linux-toradex.git/drivers/md, branch v3.14.57

md/raid5: fix locking in handle_stripe_clean_event()

2015-11-09T20:50:26+00:00

commit b8a9d66d043ffac116100775a469f05f5158c16f upstream.

After commit 566c09c53455 ("raid5: relieve lock contention in get_active_stripe()")
__find_stripe() is called under conf->hash_locks + hash.
But handle_stripe_clean_event() calls remove_hash() under
conf->device_lock.

Under some cirscumstances the hash chain can be circuited,
and we get an infinite loop with disabled interrupts and locked hash
lock in __find_stripe(). This leads to hard lockup on multiple CPUs
and following system crash.

I was able to reproduce this behavior on raid6 over 6 ssd disks.
The devices_handle_discard_safely option should be set to enable trim
support. The following script was used:

for i in `seq 1 32`; do
    dd if=/dev/zero of=large$i bs=10M count=100 &
done

neilb: original was against a 3.x kernel.  I forward-ported
  to 4.3-rc.  This verison is suitable for any kernel since
  Commit: 59fc630b8b5f ("RAID5: batch adjacent full stripe write")
  (v4.1+).  I'll post a version for earlier kernels to stable.

Signed-off-by: Roman Gushchin 
Fixes: 566c09c53455 ("raid5: relieve lock contention in get_active_stripe()")
Signed-off-by: NeilBrown 
Cc: Shaohua Li 
Cc:  # 3.13 - 4.2
Signed-off-by: Greg Kroah-Hartman

Revert "md: allow a partially recovered device to be hot-added to an array."

2015-11-09T20:50:26+00:00

commit d01552a76d71f9879af448e9142389ee9be6e95b upstream.

This reverts commit 7eb418851f3278de67126ea0c427641ab4792c57.

This commit is poorly justified, I can find not discusison in email,
and it clearly causes a problem.

If a device which is being recovered fails and is subsequently
re-added to an array, there could easily have been changes to the
array *before* the point where the recovery was up to.  So the
recovery must start again from the beginning.

If a spare is being recovered and fails, then when it is re-added we
really should do a bitmap-based recovery up to the recovery-offset,
and then a full recovery from there.  Before this reversion, we only
did the "full recovery from there" which is not corect.  After this
reversion with will do a full recovery from the start, which is safer
but not ideal.

It will be left to a future patch to arrange the two different styles
of recovery.

Reported-and-tested-by: Nate Dailey 
Signed-off-by: NeilBrown 
Fixes: 7eb418851f32 ("md: allow a partially recovered device to be hot-added to an array.")
Signed-off-by: Greg Kroah-Hartman

md/raid10: submit_bio_wait() returns 0 on success

2015-11-09T20:50:26+00:00

commit 681ab4696062f5aa939c9e04d058732306a97176 upstream.

This was introduced with 9e882242c6193ae6f416f2d8d8db0d9126bd996b
which changed the return value of submit_bio_wait() to return != 0 on
error, but didn't update the caller accordingly.

Fixes: 9e882242c6 ("block: Add submit_bio_wait(), remove from md")
Reported-by: Bill Kuzeja 
Signed-off-by: Jes Sorensen 
Signed-off-by: NeilBrown 
Signed-off-by: Greg Kroah-Hartman

md/raid1: submit_bio_wait() returns 0 on success

2015-11-09T20:50:26+00:00

commit 203d27b0226a05202438ddb39ef0ef1acb14a759 upstream.

This was introduced with 9e882242c6193ae6f416f2d8d8db0d9126bd996b
which changed the return value of submit_bio_wait() to return != 0 on
error, but didn't update the caller accordingly.

Fixes: 9e882242c6 ("block: Add submit_bio_wait(), remove from md")
Reported-by: Bill Kuzeja 
Signed-off-by: Jes Sorensen 
Signed-off-by: NeilBrown 
Signed-off-by: Greg Kroah-Hartman

dm btree: fix leak of bufio-backed block in btree_split_beneath error path

2015-11-09T20:50:25+00:00

commit 4dcb8b57df3593dcb20481d9d6cf79d1dc1534be upstream.

btree_split_beneath()'s error path had an outstanding FIXME that speaks
directly to the potential for _not_ cleaning up a previously allocated
bufio-backed block.

Fix this by releasing the previously allocated bufio block using
unlock_block().

Reported-by: Mikulas Patocka 
Signed-off-by: Mike Snitzer 
Acked-by: Joe Thornber 
Signed-off-by: Greg Kroah-Hartman

dm btree remove: fix a bug when rebalancing nodes after removal

2015-11-09T20:50:25+00:00

commit 2871c69e025e8bc507651d5a9cf81a8a7da9d24b upstream.

Commit 4c7e309340ff ("dm btree remove: fix bug in redistribute3") wasn't
a complete fix for redistribute3().

The redistribute3 function takes 3 btree nodes and shares out the entries
evenly between them.  If the three nodes in total contained
(MAX_ENTRIES * 3) - 1 entries between them then this was erroneously getting
rebalanced as (MAX_ENTRIES - 1) on the left and right, and (MAX_ENTRIES + 1) in
the center.

Fix this issue by being more careful about calculating the target number
of entries for the left and right nodes.

Unit tested in userspace using this program:
https://github.com/jthornber/redistribute3-test/blob/master/redistribute3_t.c

Signed-off-by: Joe Thornber 
Signed-off-by: Mike Snitzer 
Signed-off-by: Greg Kroah-Hartman

dm thin: fix missing pool reference count decrement in pool_ctr error path

2015-10-27T00:45:59+00:00

commit ba30670f4d5292c4e7f7980bbd5071f7c4794cdd upstream.

Fixes: ac8c3f3df ("dm thin: generate event when metadata threshold passed")
Signed-off-by: Mike Snitzer 
Signed-off-by: Greg Kroah-Hartman

dm cache: fix NULL pointer when switching from cleaner policy

2015-10-22T21:39:22+00:00

commit 2bffa1503c5c06192eb1459180fac4416575a966 upstream.

The cleaner policy doesn't make use of the per cache block hint space in
the metadata (unlike the other policies).  When switching from the
cleaner policy to mq or smq a NULL pointer crash (in dm_tm_new_block)
was observed.  The crash was caused by bugs in dm-cache-metadata.c
when trying to skip creation of the hint btree.

The minimal fix is to change hint size for the cleaner policy to 4 bytes
(only hint size supported).

Signed-off-by: Joe Thornber 
Signed-off-by: Mike Snitzer 
Signed-off-by: Greg Kroah-Hartman

md: flush ->event_work before stopping array.

2015-10-22T21:39:21+00:00

commit ee5d004fd0591536a061451eba2b187092e9127c upstream.

The 'event_work' worker used by dm-raid may still be running
when the array is stopped.  This can result in an oops.

So flush the workqueue on which it is run after detaching
and before destroying the device.

Reported-by: Heinz Mauelshagen 
Signed-off-by: NeilBrown 
Fixes: 9d09e663d550 ("dm: raid456 basic support")
Signed-off-by: Greg Kroah-Hartman

dm raid: fix round up of default region size

2015-10-22T21:39:19+00:00

commit 042745ee53a0a7c1f5aff191a4a24213c6dcfb52 upstream.

Commit 3a0f9aaee028 ("dm raid: round region_size to power of two")
intended to make sure that the default region size is a power of two.
However, the logic in that commit is incorrect and sets the variable
region_size to 0 or 1, depending on whether min_region_size is a power
of two.

Fix this logic, using roundup_pow_of_two(), so that region_size is
properly rounded up to the next power of two.

Signed-off-by: Mikulas Patocka 
Fixes: 3a0f9aaee028 ("dm raid: round region_size to power of two")
Signed-off-by: Mike Snitzer 
Signed-off-by: Greg Kroah-Hartman