This fixes the case when md array assembly fails because of raid cache recovery
unable to allocate a stripe, despite attempts to replay stripes and increase
cache size. This happens because stripes released by r5c_recovery_replay_stripes
and raid5_set_cache_size don't become available for allocation immediately.
Released stripes first are placed on conf->released_stripes list and require
md thread to merge them on conf->inactive_list before they can be allocated.

Patch allows final allocation attempt during cache recovery to wait for
new stripes to become availabe for allocation.

Cc: linux-raid@vger.kernel.org
Cc: Shaohua Li <shli@kernel.org>
Cc: linux-stable <stable@vger.kernel.org> # 4.10+
Fixes: b4c625c67362 ("md/r5cache: r5cache recovery: part 1")
Signed-off-by: Alexei Naberezhnov <anaberezhnov@fb.com>
Signed-off-by: Song Liu <songliubraving@fb.com>

Pull device mapper fixes from Mike Snitzer:

 - Fix DM crypt's parsing of extended IV arguments.

 - Fix DM thinp's discard passdown to properly account for extra
   reference that is taken to guard against reallocating a block before
   a discard has been issued.

 - Fix bio-based DM's redundant IO accounting that was occurring for
   bios that must be split due to the nature of the DM target (e.g.
   dm-stripe, dm-thinp, etc).

* tag 'for-5.0/dm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm: add missing trace_block_split() to __split_and_process_bio()
  dm: fix dm_wq_work() to only use __split_and_process_bio() if appropriate
  dm: fix redundant IO accounting for bios that need splitting
  dm: fix clone_bio() to trigger blk_recount_segments()
  dm thin: fix passdown_double_checking_shared_status()
  dm crypt: fix parsing of extended IV arguments

Provides useful context about bio splits in blktrace.

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

Otherwise targets that don't support/expect IO splitting could resubmit
bios using code paths with unnecessary IO splitting complexity.

Depends-on: 24113d487843 ("dm: avoid indirect call in __dm_make_request")
Fixes: 978e51ba38e00 ("dm: optimize bio-based NVMe IO submission")
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

The risk of redundant IO accounting was not taken into consideration
when commit 18a25da84354 ("dm: ensure bio submission follows a
depth-first tree walk") introduced IO splitting in terms of recursion
via generic_make_request().

Fix this by subtracting the split bio's payload from the IO stats that
were already accounted for by start_io_acct() upon dm_make_request()
entry.  This repeat oscillation of the IO accounting, up then down,
isn't ideal but refactoring DM core's IO splitting to pre-split bios
_before_ they are accounted turned out to be an excessive amount of
change that will need a full development cycle to refine and verify.

Before this fix:

  /dev/mapper/stripe_dev is a 4-way stripe using a 32k chunksize, so
  bios are split on 32k boundaries.

  # fio --name=16M --filename=/dev/mapper/stripe_dev --rw=write --bs=64k --size=16M \
    	--iodepth=1 --ioengine=libaio --direct=1 --refill_buffers

  with debugging added:
  [103898.310264] device-mapper: core: start_io_acct: dm-2 WRITE bio->bi_iter.bi_sector=0 len=128
  [103898.318704] device-mapper: core: __split_and_process_bio: recursing for following split bio:
  [103898.329136] device-mapper: core: start_io_acct: dm-2 WRITE bio->bi_iter.bi_sector=64 len=64
  ...

  16M written yet 136M (278528 * 512b) accounted:
  # cat /sys/block/dm-2/stat | awk '{ print $7 }'
  278528

After this fix:

  16M written and 16M (32768 * 512b) accounted:
  # cat /sys/block/dm-2/stat | awk '{ print $7 }'
  32768

Fixes: 18a25da84354 ("dm: ensure bio submission follows a depth-first tree walk")
Cc: stable@vger.kernel.org # 4.16+
Reported-by: Bryan Gurney <bgurney@redhat.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

DM's clone_bio() now benefits from using bio_trim() by fixing the fact
that clone_bio() wasn't clearing BIO_SEG_VALID like bio_trim() does;
which triggers blk_recount_segments() via bio_phys_segments().

Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

Commit 00a0ea33b495 ("dm thin: do not queue freed thin mapping for next
stage processing") changed process_prepared_discard_passdown_pt1() to
increment all the blocks being discarded until after the passdown had
completed to avoid them being prematurely reused.

IO issued to a thin device that breaks sharing with a snapshot, followed
by a discard issued to snapshot(s) that previously shared the block(s),
results in passdown_double_checking_shared_status() being called to
iterate through the blocks double checking their reference count is zero
and issuing the passdown if so.  So a side effect of commit 00a0ea33b495
is passdown_double_checking_shared_status() was broken.

Fix this by checking if the block reference count is greater than 1.
Also, rename dm_pool_block_is_used() to dm_pool_block_is_shared().

Fixes: 00a0ea33b495 ("dm thin: do not queue freed thin mapping for next stage processing")
Cc: stable@vger.kernel.org # 4.9+
Reported-by: ryan.p.norwood@gmail.com
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

bio_alloc_bioset returns a bio pointer or NULL, so we can avoid storing
the returned data into a new variable.

Acked-by: Guoqing Jiang <gqjiang@suse.com>
Acked-by: Artur Paszkiewicz <artur.paszkiewicz@intel.com>
Signed-off-by: Marcos Paulo de Souza <marcos.souza.org@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

The dm-crypt cipher specification in a mapping table is defined as:
  cipher[:keycount]-chainmode-ivmode[:ivopts]
or (new crypt API format):
  capi:cipher_api_spec-ivmode[:ivopts]

For ESSIV, the parameter includes hash specification, for example:
aes-cbc-essiv:sha256

The implementation expected that additional IV option to never include
another dash '-' character.

But, with SHA3, there are names like sha3-256; so the mapping table
parser fails:

dmsetup create test --table "0 8 crypt aes-cbc-essiv:sha3-256 9c1185a5c5e9fc54612808977ee8f5b9e 0 /dev/sdb 0"
  or (new crypt API format)
dmsetup create test --table "0 8 crypt capi:cbc(aes)-essiv:sha3-256 9c1185a5c5e9fc54612808977ee8f5b9e 0 /dev/sdb 0"

  device-mapper: crypt: Ignoring unexpected additional cipher options
  device-mapper: table: 253:0: crypt: Error creating IV
  device-mapper: ioctl: error adding target to table

Fix the dm-crypt constructor to ignore additional dash in IV options and
also remove a bogus warning (that is ignored anyway).

Cc: stable@vger.kernel.org # 4.12+
Signed-off-by: Milan Broz <gmazyland@gmail.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

Pull the pending 4.21 changes for md from Shaohua.

* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md:
  md: fix raid10 hang issue caused by barrier
  raid10: refactor common wait code from regular read/write request
  md: remvoe redundant condition check
  lib/raid6: add option to skip algo benchmarking
  lib/raid6: sort algos in rough performance order
  lib/raid6: check for assembler SSSE3 support
  lib/raid6: avoid __attribute_const__ redefinition
  lib/raid6: add missing include for raid6test
  md: remove set but not used variable 'bi_rdev'