linux/drivers/md
Mikulas Patocka d4a671772a dm: allocate a special workqueue for deferred device removal
commit acfe0ad74d upstream.

The commit 2c140a246d ("dm: allow remove to be deferred") introduced a
deferred removal feature for the device mapper.  When this feature is
used (by passing a flag DM_DEFERRED_REMOVE to DM_DEV_REMOVE_CMD ioctl)
and the user tries to remove a device that is currently in use, the
device will be removed automatically in the future when the last user
closes it.

Device mapper used the system workqueue to perform deferred removals.
However, some targets (dm-raid1, dm-mpath, dm-stripe) flush work items
scheduled for the system workqueue from their destructor.  If the
destructor itself is called from the system workqueue during deferred
removal, it introduces a possible deadlock - the workqueue tries to flush
itself.

Fix this possible deadlock by introducing a new workqueue for deferred
removals.  We allocate just one workqueue for all dm targets.  The
ability of dm targets to process IOs isn't dependent on deferred removal
of unused targets, so a deadlock due to shared workqueue isn't possible.

Also, cleanup local_init() to eliminate potential for returning success
on failure.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
History 2014-07-17 16:23:14 -07:00
..
bcache bcache: remove nested function usage 2014-03-18 12:39:28 -07:00
persistent-data dm transaction manager: fix corruption due to non-atomic transaction commit 2014-03-27 16:56:23 -04:00
bitmap.c md/bitmap: don't abuse i_writecount for bitmap files. 2014-04-09 12:26:59 +10:00
bitmap.h kernfs: s/sysfs_dirent/kernfs_node/ and rename its friends accordingly 2013-12-11 15:28:36 -08:00
dm-bio-prison.c dm: add cache target 2013-03-01 22:45:51 +00:00
dm-bio-prison.h dm: add cache target 2013-03-01 22:45:51 +00:00
dm-bio-record.h dm: Refactor for new bio cloning/splitting 2013-11-23 22:33:55 -08:00
dm-bufio.c Merge branch 'for-3.14/core' of git://git.kernel.dk/linux-block 2014-01-30 11:19:05 -08:00
dm-bufio.h dm snapshot: use dm-bufio prefetch 2014-01-14 23:23:03 -05:00
dm-builtin.c dm sysfs: fix a module unload race 2014-01-14 23:23:04 -05:00
dm-cache-block-types.h dm cache: remove remainder of distinct discard block size 2014-03-27 16:56:23 -04:00
dm-cache-metadata.c dm cache: fix a lock-inversion 2014-04-04 14:53:05 -04:00
dm-cache-metadata.h dm cache: fix a lock-inversion 2014-04-04 14:53:05 -04:00
dm-cache-policy-cleaner.c dm cache: policy change version from string to integer set 2013-03-20 17:21:27 +00:00
dm-cache-policy-internal.h dm cache: add remove_cblock method to policy interface 2013-11-11 11:37:50 -05:00
dm-cache-policy-mq.c dm cache mq: fix memory allocation failure for large cache devices 2014-02-28 12:18:29 -05:00
dm-cache-policy.c dm cache: add policy name to status output 2014-01-16 13:44:11 -05:00
dm-cache-policy.h dm cache: add policy name to status output 2014-01-16 13:44:11 -05:00
dm-cache-target.c dm cache: always split discards on cache block boundaries 2014-05-27 10:33:05 -04:00
dm-crypt.c dm crypt: fix cpu hotplug crash by removing per-cpu structure 2014-05-14 16:11:35 -04:00
dm-delay.c Merge branch 'for-3.14/core' of git://git.kernel.dk/linux-block 2014-01-30 11:19:05 -08:00
dm-era-target.c dm era: check for a non-NULL metadata object before closing it 2014-07-09 11:21:27 -07:00
dm-exception-store.c dm: replace simple_strtoul 2012-07-27 15:07:59 +01:00
dm-exception-store.h dm snapshot: test chunk size against both origin and snapshot 2010-08-12 04:13:51 +01:00
dm-flakey.c block: Abstract out bvec iterator 2013-11-23 22:33:47 -08:00
dm-io.c dm io: fix a race condition in the wake up code for sync_io 2014-07-17 16:23:14 -07:00
dm-ioctl.c dm: allow remove to be deferred 2013-11-09 18:20:22 -05:00
dm-kcopyd.c dm: stop using WQ_NON_REENTRANT 2013-08-23 09:02:13 -04:00
dm-linear.c block: Abstract out bvec iterator 2013-11-23 22:33:47 -08:00
dm-log-userspace-base.c dm log userspace: allow mark requests to piggyback on flush requests 2014-01-21 23:46:27 -05:00
dm-log-userspace-transfer.c connector: add portid to unicast in addition to broadcasting 2014-02-07 15:40:17 -08:00
dm-log-userspace-transfer.h dm log: userspace add luid to distinguish between concurrent log instances 2009-09-04 20:40:34 +01:00
dm-log.c dm: use memweight() 2012-07-30 17:25:16 -07:00
dm-mpath.c dm mpath: fix IO hang due to logic bug in multipath_busy 2014-07-17 16:23:14 -07:00
dm-mpath.h dm mpath: remove is_active from struct dm_path 2008-10-10 13:36:58 +01:00
dm-path-selector.c md: Add module.h to all files using it implicitly 2011-10-31 19:31:18 -04:00
dm-path-selector.h dm mpath: add start_io and nr_bytes to path selectors 2009-06-22 10:12:27 +01:00
dm-queue-length.c dm: reject trailing characters in sccanf input 2012-03-28 18:41:26 +01:00
dm-raid.c MD: Remember the last sync operation that was performed 2013-06-26 12:38:24 +10:00
dm-raid1.c dm raid1: fix immutable biovec related BUG when retrying read bio 2014-02-18 10:48:57 -05:00
dm-region-hash.c block: Abstract out bvec iterator 2013-11-23 22:33:47 -08:00
dm-round-robin.c dm: reject trailing characters in sccanf input 2012-03-28 18:41:26 +01:00
dm-service-time.c dm: reject trailing characters in sccanf input 2012-03-28 18:41:26 +01:00
dm-snap-persistent.c dm snapshot: fix metadata corruption 2014-03-03 17:58:13 -05:00
dm-snap-transient.c md: Add in export.h for files using EXPORT_SYMBOL 2011-10-31 19:31:19 -04:00
dm-snap.c Merge branch 'for-3.14/core' of git://git.kernel.dk/linux-block 2014-01-30 11:19:05 -08:00
dm-stats.c dm stats: initialize read-only module parameter 2013-12-10 19:13:21 -05:00
dm-stats.h dm: add statistics support 2013-09-05 20:46:06 -04:00
dm-stripe.c block: Abstract out bvec iterator 2013-11-23 22:33:47 -08:00
dm-switch.c block: Abstract out bvec iterator 2013-11-23 22:33:47 -08:00
dm-sysfs.c dm sysfs: fix a module unload race 2014-01-14 23:23:04 -05:00
dm-table.c dm table: add dm_table_run_md_queue_async 2014-03-27 16:56:24 -04:00
dm-target.c dm: allow error target to replace bio-based and request-based targets 2013-09-05 20:46:05 -04:00
dm-thin-metadata.c dm: take care to copy the space map roots before locking the superblock 2014-03-27 16:56:23 -04:00
dm-thin-metadata.h dm thin: ensure user takes action to validate data and metadata consistency 2014-03-05 15:25:35 -05:00
dm-thin.c dm thin: update discard_granularity to reflect the thin-pool blocksize 2014-07-09 11:21:28 -07:00
dm-uevent.c md: Add in export.h for files using EXPORT_SYMBOL 2011-10-31 19:31:19 -04:00
dm-uevent.h dm: uevent generate events 2007-10-20 02:01:26 +01:00
dm-verity.c dm verity: fix biovecs hash calculation regression 2014-04-15 12:19:24 -04:00
dm-zero.c dm: rename request variables to bios 2013-03-01 22:45:47 +00:00
dm.c dm: allocate a special workqueue for deferred device removal 2014-07-17 16:23:14 -07:00
dm.h dm table: add dm_table_run_md_queue_async 2014-03-27 16:56:24 -04:00
faulty.c block: Abstract out bvec iterator 2013-11-23 22:33:47 -08:00
Kconfig dm: add era target 2014-03-27 16:56:23 -04:00
linear.c block: Introduce new bio_split() 2013-11-23 22:33:57 -08:00
linear.h md/linear: typedef removal: linear_conf_t -> struct linear_conf 2011-10-11 16:48:54 +11:00
Makefile dm: add era target 2014-03-27 16:56:23 -04:00
md.c md: flush writes before starting a recovery. 2014-07-09 11:21:31 -07:00
md.h md/bitmap: don't abuse i_writecount for bitmap files. 2014-04-09 12:26:59 +10:00
multipath.c block: Abstract out bvec iterator 2013-11-23 22:33:47 -08:00
multipath.h md/multipath: typedef removal: multipath_conf_t -> struct mpconf 2011-10-11 16:48:57 +11:00
raid0.c block: Introduce new bio_split() 2013-11-23 22:33:57 -08:00
raid0.h md: add proper merge_bvec handling to RAID0 and Linear. 2012-03-19 12:46:39 +11:00
raid1.c md/raid1: r1buf_pool_alloc: free allocate pages when subsequent allocation fails. 2014-04-09 14:42:23 +10:00
raid1.h raid1: Rewrite the implementation of iobarrier. 2013-11-19 15:19:18 +11:00
raid5.c raid5: fix a race of stripe count check 2014-04-17 17:05:28 +10:00
raid5.h md update for 3.13. 2013-11-20 13:05:25 -08:00
raid10.c md/raid10: call wait_barrier() for each request submitted. 2014-05-06 09:49:26 +10:00
raid10.h MD RAID10: Improve redundancy for 'far' and 'offset' algorithms (part 1) 2013-02-26 11:55:30 +11:00