Pull more block layer changes from Jens Axboe:
 "This is a collection of both stragglers, and fixes that came in after
  I finalized the initial pull. This contains:

   - An MD pull request from Song, with a few minor fixes

   - Set of NVMe patches via Christoph

   - Pull request from Konrad, with a few fixes for xen/blkback

   - pblk fix IO calculation fix (Javier)

   - Segment calculation fix for pass-through (Ming)

   - Fallthrough annotation for blkcg (Mathieu)"

* tag 'for-5.1/block-post-20190315' of git://git.kernel.dk/linux-block: (25 commits)
  blkcg: annotate implicit fall through
  nvme-tcp: support C2HData with SUCCESS flag
  nvmet: ignore EOPNOTSUPP for discard
  nvme: add proper write zeroes setup for the multipath device
  nvme: add proper discard setup for the multipath device
  nvme: remove nvme_ns_config_oncs
  nvme: disable Write Zeroes for qemu controllers
  nvmet-fc: bring Disconnect into compliance with FC-NVME spec
  nvmet-fc: fix issues with targetport assoc_list list walking
  nvme-fc: reject reconnect if io queue count is reduced to zero
  nvme-fc: fix numa_node when dev is null
  nvme-fc: use nr_phys_segments to determine existence of sgl
  nvme-loop: init nvmet_ctrl fatal_err_work when allocate
  nvme: update comment to make the code easier to read
  nvme: put ns_head ref if namespace fails allocation
  nvme-trace: fix cdw10 buffer overrun
  nvme: don't warn on block content change effects
  nvme: add get-feature to admin cmds tracer
  md: Fix failed allocation of md_register_thread
  It's wrong to add len to sector_nr in raid10 reshape twice
  ...

mddev->sync_thread can be set to NULL on kzalloc failure downstream.
The patch checks for such a scenario and frees allocated resources.

Committer node:

Added similar fix to raid5.c, as suggested by Guoqing.

Cc: stable@vger.kernel.org # v3.16+
Acked-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Aditya Pakki <pakki001@umn.edu>
Signed-off-by: Song Liu <songliubraving@fb.com>

In reshape_request it already adds len to sector_nr already. It's wrong to add len to
sector_nr again after adding pages to bio. If there is bad block it can't copy one chunk
at a time, it needs to goto read_more. Now the sector_nr is wrong. It can cause data
corruption.

Cc: stable@vger.kernel.org # v3.16+
Signed-off-by: Xiao Ni <xni@redhat.com>
Signed-off-by: Song Liu <songliubraving@fb.com>

When the Partial Parity Log is enabled, circular buffer is used to store
PPL data. Each write to RAID device causes overwrite of data in this buffer
so some write_hint can be set to those request to help drives handle
garbage collection. This patch adds new sysfs attribute which can be used
to specify which write_hint should be assigned to PPL.

Acked-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Mariusz Dabrowski <mariusz.dabrowski@intel.com>
Signed-off-by: Song Liu <songliubraving@fb.com>

The code really just wants a big flat buffer, so just do that.

Link: http://lkml.kernel.org/r/20181217131929.11727-3-kent.overstreet@gmail.com
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Reviewed-by: Matthew Wilcox <willy@infradead.org>
Cc: Shaohua Li <shli@kernel.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Eric Paris <eparis@parisplace.org>
Cc: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Pravin B Shelar <pshelar@ovn.org>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: Vlad Yasevich <vyasevich@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull device mapper updates from Mike Snitzer:

 - Update bio-based DM core to always call blk_queue_split() and update
   DM targets to properly advertise discard limits that
   blk_queue_split() looks at when dtermining to split discard. Whereby
   allowing DM core's own 'split_discard_bios' to be removed.

 - Improve DM cache target to provide support for discard passdown to
   the origin device.

 - Introduce support to directly boot to a DM mapped device from init by
   using dm-mod.create= module param. This eliminates the need for an
   elaborate initramfs that is otherwise needed to create DM devices.

   This feature's implementation has been worked on for quite some time
   (got up to v12) and is of particular interest to Android and other
   more embedded platforms (e.g. ARM).

 - Rate limit errors from the DM integrity target that were identified
   as the cause for recent NMI hangs due to console limitations.

 - Add sanity checks for user input to thin-pool and external snapshot
   creation.

 - Remove some unused leftover kmem caches from when old .request_fn
   request-based support was removed.

 - Various small cleanups and fixes to targets (e.g. typos, needless
   unlikely() annotations, use struct_size(), remove needless
   .direct_access method from dm-snapshot)

* tag 'for-5.1/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm integrity: limit the rate of error messages
  dm snapshot: don't define direct_access if we don't support it
  dm cache: add support for discard passdown to the origin device
  dm writecache: fix typo in name for writeback_wq
  dm: add support to directly boot to a mapped device
  dm thin: add sanity checks to thin-pool and external snapshot creation
  dm block manager: remove redundant unlikely annotation
  dm verity fec: remove redundant unlikely annotation
  dm integrity: remove redundant unlikely annotation
  dm: always call blk_queue_split() in dm_process_bio()
  dm: fix to_sector() for 32bit
  dm switch: use struct_size() in kzalloc()
  dm: remove unused _rq_tio_cache and _rq_cache
  dm: eliminate 'split_discard_bios' flag from DM target interface
  dm: update dm_process_bio() to split bio if in ->make_request_fn()

Pull block layer updates from Jens Axboe:
 "Not a huge amount of changes in this round, the biggest one is that we
  finally have Mings multi-page bvec support merged. Apart from that,
  this pull request contains:

   - Small series that avoids quiescing the queue for sysfs changes that
     match what we currently have (Aleksei)

   - Series of bcache fixes (via Coly)

   - Series of lightnvm fixes (via Mathias)

   - NVMe pull request from Christoph. Nothing major, just SPDX/license
     cleanups, RR mp policy (Hannes), and little fixes (Bart,
     Chaitanya).

   - BFQ series (Paolo)

   - Save blk-mq cpu -> hw queue mapping, removing a pointer indirection
     for the fast path (Jianchao)

   - fops->iopoll() added for async IO polling, this is a feature that
     the upcoming io_uring interface will use (Christoph, me)

   - Partition scan loop fixes (Dongli)

   - mtip32xx conversion from managed resource API (Christoph)

   - cdrom registration race fix (Guenter)

   - MD pull from Song, two minor fixes.

   - Various documentation fixes (Marcos)

   - Multi-page bvec feature. This brings a lot of nice improvements
     with it, like more efficient splitting, larger IOs can be supported
     without growing the bvec table size, and so on. (Ming)

   - Various little fixes to core and drivers"

* tag 'for-5.1/block-20190302' of git://git.kernel.dk/linux-block: (117 commits)
  block: fix updating bio's front segment size
  block: Replace function name in string with __func__
  nbd: propagate genlmsg_reply return code
  floppy: remove set but not used variable 'q'
  null_blk: fix checking for REQ_FUA
  block: fix NULL pointer dereference in register_disk
  fs: fix guard_bio_eod to check for real EOD errors
  blk-mq: use HCTX_TYPE_DEFAULT but not 0 to index blk_mq_tag_set->map
  block: optimize bvec iteration in bvec_iter_advance
  block: introduce mp_bvec_for_each_page() for iterating over page
  block: optimize blk_bio_segment_split for single-page bvec
  block: optimize __blk_segment_map_sg() for single-page bvec
  block: introduce bvec_nth_page()
  iomap: wire up the iopoll method
  block: add bio_set_polled() helper
  block: wire up block device iopoll method
  fs: add an iopoll method to struct file_operations
  loop: set GENHD_FL_NO_PART_SCAN after blkdev_reread_part()
  loop: do not print warn message if partition scan is successful
  block: bounce: make sure that bvec table is updated
  ...

When using dm-integrity underneath md-raid, some tests with raid
auto-correction trigger large amounts of integrity failures - and all
these failures print an error message. These messages can bring the
system to a halt if the system is using serial console.

Fix this by limiting the rate of error messages - it improves the speed
of raid recovery and avoids the hang.

Fixes: 7eada909bfd7a ("dm: add integrity target")
Cc: stable@vger.kernel.org # v4.12+
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

Don't define a direct_access function that fails, dm_dax_direct_access
already fails with -EIO if the pointer is zero;

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

DM cache now defaults to passing discards down to the origin device.
User may disable this using the "no_discard_passdown" feature when
creating the cache device.

If the cache's underlying origin device doesn't support discards then
passdown is disabled (with warning).  Similarly, if the underlying
origin device's max_discard_sectors is less than a cache block discard
passdown will be disabled (this is required because sizing of the cache
internal discard bitset depends on it).

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