_core_dump(), neither of which expects stray munmap() being done
to them...

We do need to prevent _freeing_ ioctx until aio_fput_routine() is done
with that, but that's all we care about - neither io_destroy() nor
exit_aio() will progress past wait_for_all_aios() until aio_fput_routine()
does really_put_req(), so the ioctx teardown won't be done until then
and we don't care about the contents of ioctx past that point.

Since actual freeing of these suckers is RCU-delayed, we don't need to
bump ioctx refcount when request goes into list for async removal.
All we need is rcu_read_lock held just over the ->ctx_lock-protected
area in aio_fput_routine().
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Acked-by: Benjamin LaHaise <bcrl@kvack.org>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Have ioctx_alloc() return an extra reference, so that caller would drop it
on success and not bother with re-grabbing it on failure exit.  The current
code is obviously broken - io_destroy() from another thread that managed
to guess the address io_setup() would've returned would free ioctx right
under us; gets especially interesting if aio_context_t * we pass to
io_setup() points to PROT_READ mapping, so put_user() fails and we end
up doing io_destroy() on kioctx another thread has just got freed...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Benjamin LaHaise <bcrl@kvack.org>
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull btrfs updates from Chris Mason:
 "I have two additional and btrfs fixes in my for-linus branch.  One is
  a casting error that leads to memory corruption on i386 during scrub,
  and the other fixes a corner case in the backref walking code (also
  triggered by scrub)."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: fix casting error in scrub reada code
  btrfs: fix locking issues in find_parent_nodes()

Respectfully revert commit e6ca7b89 "memcg: fix mapcount check
in move charge code for anonymous page" for the 3.3 release, so that
it behaves exactly like releases 2.6.35 through 3.2 in this respect.

Horiguchi-san's commit is correct in itself, 1 makes much more sense
than 2 in that check; but it does not go far enough - swapcount
should be considered too - if we really want such a check at all.

We appear to have reached agreement now, and expect that 3.4 will
remove the mapcount check, but had better not make 3.3 different.
Signed-off-by: Hugh Dickins <hughd@google.com>
Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Commit f0fbf0ab ("x86: integrate delay functions") converted
delay_tsc() into a random delay generator for 64 bit.  The reason is
that it merged the mostly identical versions of delay_32.c and
delay_64.c.  Though the subtle difference of the result was:

 static void delay_tsc(unsigned long loops)
 {
-	unsigned bclock, now;
+	unsigned long bclock, now;

Now the function uses rdtscl() which returns the lower 32bit of the
TSC. On 32bit that's not problematic as unsigned long is 32bit. On 64
bit this fails when the lower 32bit are close to wrap around when
bclock is read, because the following check

       if ((now - bclock) >= loops)
       	  	break;

evaluated to true on 64bit for e.g. bclock = 0xffffffff and now = 0
because the unsigned long (now - bclock) of these values results in
0xffffffff00000001 which is definitely larger than the loops
value. That explains Tvortkos observation:

"Because I am seeing udelay(500) (_occasionally_) being short, and
 that by delaying for some duration between 0us (yep) and 491us."

Make those variables explicitely u32 again, so this works for both 32
and 64 bit.
Reported-by: Tvrtko Ursulin <tvrtko.ursulin@onelan.co.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org # >= 2.6.27
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull sound fixes from Takashi Iwai:
 "Nothing exciting here: just a few regression fixes for HD-audio and
  ASoC, also the support of missing 32bit compat ioctl for HDSPM."

* tag 'sound-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
  ALSA: hdspm - Provide ioctl_compat
  ALSA: hda/realtek - Apply the coef-setup only to ALC269VB
  ALSA: hda - add quirk to detect CD input on Gigabyte EP45-DS3
  ASoC: neo1973: fix neo1973 wm8753 initialization

The msm git tree moved to

  git://git.kernel.org/pub/scm/linux/kernel/git/davidb/linux-msm.gitSigned-off-by: David Brown <davidb@codeaurora.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull C6X fix from Mark Salter:
 "Fix for C6X KSTK_EIP and KSTK_ESP macros."

* tag 'for-linus' of git://linux-c6x.org/git/projects/linux-c6x-upstreaming:
  C6X: fix KSTK_EIP and KSTK_ESP macros

Pull two IOMMU fixes from Joerg Roedel:
 "The first is an additional fix for the OMAP initialization order issue
  and the second patch fixes a possible section mismatch which can lead
  to a kernel crash in the AMD IOMMU driver when suspend/resume is used
  and the compiler has not inlined the iommu_set_device_table function."

* tag 'iommu-fixes-v3.3-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu:
  x86/amd: iommu_set_device_table() must not be __init
  ARM: OMAP: fix iommu, not mailbox

Pull radeon drm stuff from Dave Airlie:
 "Just some radeon fixes, one is for an oops where we run out of ioremap
  space on some big hardware systems in 32-bit mode, stuff doesn't work
  properly but at least the machine will boot.

  One regression fix, and two bugs, one hw, one blit code."

* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux:
  drm/radeon/kms: fix hdmi duallink checks
  drm/radeon/kms: set SX_MISC in the r6xx blit code (v2)
  drm/radeon: deal with errors from framebuffer init path.
  drm/radeon: fix a semaphore deadlock on pre cayman asics

Pull networking from David Miller:

1) IPV4 routing metrics can become stale when routes are changed by the
   administrator, fix from Steffen Klassert.

2) atl1c does "val |= XXX;" where XXX is a bit number not a bit mask,
   fix by using set_bit.  From Dan Carpenter.

3) Memory accounting bug in carl9170 driver results in wedged TX queue.
   Fix from Nicolas Cavallari.

4) iwlwifi accidently uses "sizeof(ptr)" instead of "sizeof(*ptr)", fix
   from Johannes Berg.

5) Openvswitch doesn't honor dp_ifindex when doing vport lookups, fix
   from Ben Pfaff.

6) ehea conversion to 64-bit stats lost multicast and rx_errors
   accounting, fix from Eric Dumazet.

7) Bridge state transition logging in br_stp_disable_port() is busted,
   it's emitted at the wrong time and the message is in the wrong tense,
   fix from Paulius Zaleckas.

8) mlx4 device erroneously invokes the queue resize firmware operation
   twice, fix from Jack Morgenstein.

9) Fix deadlock in usbnet, need to drop lock when invoking usb_unlink_urb()
   otherwise we recurse into taking it again.  Fix from Sebastian Siewior.

10) hyperv network driver uses the wrong driver name string, fix from
    Haiyang Zhang.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net:
  net/hyperv: Use the built-in macro KBUILD_MODNAME for this driver
  net/usbnet: avoid recursive locking in usbnet_stop()
  route: Remove redirect_genid
  inetpeer: Invalidate the inetpeer tree along with the routing cache
  mlx4_core: fix bug in modify_cq wrapper for resize flow.
  atl1c: set ATL1C_WORK_EVENT_RESET bit correctly
  bridge: fix state reporting when port is disabled
  bridge: br_log_state() s/entering/entered/
  ehea: restore multicast and rx_errors fields
  openvswitch: Fix checksum update for actions on UDP packets.
  openvswitch: Honor dp_ifindex, when specified, for vport lookup by name.
  iwlwifi: fix wowlan suspend
  mwifiex: reset encryption mode flag before association
  carl9170: fix frame delivery if sta is in powersave mode
  carl9170: Fix memory accounting when sta is in power-save mode.

Pull last minute fixes from Olof Johansson:
 "One samsung build fix due to a mis-applied patch, and a small set of
  OMAP fixes.  This should be the last from arm-soc for 3.3, hopefully."

* tag 'fixes-urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
  ARM: S3C2440: Fixed build error for s3c244x
  ARM: OMAP2+: Fix module build errors with CONFIG_OMAP4_ERRATA_I688
  ARM: OMAP: id: Add missing break statement in omap3xxx_check_revision
  ARM: OMAP2+: Remove apply_uV constraints for fixed regulator
  ARM: OMAP: irqs: Fix NR_IRQS value to handle PRCM interrupts

Pull regulator fix from Mark Brown:
 "Another small, clear fix in a specific driver."

* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator:
  regulator: tps65910: Configure correct value for VDDCTRL vout reg

Pull minor devicetree bug fixes and documentation updates from Grant Likely:
 "Fixes up a duplicate #include, adds an empty implementation of
  of_find_compatible_node() and make git ignore .dtb files.  And fix up
  bus name on OF described PHYs.  Nothing exciting here."

* tag 'devicetree-for-linus' of git://git.secretlab.ca/git/linux-2.6:
  doc: dt: Fix broken reference in gpio-leds documentation
  of/mdio: fix fixed link bus name
  of/fdt.c: asm/setup.h included twice
  of: add picochip vendor prefix
  dt: add empty of_find_compatible_node function
  ARM: devicetree: Add .dtb files to arch/arm/boot/.gitignore

Pull SPI section mismatch bug fix for v3.3-rc3 from Grant Likely:
 "Minor fix for pl022_dma_probe() function which was put in the wrong
  section."

* tag 'spi-for-linus' of git://git.secretlab.ca/git/linux-2.6:
  Fix section mismatch in spi-pl022.c

Pull four hwmon patches from Guenter Roeck

* tag 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging:
  hwmon: (jc42) Add support for AT30TS00, TS3000GB2, TSE2002GB2, and MCP9804
  hwmon: (zl6100) Maintain delay parameter in driver instance data
  hwmon: (pmbus_core) Fix maximum number of POUT alarm attributes
  hwmon: (jc42) Add support for ST Microelectronics STTS2002 and STTS3000

Pull device-mapper fixes for 3.3 from Alasdair Kergon

Eight small device-mapper bug fixes.

* tag 'dm-3.3-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-dm:
  dm raid: fix flush support
  dm raid: set MD_CHANGE_DEVS when rebuilding
  dm thin metadata: decrement counter after removing mapped block
  dm thin metadata: unlock superblock in init_pmd error path
  dm thin metadata: remove incorrect close_device on creation error paths
  dm flakey: fix crash on read when corrupt_bio_byte not set
  dm io: fix discard support
  dm ioctl: do not leak argv if target message only contains whitespace

Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Cc: Olaf Hering <olaf@aepfle.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap:
  ARM: OMAP2+: Fix module build errors with CONFIG_OMAP4_ERRATA_I688
  ARM: OMAP: id: Add missing break statement in omap3xxx_check_revision
  ARM: OMAP2+: Remove apply_uV constraints for fixed regulator
  ARM: OMAP: irqs: Fix NR_IRQS value to handle PRCM interrupts

Fixed following:
arch/arm/mach-s3c2440/s3c244x.c: In function 's3c244x_restart':
arch/arm/mach-s3c2440/s3c244x.c:209: error: expected declaration or statement at end of input
make[1]: *** [arch/arm/mach-s3c24xx/s3c244x.o] Error 1
make: *** [arch/arm/mach-s3c24xx] Error 2
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Olof Johansson <olof@lixom.net>

snd_hdspm uses its own ioctls to acquire config- and status information.
Expose the corresponding ioctl handler via ioctl_compat, so that 32bit
applications can use it on 64bit kernels.
Signed-off-by: Adrian Knoth <adi@drcomp.erfurt.thur.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>