Filipe David Borba Manana 3fe81ce206 Btrfs: fix deadlock when iterating inode refs and running delayed inodes ... While running btrfs/004 from xfstests, after 503 iterations, dmesg reported a deadlock between tasks iterating inode refs and tasks running delayed inodes (during a transaction commit). It turns out that iterating inode refs implies doing one tree search and release all nodes in the path except the leaf node, and then passing that leaf node to btrfs_ref_to_path(), which in turn does another tree search without releasing the lock on the leaf node it received as parameter. This is a problem when other task wants to write to the btree as well and ends up updating the leaf that is read locked - the writer task locks the parent of the leaf and then blocks waiting for the leaf's lock to be released - at the same time, the task executing btrfs_ref_to_path() does a second tree search, without releasing the lock on the first leaf, and wants to access a leaf (the same or another one) that is a child of the same parent, resulting in a deadlock. The trace reported by lockdep follows. [84314.936373] INFO: task fsstress:11930 blocked for more than 120 seconds. [84314.936381] Tainted: G W O 3.12.0-fdm-btrfs-next-16+ #70 [84314.936383] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [84314.936386] fsstress D ffff8806e1bf8000 0 11930 11926 0x00000000 [84314.936393] ffff8804d6d89b78 0000000000000046 ffff8804d6d89b18 ffffffff810bd8bd [84314.936399] ffff8806e1bf8000 ffff8804d6d89fd8 ffff8804d6d89fd8 ffff8804d6d89fd8 [84314.936405] ffff880806308000 ffff8806e1bf8000 ffff8804d6d89c08 ffff8804deb8f190 [84314.936410] Call Trace: [84314.936421] [<ffffffff810bd8bd>] ? trace_hardirqs_on+0xd/0x10 [84314.936428] [<ffffffff81774269>] schedule+0x29/0x70 [84314.936451] [<ffffffffa0715bf5>] btrfs_tree_lock+0x75/0x270 [btrfs] [84314.936457] [<ffffffff810715c0>] ? __init_waitqueue_head+0x60/0x60 [84314.936470] [<ffffffffa06ba231>] btrfs_search_slot+0x7f1/0x930 [btrfs] [84314.936489] [<ffffffffa0731c2a>] ? __btrfs_run_delayed_items+0x13a/0x1e0 [btrfs] [84314.936504] [<ffffffffa06d2e1f>] btrfs_lookup_inode+0x2f/0xa0 [btrfs] [84314.936510] [<ffffffff810bd6ef>] ? trace_hardirqs_on_caller+0x1f/0x1e0 [84314.936528] [<ffffffffa073173c>] __btrfs_update_delayed_inode+0x4c/0x1d0 [btrfs] [84314.936543] [<ffffffffa0731c2a>] ? __btrfs_run_delayed_items+0x13a/0x1e0 [btrfs] [84314.936558] [<ffffffffa0731c2a>] ? __btrfs_run_delayed_items+0x13a/0x1e0 [btrfs] [84314.936573] [<ffffffffa0731c82>] __btrfs_run_delayed_items+0x192/0x1e0 [btrfs] [84314.936589] [<ffffffffa0731d03>] btrfs_run_delayed_items+0x13/0x20 [btrfs] [84314.936604] [<ffffffffa06dbcd4>] btrfs_flush_all_pending_stuffs+0x24/0x80 [btrfs] [84314.936620] [<ffffffffa06ddc13>] btrfs_commit_transaction+0x223/0xa20 [btrfs] [84314.936630] [<ffffffffa06ae5ae>] btrfs_sync_fs+0x6e/0x110 [btrfs] [84314.936635] [<ffffffff811d0b50>] ? __sync_filesystem+0x60/0x60 [84314.936639] [<ffffffff811d0b50>] ? __sync_filesystem+0x60/0x60 [84314.936643] [<ffffffff811d0b70>] sync_fs_one_sb+0x20/0x30 [84314.936648] [<ffffffff811a3541>] iterate_supers+0xf1/0x100 [84314.936652] [<ffffffff811d0c45>] sys_sync+0x55/0x90 [84314.936658] [<ffffffff8177ef12>] system_call_fastpath+0x16/0x1b [84314.936660] INFO: lockdep is turned off. [84314.936663] INFO: task btrfs:11955 blocked for more than 120 seconds. [84314.936666] Tainted: G W O 3.12.0-fdm-btrfs-next-16+ #70 [84314.936668] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [84314.936670] btrfs D ffff880541729a88 0 11955 11608 0x00000000 [84314.936674] ffff880541729a38 0000000000000046 ffff8805417299d8 ffffffff810bd8bd [84314.936680] ffff88075430c8a0 ffff880541729fd8 ffff880541729fd8 ffff880541729fd8 [84314.936685] ffffffff81c104e0 ffff88075430c8a0 ffff8804de8b00b8 ffff8804de8b0000 [84314.936690] Call Trace: [84314.936695] [<ffffffff810bd8bd>] ? trace_hardirqs_on+0xd/0x10 [84314.936700] [<ffffffff81774269>] schedule+0x29/0x70 [84314.936717] [<ffffffffa0715815>] btrfs_tree_read_lock+0xd5/0x140 [btrfs] [84314.936721] [<ffffffff810715c0>] ? __init_waitqueue_head+0x60/0x60 [84314.936733] [<ffffffffa06ba201>] btrfs_search_slot+0x7c1/0x930 [btrfs] [84314.936746] [<ffffffffa06bd505>] btrfs_find_item+0x55/0x160 [btrfs] [84314.936763] [<ffffffffa06ff689>] ? free_extent_buffer+0x49/0xc0 [btrfs] [84314.936780] [<ffffffffa073c9ca>] btrfs_ref_to_path+0xba/0x1e0 [btrfs] [84314.936797] [<ffffffffa06f9719>] ? release_extent_buffer+0xb9/0xe0 [btrfs] [84314.936813] [<ffffffffa06ff689>] ? free_extent_buffer+0x49/0xc0 [btrfs] [84314.936830] [<ffffffffa073cb50>] inode_to_path+0x60/0xd0 [btrfs] [84314.936846] [<ffffffffa073d365>] paths_from_inode+0x115/0x3c0 [btrfs] [84314.936851] [<ffffffff8118dd44>] ? kmem_cache_alloc_trace+0x114/0x200 [84314.936868] [<ffffffffa0714494>] btrfs_ioctl+0xf14/0x2030 [btrfs] [84314.936873] [<ffffffff817762db>] ? _raw_spin_unlock+0x2b/0x50 [84314.936877] [<ffffffff8116598f>] ? handle_mm_fault+0x34f/0xb00 [84314.936882] [<ffffffff81075563>] ? up_read+0x23/0x40 [84314.936886] [<ffffffff8177a41c>] ? __do_page_fault+0x20c/0x5a0 [84314.936892] [<ffffffff811b2946>] do_vfs_ioctl+0x96/0x570 [84314.936896] [<ffffffff81776e23>] ? error_sti+0x5/0x6 [84314.936901] [<ffffffff810b71e8>] ? trace_hardirqs_off_caller+0x28/0xd0 [84314.936906] [<ffffffff81776a09>] ? retint_swapgs+0xe/0x13 [84314.936910] [<ffffffff811b2eb1>] SyS_ioctl+0x91/0xb0 [84314.936915] [<ffffffff813eecde>] ? trace_hardirqs_on_thunk+0x3a/0x3f [84314.936920] [<ffffffff8177ef12>] system_call_fastpath+0x16/0x1b [84314.936922] INFO: lockdep is turned off. [84434.866873] INFO: task btrfs-transacti:11921 blocked for more than 120 seconds. [84434.866881] Tainted: G W O 3.12.0-fdm-btrfs-next-16+ #70 [84434.866883] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [84434.866886] btrfs-transacti D ffff880755b6a478 0 11921 2 0x00000000 [84434.866893] ffff8800735b9ce8 0000000000000046 ffff8800735b9c88 ffffffff810bd8bd [84434.866899] ffff8805a1b848a0 ffff8800735b9fd8 ffff8800735b9fd8 ffff8800735b9fd8 [84434.866904] ffffffff81c104e0 ffff8805a1b848a0 ffff880755b6a478 ffff8804cece78f0 [84434.866910] Call Trace: [84434.866920] [<ffffffff810bd8bd>] ? trace_hardirqs_on+0xd/0x10 [84434.866927] [<ffffffff81774269>] schedule+0x29/0x70 [84434.866948] [<ffffffffa06dd2ef>] wait_current_trans.isra.33+0xbf/0x120 [btrfs] [84434.866954] [<ffffffff810715c0>] ? __init_waitqueue_head+0x60/0x60 [84434.866970] [<ffffffffa06dec18>] start_transaction+0x388/0x5a0 [btrfs] [84434.866985] [<ffffffffa06db9b5>] ? transaction_kthread+0xb5/0x280 [btrfs] [84434.866999] [<ffffffffa06dee97>] btrfs_attach_transaction+0x17/0x20 [btrfs] [84434.867012] [<ffffffffa06dba9e>] transaction_kthread+0x19e/0x280 [btrfs] [84434.867026] [<ffffffffa06db900>] ? open_ctree+0x2260/0x2260 [btrfs] [84434.867030] [<ffffffff81070dad>] kthread+0xed/0x100 [84434.867035] [<ffffffff81070cc0>] ? flush_kthread_worker+0x190/0x190 [84434.867040] [<ffffffff8177ee6c>] ret_from_fork+0x7c/0xb0 [84434.867044] [<ffffffff81070cc0>] ? flush_kthread_worker+0x190/0x190 Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com> Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Chris Mason <clm@fb.com>		2014-01-28 13:19:59 -08:00
..
tests	Btrfs: add a sanity test for a vacant extent at the front of a file	2013-11-11 21:58:19 -05:00
acl.c	btrfs: remove dead code	2014-01-28 13:19:50 -08:00
async-thread.c	Btrfs: fix __btrfs_start_workers retval	2013-11-20 20:42:11 -05:00
async-thread.h	Btrfs: eliminate races in worker stopping code	2013-10-04 16:02:13 -04:00
backref.c	Btrfs: fix deadlock when iterating inode refs and running delayed inodes	2014-01-28 13:19:59 -08:00
backref.h	Btrfs: allocate prelim_ref with a slab allocater	2013-09-01 08:16:27 -04:00
btrfs_inode.h	Btrfs: improve inode hash function/inode lookup	2013-11-11 21:55:19 -05:00
check-integrity.c	Btrfs: fix check-integrity to look at the referenced data properly	2014-01-28 13:19:21 -08:00
check-integrity.h	block: submit_bio_wait() conversions	2013-11-24 16:33:41 -07:00
compression.c	btrfs: Fix checkpatch.pl warning of spacing issues	2013-11-11 22:12:31 -05:00
compression.h	btrfs: make static code static & remove dead code	2013-05-06 15:55:23 -04:00
ctree.c	Btrfs: return immediately if tree log mod is not necessary	2014-01-28 13:19:56 -08:00
ctree.h	Btrfs: remove field tree_mod_seq_elem from btrfs_fs_info struct	2014-01-28 13:19:58 -08:00
delayed-inode.c	btrfs: Replace kmalloc with kmalloc_array	2013-11-11 22:12:22 -05:00
delayed-inode.h	[readdir] convert btrfs	2013-06-29 12:57:00 +04:00
delayed-ref.c	Btrfs: skip merge part for delayed data refs	2014-01-28 13:19:23 -08:00
delayed-ref.h	Btrfs: introduce a head ref rbtree	2014-01-28 13:19:22 -08:00
dev-replace.c	btrfs: fix typo in the log message	2013-11-20 20:44:47 -05:00
dev-replace.h	Btrfs: add new sources for device replace code	2012-12-12 17:15:41 -05:00
dir-item.c	Btrfs: fix max dir item size calculation	2014-01-28 13:19:49 -08:00
disk-io.c	Btrfs: move the extent buffer radix tree into the fs_info	2014-01-28 13:19:55 -08:00
disk-io.h	Btrfs: add a sanity test for btrfs_split_item	2013-11-11 21:51:02 -05:00
export.c	btrfs: remove fs/btrfs/compat.h	2013-11-11 22:03:19 -05:00
export.h
extent-tree.c	btrfs: fix static checker warnings	2014-01-28 13:19:44 -08:00
extent_io.c	Btrfs: move the extent buffer radix tree into the fs_info	2014-01-28 13:19:55 -08:00
extent_io.h	Btrfs: move the extent buffer radix tree into the fs_info	2014-01-28 13:19:55 -08:00
extent_map.c	Btrfs: fix extent_map block_len after merging	2014-01-28 13:19:51 -08:00
extent_map.h	btrfs: Enclose macros with complex values within parenthesis	2013-11-11 22:12:06 -05:00
file-item.c	btrfs: Use WARN_ON()'s return value in place of WARN_ON(1)	2013-11-11 22:11:53 -05:00
file.c	Btrfs: fix use of uninitialized err variable	2014-01-28 13:19:57 -08:00
free-space-cache.c	btrfs: remove unused variable from setup_cluster_no_bitmap	2014-01-28 13:19:33 -08:00
free-space-cache.h	Btrfs: remove path arg from btrfs_truncate_free_space_cache	2013-11-11 21:51:33 -05:00
hash.h	btrfs: extended inode refs	2012-10-09 09:14:45 -04:00
inode-item.c	btrfs: cleanup: removed unused 'btrfs_get_inode_ref_index'	2014-01-28 13:19:39 -08:00
inode-map.c	btrfs: Use WARN_ON()'s return value in place of WARN_ON(1)	2013-11-11 22:11:53 -05:00
inode-map.h
inode.c	Btrfs: remove dead comments for read_csums()	2014-01-28 13:19:59 -08:00
ioctl.c	Btrfs: fix error check of btrfs_lookup_dentry()	2014-01-28 13:19:56 -08:00
Kconfig	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs	2013-11-22 08:38:55 -08:00
locking.c	btrfs: make static code static & remove dead code	2013-05-06 15:55:23 -04:00
locking.h	Btrfs: remove btrfs_try_spin_lock	2013-03-14 14:57:10 -04:00
lzo.c	Btrfs: return -1 when lzo compression makes data bigger	2013-09-01 07:57:19 -04:00
Makefile	Btrfs: add tests for btrfs_get_extent	2013-11-11 21:57:30 -05:00
math.h	Btrfs: cleanup duplicated division functions	2012-12-11 13:31:30 -05:00
ordered-data.c	Btrfs: avoid unnecessary ordered extent cache resets	2014-01-28 13:19:46 -08:00
ordered-data.h	Btrfs: don't wait for the completion of all the ordered extents	2013-11-11 22:13:44 -05:00
orphan.c	btrfs: expand btrfs_find_item() to include find_orphan_item functionality	2014-01-28 13:19:37 -08:00
print-tree.c	btrfs: drop unused parameter from btrfs_item_nr	2013-11-11 21:50:48 -05:00
print-tree.h	btrfs: make static code static & remove dead code	2013-05-06 15:55:23 -04:00
qgroup.c	btrfs: fix unused variables in qgroup.c	2014-01-28 13:19:35 -08:00
raid56.c	btrfs: remove fs/btrfs/compat.h	2013-11-11 22:03:19 -05:00
raid56.h	Btrfs: RAID5 and RAID6	2013-02-01 14:24:23 -05:00
rcu-string.h
reada.c	Btrfs: fix reada debug code compilation	2013-05-06 15:54:55 -04:00
relocation.c	Btrfs: remove unnecessary filemap writting and waiting after block group relocation	2014-01-28 13:19:57 -08:00
root-tree.c	btrfs: expand btrfs_find_item() to include find_root_ref functionality	2014-01-28 13:19:36 -08:00
scrub.c	Btrfs: wrap repeated code into scrub_blocked_if_needed()	2014-01-28 13:19:53 -08:00
send.c	Btrfs: fix pass of transid with wrong endianness in send.c	2014-01-28 13:19:51 -08:00
send.h	btrfs: make static code static & remove dead code	2013-05-06 15:55:23 -04:00
struct-funcs.c
super.c	Btrfs: don't clear the default compression type	2013-12-12 07:11:19 -08:00
sysfs.c	btrfs: fix leaks during sysfs teardown	2014-01-28 13:19:45 -08:00
sysfs.h	btrfs: publish allocation data in sysfs	2014-01-28 13:19:29 -08:00
transaction.c	Btrfs: wrap repeated code into scrub_blocked_if_needed()	2014-01-28 13:19:53 -08:00
transaction.h	Btrfs: fix BUG_ON() casued by the reserved space migration	2013-11-11 21:54:28 -05:00
tree-defrag.c	Btrfs: cleanup dead code of defragment	2013-11-11 21:59:45 -05:00
tree-log.c	btrfs: expand btrfs_find_item() to include find_orphan_item functionality	2014-01-28 13:19:37 -08:00
tree-log.h	btrfs: make static code static & remove dead code	2013-05-06 15:55:23 -04:00
ulist.c	Btrfs: fix crash regarding to ulist_add_merge	2013-07-02 11:50:59 -04:00
ulist.h	Btrfs: add a rb_tree to improve performance of ulist search	2013-05-06 15:54:44 -04:00
uuid-tree.c	Btrfs: remove unused max_key arg from btrfs_search_forward	2013-11-11 21:54:57 -05:00
volumes.c	btrfs: fix bio_size_ok() for max_sectors > 0xffff	2013-11-20 20:48:44 -05:00
volumes.h	btrfs: Pack struct btrfs_device	2013-11-11 22:11:26 -05:00
xattr.c	btrfs: make static code static & remove dead code	2013-05-06 15:55:23 -04:00
xattr.h
zlib.c	btrfs: fix message printing	2012-10-09 09:19:57 -04:00