linux-brain/drivers/md
NeilBrown eb2593fbd6 md: only allow remove_and_add_spares when no sync_thread running.
commit 39772f0a7b upstream.

The locking protocols in md assume that a device will
never be removed from an array during resync/recovery/reshape.
When that isn't happening, rcu or reconfig_mutex is needed
to protect an rdev pointer while taking a refcount.  When
it is happening, that protection isn't needed.

Unfortunately there are cases were remove_and_add_spares() is
called when recovery might be happening: is state_store(),
slot_store() and hot_remove_disk().
In each case, this is just an optimization, to try to expedite
removal from the personality so the device can be removed from
the array.  If resync etc is happening, we just have to wait
for md_check_recover to find a suitable time to call
remove_and_add_spares().

This optimization and not essential so it doesn't
matter if it fails.
So change remove_and_add_spares() to abort early if
resync/recovery/reshape is happening, unless it is called
from md_check_recovery() as part of a newly started recovery.
The parameter "this" is only NULL when called from
md_check_recovery() so when it is NULL, there is no need to abort.

As this can result in a NULL dereference, the fix is suitable
for -stable.

cc: yuyufen <yuyufen@huawei.com>
Cc: Tomasz Majchrzak <tomasz.majchrzak@intel.com>
Fixes: 8430e7e0af ("md: disconnect device from personality before trying to remove it.")
Cc: stable@ver.kernel.org (v4.8+)
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <sh.li@alibaba-inc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-11 16:21:31 +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
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 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: 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: 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: 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 dm io: fix duplicate bio completion due to missing ref count 2018-03-11 16:21:30 +01:00
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
Kconfig dm raid: select the Kconfig option CONFIG_MD_RAID0 2017-05-25 15:44:33 +02:00
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
Makefile dm: move request-based code out to dm-rq.[hc] 2016-06-10 15:15:44 -04:00
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: only allow remove_and_add_spares when no sync_thread running. 2018-03-11 16:21:31 +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
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
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