linux/drivers/md
Mikulas Patocka 21582cd0b6 dm: flush queued bios when process blocks to avoid deadlock
commit d67a5f4b59 upstream.

Commit df2cb6daa4 ("block: Avoid deadlocks with bio allocation by
stacking drivers") created a workqueue for every bio set and code
in bio_alloc_bioset() that tries to resolve some low-memory deadlocks
by redirecting bios queued on current->bio_list to the workqueue if the
system is low on memory.  However other deadlocks (see below **) may
happen, without any low memory condition, because generic_make_request
is queuing bios to current->bio_list (rather than submitting them).

** the related dm-snapshot deadlock is detailed here:
https://www.redhat.com/archives/dm-devel/2016-July/msg00065.html

Fix this deadlock by redirecting any bios on current->bio_list to the
bio_set's rescue workqueue on every schedule() call.  Consequently,
when the process blocks on a mutex, the bios queued on
current->bio_list are dispatched to independent workqueus and they can
complete without waiting for the mutex to be available.

The structure blk_plug contains an entry cb_list and this list can contain
arbitrary callback functions that are called when the process blocks.
To implement this fix DM (ab)uses the onstack plug's cb_list interface
to get its flush_current_bio_list() called at schedule() time.

This fixes the snapshot deadlock - if the map method blocks,
flush_current_bio_list() will be called and it redirects bios waiting
on current->bio_list to appropriate workqueues.

Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1267650
Depends-on: df2cb6daa4 ("block: Avoid deadlocks with bio allocation by stacking drivers")
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
History 2017-03-18 19:14:34 +08:00
..
bcache bcache: Make gc wakeup sane, remove set_task_state() 2017-02-23 17:44:36 +01:00
persistent-data dm space map metadata: fix 'struct sm_metadata' leak on failed create 2017-01-06 10:40:16 +01:00
bitmap.c md/bitmap: fix wrong cleanup 2016-09-21 09:09:44 -07:00
bitmap.h md-cluster: sync bitmap when node received RESYNCING msg 2016-05-04 12:39:35 -07:00
dm-bio-prison.c block: add a bi_error field to struct bio 2015-07-29 08:55:15 -06:00
dm-bio-prison.h dm bio prison: add dm_cell_promote_or_release() 2015-05-29 14:19:06 -04:00
dm-bio-record.h dm: Refactor for new bio cloning/splitting 2013-11-23 22:33:55 -08:00
dm-bufio.c . various fixes and cleanups for request-based DM core 2016-10-09 17:16:18 -07:00
dm-bufio.h dm snapshot: use dm-bufio prefetch 2014-01-14 23:23:03 -05:00
dm-builtin.c dm: move request-based code out to dm-rq.[hc] 2016-06-10 15:15:44 -04:00
dm-cache-block-types.h dm cache: revert "remove remainder of distinct discard block size" 2014-11-10 15:25:30 -05:00
dm-cache-metadata.c dm cache metadata: switch to using the new cursor api for loading metadata 2016-09-22 11:15:05 -04:00
dm-cache-metadata.h dm cache: make sure every metadata function checks fail_io 2016-03-10 17:12:12 -05:00
dm-cache-policy-cleaner.c dm cache: speed up writing of the hint array 2016-09-22 11:15:02 -04:00
dm-cache-policy-internal.h dm cache: speed up writing of the hint array 2016-09-22 11:15:02 -04:00
dm-cache-policy-smq.c dm cache policy smq: distribute entries to random levels when switching to smq 2016-09-22 11:15:03 -04:00
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: speed up writing of the hint array 2016-09-22 11:15:02 -04:00
dm-cache-target.c dm cache: fix corruption seen when using cache > 2TB 2017-03-12 06:41:44 +01:00
dm-core.h dm: move request-based code out to dm-rq.[hc] 2016-06-10 15:15:44 -04:00
dm-crypt.c dm crypt: mark key as invalid until properly loaded 2017-01-06 10:40:15 +01:00
dm-delay.c dm: rename target's per_bio_data_size to per_io_data_size 2016-02-22 22:34:37 -05:00
dm-era-target.c block: rename bio bi_rw to bi_opf 2016-08-07 14:41:02 -06:00
dm-exception-store.c - Revert a dm-multipath change that caused a regression for unprivledged 2015-11-04 21:19:53 -08:00
dm-exception-store.h dm snapshot: fix hung bios when copy error occurs 2016-01-08 20:03:05 -05:00
dm-flakey.c dm flakey: return -EINVAL on interval bounds error in flakey_ctr() 2017-01-06 10:40:15 +01:00
dm-io.c block: rename bio bi_rw to bi_opf 2016-08-07 14:41:02 -06:00
dm-ioctl.c dm: allow bio-based table to be upgraded to bio-based with DAX support 2016-07-20 23:49:52 -04:00
dm-kcopyd.c dm: move request-based code out to dm-rq.[hc] 2016-06-10 15:15:44 -04:00
dm-linear.c libnvdimm for 4.8 2016-07-28 17:38:16 -07:00
dm-log-userspace-base.c dm: drop NULL test before kmem_cache_destroy() and mempool_destroy() 2015-10-31 19:06:00 -04:00
dm-log-userspace-transfer.c dm log userspace transfer: match wait_for_completion_timeout return type 2015-04-15 12:10:20 -04:00
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-writes.c Merge branch 'for-4.9/block' of git://git.kernel.dk/linux-block 2016-10-07 14:42:05 -07:00
dm-log.c dm log: fix unitialized bio operation flags 2016-08-24 21:55:05 -04:00
dm-mpath.c dm mpath: always return reservation conflict without failing over 2016-09-29 10:57:07 -04:00
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 path selector: remove 'repeat_count' return from .select_path hook 2016-02-22 22:34:42 -05:00
dm-queue-length.c dm path selector: remove 'repeat_count' return from .select_path hook 2016-02-22 22:34:42 -05:00
dm-raid.c dm raid: fix data corruption on reshape request 2017-03-12 06:41:44 +01:00
dm-raid1.c dm mirror: use all available legs on multiple failures 2016-10-14 11:55:17 -04:00
dm-region-hash.c block: rename bio bi_rw to bi_opf 2016-08-07 14:41:02 -06:00
dm-round-robin.c dm round robin: revert "use percpu 'repeat_count' and 'current_path'" 2017-03-12 06:41:44 +01:00
dm-rq.c dm rq: cope with DM device destruction while in dm_old_request_fn() 2017-02-14 15:25:32 -08:00
dm-rq.h dm rq: introduce dm_mq_kick_requeue_list() 2016-09-15 11:16:05 -04:00
dm-service-time.c dm path selector: remove 'repeat_count' return from .select_path hook 2016-02-22 22:34:42 -05:00
dm-snap-persistent.c dm: use bio op accessors 2016-06-07 13:41:38 -06:00
dm-snap-transient.c dm snapshot: fix hung bios when copy error occurs 2016-01-08 20:03:05 -05:00
dm-snap.c block: rename bio bi_rw to bi_opf 2016-08-07 14:41:02 -06:00
dm-stats.c dm stats: fix a leaked s->histogram_boundaries array 2017-03-12 06:41:44 +01:00
dm-stats.h dm stats: support precise timestamps 2015-06-17 12:40:40 -04:00
dm-stripe.c block: rename bio bi_rw to bi_opf 2016-08-07 14:41:02 -06:00
dm-switch.c dm switch: simplify conditional in alloc_region_table() 2015-10-31 19:06:06 -04:00
dm-sysfs.c dm: move request-based code out to dm-rq.[hc] 2016-06-10 15:15:44 -04:00
dm-table.c dm table: an 'all_blk_mq' table must be loaded for a blk-mq DM device 2017-01-06 10:40:15 +01:00
dm-target.c libnvdimm for 4.8 2016-07-28 17:38:16 -07:00
dm-thin-metadata.c dm thin: fix a race condition between discarding and provisioning a block 2016-07-20 12:43:35 -04:00
dm-thin-metadata.h dm thin: fix a race condition between discarding and provisioning a block 2016-07-20 12:43:35 -04:00
dm-thin.c block: rename bio bi_rw to bi_opf 2016-08-07 14:41:02 -06:00
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-fec.c dm verity fec: fix block calculation 2016-07-01 23:29:08 -04:00
dm-verity-fec.h dm verity: add support for forward error correction 2015-12-10 10:39:03 -05:00
dm-verity-target.c dm: rename target's per_bio_data_size to per_io_data_size 2016-02-22 22:34:37 -05:00
dm-verity.h dm verity: add ignore_zero_blocks feature 2015-12-10 10:39:03 -05:00
dm-zero.c block: rename bio bi_rw to bi_opf 2016-08-07 14:41:02 -06:00
dm.c dm: flush queued bios when process blocks to avoid deadlock 2017-03-18 19:14:34 +08:00
dm.h dm: add infrastructure for DAX support 2016-07-20 23:49:49 -04:00
faulty.c MD: rename some functions 2016-01-20 13:52:20 -08:00
Kconfig dm: add missing newline between DM_DEBUG_BLOCK_STACK_TRACING and DM_BUFIO 2016-03-10 17:12:11 -05:00
linear.c md linear: fix a race between linear_add() and linear_congested() 2017-03-12 06:41:52 +01:00
linear.h md linear: fix a race between linear_add() and linear_congested() 2017-03-12 06:41:52 +01:00
Makefile dm: move request-based code out to dm-rq.[hc] 2016-06-10 15:15:44 -04:00
md-cluster.c md-cluster: make resync lock also could be interruptted 2016-09-21 09:09:44 -07:00
md-cluster.h md-cluster: gather resync infos and enable recv_thread after bitmap is ready 2016-05-09 09:24:03 -07:00
md.c md: fix refcount problem on mddev when stopping array. 2017-01-12 11:39:35 +01:00
md.h md: changes for MD_STILL_CLOSED flag 2016-09-21 09:09:44 -07:00
multipath.c block: rename bio bi_rw to bi_opf 2016-08-07 14:41:02 -06:00
multipath.h md/multipath: typedef removal: multipath_conf_t -> struct mpconf 2011-10-11 16:48:57 +11:00
raid0.c block: rename bio bi_rw to bi_opf 2016-08-07 14:41:02 -06:00
raid0.h block: kill merge_bvec_fn() completely 2015-08-13 12:31:57 -06:00
raid1.c raid1: handle read error also in readonly mode 2016-10-28 22:04:04 -07:00
raid1.h md-cluster: Use a small window for resync 2015-10-12 01:32:05 -05:00
raid5-cache.c raid5-cache: correct condition for empty metadata write 2016-10-28 22:04:03 -07:00
raid5.c md/raid5: limit request size according to implementation limits 2017-01-09 08:32:22 +01:00
raid5.h md/raid5: Convert to hotplug state machine 2016-09-06 18:30:23 +02:00
raid10.c RAID10: ignore discard error 2016-10-24 15:28:17 -07:00
raid10.h raid10: improve random reads performance 2016-07-19 15:20:28 -07:00