linux/drivers/md
Coly Li ecb2ba8cb8 bcache: add wait_for_kthread_stop() in bch_allocator_thread()
When CACHE_SET_IO_DISABLE is set on cache set flags, bcache allocator
thread routine bch_allocator_thread() may stop the while-loops and
exit. Then it is possible to observe the following kernel oops message,

[  631.068366] bcache: bch_btree_insert() error -5
[  631.069115] bcache: cached_dev_detach_finish() Caching disabled for sdf
[  631.070220] BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
[  631.070250] PGD 0 P4D 0
[  631.070261] Oops: 0002 [#1] SMP PTI
[snipped]
[  631.070578] Workqueue: events cache_set_flush [bcache]
[  631.070597] RIP: 0010:exit_creds+0x1b/0x50
[  631.070610] RSP: 0018:ffffc9000705fe08 EFLAGS: 00010246
[  631.070626] RAX: 0000000000000001 RBX: ffff880a622ad300 RCX: 000000000000000b
[  631.070645] RDX: 0000000000000601 RSI: 000000000000000c RDI: 0000000000000000
[  631.070663] RBP: ffff880a622ad300 R08: ffffea00190c66e0 R09: 0000000000000200
[  631.070682] R10: ffff880a48123000 R11: ffff880000000000 R12: 0000000000000000
[  631.070700] R13: ffff880a4b160e40 R14: ffff880a4b160000 R15: 0ffff880667e2530
[  631.070719] FS:  0000000000000000(0000) GS:ffff880667e00000(0000) knlGS:0000000000000000
[  631.070740] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  631.070755] CR2: 0000000000000000 CR3: 000000000200a001 CR4: 00000000003606e0
[  631.070774] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  631.070793] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[  631.070811] Call Trace:
[  631.070828]  __put_task_struct+0x55/0x160
[  631.070845]  kthread_stop+0xee/0x100
[  631.070863]  cache_set_flush+0x11d/0x1a0 [bcache]
[  631.070879]  process_one_work+0x146/0x340
[  631.070892]  worker_thread+0x47/0x3e0
[  631.070906]  kthread+0xf5/0x130
[  631.070917]  ? max_active_store+0x60/0x60
[  631.070930]  ? kthread_bind+0x10/0x10
[  631.070945]  ret_from_fork+0x35/0x40
[snipped]
[  631.071017] RIP: exit_creds+0x1b/0x50 RSP: ffffc9000705fe08
[  631.071033] CR2: 0000000000000000
[  631.071045] ---[ end trace 011c63a24b22c927 ]---
[  631.071085] bcache: bcache_device_free() bcache0 stopped

The reason is when cache_set_flush() tries to call kthread_stop() to stop
allocator thread, but it exits already due to cache device I/O errors.

This patch adds wait_for_kthread_stop() at tail of bch_allocator_thread(),
to prevent the thread routine exiting directly. Then the allocator thread
can be blocked at wait_for_kthread_stop() and wait for cache_set_flush()
to stop it by calling kthread_stop().

changelog:
v3: add Reviewed-by from Hannnes.
v2: not directly return from allocator_wait(), move 'return 0' to tail of
    bch_allocator_thread().
v1: initial version.

Fixes: 771f393e8f ("bcache: add CACHE_SET_IO_DISABLE to struct cache_set flags")
Signed-off-by: Coly Li <colyli@suse.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-05-03 08:35:13 -06:00
..
bcache bcache: add wait_for_kthread_stop() in bch_allocator_thread() 2018-05-03 08:35:13 -06:00
persistent-data dm bufio: move dm-bufio.h to include/linux/ 2018-04-03 15:04:23 -04:00
dm-bio-prison-v1.c dm bio prison: use rb_entry() rather than container_of() 2017-06-19 11:03:50 -04:00
dm-bio-prison-v1.h block: switch bios to blk_status_t 2017-06-09 09:27:32 -06:00
dm-bio-prison-v2.c dm bio prison: use rb_entry() rather than container_of() 2017-06-19 11:03:50 -04:00
dm-bio-prison-v2.h
dm-bio-record.h block: replace bi_bdev with a gendisk pointer and partitions index 2017-08-23 12:49:55 -06:00
dm-bufio.c dm bufio: don't embed a bio in the dm_buffer structure 2018-04-03 15:04:29 -04:00
dm-builtin.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
dm-cache-background-tracker.c dm cache background tracker: limit amount of background work that may be issued at once 2017-11-10 15:45:03 -05:00
dm-cache-background-tracker.h dm cache: significant rework to leverage dm-bio-prison-v2 2017-03-07 13:28:31 -05:00
dm-cache-block-types.h
dm-cache-metadata.c dm cache: convert dm_cache_metadata.ref_count from atomic_t to refcount_t 2017-10-24 15:09:51 -04:00
dm-cache-metadata.h dm cache: significant rework to leverage dm-bio-prison-v2 2017-03-07 13:28:31 -05:00
dm-cache-policy-internal.h dm cache: significant rework to leverage dm-bio-prison-v2 2017-03-07 13:28:31 -05:00
dm-cache-policy-smq.c dm cache policy smq: allocate cache blocks in order 2017-11-10 15:45:05 -05:00
dm-cache-policy.c
dm-cache-policy.h dm cache: significant rework to leverage dm-bio-prison-v2 2017-03-07 13:28:31 -05:00
dm-cache-target.c dm: allow targets to return output from messages they are sent 2018-04-03 15:04:10 -04:00
dm-core.h dm: various cleanups to md->queue initialization code 2018-01-29 13:44:55 -05:00
dm-crypt.c dm crypt: limit the number of allocated pages 2018-04-03 15:04:11 -04:00
dm-delay.c dm: backfill missing calls to mutex_destroy() 2018-01-17 09:16:15 -05:00
dm-era-target.c dm: allow targets to return output from messages they are sent 2018-04-03 15:04:10 -04:00
dm-exception-store.c
dm-exception-store.h
dm-flakey.c dm: remove fmode_t argument from .prepare_ioctl hook 2018-04-04 12:12:39 -04:00
dm-integrity.c dm bufio: move dm-bufio.h to include/linux/ 2018-04-03 15:04:23 -04:00
dm-io.c dm io: remove BIOSET_NEED_RESCUER flag from bios bioset 2017-12-13 12:15:56 -05:00
dm-ioctl.c dm: allow targets to return output from messages they are sent 2018-04-03 15:04:10 -04:00
dm-kcopyd.c dm: backfill missing calls to mutex_destroy() 2018-01-17 09:16:15 -05:00
dm-linear.c libnvdimm for 4.17 2018-04-10 10:25:57 -07:00
dm-log-userspace-base.c
dm-log-userspace-transfer.c
dm-log-userspace-transfer.h
dm-log-writes.c libnvdimm for 4.17 2018-04-10 10:25:57 -07:00
dm-log.c
dm-mpath.c dm: remove fmode_t argument from .prepare_ioctl hook 2018-04-04 12:12:39 -04:00
dm-mpath.h
dm-path-selector.c
dm-path-selector.h
dm-queue-length.c dm mpath selector: more evenly distribute ties 2018-01-29 13:44:58 -05:00
dm-raid1.c md: Convert timers to use timer_setup() 2017-11-14 20:11:57 -07:00
dm-raid.c dm raid: fix parse_raid_params() variable range issue 2018-04-04 12:12:37 -04:00
dm-region-hash.c
dm-round-robin.c
dm-rq.c for-linus-20180204 2018-02-04 11:16:35 -08:00
dm-rq.h dm rq: do not update rq partially in each ending bio 2017-08-28 10:23:28 -04:00
dm-service-time.c dm mpath selector: more evenly distribute ties 2018-01-29 13:44:58 -05:00
dm-snap-persistent.c dm bufio: move dm-bufio.h to include/linux/ 2018-04-03 15:04:23 -04:00
dm-snap-transient.c
dm-snap.c dm snapshot: use mutex instead of rw_semaphore 2018-01-17 09:16:14 -05:00
dm-stats.c dm: backfill missing calls to mutex_destroy() 2018-01-17 09:16:15 -05:00
dm-stats.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
dm-stripe.c libnvdimm for 4.17 2018-04-10 10:25:57 -07:00
dm-switch.c dm: remove fmode_t argument from .prepare_ioctl hook 2018-04-04 12:12:39 -04:00
dm-sysfs.c
dm-table.c - DM core passthrough ioctl fix to retain reference to DM table, and 2018-04-06 11:50:19 -07:00
dm-target.c dm: remove unused macro DM_MOD_NAME_SIZE 2018-04-03 15:04:15 -04:00
dm-thin-metadata.c dm thin metadata: THIN_MAX_CONCURRENT_LOCKS should be 6 2018-01-17 09:07:54 -05:00
dm-thin-metadata.h
dm-thin.c dm: allow targets to return output from messages they are sent 2018-04-03 15:04:10 -04:00
dm-uevent.c
dm-uevent.h
dm-unstripe.c dm unstripe: remove unnecessary header includes 2018-04-03 15:04:15 -04:00
dm-verity-fec.c dm verity fec: fix GFP flags used with mempool_alloc() 2017-07-26 15:55:44 -04:00
dm-verity-fec.h dm verity fec: limit error correction recursion 2017-03-16 09:37:31 -04:00
dm-verity-target.c dm: remove fmode_t argument from .prepare_ioctl hook 2018-04-04 12:12:39 -04:00
dm-verity.h dm verity: add 'check_at_most_once' option to only validate hashes once 2018-04-03 15:04:29 -04:00
dm-zero.c dm: don't return errnos from ->map 2017-06-09 09:27:32 -06:00
dm-zoned-metadata.c dm: backfill missing calls to mutex_destroy() 2018-01-17 09:16:15 -05:00
dm-zoned-reclaim.c dm zoned: use GFP_NOIO in I/O path 2017-07-26 15:55:43 -04:00
dm-zoned-target.c dm: remove fmode_t argument from .prepare_ioctl hook 2018-04-04 12:12:39 -04:00
dm-zoned.h dm zoned: drive-managed zoned block device target 2017-06-19 11:05:20 -04:00
dm.c libnvdimm for 4.17 2018-04-10 10:25:57 -07:00
dm.h dm: move dm_table_destroy() to same header as dm_table_create() 2018-01-17 09:16:06 -05:00
Kconfig dax, dm: allow device-mapper to operate without dax support 2018-04-03 05:41:19 -07:00
Makefile dm: add unstriped target 2018-01-17 09:16:00 -05:00
md-bitmap.c Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md 2017-11-14 16:07:26 -08:00
md-bitmap.h Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md 2017-11-14 16:07:26 -08:00
md-cluster.c md-cluster: update document for raid10 2017-11-01 21:32:25 -07:00
md-cluster.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
md-faulty.c md: rename some drivers/md/ files to have an "md-" prefix 2017-10-16 19:06:36 -07:00
md-linear.c block: Use blk_queue_flag_*() in drivers instead of queue_flag_*() 2018-03-08 14:13:48 -07:00
md-linear.h Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md 2017-11-14 16:07:26 -08:00
md-multipath.c md-multipath: Use seq_putc() in multipath_status() 2018-02-17 13:00:35 -08:00
md-multipath.h Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md 2017-11-14 16:07:26 -08:00
md.c md-cluster: don't update recovery_offset for faulty device 2018-04-09 08:39:36 -07:00
md.h md: fix md_write_start() deadlock w/o metadata devices 2018-02-18 10:11:59 -08:00
raid0.c block: Use blk_queue_flag_*() in drivers instead of queue_flag_*() 2018-03-08 14:13:48 -07:00
raid0.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
raid1-10.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
raid1.c raid1: copy write hint from master bio to behind bio 2018-04-09 08:54:34 -07:00
raid1.h md: document lifetime of internal rdev pointer. 2018-02-18 10:22:27 -08:00
raid5-cache.c raid5-ppl: PPL support for disks with write-back cache enabled 2018-01-15 14:29:42 -08:00
raid5-log.h raid5-ppl: fix handling flush requests 2018-02-21 09:40:40 -08:00
raid5-ppl.c raid5-ppl: fix handling flush requests 2018-02-21 09:40:40 -08:00
raid5.c for-4.17/block-20180402 2018-04-05 14:27:02 -07:00
raid5.h md: document lifetime of internal rdev pointer. 2018-02-18 10:22:27 -08:00
raid10.c for-4.17/block-20180402 2018-04-05 14:27:02 -07:00
raid10.h md: document lifetime of internal rdev pointer. 2018-02-18 10:22:27 -08:00