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NeilBrown e6701adbba dm: correctly handle chained bios in dec_pending()
commit 8dd601fa83 upstream.

dec_pending() is given an error status (possibly 0) to be recorded
against a bio.  It can be called several times on the one 'struct
dm_io', and it is careful to only assign a non-zero error to
io->status.  However when it then assigned io->status to bio->bi_status,
it is not careful and could overwrite a genuine error status with 0.

This can happen when chained bios are in use.  If a bio is chained
beneath the bio that this dm_io is handling, the child bio might
complete and set bio->bi_status before the dm_io completes.

This has been possible since chained bios were introduced in 3.14, and
has become a lot easier to trigger with commit 18a25da843 ("dm: ensure
bio submission follows a depth-first tree walk") as that commit caused
dm to start using chained bios itself.

A particular failure mode is that if a bio spans an 'error' target and a
working target, the 'error' fragment will complete instantly and set the
->bi_status, and the other fragment will normally complete a little
later, and will clear ->bi_status.

The fix is simply to only assign io_error to bio->bi_status when
io_error is not zero.

Reported-and-tested-by: Milan Broz <gmazyland@gmail.com>
Cc: stable@vger.kernel.org (v3.14+)
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-22 15:43:51 +01:00
..
bcache bcache: check return value of register_shrinker 2018-02-03 17:05:37 +01:00
persistent-data dm btree: fix serious bug in btree_split_beneath() 2018-01-23 19:57:08 +01:00
Kconfig dm raid: select the Kconfig option CONFIG_MD_RAID0 2017-05-25 15:44:33 +02:00
Makefile dm: move request-based code out to dm-rq.[hc] 2016-06-10 15:15:44 -04:00
bitmap.c md: free unused memory after bitmap resize 2017-12-16 16:25:47 +01:00
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-bufio.c dm bufio: fix shrinker scans when (nr_to_scan < retain_target) 2018-01-17 09:38:49 +01:00
dm-bufio.h
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: fail operations if fail_io mode has been established 2017-05-25 15:44:33 +02:00
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-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: allocate struct mapped_device with kvzalloc 2017-11-30 08:39:02 +00:00
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 dm era: save spacemap metadata root after the pre-commit 2017-05-20 14:28:37 +02:00
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 ioctl: prevent stack leak in dm ioctl call 2017-05-08 07:47:55 +02:00
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-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: cleanup -Wbool-operation warning in choose_pgpath() 2017-07-27 15:07:55 -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-raid.c dm raid: fix NULL pointer dereference for raid1 without bitmap 2017-04-12 12:41:13 +02:00
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: check blk_mq_register_dev() return value in dm_mq_init_request_queue() 2017-05-20 14:28:37 +02:00
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 metadata: THIN_MAX_CONCURRENT_LOCKS should be 6 2018-01-23 19:57:09 +01:00
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 dm thin: do not queue freed thin mapping for next stage processing 2017-07-05 14:40:18 +02:00
dm-uevent.c
dm-uevent.h
dm-verity-fec.c dm verity fec: fix bufio leaks 2017-04-12 12:41:12 +02:00
dm-verity-fec.h dm verity fec: limit error correction recursion 2017-04-12 12:41:12 +02:00
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: correctly handle chained bios in dec_pending() 2018-02-22 15:43:51 +01:00
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
linear.c md/linear: shutup lockdep warnning 2017-10-21 17:21:35 +02:00
linear.h md linear: fix a race between linear_add() and linear_congested() 2017-03-12 06:41:52 +01:00
md-cluster.c md-cluster: free md_cluster_info if node leave cluster 2017-12-20 10:07:18 +01:00
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 super_offset endianness in super_1_rdev_size_change 2017-07-15 12:16:15 +02:00
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
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 md: don't use flush_signals in userspace processes 2017-07-27 15:08:01 -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 raid5: Set R5_Expanded on parity devices as well as data. 2017-12-20 10:07:32 +01:00
raid5.h md/raid5: Convert to hotplug state machine 2016-09-06 18:30:23 +02:00
raid10.c md/raid10: submit bio directly to replacement disk 2017-10-08 10:26:11 +02:00
raid10.h raid10: improve random reads performance 2016-07-19 15:20:28 -07:00