linux-stable.git/drivers/md, branch v3.18.41

dm flakey: fix reads to be issued if drop_writes configured

2016-09-01T02:05:44+00:00

[ Upstream commit 299f6230bc6d0ccd5f95bb0fb865d80a9c7d5ccc ]

v4.8-rc3 commit 99f3c90d0d ("dm flakey: error READ bios during the
down_interval") overlooked the 'drop_writes' feature, which is meant to
allow reads to be issued rather than errored, during the down_interval.

Fixes: 99f3c90d0d ("dm flakey: error READ bios during the down_interval")
Reported-by: Qu Wenruo 
Signed-off-by: Mike Snitzer 
Cc: stable@vger.kernel.org
Signed-off-by: Sasha Levin

bcache: RESERVE_PRIO is too small by one when prio_buckets() is a power of two.

2016-09-01T02:05:44+00:00

[ Upstream commit acc9cf8c66c66b2cbbdb4a375537edee72be64df ]

This patch fixes a cachedev registration-time allocation deadlock.
This can deadlock on boot if your initrd auto-registeres bcache devices:

Allocator thread:
[  720.727614] INFO: task bcache_allocato:3833 blocked for more than 120 seconds.
[  720.732361]  [] schedule+0x37/0x90
[  720.732963]  [] bch_bucket_alloc+0x188/0x360 [bcache]
[  720.733538]  [] ? prepare_to_wait_event+0xf0/0xf0
[  720.734137]  [] bch_prio_write+0x19d/0x340 [bcache]
[  720.734715]  [] bch_allocator_thread+0x3ff/0x470 [bcache]
[  720.735311]  [] ? __schedule+0x2dc/0x950
[  720.735884]  [] ? invalidate_buckets+0x980/0x980 [bcache]

Registration thread:
[  720.710403] INFO: task bash:3531 blocked for more than 120 seconds.
[  720.715226]  [] schedule+0x37/0x90
[  720.715805]  [] __bch_btree_map_nodes+0x12d/0x150 [bcache]
[  720.716409]  [] ? bch_btree_insert_check_key+0x1c0/0x1c0 [bcache]
[  720.717008]  [] bch_btree_insert+0xf4/0x170 [bcache]
[  720.717586]  [] ? prepare_to_wait_event+0xf0/0xf0
[  720.718191]  [] bch_journal_replay+0x14a/0x290 [bcache]
[  720.718766]  [] ? ttwu_do_activate.constprop.94+0x5d/0x70
[  720.719369]  [] ? try_to_wake_up+0x1d4/0x350
[  720.719968]  [] run_cache_set+0x580/0x8e0 [bcache]
[  720.720553]  [] register_bcache+0xe2e/0x13b0 [bcache]
[  720.721153]  [] kobj_attr_store+0xf/0x20
[  720.721730]  [] sysfs_kf_write+0x3d/0x50
[  720.722327]  [] kernfs_fop_write+0x12a/0x180
[  720.722904]  [] __vfs_write+0x37/0x110
[  720.723503]  [] ? __sb_start_write+0x58/0x110
[  720.724100]  [] ? security_file_permission+0x23/0xa0
[  720.724675]  [] vfs_write+0xa9/0x1b0
[  720.725275]  [] ? do_audit_syscall_entry+0x6c/0x70
[  720.725849]  [] SyS_write+0x55/0xd0
[  720.726451]  [] ? do_page_fault+0x30/0x80
[  720.727045]  [] system_call_fastpath+0x12/0x71

The fifo code in upstream bcache can't use the last element in the buffer,
which was the cause of the bug: if you asked for a power of two size,
it'd give you a fifo that could hold one less than what you asked for
rather than allocating a buffer twice as big.

Signed-off-by: Kent Overstreet 
Tested-by: Eric Wheeler 
Cc: stable@vger.kernel.org
Signed-off-by: Sasha Levin

bcache: register_bcache(): call blkdev_put() when cache_alloc() fails

2016-09-01T02:05:44+00:00

[ Upstream commit d9dc1702b297ec4a6bb9c0326a70641b322ba886 ]

register_cache() is supposed to return an error string on error so that
register_bcache() will will blkdev_put and cleanup other user counters,
but it does not set 'char *err' when cache_alloc() fails (eg, due to
memory pressure) and thus register_bcache() performs no cleanup.

register_bcache() <----------\  <- no jump to err_close, no blkdev_put()
   |                         |
   +->register_cache()       |  <- fails to set char *err
         |                   |
         +->cache_alloc() ---/  <- returns error

This patch sets `char *err` for this failure case so that register_cache()
will cause register_bcache() to correctly jump to err_close and do
cleanup.  This was tested under OOM conditions that triggered the bug.

Signed-off-by: Eric Wheeler 
Cc: Kent Overstreet 
Cc: stable@vger.kernel.org
Signed-off-by: Sasha Levin

dm flakey: error READ bios during the down_interval

2016-08-22T16:23:27+00:00

[ Upstream commit 99f3c90d0d85708e7401a81ce3314e50bf7f2819 ]

When the corrupt_bio_byte feature was introduced it caused READ bios to
no longer be errored with -EIO during the down_interval.  This had to do
with the complexity of needing to submit READs if the corrupt_bio_byte
feature was used.

Fix it so READ bios are properly errored with -EIO; doing so early in
flakey_map() as long as there isn't a match for the corrupt_bio_byte
feature.

Fixes: a3998799fb4df ("dm flakey: add corrupt_bio_byte feature")
Reported-by: Akira Hayakawa 
Signed-off-by: Mike Snitzer 
Cc: stable@vger.kernel.org
Signed-off-by: Sasha Levin

MD: make bio mergeable

2016-05-17T18:32:05+00:00

[ Upstream commit 9c573de3283af007ea11c17bde1e4568d9417328 ]

blk_queue_split marks bio unmergeable, which makes sense for normal bio.
But if dispatching the bio to underlayer disk, the blk_queue_split
checks are invalid, hence it's possible the bio becomes mergeable.

In the reported bug, this bug causes trim against raid0 performance slash
https://bugzilla.kernel.org/show_bug.cgi?id=117051

Reported-and-tested-by: Park Ju Hyung 
Fixes: 6ac45aeb6bca(block: avoid to merge splitted bio)
Cc: stable@vger.kernel.org (v4.3+)
Cc: Ming Lei 
Cc: Neil Brown 
Reviewed-by: Jens Axboe 
Signed-off-by: Shaohua Li 
Signed-off-by: Sasha Levin

md: multipath: don't hardcopy bio in .make_request path

2016-04-18T12:49:31+00:00

[ Upstream commit fafcde3ac1a418688a734365203a12483b83907a ]

Inside multipath_make_request(), multipath maps the incoming
bio into low level device's bio, but it is totally wrong to
copy the bio into mapped bio via '*mapped_bio = *bio'. For
example, .__bi_remaining is kept in the copy, especially if
the incoming bio is chained to via bio splitting, so .bi_end_io
can't be called for the mapped bio at all in the completing path
in this kind of situation.

This patch fixes the issue by using clone style.

Cc: stable@vger.kernel.org (v3.14+)
Reported-and-tested-by: Andrea Righi 
Signed-off-by: Ming Lei 
Signed-off-by: Shaohua Li 
Signed-off-by: Sasha Levin

bcache: fix cache_set_flush() NULL pointer dereference on OOM

2016-04-18T12:49:25+00:00

[ Upstream commit f8b11260a445169989d01df75d35af0f56178f95 ]

When bch_cache_set_alloc() fails to kzalloc the cache_set, the
asyncronous closure handling tries to dereference a cache_set that
hadn't yet been allocated inside of cache_set_flush() which is called
by __cache_set_unregister() during cleanup.  This appears to happen only
during an OOM condition on bcache_register.

Signed-off-by: Eric Wheeler 
Cc: stable@vger.kernel.org
Signed-off-by: Sasha Levin

bcache: cleaned up error handling around register_cache()

2016-04-18T12:49:25+00:00

[ Upstream commit 9b299728ed777428b3908ac72ace5f8f84b97789 ]

Fix null pointer dereference by changing register_cache() to return an int
instead of being void.  This allows it to return -ENOMEM or -ENODEV and
enables upper layers to handle the OOM case without NULL pointer issues.

See this thread:
  http://thread.gmane.org/gmane.linux.kernel.bcache.devel/3521

Fixes this error:
  gargamel:/sys/block/md5/bcache# echo /dev/sdh2 > /sys/fs/bcache/register

  bcache: register_cache() error opening sdh2: cannot allocate memory
  BUG: unable to handle kernel NULL pointer dereference at 00000000000009b8
  IP: [] cache_set_flush+0x102/0x15c [bcache]
  PGD 120dff067 PUD 1119a3067 PMD 0
  Oops: 0000 [#1] SMP
  Modules linked in: veth ip6table_filter ip6_tables
  (...)
  CPU: 4 PID: 3371 Comm: kworker/4:3 Not tainted 4.4.2-amd64-i915-volpreempt-20160213bc1 #3
  Hardware name: System manufacturer System Product Name/P8H67-M PRO, BIOS 3904 04/27/2013
  Workqueue: events cache_set_flush [bcache]
  task: ffff88020d5dc280 ti: ffff88020b6f8000 task.ti: ffff88020b6f8000
  RIP: 0010:[]  [] cache_set_flush+0x102/0x15c [bcache]

Signed-off-by: Eric Wheeler 
Tested-by: Marc MERLIN 
Cc: 
Signed-off-by: Sasha Levin

bcache: fix race of writeback thread starting before complete initialization

2016-04-18T12:49:25+00:00

[ Upstream commit 07cc6ef8edc47f8b4fc1e276d31127a0a5863d4d ]

The bch_writeback_thread might BUG_ON in read_dirty() if
dc->sb==BDEV_STATE_DIRTY and bch_sectors_dirty_init has not yet completed
its related initialization.  This patch downs the dc->writeback_lock until
after initialization is complete, thus preventing bch_writeback_thread
from proceeding prematurely.

See this thread:
  http://thread.gmane.org/gmane.linux.kernel.bcache.devel/3453

Signed-off-by: Eric Wheeler 
Tested-by: Marc MERLIN 
Cc: 
Signed-off-by: Jens Axboe 
Signed-off-by: Sasha Levin

md/raid5: Compare apples to apples (or sectors to sectors)

2016-04-18T12:49:19+00:00

[ Upstream commit e7597e69dec59b65c5525db1626b9d34afdfa678 ]

'max_discard_sectors' is in sectors, while 'stripe' is in bytes.

This fixes the problem where DISCARD would get disabled on some larger
RAID5 configurations (6 or more drives in my testing), while it worked
as expected with smaller configurations.

Fixes: 620125f2bf8 ("MD: raid5 trim support")
Cc: stable@vger.kernel.org v3.7+
Signed-off-by: Jes Sorensen 
Signed-off-by: Shaohua Li 
Signed-off-by: Sasha Levin