linux_dsm_epyc7002/fs/btrfs
Qu Wenruo 12b894cb28 btrfs: Fix a deadlock in btrfs_dev_replace_finishing()
btrfs-transacion:5657
[stack snip]
btrfs_bio_map()
    btrfs_bio_counter_inc_blocked()
        percpu_counter_inc(&fs_info->bio_counter)  ###bio_counter > 0(A)
        __btrfs_bio_map()
            btrfs_dev_replace_lock()
                mutex_lock(dev_replace->lock)	   ###wait mutex(B)

btrfs:32612
[stack snip]
btrfs_dev_replace_start()
    btrfs_dev_replace_lock()
	mutex_lock(dev_replace->lock)		   ###hold mutex(B)
    btrfs_dev_replace_finishing()
        btrfs_rm_dev_replace_blocked()
            wait until percpu_counter_sum == 0	   ###wait on bio_counter(A)

This bug can be triggered quite easily by the following test script:
http://pastebin.com/MQmb37Cy

This patch will fix the ABBA problem by calling
btrfs_dev_replace_unlock() before btrfs_rm_dev_replace_blocked().

The consistency of btrfs devices list and their superblocks is protected
by device_list_mutex, not btrfs_dev_replace_lock/unlock().
So it is safe the move btrfs_dev_replace_unlock() before
btrfs_rm_dev_replace_blocked().

Reported-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Cc: Stefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17 13:38:22 -07:00
..
tests Btrfs: improve free space cache management and space allocation 2014-09-17 13:38:13 -07:00
acl.c btrfs: remove useless ACL check 2014-06-09 17:20:42 -07:00
async-thread.c Btrfs: fix task hang under heavy compressed write 2014-08-24 07:17:02 -07:00
async-thread.h Btrfs: fix task hang under heavy compressed write 2014-08-24 07:17:02 -07:00
backref.c btrfs: use nodesize everywhere, kill leafsize 2014-09-17 13:37:14 -07:00
backref.h Btrfs: fix scrub_print_warning to handle skinny metadata extents 2014-06-09 17:21:17 -07:00
btrfs_inode.h Btrfs: make defragment work with nodatacow option 2014-09-17 13:37:26 -07:00
check-integrity.c btrfs: use DIV_ROUND_UP instead of open-coded variants 2014-09-17 13:37:17 -07:00
check-integrity.h block: submit_bio_wait() conversions 2013-11-24 16:33:41 -07:00
compression.c btrfs: use DIV_ROUND_UP instead of open-coded variants 2014-09-17 13:37:17 -07:00
compression.h btrfs: make static code static & remove dead code 2013-05-06 15:55:23 -04:00
ctree.c Btrfs: make btrfs_search_forward return with nodes unlocked 2014-09-17 13:38:02 -07:00
ctree.h btrfs: remove stale define after removing ordered operations 2014-09-17 13:38:15 -07:00
delayed-inode.c btrfs: kill the key type accessor helpers 2014-09-17 13:37:12 -07:00
delayed-inode.h Btrfs: introduce the delayed inode ref deletion for the single link inode 2014-01-28 13:20:09 -08:00
delayed-ref.c Btrfs: rework qgroup accounting 2014-06-09 17:20:48 -07:00
delayed-ref.h Btrfs: rework qgroup accounting 2014-06-09 17:20:48 -07:00
dev-replace.c btrfs: Fix a deadlock in btrfs_dev_replace_finishing() 2014-09-17 13:38:22 -07:00
dev-replace.h Btrfs: add new sources for device replace code 2012-12-12 17:15:41 -05:00
dir-item.c btrfs: kill the key type accessor helpers 2014-09-17 13:37:12 -07:00
disk-io.c btrfs: Drop stray check of fixup_workers creation 2014-09-17 13:38:03 -07:00
disk-io.h btrfs: make close_ctree return void 2014-09-17 13:37:11 -07:00
export.c btrfs: kill the key type accessor helpers 2014-09-17 13:37:12 -07:00
export.h NFS support for btrfs - v3 2008-09-25 11:04:06 -04:00
extent_io.c Btrfs: cleanup the same name in end_bio_extent_readpage 2014-09-17 13:38:20 -07:00
extent_io.h Btrfs: shrink further sizeof(struct extent_buffer) 2014-09-17 13:38:17 -07:00
extent_map.c Btrfs: fix NULL pointer crash when running balance and scrub concurrently 2014-06-19 14:20:55 -07:00
extent_map.h Btrfs: fix NULL pointer crash when running balance and scrub concurrently 2014-06-19 14:20:55 -07:00
extent-tree.c btrfs: clean away stripe_align helper 2014-09-17 13:37:16 -07:00
file-item.c btrfs: use IS_ALIGNED() for assertion in btrfs_lookup_csums_range() for simplicity 2014-09-17 13:37:54 -07:00
file.c btrfs: use DIV_ROUND_UP instead of open-coded variants 2014-09-17 13:37:17 -07:00
free-space-cache.c Btrfs: improve free space cache management and space allocation 2014-09-17 13:38:13 -07:00
free-space-cache.h Btrfs: remove path arg from btrfs_truncate_free_space_cache 2013-11-11 21:51:33 -05:00
hash.c btrfs: use PTR_ERR_OR_ZERO 2014-09-17 13:37:29 -07:00
hash.h Btrfs: fix btrfs boot when compiled as built-in 2014-01-28 13:20:31 -08:00
inode-item.c btrfs: kill the key type accessor helpers 2014-09-17 13:37:12 -07:00
inode-map.c btrfs: cleanup ino cache members of btrfs_root 2014-09-17 13:37:09 -07:00
inode-map.h Btrfs: Support reading/writing on disk free ino cache 2011-04-25 16:46:11 +08:00
inode.c Btrfs: fix off-by-one in cow_file_range_inline() 2014-09-17 13:37:39 -07:00
ioctl.c Btrfs: make btrfs_search_forward return with nodes unlocked 2014-09-17 13:38:02 -07:00
Kconfig Btrfs: fix btrfs boot when compiled as built-in 2014-01-28 13:20:31 -08:00
locking.c Btrfs: fix deadlocks with trylock on tree nodes 2014-06-19 14:19:55 -07:00
locking.h Btrfs: remove btrfs_try_spin_lock 2013-03-14 14:57:10 -04:00
lzo.c btrfs: use DIV_ROUND_UP instead of open-coded variants 2014-09-17 13:37:17 -07:00
Makefile Btrfs: add sanity tests for new qgroup accounting code 2014-06-09 17:20:49 -07:00
math.h Btrfs: cleanup duplicated division functions 2012-12-11 13:31:30 -05:00
ordered-data.c Btrfs: fix task hang under heavy compressed write 2014-08-24 07:17:02 -07:00
ordered-data.h btrfs: disable strict file flushes for renames and truncates 2014-08-15 07:43:42 -07:00
orphan.c btrfs: kill the key type accessor helpers 2014-09-17 13:37:12 -07:00
print-tree.c btrfs: use nodesize everywhere, kill leafsize 2014-09-17 13:37:14 -07:00
print-tree.h btrfs: make static code static & remove dead code 2013-05-06 15:55:23 -04:00
props.c Btrfs: add support for inode properties 2014-01-28 13:20:24 -08:00
props.h Btrfs: add support for inode properties 2014-01-28 13:20:24 -08:00
qgroup.c btrfs: don't go readonly on existing qgroup items 2014-09-17 13:38:19 -07:00
qgroup.h btrfs: qgroup: account shared subtrees during snapshot delete 2014-08-15 07:43:14 -07:00
raid56.c btrfs: use DIV_ROUND_UP instead of open-coded variants 2014-09-17 13:37:17 -07:00
raid56.h Btrfs: RAID5 and RAID6 2013-02-01 14:24:23 -05:00
rcu-string.h Btrfs: use rcu to protect device->name 2012-06-14 21:29:16 -04:00
reada.c btrfs: use nodesize everywhere, kill leafsize 2014-09-17 13:37:14 -07:00
relocation.c btrfs: use nodesize everywhere, kill leafsize 2014-09-17 13:37:14 -07:00
root-tree.c Btrfs: use bitfield instead of integer data type for the some variants in btrfs_root 2014-06-09 17:20:40 -07:00
scrub.c Btrfs: fix wrong generation check of super block on a seed device 2014-09-17 13:37:44 -07:00
send.c Btrfs: send, lower mem requirements for processing xattrs 2014-09-17 13:38:16 -07:00
send.h btrfs: make static code static & remove dead code 2013-05-06 15:55:23 -04:00
struct-funcs.c Btrfs: rewrite BTRFS_SETGET_FUNCS 2012-07-23 16:28:06 -04:00
super.c btrfs: add trace for qgroup accounting 2014-09-17 13:37:50 -07:00
sysfs.c btrfs: sysfs label interface should check for read only FS 2014-09-17 13:38:01 -07:00
sysfs.h btrfs: code optimize: BTRFS_ATTR_RW could set the mode 2014-09-17 13:37:59 -07:00
transaction.c btrfs: use nodesize everywhere, kill leafsize 2014-09-17 13:37:14 -07:00
transaction.h btrfs: disable strict file flushes for renames and truncates 2014-08-15 07:43:42 -07:00
tree-defrag.c Btrfs: use bitfield instead of integer data type for the some variants in btrfs_root 2014-06-09 17:20:40 -07:00
tree-log.c Btrfs: make btrfs_search_forward return with nodes unlocked 2014-09-17 13:38:02 -07:00
tree-log.h Btrfs: fix fsync data loss after a ranged fsync 2014-09-08 13:56:43 -07:00
ulist.c Btrfs: do not export ulist functions 2014-01-29 07:06:27 -08:00
ulist.h Btrfs: Fix memory corruption by ulist_add_merge() on 32bit arch 2014-08-15 07:43:19 -07:00
uuid-tree.c Btrfs: make btrfs_search_forward return with nodes unlocked 2014-09-17 13:38:02 -07:00
volumes.c btrfs: rename total_bytes to avoid confusion 2014-09-17 13:38:12 -07:00
volumes.h Btrfs: cleanup unused latest_devid and latest_trans in fs_devices 2014-09-17 13:37:49 -07:00
xattr.c btrfs: kill the key type accessor helpers 2014-09-17 13:37:12 -07:00
xattr.h btrfs: use generic posix ACL infrastructure 2014-01-25 23:58:18 -05:00
zlib.c btrfs compression: merge inflate and deflate z_streams 2014-09-17 13:37:33 -07:00