Pull device mapper updates from Mike Snitzer:
 "This pull request is later than I'd have liked because I was waiting
  for some performance data to help finally justify sending the
  long-standing dm-crypt cpu scalability improvements upstream.

  Unfortunately we came up short, so those dm-crypt changes will
  continue to wait, but it seems we're not far off.

   . Add dm_accept_partial_bio interface to DM core to allow DM targets
     to only process a portion of a bio, the remainder being sent in the
     next bio.  This enables the old dm snapshot-origin target to only
     split write bios on chunk boundaries, read bios are now sent to the
     origin device unchanged.

   . Add DM core support for disabling WRITE SAME if the underlying SCSI
     layer disables it due to command failure.

   . Reduce lock contention in DM's bio-prison.

   . A few small cleanups and fixes to dm-thin and dm-era"

* tag 'dm-3.16-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm thin: update discard_granularity to reflect the thin-pool blocksize
  dm bio prison: implement per bucket locking in the dm_bio_prison hash table
  dm: remove symbol export for dm_set_device_limits
  dm: disable WRITE SAME if it fails
  dm era: check for a non-NULL metadata object before closing it
  dm thin: return ENOSPC instead of EIO when error_if_no_space enabled
  dm thin: cleanup noflush_work to use a proper completion
  dm snapshot: do not split read bios sent to snapshot-origin target
  dm snapshot: allocate a per-target structure for snapshot-origin target
  dm: introduce dm_accept_partial_bio
  dm: change sector_count member in clone_info from sector_t to unsigned

DM thinp already checks whether the discard_granularity of the data
device is a factor of the thin-pool block size.  But when using the
dm-thin-pool's discard passdown support, DM thinp was not selecting the
max of the underlying data device's discard_granularity and the
thin-pool's block size.

Update set_discard_limits() to set discard_granularity to the max of
these values.  This enables blkdev_issue_discard() to properly align the
discards that are sent to the DM thin device on a full block boundary.
As such each discard will now cover an entire DM thin-pool block and the
block will be reclaimed.

Reported-by: Zdenek Kabelac <zkabelac@redhat.com>
Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org

Split the single per bio-prison lock by using per bucket locking.  Per
bucket locking benefits both dm-thin and dm-cache targets by reducing
bio-prison lock contention.

Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

Pull md updates from Neil Brown:
 "Assorted md fixes for 3.16

  Mostly performance improvements with a few corner-case bug fixes"

* tag 'md/3.16' of git://neil.brown.name/md:
  raid5: speedup sync_request processing
  md/raid5: deadlock between retry_aligned_read with barrier io
  raid5: add an option to avoid copy data from bio to stripe cache
  md/bitmap: remove confusing code from filemap_get_page.
  raid5: avoid release list until last reference of the stripe
  md: md_clear_badblocks should return an error code on failure.
  md/raid56: Don't perform reads to support writes until stripe is ready.
  md: refuse to change shape of array if it is active but read-only

The raid5 sync_request() processing calls handle_stripe() within the context of
the resync-thread.  The resync-thread issues the first set of read requests
and this adds execution latency and slows down the scheduling of the next
sync_request().
The current rebuild/resync speed of raid5 is not much faster than what
rotational HDDs can sustain.
Testing the following patch on a 6-drive array, I can increase the rebuild
speed from 100 MB/s to 175 MB/s.
The sync_request() now just sets STRIPE_HANDLE and releases the stripe.  This
creates some more parallelism between the resync-thread and raid5 kernel daemon.

Signed-off-by: Eivind Sarto <esarto@fusionio.com>
Signed-off-by: NeilBrown <neilb@suse.de>

Now that 3.15 is released, this merges the 'next' branch into 'master',
bringing us to the normal situation where my 'master' branch is the
merge window.

* accumulated work in next: (6809 commits)
  ufs: sb mutex merge + mutex_destroy
  powerpc: update comments for generic idle conversion
  cris: update comments for generic idle conversion
  idle: remove cpu_idle() forward declarations
  nbd: zero from and len fields in NBD_CMD_DISCONNECT.
  mm: convert some level-less printks to pr_*
  MAINTAINERS: adi-buildroot-devel is moderated
  MAINTAINERS: add linux-api for review of API/ABI changes
  mm/kmemleak-test.c: use pr_fmt for logging
  fs/dlm/debug_fs.c: replace seq_printf by seq_puts
  fs/dlm/lockspace.c: convert simple_str to kstr
  fs/dlm/config.c: convert simple_str to kstr
  mm: mark remap_file_pages() syscall as deprecated
  mm: memcontrol: remove unnecessary memcg argument from soft limit functions
  mm: memcontrol: clean up memcg zoneinfo lookup
  mm/memblock.c: call kmemleak directly from memblock_(alloc|free)
  mm/mempool.c: update the kmemleak stack trace for mempool allocations
  lib/radix-tree.c: update the kmemleak stack trace for radix tree allocations
  mm: introduce kmemleak_update_trace()
  mm/kmemleak.c: use %u to print ->checksum
  ...

A chunk aligned read increases counter active_aligned_reads and
decreases it after sub-device handle it successfully. But when a read
error occurs,  the read redispatched by raid5d, and the
active_aligned_reads will not be decreased until we can grab a stripe
head in retry_aligned_read. Now suppose, a barrier io comes, set
conf->quiesce to 2, and wait until both active_stripes and
active_aligned_reads are zero. The retried chunk aligned read gets
stuck at get_active_stripe waiting until conf->quiesce becomes 0.
Retry_aligned_read and barrier io are waiting each other now.
One possible solution is that we ignore conf->quiesce, let the retried
aligned read finish. I reproduced this deadlock and test this patch on
centos6.0

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

There is no need for code other than DM core to use dm_set_device_limits
so remove its EXPORT_SYMBOL_GPL.  Also, cleanup a couple whitespace nits.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>

Add DM core support for disabling WRITE SAME on first failure to both
request-based and bio-based targets.  The need to disable WRITE SAME
stems from SCSI enabling it by default but then disabling it when it
fails.  When SCSI does this it returns "permanent target failure, do
not retry" using -EREMOTEIO.  Update DM core to only disable WRITE SAME
on failure if the returned error is -EREMOTEIO.

Commit f84cb8a4 ("dm mpath: disable WRITE SAME if it fails")
implemented multipath specific disabling of WRITE SAME if it fails.
However, as that commit detailed, the multipath-only solution doesn't go
far enough if bio-based DM targets are stacked ontop of the
request-based dm-multipath target (as is commonly done using dm-linear
to support partitions on multipath devices, via kpartx).

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
Tested-by: Alex Chen <alex.chen@huawei.com>

Pull core locking updates from Ingo Molnar:
 "The main changes in this cycle were:

   - reduced/streamlined smp_mb__*() interface that allows more usecases
     and makes the existing ones less buggy, especially in rarer
     architectures

   - add rwsem implementation comments

   - bump up lockdep limits"

* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (33 commits)
  rwsem: Add comments to explain the meaning of the rwsem's count field
  lockdep: Increase static allocations
  arch: Mass conversion of smp_mb__*()
  arch,doc: Convert smp_mb__*()
  arch,xtensa: Convert smp_mb__*()
  arch,x86: Convert smp_mb__*()
  arch,tile: Convert smp_mb__*()
  arch,sparc: Convert smp_mb__*()
  arch,sh: Convert smp_mb__*()
  arch,score: Convert smp_mb__*()
  arch,s390: Convert smp_mb__*()
  arch,powerpc: Convert smp_mb__*()
  arch,parisc: Convert smp_mb__*()
  arch,openrisc: Convert smp_mb__*()
  arch,mn10300: Convert smp_mb__*()
  arch,mips: Convert smp_mb__*()
  arch,metag: Convert smp_mb__*()
  arch,m68k: Convert smp_mb__*()
  arch,m32r: Convert smp_mb__*()
  arch,ia64: Convert smp_mb__*()
  ...