Filipe Manana 24b89d08ef Btrfs: fix deadlock when starting writeback of bg caches ... While starting the writes of the dirty block group caches, if we don't find a block group item in the extent tree we were leaving without releasing our path, running delayed references and then looping again to process any new dirty block groups. However this second iteration of the loop could cause a deadlock because it tries to lock some other extent tree node/leaf which another task already locked and it's blocked because it's waiting for a lock on some node/leaf that is in our path that was not released before. We could also deadlock when running the delayed references - as we could end up trying to lock the same nodes/leafs that we have in our local path (with a different lock type). Got into such case when running xfstests: [20892.242791] ------------[ cut here ]------------ [20892.243776] WARNING: CPU: 0 PID: 13299 at fs/btrfs/super.c:260 __btrfs_abort_transaction+0x52/0x114 [btrfs]() [20892.245874] BTRFS: Transaction aborted (error -2) (...) [20892.269378] Call Trace: [20892.269915] [<ffffffff8142fa46>] dump_stack+0x4f/0x7b [20892.271097] [<ffffffff8108b6a2>] ? console_unlock+0x361/0x3ad [20892.272173] [<ffffffff81045ea5>] warn_slowpath_common+0xa1/0xbb [20892.273386] [<ffffffffa0509a6d>] ? __btrfs_abort_transaction+0x52/0x114 [btrfs] [20892.274857] [<ffffffff81045f05>] warn_slowpath_fmt+0x46/0x48 [20892.275851] [<ffffffffa0509a6d>] __btrfs_abort_transaction+0x52/0x114 [btrfs] [20892.277341] [<ffffffffa0515e10>] write_one_cache_group+0x68/0xaf [btrfs] [20892.278628] [<ffffffffa052088a>] btrfs_start_dirty_block_groups+0x18d/0x29b [btrfs] [20892.280191] [<ffffffffa052f077>] btrfs_commit_transaction+0x130/0x9c9 [btrfs] (...) [20892.291316] ---[ end trace 597f77e664245373 ]--- [20892.293955] BTRFS: error (device sdg) in write_one_cache_group:3184: errno=-2 No such entry [20892.297390] BTRFS info (device sdg): forced readonly [20892.298222] ------------[ cut here ]------------ [20892.299190] WARNING: CPU: 0 PID: 13299 at fs/btrfs/ctree.c:2683 btrfs_search_slot+0x7e/0x7d2 [btrfs]() (...) [20892.326253] Call Trace: [20892.326904] [<ffffffff8142fa46>] dump_stack+0x4f/0x7b [20892.329503] [<ffffffff8108b6a2>] ? console_unlock+0x361/0x3ad [20892.330815] [<ffffffff81045ea5>] warn_slowpath_common+0xa1/0xbb [20892.332556] [<ffffffffa0510b73>] ? btrfs_search_slot+0x7e/0x7d2 [btrfs] [20892.333955] [<ffffffff81045f62>] warn_slowpath_null+0x1a/0x1c [20892.335562] [<ffffffffa0510b73>] btrfs_search_slot+0x7e/0x7d2 [btrfs] [20892.336849] [<ffffffff8107b024>] ? arch_local_irq_save+0x9/0xc [20892.338222] [<ffffffffa051ad52>] ? cache_save_setup+0x43/0x2a5 [btrfs] [20892.339823] [<ffffffffa051ad66>] ? cache_save_setup+0x57/0x2a5 [btrfs] [20892.341275] [<ffffffff814351a4>] ? _raw_spin_unlock+0x32/0x46 [20892.342810] [<ffffffffa0515de7>] write_one_cache_group+0x3f/0xaf [btrfs] [20892.344184] [<ffffffffa052088a>] btrfs_start_dirty_block_groups+0x18d/0x29b [btrfs] [20892.347162] [<ffffffffa052f077>] btrfs_commit_transaction+0x130/0x9c9 [btrfs] (...) [20892.361015] ---[ end trace 597f77e664245374 ]--- [21120.688097] INFO: task kworker/u8:17:29854 blocked for more than 120 seconds. [21120.689881] Tainted: G W 4.0.0-rc5-btrfs-next-9+ #2 [21120.691384] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. (...) [21120.703696] Call Trace: [21120.704310] [<ffffffff8143107e>] schedule+0x74/0x83 [21120.705490] [<ffffffffa055f025>] btrfs_tree_lock+0xd7/0x236 [btrfs] [21120.706757] [<ffffffff81075cd6>] ? signal_pending_state+0x31/0x31 [21120.708156] [<ffffffffa054ac1e>] lock_extent_buffer_for_io+0x3e/0x194 [btrfs] [21120.709892] [<ffffffffa054bb86>] ? btree_write_cache_pages+0x273/0x385 [btrfs] [21120.711605] [<ffffffffa054bc42>] btree_write_cache_pages+0x32f/0x385 [btrfs] [21120.723440] [<ffffffffa0527552>] btree_writepages+0x23/0x5c [btrfs] [21120.724943] [<ffffffff8110c4c8>] do_writepages+0x23/0x2c [21120.726008] [<ffffffff81176dde>] __writeback_single_inode+0x73/0x2fa [21120.727230] [<ffffffff8117714a>] ? writeback_sb_inodes+0xe5/0x38b [21120.728526] [<ffffffff811771fb>] ? writeback_sb_inodes+0x196/0x38b [21120.729701] [<ffffffff8117726a>] writeback_sb_inodes+0x205/0x38b (...) [21120.747853] INFO: task btrfs:13282 blocked for more than 120 seconds. [21120.749459] Tainted: G W 4.0.0-rc5-btrfs-next-9+ #2 [21120.751137] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. (...) [21120.768457] Call Trace: [21120.769039] [<ffffffff8143107e>] schedule+0x74/0x83 [21120.770107] [<ffffffffa052f25c>] btrfs_commit_transaction+0x315/0x9c9 [btrfs] [21120.771558] [<ffffffff81075cd6>] ? signal_pending_state+0x31/0x31 [21120.773659] [<ffffffffa056fd8c>] prepare_to_relocate+0xcb/0xd2 [btrfs] [21120.776257] [<ffffffffa05741da>] relocate_block_group+0x44/0x4a9 [btrfs] [21120.777755] [<ffffffffa05747a0>] ? btrfs_relocate_block_group+0x161/0x288 [btrfs] [21120.779459] [<ffffffffa05747a8>] btrfs_relocate_block_group+0x169/0x288 [btrfs] [21120.781153] [<ffffffffa0550403>] btrfs_relocate_chunk.isra.29+0x3e/0xa7 [btrfs] [21120.783918] [<ffffffffa05518fd>] btrfs_balance+0xaa4/0xc52 [btrfs] [21120.785436] [<ffffffff8114306e>] ? cpu_cache_get.isra.39+0xe/0x1f [21120.786434] [<ffffffffa0559252>] btrfs_ioctl_balance+0x23f/0x2b0 [btrfs] (...) [21120.889251] INFO: task fsstress:13288 blocked for more than 120 seconds. [21120.890526] Tainted: G W 4.0.0-rc5-btrfs-next-9+ #2 [21120.891773] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. (...) [21120.899960] Call Trace: [21120.900743] [<ffffffff8143107e>] schedule+0x74/0x83 [21120.903004] [<ffffffffa055f025>] btrfs_tree_lock+0xd7/0x236 [btrfs] [21120.904383] [<ffffffff81075cd6>] ? signal_pending_state+0x31/0x31 [21120.905608] [<ffffffffa051125b>] btrfs_search_slot+0x766/0x7d2 [btrfs] [21120.906812] [<ffffffff8114290e>] ? virt_to_head_page+0x9/0x2c [21120.907874] [<ffffffff81144b7f>] ? cache_alloc_debugcheck_after.isra.42+0x16c/0x1cb [21120.909551] [<ffffffffa05124e0>] btrfs_insert_empty_items+0x5d/0xa8 [btrfs] [21120.910914] [<ffffffffa0512585>] btrfs_insert_item+0x5a/0xa5 [btrfs] [21120.912181] [<ffffffffa0520271>] ? btrfs_create_pending_block_groups+0x96/0x130 [btrfs] [21120.913784] [<ffffffffa052028a>] btrfs_create_pending_block_groups+0xaf/0x130 [btrfs] [21120.915374] [<ffffffffa052ffc2>] __btrfs_end_transaction+0x84/0x366 [btrfs] [21120.916735] [<ffffffffa05302b4>] btrfs_end_transaction+0x10/0x12 [btrfs] [21120.917996] [<ffffffffa051ab26>] btrfs_check_data_free_space+0x11f/0x27c [btrfs] [21120.919478] [<ffffffffa051ba25>] btrfs_delalloc_reserve_space+0x1e/0x51 [btrfs] [21120.921226] [<ffffffffa05382f2>] btrfs_truncate_page+0x85/0x2c4 [btrfs] [21120.923121] [<ffffffffa0538572>] btrfs_cont_expand+0x41/0x3ef [btrfs] [21120.924449] [<ffffffffa0541091>] ? btrfs_file_write_iter+0x19a/0x431 [btrfs] [21120.926602] [<ffffffff8107b024>] ? arch_local_irq_save+0x9/0xc [21120.927769] [<ffffffffa0541091>] ? btrfs_file_write_iter+0x19a/0x431 [btrfs] [21120.929324] [<ffffffffa05410a0>] ? btrfs_file_write_iter+0x1a9/0x431 [btrfs] [21120.930723] [<ffffffffa05410d9>] btrfs_file_write_iter+0x1e2/0x431 [btrfs] [21120.931897] [<ffffffff81067d85>] ? get_parent_ip+0xe/0x3e [21120.934446] [<ffffffff811534c3>] new_sync_write+0x7c/0xa0 [21120.935528] [<ffffffff81153b58>] vfs_write+0xb2/0x117 (...) Fixes: 1bbc621ef2 ("Btrfs: allow block group cache writeout outside critical section in commit") Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>		2015-04-26 06:26:37 -07:00
..
tests	Btrfs: qgroup: cleanup, remove an unsued parameter in btrfs_create_qgroup().	2015-04-13 07:52:44 -07:00
acl.c	btrfs: remove useless ACL check	2014-06-09 17:20:42 -07:00
async-thread.c	btrfs: use correct type for workqueue flags	2015-02-16 18:48:47 +01:00
async-thread.h	btrfs: use correct type for workqueue flags	2015-02-16 18:48:47 +01:00
backref.c	btrfs: use explicit initializer for seq_elem	2015-03-03 17:23:59 +01:00
backref.h	btrfs: cleanup, remove inode_item_info helper	2015-01-14 19:23:47 +01:00
btrfs_inode.h	Btrfs: fix metadata inconsistencies after directory fsync	2015-03-26 17:56:23 -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	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
ctree.h	btrfs: Don't allow subvolid >= (1 << BTRFS_QGROUP_LEVEL_SHIFT) to be created	2015-04-13 07:52:54 -07:00
delayed-inode.c	Btrfs: delayed-inode: replace root args iff only fs_info used	2015-02-16 18:48:43 +01:00
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: account for crcs in delayed ref processing	2015-04-10 14:04:47 -07:00
delayed-ref.h	Btrfs: account for crcs in delayed ref processing	2015-04-10 14:04:47 -07:00
dev-replace.c	btrfs: cleanup 64bit/32bit divs, compile time constants	2015-03-03 17:23:57 +01:00
dev-replace.h
dir-item.c	Btrfs: make xattr replace operations atomic	2014-11-20 17:20:07 -08:00
disk-io.c	btrfs: Fix NO_SPACE bug caused by delayed-iput	2015-04-13 07:27:41 -07:00
disk-io.h	Btrfs: disk-io: replace root args iff only fs_info used	2015-02-16 18:48:43 +01:00
export.c	btrfs: kill the key type accessor helpers	2014-09-17 13:37:12 -07:00
export.h
extent_io.c	btrfs: incorrect handling for fiemap_fill_next_extent return	2015-03-26 18:10:24 -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
extent-tree.c	Btrfs: fix deadlock when starting writeback of bg caches	2015-04-26 06:26:37 -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	btrfs: qgroup: do a reservation in a higher level.	2015-04-13 07:52:50 -07:00
free-space-cache.c	Btrfs: prevent list corruption during free space cache processing	2015-04-24 11:52:25 -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: allow block group cache writeout outside critical section in commit	2015-04-10 14:07:22 -07:00
inode-map.h
inode.c	btrfs: qgroup: do a reservation in a higher level.	2015-04-13 07:52:50 -07:00
ioctl.c	btrfs: quota: Update quota tree after qgroup relationship change.	2015-04-13 07:53:00 -07:00
Kconfig	rcu: Make SRCU optional by using CONFIG_SRCU	2015-01-06 11:04:29 -08:00
locking.c	btrfs: fix lockups from btrfs_clear_path_blocking	2014-11-19 10:34:35 -08:00
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 fsync race leading to ordered extent memory leaks	2015-03-02 14:04:44 -08:00
ordered-data.h	Btrfs: collect only the necessary ordered extents on ranged fsync	2014-11-21 11:59:56 -08:00
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	btrfs: make static code static & remove dead code	2013-05-06 15:55:23 -04:00
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: quota: Automatically update related qgroups or mark INCONSISTENT flags when assigning/deleting a qgroup relations.	2015-04-13 07:52:59 -07:00
qgroup.h	btrfs: qgroup: do a reservation in a higher level.	2015-04-13 07:52:50 -07:00
raid56.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
raid56.h	Btrfs: Make raid_map array be inlined in btrfs_bio structure	2015-01-21 18:06:47 -08:00
rcu-string.h
reada.c	Btrfs: add ref_count and free function for btrfs_bio	2015-01-21 18:06:48 -08:00
relocation.c	btrfs: qgroup: do a reservation in a higher level.	2015-04-13 07:52:50 -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	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
send.c	Btrfs: incremental send, remove dead code	2015-03-26 17:55:52 -07:00
send.h	btrfs: make static code static & remove dead code	2013-05-06 15:55:23 -04:00
struct-funcs.c
super.c	btrfs: cleanup orphans while looking up default subvolume	2015-03-26 18:10:25 -07:00
sysfs.c	btrfs: constify structs with op functions or static definitions	2015-02-16 18:48:44 +01:00
sysfs.h	btrfs: switch helper macros to static inlines in sysfs.h	2015-03-03 17:24:02 +01:00
transaction.c	Btrfs: allow block group cache writeout outside critical section in commit	2015-04-10 14:07:22 -07:00
transaction.h	Btrfs: allow block group cache writeout outside critical section in commit	2015-04-10 14:07:22 -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: actively run the delayed refs while deleting large files	2015-04-10 14:00:14 -07:00
tree-log.h	Btrfs: fix metadata inconsistencies after directory fsync	2015-03-26 17:56:23 -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: Fix tail space processing in find_free_dev_extent()	2015-04-13 07:27:18 -07:00
volumes.h	btrfs: remove unused fs_info arg from btrfs_close_extra_devices()	2015-02-16 18:48:45 +01:00
xattr.c	btrfs: don't accept bare namespace as a valid xattr	2015-03-26 18:10:24 -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