Pull device mapper fixes from Mike Snitzer:

 - a stable fix in both DM crypt and DM log-writes for too large bios
   (as generated by bcache)

 - two other stable fixes for DM log-writes

 - a stable fix for a DM crypt bug that could result in freeing pointers
   from uninitialized memory in the tfm allocation error path

 - a DM bufio cleanup to discontinue using create_singlethread_workqueue()

* tag 'dm-4.8-fixes-4' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm bufio: remove use of deprecated create_singlethread_workqueue()
  dm crypt: fix free of bad values after tfm allocation failure
  dm crypt: fix error with too large bios
  dm log writes: fix check of kthread_run() return value
  dm log writes: fix bug with too large bios
  dm log writes: move IO accounting earlier to fix error path

The workqueue "dm_bufio_wq" queues a single work item &dm_bufio_work so
it doesn't require execution ordering.  Hence, alloc_workqueue() has
been used to replace the deprecated create_singlethread_workqueue().

The WQ_MEM_RECLAIM flag has been set since DM requires forward progress
under memory pressure.

Since there are fixed number of work items, explicit concurrency
limit is unnecessary here.

Signed-off-by: Bhaktipriya Shridhar <bhaktipriya96@gmail.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

If crypt_alloc_tfms() had to allocate multiple tfms and it failed before
the last allocation, then it would call crypt_free_tfms() and could free
pointers from uninitialized memory -- due to the crypt_free_tfms() check
for non-zero cc->tfms[i].  Fix by allocating zeroed memory.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org

When dm-crypt processes writes, it allocates a new bio in
crypt_alloc_buffer().  The bio is allocated from a bio set and it can
have at most BIO_MAX_PAGES vector entries, however the incoming bio can be
larger (e.g. if it was allocated by bcache).  If the incoming bio is
larger, bio_alloc_bioset() fails and an error is returned.

To avoid the error, we test for a too large bio in the function
crypt_map() and use dm_accept_partial_bio() to split the bio.
dm_accept_partial_bio() trims the current bio to the desired size and
asks DM core to send another bio with the rest of the data.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # v3.16+

The kthread_run() function returns either a valid task_struct or
ERR_PTR() value, check for NULL is invalid.  This change fixes potential
for oops, e.g. in OOM situation.

Signed-off-by: Vladimir Zapolskiy <vz@mleia.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org

bio_alloc() can allocate a bio with at most BIO_MAX_PAGES (256) vector
entries.  However, the incoming bio may have more vector entries if it
was allocated by other means.  For example, bcache submits bios with
more than BIO_MAX_PAGES entries.  This results in bio_alloc() failure.

To avoid the failure, change the code so that it allocates bio with at
most BIO_MAX_PAGES entries.  If the incoming bio has more entries,
bio_add_page() will fail and a new bio will be allocated - the code that
handles bio_add_page() failure already exists in the dm-log-writes
target.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Reviewed-by: Josef Bacik <jbacik@fb,com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # v4.1+

Move log_one_block()'s atomic_inc(&lc->io_blocks) before bio_alloc() to
fix a bug that the target hangs if bio_alloc() fails.  The error path
does put_io_block(lc), so atomic_inc(&lc->io_blocks) must occur before
invoking the error path to avoid underflow of lc->io_blocks.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Reviewed-by: Josef Bacik <jbacik@fb,com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org

Pull MD fixes from Shaohua Li:
 "This includes several bug fixes:

   - Alexey Obitotskiy fixed a hang for faulty raid5 array with external
     management

   - Song Liu fixed two raid5 journal related bugs

   - Tomasz Majchrzak fixed a bad block recording issue and an
     accounting issue for raid10

   - ZhengYuan Liu fixed an accounting issue for raid5

   - I fixed a potential race condition and memory leak with DIF/DIX
     enabled

   - other trival fixes"

* tag 'md/4.8-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md:
  raid5: avoid unnecessary bio data set
  raid5: fix memory leak of bio integrity data
  raid10: record correct address of bad block
  md-cluster: fix error return code in join()
  r5cache: set MD_JOURNAL_CLEAN correctly
  md: don't print the same repeated messages about delayed sync operation
  md: remove obsolete ret in md_start_sync
  md: do not count journal as spare in GET_ARRAY_INFO
  md: Prevent IO hold during accessing to faulty raid5 array
  MD: hold mddev lock to change bitmap location
  raid5: fix incorrectly counter of conf->empty_inactive_list_nr
  raid10: increment write counter after bio is split

Pull device mapper fixes from Mike Snitzer:

 - another stable fix for DM flakey (that tweaks the previous fix that
   didn't factor in expected 'drop_writes' behavior for read IO).

 - a dm-log bio operation flags fix for the broader block changes that
   were merged during the 4.8 merge window.

* tag 'dm-4.8-fixes-3' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm log: fix unitialized bio operation flags
  dm flakey: fix reads to be issued if drop_writes configured

Pull block fixes from Jens Axboe:
 "Here's a set of block fixes for the current 4.8-rc release.  This
  contains:

   - a fix for a secure erase regression, from Adrian.

   - a fix for an mmc use-after-free bug regression, also from Adrian.

   - potential zero pointer deference in bdev freezing, from Andrey.

   - a race fix for blk_set_queue_dying() from Bart.

   - a set of xen blkfront fixes from Bob Liu.

   - three small fixes for bcache, from Eric and Kent.

   - a fix for a potential invalid NVMe state transition, from Gabriel.

   - blk-mq CPU offline fix, preventing us from issuing and completing a
     request on the wrong queue.  From me.

   - revert two previous floppy changes, since they caused a user
     visibile regression.  A better fix is in the works.

   - ensure that we don't send down bios that have more than 256
     elements in them.  Fixes a crash with bcache, for example.  From
     Ming.

   - a fix for deferencing an error pointer with cgroup writeback.
     Fixes a regression.  From Vegard"

* 'for-linus' of git://git.kernel.dk/linux-block:
  mmc: fix use-after-free of struct request
  Revert "floppy: refactor open() flags handling"
  Revert "floppy: fix open(O_ACCMODE) for ioctl-only open"
  fs/block_dev: fix potential NULL ptr deref in freeze_bdev()
  blk-mq: improve warning for running a queue on the wrong CPU
  blk-mq: don't overwrite rq->mq_ctx
  block: make sure a big bio is split into at most 256 bvecs
  nvme: Fix nvme_get/set_features() with a NULL result pointer
  bdev: fix NULL pointer dereference
  xen-blkfront: free resources if xlvbd_alloc_gendisk fails
  xen-blkfront: introduce blkif_set_queue_limits()
  xen-blkfront: fix places not updated after introducing 64KB page granularity
  bcache: pr_err: more meaningful error message when nr_stripes is invalid
  bcache: RESERVE_PRIO is too small by one when prio_buckets() is a power of two.
  bcache: register_bcache(): call blkdev_put() when cache_alloc() fails
  block: Fix race triggered by blk_set_queue_dying()
  block: Fix secure erase
  nvme: Prevent controller state invalid transition