linux.git/drivers/md, branch v3.12-rc4

Merge tag 'dm-3.12-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

2013-09-25T22:12:46+00:00

Pull device-mapper fixes from Mike Snitzer:
 "A few fixes for dm-snapshot, a 32 bit fix for dm-stats, a couple error
  handling fixes for dm-multipath.  A fix for the thin provisioning
  target to not expose non-zero discard limits if discards are disabled.

  Lastly, add two DM module parameters which allow users to tune the
  emergency memory reserves that DM mainatins per device -- this helps
  fix a long-standing issue for dm-multipath.  The conservative default
  reserve for request-based dm-multipath devices (256) has proven
  problematic for users with many multipathed SCSI devices but
  relatively little memory.  To responsibly select a smaller value users
  should use the new nr_bios tracepoint info (via commit 75afb352
  "block: Add nr_bios to block_rq_remap tracepoint") to determine the
  peak number of bios their workloads create"

* tag 'dm-3.12-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm: add reserved_bio_based_ios module parameter
  dm: add reserved_rq_based_ios module parameter
  dm: lower bio-based mempool reservation
  dm thin: do not expose non-zero discard limits if discards disabled
  dm mpath: disable WRITE SAME if it fails
  dm-snapshot: fix performance degradation due to small hash size
  dm snapshot: workaround for a false positive lockdep warning
  dm stats: fix possible counter corruption on 32-bit systems
  dm mpath: do not fail path on -ENOSPC

bcache: Fix flushes in writeback mode

2013-09-24T21:41:43+00:00

In writeback mode, when we get a cache flush we need to make sure we
issue a flush to the backing device.

The code for sending down an extra flush was wrong - by cloning the bio
we were probably getting flags that didn't make sense for a bare flush,
and also the old code was firing for FUA bios, for which we don't need
to send a flush to the backing device.

This was causing data corruption somehow - the mechanism was never
determined, but this patch fixes it for the users that were seeing it.

Signed-off-by: Kent Overstreet 
Cc: linux-stable  # >= v3.10
Signed-off-by: Linus Torvalds

bcache: Fix for handling overlapping extents when reading in a btree node

2013-09-24T21:41:43+00:00

btree_sort_fixup() was overly clever, because it was trying to avoid
pulling a key off the btree iterator in more than one place.

This led to a really obscure bug where we'd break early from the loop in
btree_sort_fixup() if the current key overlapped with keys in more than
one older set, and the next key it overlapped with was zero size.

Signed-off-by: Kent Overstreet 
Cc: linux-stable  # >= v3.10
Signed-off-by: Linus Torvalds

bcache: Fix a shrinker deadlock

2013-09-24T21:41:43+00:00

GFP_NOIO means we could be getting called recursively - mca_alloc() ->
mca_data_alloc() - definitely can't use mutex_lock(bucket_lock) then.
Whoops.

Signed-off-by: Kent Overstreet 
Cc: linux-stable  # >= v3.10
Signed-off-by: Linus Torvalds

bcache: Fix a dumb CPU spinning bug in writeback

2013-09-24T21:41:43+00:00

schedule_timeout() != schedule_timeout_uninterruptible()

Signed-off-by: Kent Overstreet 
Cc: linux-stable  # >= v3.10
Signed-off-by: Linus Torvalds

bcache: Fix a flush/fua performance bug

2013-09-24T21:41:43+00:00

bch_journal_meta() was missing the flush to make the journal write
actually go down (instead of waiting up to journal_delay_ms)...

Whoops

Signed-off-by: Kent Overstreet 
Cc: linux-stable  # >= v3.10
Signed-off-by: Linus Torvalds

bcache: Fix a writeback performance regression

2013-09-24T21:41:43+00:00

Background writeback works by scanning the btree for dirty data and
adding those keys into a fixed size buffer, then for each dirty key in
the keybuf writing it to the backing device.

When read_dirty() finishes and it's time to scan for more dirty data, we
need to wait for the outstanding writeback IO to finish - they still
take up slots in the keybuf (so that foreground writes can check for
them to avoid races) - without that wait, we'll continually rescan when
we'll be able to add at most a key or two to the keybuf, and that takes
locks that starves foreground IO.  Doh.

Signed-off-by: Kent Overstreet 
Cc: linux-stable  # >= v3.10
Signed-off-by: Linus Torvalds

bcache: Correct printf()-style format length modifier

2013-09-24T21:41:43+00:00

Fix

  drivers/md/bcache/btree.c: In function ‘bch_btree_node_read’:
  drivers/md/bcache/btree.c:259: warning: format ‘%lu’ expects type ‘long unsigned int’, but argument 3 has type ‘size_t’

Signed-off-by: Geert Uytterhoeven 
Signed-off-by: Kent Overstreet 
Signed-off-by: Linus Torvalds

bcache: Fix for when no journal entries are found

2013-09-24T21:41:43+00:00

The journal replay code didn't handle this case, causing it to go into
an infinite loop...

Signed-off-by: Kent Overstreet 
Cc: linux-stable  # >= v3.10
Signed-off-by: Linus Torvalds

bcache: Strip endline when writing the label through sysfs

2013-09-24T21:41:43+00:00

sysfs attributes with unusual characters have crappy failure modes
in Squeeze (udev 164); later versions of udev are unaffected.

This should make these characters more unusual.

Signed-off-by: Gabriel de Perthuis 
Signed-off-by: Kent Overstreet 
Cc: linux-stable  # >= v3.10
Signed-off-by: Linus Torvalds