Josef Bacik 3c4276936f Btrfs: fix btrfs_write_inode vs delayed iput deadlock ... We recently ran into the following deadlock involving btrfs_write_inode(): [ +0.005066] __schedule+0x38e/0x8c0 [ +0.007144] schedule+0x36/0x80 [ +0.006447] bit_wait+0x11/0x60 [ +0.006446] __wait_on_bit+0xbe/0x110 [ +0.007487] ? bit_wait_io+0x60/0x60 [ +0.007319] __inode_wait_for_writeback+0x96/0xc0 [ +0.009568] ? autoremove_wake_function+0x40/0x40 [ +0.009565] inode_wait_for_writeback+0x21/0x30 [ +0.009224] evict+0xb0/0x190 [ +0.006099] iput+0x1a8/0x210 [ +0.006103] btrfs_run_delayed_iputs+0x73/0xc0 [ +0.009047] btrfs_commit_transaction+0x799/0x8c0 [ +0.009567] btrfs_write_inode+0x81/0xb0 [ +0.008008] __writeback_single_inode+0x267/0x320 [ +0.009569] writeback_sb_inodes+0x25b/0x4e0 [ +0.008702] wb_writeback+0x102/0x2d0 [ +0.007487] wb_workfn+0xa4/0x310 [ +0.006794] ? wb_workfn+0xa4/0x310 [ +0.007143] process_one_work+0x150/0x410 [ +0.008179] worker_thread+0x6d/0x520 [ +0.007490] kthread+0x12c/0x160 [ +0.006620] ? put_pwq_unlocked+0x80/0x80 [ +0.008185] ? kthread_park+0xa0/0xa0 [ +0.007484] ? do_syscall_64+0x53/0x150 [ +0.007837] ret_from_fork+0x29/0x40 Writeback calls: btrfs_write_inode btrfs_commit_transaction btrfs_run_delayed_iputs If iput() is called on that same inode, evict() will wait for writeback forever. btrfs_write_inode() was originally added way back in 4730a4bc5b ("btrfs_dirty_inode") to support O_SYNC writes. However, ->write_inode() hasn't been used for O_SYNC since 148f948ba8 ("vfs: Introduce new helpers for syncing after writing to O_SYNC file or IS_SYNC inode"), so btrfs_write_inode() is actually unnecessary (and leads to a bunch of unnecessary commits). Get rid of it, which also gets rid of the deadlock. CC: stable@vger.kernel.org # 3.2+ Signed-off-by: Josef Bacik <jbacik@fb.com> [Omar: new commit message] Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: David Sterba <dsterba@suse.com>		2018-08-06 13:12:58 +02:00
..
tests	btrfs: qgroup: Drop fs_info parameter from btrfs_qgroup_account_extent	2018-08-06 13:12:52 +02:00
acl.c	btrfs: remove unnecessary curly braces in btrfs_get_acl	2018-08-06 13:12:41 +02:00
async-thread.c
async-thread.h
backref.c	btrfs: return EUCLEAN if extent_inline_ref type is invalid	2018-08-06 13:12:40 +02:00
backref.h
btrfs_inode.h	btrfs: use timespec64 for i_otime	2018-08-06 13:12:39 +02:00
check-integrity.c	btrfs: open-code bio_set_op_attrs	2018-08-06 13:12:44 +02:00
check-integrity.h
compression.c	btrfs: drop extent_io_ops::merge_bio_hook callback	2018-08-06 13:12:56 +02:00
compression.h
ctree.c	btrfs: Remove V0 extent support	2018-08-06 13:12:41 +02:00
ctree.h	btrfs: drop extent_io_ops::set_range_writeback callback	2018-08-06 13:12:56 +02:00
dedupe.h
delayed-inode.c	btrfs: simplify pointer chasing of local fs_info variables	2018-08-06 13:12:43 +02:00
delayed-inode.h
delayed-ref.c	btrfs: Streamline memory allocation failure handling in btrfs_add_delayed_tree_ref	2018-08-06 13:12:39 +02:00
delayed-ref.h	btrfs: Remove fs_info from btrfs_add_delayed_data_ref	2018-08-06 13:12:34 +02:00
dev-replace.c	btrfs: Remove fs_info from btrfs_destroy_dev_replace_tgtdev	2018-08-06 13:12:57 +02:00
dev-replace.h
dir-item.c
disk-io.c	btrfs: drop extent_io_ops::set_range_writeback callback	2018-08-06 13:12:56 +02:00
disk-io.h	btrfs: unify end_io callbacks of async_submit_bio	2018-08-06 13:12:55 +02:00
export.c
export.h
extent_io.c	btrfs: drop extent_io_ops::set_range_writeback callback	2018-08-06 13:12:56 +02:00
extent_io.h	btrfs: drop extent_io_ops::set_range_writeback callback	2018-08-06 13:12:56 +02:00
extent_map.c
extent_map.h
extent-tree.c	btrfs: Remove fs_info from btrfs_finish_chunk_alloc	2018-08-06 13:12:58 +02:00
file-item.c	btrfs: simplify pointer chasing of local fs_info variables	2018-08-06 13:12:43 +02:00
file.c	btrfs: prune unused includes	2018-08-06 13:12:43 +02:00
free-space-cache.c	btrfs: use copy_page for copying pages instead of memcpy	2018-08-06 13:12:43 +02:00
free-space-cache.h
free-space-tree.c
free-space-tree.h
inode-item.c
inode-map.c	btrfs: prune unused includes	2018-08-06 13:12:43 +02:00
inode-map.h
inode.c	Btrfs: fix btrfs_write_inode vs delayed iput deadlock	2018-08-06 13:12:58 +02:00
ioctl.c	btrfs: qgroup: Drop fs_info parameter from btrfs_qgroup_inherit	2018-08-06 13:12:53 +02:00
Kconfig
locking.c
locking.h
lzo.c
Makefile
math.h
ordered-data.c	btrfs: prune unused includes	2018-08-06 13:12:43 +02:00
ordered-data.h	btrfs: remove remaing full_sync logic from btrfs_sync_file	2018-08-06 13:12:31 +02:00
orphan.c
print-tree.c	btrfs: annotate unlikely branches after V0 extent type removal	2018-08-06 13:12:41 +02:00
print-tree.h
props.c
props.h
qgroup.c	btrfs: qgroup: Drop fs_info parameter from qgroup_rescan_leaf	2018-08-06 13:12:53 +02:00
qgroup.h	btrfs: qgroup: Drop fs_info parameter from btrfs_qgroup_inherit	2018-08-06 13:12:53 +02:00
raid56.c	btrfs: raid56: catch errors from full_stripe_write	2018-08-06 13:12:45 +02:00
raid56.h
rcu-string.h
reada.c	btrfs: prune unused includes	2018-08-06 13:12:43 +02:00
ref-verify.c
ref-verify.h
relocation.c	btrfs: qgroup: Drop root parameter from btrfs_qgroup_trace_subtree	2018-08-06 13:12:52 +02:00
root-tree.c
scrub.c	btrfs: scrub: cleanup the remaining nodatasum fixup code	2018-08-06 13:12:53 +02:00
send.c	Btrfs: remove unused key assignment when doing a full send	2018-08-06 13:12:56 +02:00
send.h
struct-funcs.c	btrfs: prune unused includes	2018-08-06 13:12:43 +02:00
super.c	Btrfs: fix btrfs_write_inode vs delayed iput deadlock	2018-08-06 13:12:58 +02:00
sysfs.c	btrfs: prune unused includes	2018-08-06 13:12:43 +02:00
sysfs.h
transaction.c	btrfs: qgroup: Drop fs_info parameter from btrfs_qgroup_inherit	2018-08-06 13:12:53 +02:00
transaction.h
tree-checker.c	btrfs: tree-checker: Detect invalid and empty essential trees	2018-08-06 13:12:42 +02:00
tree-checker.h
tree-defrag.c
tree-log.c	btrfs: qgroup: Drop fs_info parameter from btrfs_qgroup_trace_extent	2018-08-06 13:12:52 +02:00
tree-log.h
ulist.c
ulist.h
uuid-tree.c
volumes.c	btrfs: Remove fs_info from btrfs_finish_chunk_alloc	2018-08-06 13:12:58 +02:00
volumes.h	btrfs: Remove fs_info from btrfs_finish_chunk_alloc	2018-08-06 13:12:58 +02:00
xattr.c
xattr.h
zlib.c
zstd.c