linux-stable.git/drivers/md/dm-thin.c, branch linux-3.12.y

dm thin: fix race condition when destroying thin pool workqueue

2016-02-12T07:58:10+00:00

commit 18d03e8c25f173f4107a40d0b8c24defb6ed69f3 upstream.

When a thin pool is being destroyed delayed work items are
cancelled using cancel_delayed_work(), which doesn't guarantee that on
return the delayed item isn't running.  This can cause the work item to
requeue itself on an already destroyed workqueue.  Fix this by using
cancel_delayed_work_sync() which guarantees that on return the work item
is not running anymore.

Fixes: 905e51b39a555 ("dm thin: commit outstanding data every second")
Fixes: 85ad643b7e7e5 ("dm thin: add timeout to stop out-of-data-space mode holding IO forever")
Signed-off-by: Nikolay Borisov 
Signed-off-by: Mike Snitzer 
Cc: Nikolay Borisov 
Signed-off-by: Jiri Slaby

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

2015-10-28T15:38:24+00:00

commit ba30670f4d5292c4e7f7980bbd5071f7c4794cdd upstream.

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

dm thin: don't allow messages to be sent to a pool target in READ_ONLY or FAIL mode

2015-02-08T19:02:01+00:00

commit 2a7eaea02b99b6e267b1e89c79acc6e9a51cee3b upstream.

You can't modify the metadata in these modes.  It's better to fail these
messages immediately than let the block-manager deny write locks on
metadata blocks.  Otherwise these failed metadata changes will trigger
'needs_check' to get set in the metadata superblock -- requiring repair
using the thin_check utility.

Signed-off-by: Joe Thornber 
Signed-off-by: Mike Snitzer 
Signed-off-by: Jiri Slaby

dm thin: grab a virtual cell before looking up the mapping

2014-11-19T17:38:20+00:00

commit c822ed967cba38505713d59ed40a114386ef6c01 upstream.

Avoids normal IO racing with discard.

Signed-off-by: Joe Thornber 
Signed-off-by: Mike Snitzer 
Signed-off-by: Jiri Slaby

dm thin: update discard_granularity to reflect the thin-pool blocksize

2014-07-17T13:04:38+00:00

commit 09869de57ed2728ae3c619803932a86cb0e2c4f8 upstream.

DM thinp already checks whether the discard_granularity of the data
device is a factor of the thin-pool block size.  But when using the
dm-thin-pool's discard passdown support, DM thinp was not selecting the
max of the underlying data device's discard_granularity and the
thin-pool's block size.

Update set_discard_limits() to set discard_granularity to the max of
these values.  This enables blkdev_issue_discard() to properly align the
discards that are sent to the DM thin device on a full block boundary.
As such each discard will now cover an entire DM thin-pool block and the
block will be reclaimed.

Reported-by: Zdenek Kabelac 
Signed-off-by: Lukas Czerner 
Signed-off-by: Mike Snitzer 
Signed-off-by: Jiri Slaby

dm thin: fix dangling bio in process_deferred_bios error path

2014-05-15T07:56:14+00:00

commit fe76cd88e654124d1431bb662a0fc6e99ca811a5 upstream.

If unable to ensure_next_mapping() we must add the current bio, which
was removed from the @bios list via bio_list_pop, back to the
deferred_bios list before all the remaining @bios.

Signed-off-by: Mike Snitzer 
Acked-by: Joe Thornber 
Signed-off-by: Jiri Slaby

dm thin: fix the error path for the thin device constructor

2014-03-05T16:13:55+00:00

commit 1acacc0784aab45627b6009e0e9224886279ac0b upstream.

dm_pool_close_thin_device() must be called if dm_set_target_max_io_len()
fails in thin_ctr().  Otherwise __pool_destroy() will fail because the
pool will still have an open thin device:

 device-mapper: thin metadata: attempt to close pmd when 1 device(s) are still open
 device-mapper: thin: __pool_destroy: dm_pool_metadata_close() failed.

Also, must establish error code if failing thin_ctr() because the pool
is in fail_io mode.

Signed-off-by: Mike Snitzer 
Acked-by: Joe Thornber 
Signed-off-by: Jiri Slaby

dm thin: avoid metadata commit if a pool's thin devices haven't changed

2014-03-05T16:13:55+00:00

commit 4d1662a30dde6e545086fe0e8fd7e474c4e0b639 upstream.

Commit 905e51b ("dm thin: commit outstanding data every second")
introduced a periodic commit.  This commit occurs regardless of whether
any thin devices have made changes.

Fix the periodic commit to check if any of a pool's thin devices have
changed using dm_pool_changed_this_transaction().

Reported-by: Alexander Larsson 
Signed-off-by: Mike Snitzer 
Acked-by: Joe Thornber 
Signed-off-by: Jiri Slaby

dm thin: fix set_pool_mode exposed pool operation races

2014-02-13T21:50:17+00:00

commit 8b64e881eb40ac8b9bfcbce068a97eef819044ee upstream.

The pool mode must not be switched until after the corresponding pool
process_* methods have been established.  Otherwise, because
set_pool_mode() isn't interlocked with the IO path for performance
reasons, the IO path can end up executing process_* operations that
don't match the mode.  This patch eliminates problems like the following
(as seen on really fast PCIe SSD storage when transitioning the pool's
mode from PM_READ_ONLY to PM_WRITE):

kernel: device-mapper: thin: 253:2: reached low water mark for data device: sending event.
kernel: device-mapper: thin: 253:2: no free data space available.
kernel: device-mapper: thin: 253:2: switching pool to read-only mode
kernel: device-mapper: thin: 253:2: switching pool to write mode
kernel: ------------[ cut here ]------------
kernel: WARNING: CPU: 11 PID: 7564 at drivers/md/dm-thin.c:995 handle_unserviceable_bio+0x146/0x160 [dm_thin_pool]()
...
kernel: Workqueue: dm-thin do_worker [dm_thin_pool]
kernel: 00000000000003e3 ffff880308831cc8 ffffffff8152ebcb 00000000000003e3
kernel: 0000000000000000 ffff880308831d08 ffffffff8104c46c ffff88032502a800
kernel: ffff880036409000 ffff88030ec7ce00 0000000000000001 00000000ffffffc3
kernel: Call Trace:
kernel: [] dump_stack+0x49/0x5e
kernel: [] warn_slowpath_common+0x8c/0xc0
kernel: [] warn_slowpath_null+0x1a/0x20
kernel: [] handle_unserviceable_bio+0x146/0x160 [dm_thin_pool]
kernel: [] process_bio_read_only+0x136/0x180 [dm_thin_pool]
kernel: [] process_deferred_bios+0xc5/0x230 [dm_thin_pool]
kernel: [] do_worker+0x51/0x60 [dm_thin_pool]
kernel: [] process_one_work+0x183/0x490
kernel: [] worker_thread+0x120/0x3a0
kernel: [] ? manage_workers+0x160/0x160
kernel: [] kthread+0xce/0xf0
kernel: [] ? kthread_freezable_should_stop+0x70/0x70
kernel: [] ret_from_fork+0x7c/0xb0
kernel: [] ? kthread_freezable_should_stop+0x70/0x70
kernel: ---[ end trace 3f00528e08ffa55c ]---
kernel: device-mapper: thin: pool mode is PM_WRITE not PM_READ_ONLY like expected!?

dm-thin.c:995 was the WARN_ON_ONCE(get_pool_mode(pool) != PM_READ_ONLY);
at the top of handle_unserviceable_bio().  And as the additional
debugging I had conveys: the pool mode was _not_ PM_READ_ONLY like
expected, it was already PM_WRITE, yet pool->process_bio was still set
to process_bio_read_only().

Also, while fixing this up, reduce logging of redundant pool mode
transitions by checking new_mode is different from old_mode.

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

dm thin: initialize dm_thin_new_mapping returned by get_next_mapping

2014-02-13T21:50:17+00:00

commit 16961b042db8cc5cf75d782b4255193ad56e1d4f upstream.

As additional members are added to the dm_thin_new_mapping structure
care should be taken to make sure they get initialized before use.

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