Filipe Manana 85e0a0f21a Btrfs: remove unnecessary locking of cleaner_mutex to avoid deadlock ... After commmit e44163e177 ("btrfs: explictly delete unused block groups in close_ctree and ro-remount"), added in the 4.3 merge window, we have calls to btrfs_delete_unused_bgs() while holding the cleaner_mutex. This can cause a deadlock with a concurrent block group relocation (when a filesystem balance or shrink operation is in progress for example) because btrfs_delete_unused_bgs() locks delete_unused_bgs_mutex and the relocation path locks first delete_unused_bgs_mutex and then it locks cleaner_mutex, resulting in a classic ABBA deadlock: CPU 0 CPU 1 lock fs_info->cleaner_mutex __btrfs_balance() || btrfs_shrink_device() lock fs_info->delete_unused_bgs_mutex btrfs_relocate_chunk() btrfs_relocate_block_group() lock fs_info->cleaner_mutex btrfs_delete_unused_bgs() lock fs_info->delete_unused_bgs_mutex Fix this by not taking the cleaner_mutex before calling btrfs_delete_unused_bgs() because it's no longer needed after commit 67c5e7d464 ("Btrfs: fix race between balance and unused block group deletion"). The mutex fs_info->delete_unused_bgs_mutex, the spinlock fs_info->unused_bgs_lock and a block group's spinlock are enough to get correct serialization between tasks running relocation and unused block group deletion (as well as between multiple tasks concurrently calling btrfs_delete_unused_bgs()). This issue was discussed (in the mailing list) during the review of the patch titled "btrfs: explictly delete unused block groups in close_ctree and ro-remount" and it was agreed that acquiring the cleaner mutex had to be dropped after the patch titled "Btrfs: fix race between balance and unused block group deletion" got merged (both patches were submitted at about the same time, but one landed in kernel 4.2 and the other in the 4.3 merge window). Signed-off-by: Filipe Manana <fdmanana@suse.com>		2015-09-10 11:27:57 +01:00
..
tests	btrfs: qgroup: Switch self test to extent-oriented qgroup mechanism.	2015-06-10 09:26:05 -07:00
acl.c	btrfs: remove useless ACL check	2014-06-09 17:20:42 -07:00
async-thread.c	btrfs: async_thread: Fix workqueue 'max_active' value when initializing	2015-08-31 11:46:40 -07:00
async-thread.h	btrfs: async_thread: Fix workqueue 'max_active' value when initializing	2015-08-31 11:46:40 -07:00
backref.c	Btrfs: fix warning in backref walking	2015-08-09 07:33:50 -07:00
backref.h	btrfs: cleanup, remove inode_item_info helper	2015-01-14 19:23:47 +01:00
btrfs_inode.h	Btrfs: fix warning of bytes_may_use	2015-07-01 17:17:21 -07:00
check-integrity.c	Merge branch 'cleanups-post-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux into for-linus-4.1	2015-03-25 10:52:48 -07:00
check-integrity.h	block: submit_bio_wait() conversions	2013-11-24 16:33:41 -07:00
compression.c	Merge branch 'cleanups-post-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux into for-linus-4.1	2015-03-25 10:52:48 -07:00
compression.h	btrfs: constify structs with op functions or static definitions	2015-02-16 18:48:44 +01:00
ctree.c	btrfs: abort transaction on btrfs_reloc_cow_block()	2015-08-09 07:07:14 -07:00
ctree.h	Merge branch 'jeffm-discard-4.3' into for-linus-4.3	2015-08-09 07:35:33 -07:00
delayed-inode.c	Btrfs: fill ->last_trans for delayed inode in btrfs_fill_inode.	2015-04-26 06:27:03 -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: delayed-ref: double free in btrfs_add_delayed_tree_ref()	2015-06-24 12:28:03 -07:00
delayed-ref.h	btrfs: qgroup: Add the ability to skip given qgroup for old/new_roots.	2015-06-10 09:26:23 -07:00
dev-replace.c	Btrfs: cleanup: remove unnecessary check before btrfs_free_path is called	2015-08-31 11:46:41 -07:00
dev-replace.h
dir-item.c	Btrfs: make xattr replace operations atomic	2014-11-20 17:20:07 -08:00
disk-io.c	Btrfs: remove unnecessary locking of cleaner_mutex to avoid deadlock	2015-09-10 11:27:57 +01:00
disk-io.h	btrfs: Add raid56 support for updating	2015-08-31 11:45:48 -07:00
export.c	VFS: normal filesystems (and lustre): d_inode() annotations	2015-04-15 15:06:57 -04:00
export.h
extent-tree.c	Btrfs: don't initialize a space info as full to prevent ENOSPC	2015-09-08 03:25:10 +01:00
extent-tree.h	btrfs: qgroup: Add new qgroup calculation function	2015-06-10 09:25:49 -07:00
extent_io.c	btrfs: fix compile when block cgroups are not enabled	2015-08-21 10:08:13 -07:00
extent_io.h	btrfs: constify structs with op functions or static definitions	2015-02-16 18:48:44 +01:00
extent_map.c	Btrfs: do not move em to modified list when unpinning	2014-11-21 11:59:54 -08:00
extent_map.h	Btrfs: fix NULL pointer crash when running balance and scrub concurrently	2014-06-19 14:20:55 -07:00
file-item.c	Merge branch 'cleanups-post-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux into for-linus-4.1	2015-03-25 10:52:48 -07:00
file.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2015-07-04 19:36:06 -07:00
free-space-cache.c	btrfs: add missing discards when unpinning extents with -o discard	2015-07-29 08:15:29 -07:00
free-space-cache.h	Btrfs: allow block group cache writeout outside critical section in commit	2015-04-10 14:07:22 -07:00
hash.c	btrfs: LLVMLinux: Remove VLAIS	2014-10-14 10:51:22 +02:00
hash.h	Btrfs: fix btrfs boot when compiled as built-in	2014-01-28 13:20:31 -08:00
inode-item.c	Btrfs: fix fsync log replay for inodes with a mix of regular refs and extrefs	2015-01-21 18:02:05 -08:00
inode-map.c	Btrfs: fix race between caching kthread and returning inode to inode cache	2015-06-30 14:36:46 -07:00
inode-map.h
inode.c	Btrfs: cleanup: remove unnecessary check before btrfs_free_path is called	2015-08-31 11:46:41 -07:00
ioctl.c	btrfs: fix clone / extent-same deadlocks	2015-08-09 07:34:25 -07:00
Kconfig	rcu: Make SRCU optional by using CONFIG_SRCU	2015-01-06 11:04:29 -08:00
locking.c	btrfs: Add WARN_ON() for double lock in btrfs_tree_lock()	2015-08-09 07:07:14 -07:00
locking.h	btrfs: fix lockups from btrfs_clear_path_blocking	2014-11-19 10:34:35 -08:00
lzo.c	btrfs: constify structs with op functions or static definitions	2015-02-16 18:48:44 +01:00
Makefile	Btrfs: add sanity tests for new qgroup accounting code	2014-06-09 17:20:49 -07:00
math.h	btrfs: cleanup 64bit/32bit divs, compile time constants	2015-03-03 17:23:57 +01:00
ordered-data.c	Btrfs: fix memory corruption on failure to submit bio for direct IO	2015-07-01 17:17:18 -07:00
ordered-data.h	Btrfs: avoid syncing log in the fast fsync path when not necessary	2015-06-10 07:02:43 -07:00
orphan.c	btrfs: kill the key type accessor helpers	2014-09-17 13:37:12 -07:00
print-tree.c	btrfs: remove parameter blocksize from read_tree_block	2014-10-02 17:14:50 +02:00
print-tree.h
props.c	btrfs: constify structs with op functions or static definitions	2015-02-16 18:48:44 +01:00
props.h	Btrfs: add support for inode properties	2014-01-28 13:20:24 -08:00
qgroup.c	btrfs: qgroup: allow user to clear the limitation on qgroup	2015-06-30 13:20:00 -07:00
qgroup.h	btrfs: qgroup: Cleanup the old ref_node-oriented mechanism.	2015-06-10 09:26:11 -07:00
raid56.c	Btrfs: add RAID 5/6 BTRFS_RBIO_REBUILD_MISSING operation	2015-08-09 07:34:26 -07:00
raid56.h	Btrfs: add RAID 5/6 BTRFS_RBIO_REBUILD_MISSING operation	2015-08-09 07:34:26 -07:00
rcu-string.h
reada.c	Btrfs: count devices correctly in readahead during RAID 5/6 replace	2015-08-09 07:34:26 -07:00
relocation.c	btrfs: Remove unnecessary variants in relocation.c	2015-08-09 07:07:14 -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: Remove noused chunk_tree and chunk_objectid from scrub_enumerate_chunks and scrub_chunk	2015-08-31 11:45:46 -07:00
send.c	Btrfs: use received_uuid of parent during send	2015-06-12 13:20:38 -07:00
send.h
struct-funcs.c
super.c	Btrfs: remove unnecessary locking of cleaner_mutex to avoid deadlock	2015-09-10 11:27:57 +01:00
sysfs.c	Btrfs: Check if kobject is initialized before put	2015-06-22 14:43:31 +02:00
sysfs.h	Btrfs: sysfs: btrfs_sysfs_remove_fsid() make it non static	2015-05-27 12:27:22 +02:00
transaction.c	Btrfs: check if previous transaction aborted to avoid fs corruption	2015-08-19 14:27:31 -07:00
transaction.h	btrfs: add missing discards when unpinning extents with -o discard	2015-07-29 08:15:29 -07:00
tree-defrag.c	Btrfs: cleanup: remove unnecessary check before btrfs_free_path is called	2015-08-31 11:46:41 -07:00
tree-log.c	Btrfs: fix file read corruption after extent cloning and fsync	2015-08-19 14:27:46 -07:00
tree-log.h	Btrfs: fix metadata inconsistencies after directory fsync	2015-03-26 17:56:23 -07:00
ulist.c	btrfs: ulist: Add ulist_del() function.	2015-06-10 09:26:17 -07:00
ulist.h	btrfs: ulist: Add ulist_del() function.	2015-06-10 09:26:17 -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: Add raid56 support for updating	2015-08-31 11:45:48 -07:00
volumes.h	Merge branch 'jeffm-discard-4.3' into for-linus-4.3	2015-08-09 07:35:33 -07:00
xattr.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2015-04-26 17:22:07 -07:00
xattr.h	btrfs: use generic posix ACL infrastructure	2014-01-25 23:58:18 -05:00
zlib.c	btrfs: constify structs with op functions or static definitions	2015-02-16 18:48:44 +01:00