Pull btrfs fixes from Chris Mason:
 "I've split out the big send/receive update from my last pull request
  and now have just the fixes in my for-linus branch.  The send/recv
  branch will wander over to linux-next shortly though.

  The largest patches in this pull are Josef's patches to fix DIO
  locking problems and his patch to fix a crash during balance.  They
  are both well tested.

  The rest are smaller fixes that we've had queued.  The last rc came
  out while I was hacking new and exciting ways to recover from a
  misplaced rm -rf on my dev box, so these missed rc3."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (25 commits)
  Btrfs: fix that repair code is spuriously executed for transid failures
  Btrfs: fix ordered extent leak when failing to start a transaction
  Btrfs: fix a dio write regression
  Btrfs: fix deadlock with freeze and sync V2
  Btrfs: revert checksum error statistic which can cause a BUG()
  Btrfs: remove superblock writing after fatal error
  Btrfs: allow delayed refs to be merged
  Btrfs: fix enospc problems when deleting a subvol
  Btrfs: fix wrong mtime and ctime when creating snapshots
  Btrfs: fix race in run_clustered_refs
  Btrfs: don't run __tree_mod_log_free_eb on leaves
  Btrfs: increase the size of the free space cache
  Btrfs: barrier before waitqueue_active
  Btrfs: fix deadlock in wait_for_more_refs
  btrfs: fix second lock in btrfs_delete_delayed_items()
  Btrfs: don't allocate a seperate csums array for direct reads
  Btrfs: do not strdup non existent strings
  Btrfs: do not use missing devices when showing devname
  Btrfs: fix that error value is changed by mistake
  Btrfs: lock extents as we map them in DIO
  ...

Pull watchdog fixes from Wim Van Sebroeck:
 "This will fix a warning for watchdog-test.c and it will remove a
  duplicate include of delay.h"

* git://www.linux-watchdog.org/linux-watchdog:
  watchdog: da9052: Remove duplicate inclusion of delay.h
  watchdog: fix watchdog-test.c build warning

cache_grow() can reenable irqs so the cpu (and node) can change, so ensure
that we take list_lock on the correct nodelist.

This fixes an issue with commit 072bb0aa ("mm: sl[au]b: add
knowledge of PFMEMALLOC reserve pages") where list_lock for the wrong
node was taken after growing the cache.
Reported-and-tested-by: NHaggai Eran <haggaie@mellanox.com>
Signed-off-by: NDavid Rientjes <rientjes@google.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

delay.h header file was included twice.
Signed-off-by: NSachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: NWim Van Sebroeck <wim@iguana.be>

Fix compiler warning by making the function static:

Documentation/watchdog/src/watchdog-test.c:34:6: warning: no previous prototype for 'term'
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>
Signed-off-by: NWim Van Sebroeck <wim@iguana.be>

If verify_parent_transid() fails for all mirrors, the current code
calls repair_io_failure() anyway which means:
- that the disk block is rewritten without repairing anything and
- that a kernel log message is printed which misleadingly claims
  that a read error was corrected.

This is an example:
parent transid verify failed on 615015833600 wanted 110423 found 110424
parent transid verify failed on 615015833600 wanted 110423 found 110424
btrfs read error corrected: ino 1 off 615015833600 (dev /dev/...)

It is wrong to ignore the results from verify_parent_transid() and to
call repair_eb_io_failure() when the verification of the transids failed.
This commit fixes the issue.
Signed-off-by: NStefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

We cannot just return error before freeing ordered extent and releasing reserved
space when we fail to start a transacion.
Signed-off-by: NLiu Bo <bo.li.liu@oracle.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

This bug is introduced by commit 3b8bde746f6f9bd36a9f05f5f3b6e334318176a9
(Btrfs: lock extents as we map them in DIO).

In dio write, we should unlock the section which we didn't do IO on in case that
we fall back to buffered write.  But we need to not only unlock the section
but also cleanup reserved space for the section.

This bug was found while running xfstests 133, with this 133 no longer complains.
Signed-off-by: NLiu Bo <bo.li.liu@oracle.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

We can deadlock with freeze right now because we unconditionally start a
transaction in our ->sync_fs() call.  To fix this just check and see if we
have a running transaction to commit.  This saves us from the deadlock
because at this point we'll have the umount sem for the sb so we're safe
from freezes coming in after we've done our check.  With this patch the
freeze xfstests no longer deadlocks.  Thanks,
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

Commit 442a4f63 added btrfs device
statistic counters for detected IO and checksum errors to Linux 3.5.
The statistic part that counts checksum errors in
end_bio_extent_readpage() can cause a BUG() in a subfunction:
"kernel BUG at fs/btrfs/volumes.c:3762!"
That part is reverted with the current patch.
However, the counting of checksum errors in the scrub context remains
active, and the counting of detected IO errors (read, write or flush
errors) in all contexts remains active.

Cc: stable <stable@vger.kernel.org> # 3.5
Signed-off-by: NStefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

With commit acce952b, btrfs was changed to flag the filesystem with
BTRFS_SUPER_FLAG_ERROR and switch to read-only mode after a fatal
error happened like a write I/O errors of all mirrors.
In such situations, on unmount, the superblock is written in
btrfs_error_commit_super(). This is done with the intention to be able
to evaluate the error flag on the next mount. A warning is printed
in this case during the next mount and the log tree is ignored.

The issue is that it is possible that the superblock points to a root
that was not written (due to write I/O errors).
The result is that the filesystem cannot be mounted. btrfsck also does
not start and all the other btrfs-progs tools fail to start as well.
However, mount -o recovery is working well and does the right things
to recover the filesystem (i.e., don't use the log root, clear the
free space cache and use the next mountable root that is stored in the
root backup array).

This patch removes the writing of the superblock when
BTRFS_SUPER_FLAG_ERROR is set, and removes the handling of the error
flag in the mount function.

These lines can be used to reproduce the issue (using /dev/sdm):
SCRATCH_DEV=/dev/sdm
SCRATCH_MNT=/mnt
echo 0 25165824 linear $SCRATCH_DEV 0 | dmsetup create foo
ls -alLF /dev/mapper/foo
mkfs.btrfs /dev/mapper/foo
mount /dev/mapper/foo $SCRATCH_MNT
echo bar > $SCRATCH_MNT/foo
sync
echo 0 25165824 error | dmsetup reload foo
dmsetup resume foo
ls -alF $SCRATCH_MNT
touch $SCRATCH_MNT/1
ls -alF $SCRATCH_MNT
sleep 35
echo 0 25165824 linear $SCRATCH_DEV 0 | dmsetup reload foo
dmsetup resume foo
sleep 1
umount $SCRATCH_MNT
btrfsck /dev/mapper/foo
dmsetup remove foo
Signed-off-by: NStefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: NJan Schmidt <list.btrfs@jan-o-sch.net>

Daniel Blueman reported a bug with fio+balance on a ramdisk setup.
Basically what happens is the balance relocates a tree block which will drop
the implicit refs for all of its children and adds a full backref.  Once the
block is relocated we have to add the implicit refs back, so when we cow the
block again we add the implicit refs for its children back.  The problem
comes when the original drop ref doesn't get run before we add the implicit
refs back.  The delayed ref stuff will specifically prefer ADD operations
over DROP to keep us from freeing up an extent that will have references to
it, so we try to add the implicit ref before it is actually removed and we
panic.  This worked fine before because the add would have just canceled the
drop out and we would have been fine.  But the backref walking work needs to
be able to freeze the delayed ref stuff in time so we have this ever
increasing sequence number that gets attached to all new delayed ref updates
which makes us not merge refs and we run into this issue.

So to fix this we need to merge delayed refs.  So everytime we run a
clustered ref we need to try and merge all of its delayed refs.  The backref
walking stuff locks the delayed ref head before processing, so if we have it
locked we are safe to merge any refs inside of the sequence number.  If
there is no sequence number we can merge all refs.  Doing this not only
fixes our bug but keeps the delayed ref code from adding and removing
useless refs and batching together multiple refs into one search instead of
one search per delayed ref, which will really help our commit times.  I ran
this with Daniels test and 276 and I haven't seen any problems.  Thanks,
Reported-by: NDaniel J Blueman <daniel@quora.org>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>

Subvol delete is a special kind of awful where we use the global reserve to
cover the ENOSPC requirements.  The problem is once we're done removing
everything we do a btrfs_update_inode(), which by default will try to do the
delayed update stuff which will use it's own reserve.  There will be no
space in this reserve and we'll return ENOSPC.  So instead use
btrfs_update_inode_fallback() which will just fallback to updating the inode
item in the case of enospc.  This is fine because the global reserve covers
the space requirements for this.  With this patch I can now delete a subvol
on a problem image Dave Sterba sent me.  Thanks,
Reported-by: NDavid Sterba <dave@jikos.cz>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

When we created a new snapshot, the mtime and ctime of its parent directory
were not updated. Fix it.
Signed-off-by: NMiao Xie <miaox@cn.fujitsu.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

With commit

commit d1270cd9
Author: Arne Jansen <sensille@gmx.net>
Date:   Tue Sep 13 15:16:43 2011 +0200

     Btrfs: put back delayed refs that are too new

I added a window where the delayed_ref's head->ref_mod code can diverge
from the sum of the remaining refs, because we release the head->mutex
in the middle. This leads to btrfs_lookup_extent_info returning wrong
numbers. This patch fixes this by adjusting the head's ref_mod with each
delayed ref we run.
Signed-off-by: NArne Jansen <sensille@gmx.net>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

When we split a leaf, we may end up inserting a new root on top of that
leaf.  The reflog code was incorrectly assuming the old root was always
a node.  This makes sure we skip over leaves.
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

Arne was complaining about the space cache having mismatching generation
numbers when debugging a deadlock.  This is because we can run out of space
in our preallocated range for our space cache if you have a pretty
fragmented amount of space in your pinned space.  So just increase the
amount of space we preallocate for space cache so we can be sure to have
enough space.  This will only really affect data ranges since their the only
chunks that end up larger than 256MB.  Thanks,
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

We need a barrir before calling waitqueue_active otherwise we will miss
wakeups.  So in places that do atomic_dec(); then atomic_read() use
atomic_dec_return() which imply a memory barrier (see memory-barriers.txt)
and then add an explicit memory barrier everywhere else that need them.
Thanks,
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>

Commit a168650c introduced a waiting mechanism to prevent busy waiting in
btrfs_run_delayed_refs. This can deadlock with btrfs_run_ordered_operations,
where a tree_mod_seq is held while waiting for the io to complete, while
the end_io calls btrfs_run_delayed_refs.
This whole mechanism is unnecessary. If not enough runnable refs are
available to satisfy count, just return as count is more like a guideline
than a strict requirement.
In case we have to run all refs, commit transaction makes sure that no
other threads are working in the transaction anymore, so we just assert
here that no refs are blocked.
Signed-off-by: NArne Jansen <sensille@gmx.net>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

Fix a real bug caught by coccinelle.

fs/btrfs/delayed-inode.c:1013:1-11: second lock on line 1013
Signed-off-by: NFengguang Wu <fengguang.wu@intel.com>

We've been allocating a big array for csums instead of storing them in the
io_tree like we do for buffered reads because previously we were locking the
entire range, so we didn't have an extent state for each sector of the
range.  But now that we do the range locking as we map the buffers we can
limit the mapping lenght to sectorsize and use the private part of the
io_tree for our csums.  This allows us to avoid an extra memory allocation
for direct reads which could incur latency.  Thanks,
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>

When we close devices we add back empty devices for some reason that escapes
me.  In the case of a missing dev we don't allocate an rcu_string for it's
name, so check to see if the device has a name and if it doesn't don't
bother strdup()'ing it.  Thanks,
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>

If you do the following

mkfs.btrfs /dev/sdb /dev/sdc
rmmod btrfs
dd if=/dev/zero of=/dev/sdb bs=1M count=1
mount -o degraded /dev/sdc /mnt/btrfs-test

the box will panic trying to deref the name for the missing dev since it is
the lower numbered devid.  So fix show_devname to not use missing devices.
Thanks,
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>

In iterate_inodes_from_logical() the error result from
extent_from_logical() is patched by mistake. Typically ENOENT is
patched to EINVAL because (-ENOENT & BTRFS_EXTENT_FLAG_TREE_BLOCK)
evaluates to true.
Signed-off-by: NStefan Behrens <sbehrens@giantdisaster.de>

A deadlock in xfstests 113 was uncovered by commit

d187663e

This is because we would not return EIOCBQUEUED for short AIO reads, instead
we'd wait for the DIO to complete and then return the amount of data we
transferred, which would allow our stuff to unlock the remaning amount.  But
with this change this no longer happens, so if we have a short AIO read (for
example if we try to read past EOF), we could leave the section from EOF to
the end of where we tried to read locked.  Fixing this is tricky since there
is no clear way to know exactly how much data DIO truly submitted for IO, so
to make this less hard on ourselves and less combersome we need to lock the
extents as we try to map them, and then we unlock any areas we didn't
actually map.  This makes us completely safe from deadlocks and reliance on
a particular behavior of the DIO code.  This also lays the groundwork for
allowing us to use the normal csum storage method for reads which means we
can remove an allocation.  Thanks,
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>

"trans->transid" is cpu endian but we want to store the data as little
endian.  "item->ctime.nsec" is only 32 bits, not 64.
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>

We should release this mutex before returning the error code.
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>

add_qgroup_rb() never returns NULL, only error pointers.
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>

These are returning zero when it should be returning a negative error
code.
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>

This should obviously not be "if (&flag)" but "if (flag)".
Signed-off-by: NStefan Behrens <sbehrens@giantdisaster.de>

Pull a hwmon fix from Guenter Roeck:
 "Fix sensor readings for Asus M5A78L in asus_atk0110 driver."

* tag 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging:
  hwmon: (asus_atk0110) Add quirk for Asus M5A78L

Pull LogFS bugfixes from Prasad Joshi:

 - "logfs: query block device for number of pages to send with bio"

	This BUG was found when LogFS was used on KVM. The patch fixes
	the problem by asking for underlaying block device the number
	of pages to send with each BIO.

 - "logfs: maintain the ordering of meta-inode destruction"

	LogFS maintains file system meta-data in special inodes. These
	inodes are releated to each other, therefore they must be
	destroyed in a proper order.

 - "logfs: initialize the number of iovecs in bio"

	LogFS used to panic when it was created on an encrypted LVM
	volume. The patch fixes the problem by properly initializing
	the BIO.

Plus a couple more:
 - logfs: create a pagecache page if it is not present
 - logfs: destroy the reserved inodes while unmounting

* tag 'for-linus' of git://github.com/prasad-joshi/logfs_upstream:
  logfs: query block device for number of pages to send with bio
  logfs: maintain the ordering of meta-inode destruction
  logfs: create a pagecache page if it is not present
  logfs: initialize the number of iovecs in bio
  logfs: destroy the reserved inodes while unmounting

Pull arm-soc fixes from Arnd Bergmann:
 "Bug fixes for various ARM platforms.  About half of these are for OMAP
  and submitted before but did not make it into v3.6-rc2."

* tag 'fixes-3.6-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (39 commits)
  ARM: ux500: don't select LEDS_GPIO for snowball
  ARM: imx: build i.MX6 functions only when needed
  ARM: imx: select CPU_FREQ_TABLE when needed
  ARM: imx: fix ksz9021rn_phy_fixup
  ARM: imx: build pm-imx5 code only when PM is enabled
  ARM: omap: allow building omap44xx without SMP
  ARM: dts: imx51-babbage: fix esdhc cd/wp properties
  ARM: imx6: spin the cpu until hardware takes it down
  ARM: ux500: Ensure probing of Audio devices when Device Tree is enabled
  ARM: ux500: Fix merge error, no matching driver name for 'snd_soc_u8500'
  ARM i.MX6q: Add virtual 1/3.5 dividers in the LDB clock path
  ARM: Kirkwood: fix Makefile.boot
  ARM: Kirkwood: Fix iconnect leds
  ARM: Orion: Set eth packet size csum offload limit
  ARM: mv78xx0: fix win_cfg_base prototype
  ARM: OMAP: dmtimers: Fix locking issue in omap_dm_timer_request*()
  ARM: mmp: fix potential NULL dereference
  ARM: OMAP4: Register the OPP table only for 4430 device
  cpufreq: OMAP: Handle missing frequency table on SMP systems
  ARM: OMAP4: sleep: Save the complete used register stack frame
  ...

Merge tag 'stable/for-linus-3.6-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen

Pull three xen bug-fixes from Konrad Rzeszutek Wilk:
 - Revert the kexec fix which caused on non-kexec shutdowns a race.
 - Reuse existing P2M leafs - instead of requiring to allocate a large
   area of bootup virtual address estate.
 - Fix a one-off error when adding PFNs for balloon pages.

* tag 'stable/for-linus-3.6-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xen/setup: Fix one-off error when adding for-balloon PFNs to the P2M.
  xen/p2m: Reuse existing P2M leafs if they are filled with 1:1 PFNs or INVALID.
  Revert "xen PVonHVM: move shared_info to MMIO before kexec"

Pull powerpc fixes from Benjamin Herrenschmidt:
 "I meant to sent that earlier but got swamped with other things, so
  here are some powerpc fixes for 3.6.  A few regression fixes and some
  bug fixes that I deemed should still make it.

  There's a FSL update from Kumar with a bunch of defconfig updates
  along with a few embedded fixes.

  I also reverted my g5_defconfig update that I merged earlier as it was
  completely busted, not too sure what happened there, I'll do a new one
  later."

* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc:
  Revert "powerpc: Update g5_defconfig"
  powerpc/perf: Use pmc_overflow() to detect rolled back events
  powerpc: Fix VMX in interrupt check in POWER7 copy loops
  powerpc: POWER7 copy_to_user/copy_from_user patch applied twice
  powerpc: Fix personality handling in ppc64_personality()
  powerpc/dma-iommu: Fix IOMMU window check
  powerpc: Remove unnecessary ifdefs
  powerpc/kgdb: Restore current_thread_info properly
  powerpc/kgdb: Bail out of KGDB when we've been triggered
  powerpc/kgdb: Do not set kgdb_single_step on ppc
  powerpc/mpic_msgr: Add missing includes
  powerpc: Fix null pointer deref in perf hardware breakpoints
  powerpc: Fixup whitespace in xmon
  powerpc: Fix xmon dl command for new printk implementation
  powerpc/fsl: fix "Failed to mount /dev: No such device" errors
  powerpc/fsl: update defconfigs
  booke/wdt: some ioctls do not return values properly
  powerpc/p4080ds: dts - add usb controller version info and port0
  powerpc/85xx: mpc85xx_defconfig - add VIA PATA support for MPC85xxCDS
  powerpc/fsl-pci: Only scan PCI bus if configured as a host

Pull kvm fixes from Marcelo Tosatti.

* git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: x86 emulator: use stack size attribute to mask rsp in stack ops
  KVM: MMU: Fix mmu_shrink() so that it can free mmu pages as intended
  ppc: e500_tlb memset clears nothing
  KVM: PPC: Add cache flush on page map
  KVM: PPC: Book3S HV: Fix incorrect branch in H_CEDE code
  KVM: x86: update KVM_SAVE_MSRS_BEGIN to correct value

Pull xfs bugfixes from Ben Myers:
 - fix uninitialised variable in xfs_rtbuf_get()
 - unlock the AGI buffer when looping in xfs_dialloc
 - check for possible overflow in xfs_ioc_trim

* tag 'for-linus-v3.6-rc4' of git://oss.sgi.com/xfs/xfs:
  xfs: check for possible overflow in xfs_ioc_trim
  xfs: unlock the AGI buffer when looping in xfs_dialloc
  xfs: fix uninitialised variable in xfs_rtbuf_get()

Pull MIPS fixes from Ralf Baechle:
 "Random fixes across the MIPS tree.  The two hotspots are several bugs
  in the module loader and the ath79 SOC support; also noteworthy is the
  restructuring of the code to synchronize CPU timers across CPUs on
  startup; the old code recently ceased to work due to unrelated
  changes.

  All except one of these patches have sat for a significant time in
  linux-next for testing."

* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus:
  MIPS: pci-ar724x: avoid data bus error due to a missing PCIe module
  MIPS: Malta: Delete duplicate PCI fixup.
  MIPS: ath79: don't hardcode the unavailability of the DSP ASE
  MIPS: Synchronize MIPS count one CPU at a time
  MIPS: BCM63xx: Fix SPI message control register handling for BCM6338/6348.
  MIPS: Module: Deal with malformed HI16/LO16 relocation sequences.
  MIPS: Fix race condition in module relocation code.
  MIPS: Fix memory leak in error path of HI16/LO16 relocation handling.
  MIPS: MTX-1: Add udelay to mtx1_pci_idsel
  MIPS: ath79: select HAVE_CLK
  MIPS: ath79: Use correct IRQ number for the OHCI controller on AR7240
  MIPS: ath79: Fix number of GPIO lines for AR724[12]
  MIPS: Octeon: Fix broken interrupt controller code.

Pull nfsd bugfixes from J. Bruce Fields:
 "Particular thanks to Michael Tokarev, Malahal Naineni, and Jamie
  Heilman for their testing and debugging help."

* 'for-3.6' of git://linux-nfs.org/~bfields/linux:
  svcrpc: fix svc_xprt_enqueue/svc_recv busy-looping
  svcrpc: sends on closed socket should stop immediately
  svcrpc: fix BUG() in svc_tcp_clear_pages
  nfsd4: fix security flavor of NFSv4.0 callback

Pull block-related fixes from Jens Axboe:

 - Improvements to the buffered and direct write IO plugging from
   Fengguang.

 - Abstract out the mapping of a bio in a request, and use that to
   provide a blk_bio_map_sg() helper.  Useful for mapping just a bio
   instead of a full request.

 - Regression fix from Hugh, fixing up a patch that went into the
   previous release cycle (and marked stable, too) attempting to prevent
   a loop in __getblk_slow().

 - Updates to discard requests, fixing up the sizing and how we align
   them.  Also a change to disallow merging of discard requests, since
   that doesn't really work properly yet.

 - A few drbd fixes.

 - Documentation updates.

* 'for-linus' of git://git.kernel.dk/linux-block:
  block: replace __getblk_slow misfix by grow_dev_page fix
  drbd: Write all pages of the bitmap after an online resize
  drbd: Finish requests that completed while IO was frozen
  drbd: fix drbd wire compatibility for empty flushes
  Documentation: update tunable options in block/cfq-iosched.txt
  Documentation: update tunable options in block/cfq-iosched.txt
  Documentation: update missing index files in block/00-INDEX
  block: move down direct IO plugging
  block: remove plugging at buffered write time
  block: disable discard request merge temporarily
  bio: Fix potential memory leak in bio_find_or_create_slab()
  block: Don't use static to define "void *p" in show_partition_start()
  block: Add blk_bio_map_sg() helper
  block: Introduce __blk_segment_map_sg() helper
  fs/block-dev.c:fix performance regression in O_DIRECT writes to md block devices
  block: split discard into aligned requests
  block: reorganize rounding of max_discard_sectors