linux/drivers/md
Coly Li d59b237959 bcache: only permit to recovery read error when cache device is clean
When bcache does read I/Os, for example in writeback or writethrough mode,
if a read request on cache device is failed, bcache will try to recovery
the request by reading from cached device. If the data on cached device is
not synced with cache device, then requester will get a stale data.

For critical storage system like database, providing stale data from
recovery may result an application level data corruption, which is
unacceptible.

With this patch, for a failed read request in writeback or writethrough
mode, recovery a recoverable read request only happens when cache device
is clean. That is to say, all data on cached device is up to update.

For other cache modes in bcache, read request will never hit
cached_dev_read_error(), they don't need this patch.

Please note, because cache mode can be switched arbitrarily in run time, a
writethrough mode might be switched from a writeback mode. Therefore
checking dc->has_data in writethrough mode still makes sense.

Changelog:
V4: Fix parens error pointed by Michael Lyle.
v3: By response from Kent Oversteet, he thinks recovering stale data is a
    bug to fix, and option to permit it is unnecessary. So this version
    the sysfs file is removed.
v2: rename sysfs entry from allow_stale_data_on_failure  to
    allow_stale_data_on_failure, and fix the confusing commit log.
v1: initial patch posted.

[small change to patch comment spelling by mlyle]

Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Michael Lyle <mlyle@lyle.org>
Reported-by: Arne Wolf <awolf@lenovo.com>
Reviewed-by: Michael Lyle <mlyle@lyle.org>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Cc: Nix <nix@esperi.org.uk>
Cc: Kai Krakow <hurikhan77@gmail.com>
Cc: Eric Wheeler <bcache@lists.ewheeler.net>
Cc: Junhui Tang <tang.junhui@zte.com.cn>
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-10-30 15:57:54 -06:00
..
bcache bcache: only permit to recovery read error when cache device is clean 2017-10-30 15:57:54 -06:00
persistent-data dm space map disk: fix some book keeping in the disk space map 2017-05-15 15:09:50 -04:00
bitmap.c buffer: have alloc_page_buffers() use __GFP_NOFAIL 2017-10-03 08:38:17 -06:00
bitmap.h md: move bitmap_destroy to the beginning of __md_stop 2017-03-16 16:55:58 -07:00
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 prison v2: new interface for the bio prison 2017-03-07 11:30:16 -05:00
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 - Some request-based DM core and DM multipath fixes and cleanups 2017-09-14 13:43:16 -07:00
dm-bufio.h dm integrity: optimize writing dm-bufio buffers that are partially changed 2017-08-28 11:47:17 -04:00
dm-builtin.c dm: move request-based code out to dm-rq.[hc] 2016-06-10 15:15:44 -04:00
dm-cache-background-tracker.c dm cache: handle kmalloc failure allocating background_tracker struct 2017-05-17 09:44:53 -04:00
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 linux: drop __bitwise__ everywhere 2016-12-16 00:13:41 +02:00
dm-cache-metadata.c dm cache metadata: fail operations if fail_io mode has been established 2017-05-05 14:40:13 -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: don't do any writebacks unless IDLE 2017-05-14 21:54:33 -04:00
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 - Some request-based DM core and DM multipath fixes and cleanups 2017-09-14 13:43:16 -07:00
dm-core.h dm: add basic support for using the select or poll function 2017-06-19 11:03:49 -04:00
dm-crypt.c - Some request-based DM core and DM multipath fixes and cleanups 2017-09-14 13:43:16 -07:00
dm-delay.c block: replace bi_bdev with a gendisk pointer and partitions index 2017-08-23 12:49:55 -06:00
dm-era-target.c block: replace bi_bdev with a gendisk pointer and partitions index 2017-08-23 12:49:55 -06:00
dm-exception-store.c
dm-exception-store.h dm snapshot: fix hung bios when copy error occurs 2016-01-08 20:03:05 -05:00
dm-flakey.c - Some request-based DM core and DM multipath fixes and cleanups 2017-09-14 13:43:16 -07:00
dm-integrity.c - Some request-based DM core and DM multipath fixes and cleanups 2017-09-14 13:43:16 -07:00
dm-io.c block: replace bi_bdev with a gendisk pointer and partitions index 2017-08-23 12:49:55 -06:00
dm-ioctl.c dm ioctl: constify ioctl lookup table 2017-08-28 11:47:18 -04:00
dm-kcopyd.c dm kcopyd: add sequential write feature 2017-06-19 11:03:51 -04:00
dm-linear.c - Some request-based DM core and DM multipath fixes and cleanups 2017-09-14 13:43:16 -07:00
dm-log-userspace-base.c
dm-log-userspace-transfer.c
dm-log-userspace-transfer.h
dm-log-writes.c - Some request-based DM core and DM multipath fixes and cleanups 2017-09-14 13:43:16 -07:00
dm-log.c block,fs: use REQ_* flags directly 2016-11-01 09:43:26 -06:00
dm-mpath.c - Some request-based DM core and DM multipath fixes and cleanups 2017-09-14 13:43:16 -07:00
dm-mpath.h
dm-path-selector.c
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-raid1.c block: replace bi_bdev with a gendisk pointer and partitions index 2017-08-23 12:49:55 -06:00
dm-raid.c dm raid: bump target version 2017-07-25 14:54:20 -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'" 2017-02-17 00:54:09 -05:00
dm-rq.c block: remove QUEUE_FLAG_STACKABLE 2017-10-05 15:22:59 -06:00
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 path selector: remove 'repeat_count' return from .select_path hook 2016-02-22 22:34:42 -05:00
dm-snap-persistent.c dm: make flush bios explicitly sync 2017-05-31 10:50:23 -04:00
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: replace bi_bdev with a gendisk pointer and partitions index 2017-08-23 12:49:55 -06:00
dm-stats.c mm: introduce kv[mz]alloc helpers 2017-05-08 17:15:12 -07:00
dm-stats.h
dm-stripe.c - Some request-based DM core and DM multipath fixes and cleanups 2017-09-14 13:43:16 -07:00
dm-switch.c - Some request-based DM core and DM multipath fixes and cleanups 2017-09-14 13:43:16 -07:00
dm-sysfs.c dm: move request-based code out to dm-rq.[hc] 2016-06-10 15:15:44 -04:00
dm-table.c block: remove QUEUE_FLAG_STACKABLE 2017-10-05 15:22:59 -06:00
dm-target.c dm: don't return errnos from ->map 2017-06-09 09:27:32 -06:00
dm-thin-metadata.c dm thin metadata: call precommit before saving the roots 2017-05-15 15:09:49 -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 - Some request-based DM core and DM multipath fixes and cleanups 2017-09-14 13:43:16 -07:00
dm-uevent.c
dm-uevent.h
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 - Some request-based DM core and DM multipath fixes and cleanups 2017-09-14 13:43:16 -07:00
dm-verity.h dm verity: switch to using asynchronous hash crypto API 2017-04-24 15:37:04 -04:00
dm-zero.c dm: don't return errnos from ->map 2017-06-09 09:27:32 -06:00
dm-zoned-metadata.c block: replace bi_bdev with a gendisk pointer and partitions index 2017-08-23 12:49:55 -06:00
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 block: replace bi_bdev with a gendisk pointer and partitions index 2017-08-23 12:49:55 -06:00
dm-zoned.h dm zoned: drive-managed zoned block device target 2017-06-19 11:05:20 -04:00
dm.c block: remove QUEUE_FLAG_STACKABLE 2017-10-05 15:22:59 -06:00
dm.h dm: introduce enum dm_queue_mode to cleanup related code 2017-04-27 17:08:44 -04:00
faulty.c block: replace bi_bdev with a gendisk pointer and partitions index 2017-08-23 12:49:55 -06:00
Kconfig dm zoned: drive-managed zoned block device target 2017-06-19 11:05:20 -04:00
linear.c block: replace bi_bdev with a gendisk pointer and partitions index 2017-08-23 12:49:55 -06:00
linear.h md linear: fix a race between linear_add() and linear_congested() 2017-02-13 09:17:50 -08:00
Makefile dm zoned: drive-managed zoned block device target 2017-06-19 11:05:20 -04:00
md-cluster.c md-cluster: fix potential lock issue in add_new_disk 2017-05-21 20:37:09 -07:00
md-cluster.h md-cluster: add the support for resize 2017-03-16 16:55:50 -07:00
md.c Merge tag 'md/4.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md 2017-09-07 12:41:48 -07:00
md.h Merge tag 'md/4.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md 2017-09-07 12:41:48 -07:00
multipath.c block: replace bi_bdev with a gendisk pointer and partitions index 2017-08-23 12:49:55 -06:00
multipath.h
raid0.c Merge tag 'md/4.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md 2017-09-07 12:41:48 -07:00
raid0.h
raid1-10.c md: raid1-10: move raid1/raid10 common code into raid1-10.c 2017-07-21 12:47:20 -07:00
raid1.c Merge tag 'md/4.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md 2017-09-07 12:41:48 -07:00
raid1.h md/raid1: Use a new variable to count flighting sync requests 2017-04-27 14:01:16 -07:00
raid5-cache.c Merge tag 'md/4.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md 2017-09-07 12:41:48 -07:00
raid5-log.h md/r5cache: gracefully handle journal device errors for writeback mode 2017-05-11 22:11:11 -07:00
raid5-ppl.c Merge tag 'md/4.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md 2017-09-07 12:41:48 -07:00
raid5.c Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md 2017-09-19 08:39:32 -07:00
raid5.h - A major update for DM cache that reduces the latency for deciding 2017-05-03 10:31:20 -07:00
raid10.c Merge tag 'md/4.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md 2017-09-07 12:41:48 -07:00
raid10.h md/raid10: simplify the splitting of requests. 2017-04-11 10:13:02 -07:00