linux/drivers/md
Coly Li 1f0ffa6734 bcache: only set BCACHE_DEV_WB_RUNNING when cached device attached
When people set a writeback percent via sysfs file,
  /sys/block/bcache<N>/bcache/writeback_percent
current code directly sets BCACHE_DEV_WB_RUNNING to dc->disk.flags
and schedules kworker dc->writeback_rate_update.

If there is no cache set attached to, the writeback kernel thread is
not running indeed, running dc->writeback_rate_update does not make
sense and may cause NULL pointer deference when reference cache set
pointer inside update_writeback_rate().

This patch checks whether the cache set point (dc->disk.c) is NULL in
sysfs interface handler, and only set BCACHE_DEV_WB_RUNNING and
schedule dc->writeback_rate_update when dc->disk.c is not NULL (it
means the cache device is attached to a cache set).

This problem might be introduced from initial bcache commit, but
commit 3fd47bfe55 ("bcache: stop dc->writeback_rate_update properly")
changes part of the original code piece, so I add 'Fixes: 3fd47bfe55b0'
to indicate from which commit this patch can be applied.

Fixes: 3fd47bfe55 ("bcache: stop dc->writeback_rate_update properly")
Reported-by: Bjørn Forsman <bjorn.forsman@gmail.com>
Signed-off-by: Coly Li <colyli@suse.de>
Reviewed-by: Bjørn Forsman <bjorn.forsman@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-06-13 03:09:15 -06:00
..
bcache bcache: only set BCACHE_DEV_WB_RUNNING when cached device attached 2019-06-13 03:09:15 -06:00
persistent-data treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
dm-bio-prison-v1.c
dm-bio-prison-v1.h
dm-bio-prison-v2.c
dm-bio-prison-v2.h
dm-bio-record.h
dm-bufio.c dm bufio: Simplify stack trace retrieval 2019-04-29 12:37:52 +02:00
dm-builtin.c
dm-cache-background-tracker.c
dm-cache-background-tracker.h
dm-cache-block-types.h
dm-cache-metadata.c dm cache metadata: Fix loading discard bitset 2019-04-18 16:18:25 -04:00
dm-cache-metadata.h
dm-cache-policy-internal.h
dm-cache-policy-smq.c dm: remove unnecessary unlikely() around WARN_ON_ONCE() 2018-10-16 14:34:59 -04:00
dm-cache-policy.c
dm-cache-policy.h
dm-cache-target.c dm cache: add support for discard passdown to the origin device 2019-03-05 14:53:52 -05:00
dm-core.h dm: disable DISCARD if the underlying storage no longer supports it 2019-04-04 15:33:59 -04:00
dm-crypt.c - Improve DM snapshot target's scalability by using finer grained 2019-05-16 15:55:48 -07:00
dm-delay.c dm delay: fix a crash when invalid device is specified 2019-04-26 11:29:32 -04:00
dm-dust.c dm dust: Make dm_dust_init and dm_dust_exit static 2019-05-07 16:05:07 -04:00
dm-era-target.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
dm-exception-store.c
dm-exception-store.h - Improve DM snapshot target's scalability by using finer grained 2019-05-16 15:55:48 -07:00
dm-flakey.c dm flakey: Properly corrupt multi-page bios. 2018-12-18 09:02:27 -05:00
dm-init.c dm init: fix max devices/targets checks 2019-04-30 16:51:23 -04:00
dm-integrity.c - Improve DM snapshot target's scalability by using finer grained 2019-05-16 15:55:48 -07:00
dm-io.c
dm-ioctl.c dm ioctl: fix hang in early create error condition 2019-05-16 09:52:06 -04:00
dm-kcopyd.c dm kcopyd: Fix bug causing workqueue stalls 2018-12-18 09:02:26 -05:00
dm-linear.c dm: Check for device sector overflow if CONFIG_LBDAF is not set 2018-12-18 09:02:26 -05:00
dm-log-userspace-base.c
dm-log-userspace-transfer.c
dm-log-userspace-transfer.h
dm-log-writes.c
dm-log.c
dm-mpath.c dm mpath: always free attached_handler_name in parse_path() 2019-04-30 16:51:30 -04:00
dm-mpath.h
dm-path-selector.c
dm-path-selector.h
dm-queue-length.c
dm-raid1.c dm: Check for device sector overflow if CONFIG_LBDAF is not set 2018-12-18 09:02:26 -05:00
dm-raid.c dm: eliminate 'split_discard_bios' flag from DM target interface 2019-02-20 23:24:55 -05:00
dm-region-hash.c
dm-round-robin.c
dm-rq.c dm mpath: fix missing call of path selector type->end_io 2019-04-25 15:38:52 -04:00
dm-rq.h dm: remove unused _rq_tio_cache and _rq_cache 2019-03-05 14:48:50 -05:00
dm-service-time.c
dm-snap-persistent.c
dm-snap-transient.c
dm-snap.c dm snapshot: Use fine-grained locking scheme 2019-04-18 16:18:30 -04:00
dm-stats.c mm: convert totalram_pages and totalhigh_pages variables to atomic 2018-12-28 12:11:47 -08:00
dm-stats.h
dm-stripe.c
dm-switch.c dm switch: use struct_size() in kzalloc() 2019-03-05 14:48:51 -05:00
dm-sysfs.c dm: remove legacy request-based IO path 2018-10-11 11:36:09 -04:00
dm-table.c dax: Arrange for dax_supported check to span multiple devices 2019-05-20 15:02:08 -07:00
dm-target.c dm mpath: fix missing call of path selector type->end_io 2019-04-25 15:38:52 -04:00
dm-thin-metadata.c dm thin metadata: do not write metadata if no changes occurred 2019-04-18 16:18:34 -04:00
dm-thin-metadata.h dm thin: fix passdown_double_checking_shared_status() 2019-01-15 16:10:41 -05:00
dm-thin.c dm thin: add sanity checks to thin-pool and external snapshot creation 2019-03-05 14:53:49 -05:00
dm-uevent.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156 2019-05-30 11:26:35 -07:00
dm-uevent.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156 2019-05-30 11:26:35 -07:00
dm-unstripe.c dm: Check for device sector overflow if CONFIG_LBDAF is not set 2018-12-18 09:02:26 -05:00
dm-verity-fec.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
dm-verity-fec.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
dm-verity-target.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 428 2019-06-05 17:37:16 +02:00
dm-verity.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 428 2019-06-05 17:37:16 +02:00
dm-writecache.c dm writecache: avoid unnecessary lookups in writecache_find_entry() 2019-04-26 11:48:03 -04:00
dm-zero.c
dm-zoned-metadata.c dm zoned: Fix zone report handling 2019-04-18 16:17:58 -04:00
dm-zoned-reclaim.c
dm-zoned-target.c dm zoned: Silence a static checker warning 2019-04-18 16:16:01 -04:00
dm-zoned.h
dm.c libnvdimm fixes v5.2-rc2 2019-05-25 10:11:23 -07:00
dm.h dax: Arrange for dax_supported check to span multiple devices 2019-05-20 15:02:08 -07:00
Kconfig treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
Makefile dm: add dust target 2019-04-30 16:37:19 -04:00
md-bitmap.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
md-bitmap.h
md-cluster.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 45 2019-05-24 17:27:12 +02:00
md-cluster.h md-cluster: introduce resync_info_get interface for sanity check 2018-10-18 09:36:35 -07:00
md-faulty.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 47 2019-05-24 17:27:13 +02:00
md-linear.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 47 2019-05-24 17:27:13 +02:00
md-linear.h
md-multipath.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 47 2019-05-24 17:27:13 +02:00
md-multipath.h
md.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 47 2019-05-24 17:27:13 +02:00
md.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 47 2019-05-24 17:27:13 +02:00
raid0.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 47 2019-05-24 17:27:13 +02:00
raid0.h
raid1-10.c
raid1.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 47 2019-05-24 17:27:13 +02:00
raid1.h
raid5-cache.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 288 2019-06-05 17:36:37 +02:00
raid5-log.h raid5: set write hint for PPL 2019-03-12 10:15:18 -07:00
raid5-ppl.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 288 2019-06-05 17:36:37 +02:00
raid5.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 47 2019-05-24 17:27:13 +02:00
raid5.h md: convert to kvmalloc 2019-03-12 10:04:02 -07:00
raid10.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 47 2019-05-24 17:27:13 +02:00
raid10.h