linux/fs/btrfs
Filipe Manana a5fb114291 Btrfs: fix deadlock with memory reclaim during scrub
When a transaction commit starts, it attempts to pause scrub and it blocks
until the scrub is paused. So while the transaction is blocked waiting for
scrub to pause, we can not do memory allocation with GFP_KERNEL from scrub,
otherwise we risk getting into a deadlock with reclaim.

Checking for scrub pause requests is done early at the beginning of the
while loop of scrub_stripe() and later in the loop, scrub_extent() and
scrub_raid56_parity() are called, which in turn call scrub_pages() and
scrub_pages_for_parity() respectively. These last two functions do memory
allocations using GFP_KERNEL. Same problem could happen while scrubbing
the super blocks, since it calls scrub_pages().

We also can not have any of the worker tasks, created by the scrub task,
doing GFP_KERNEL allocations, because before pausing, the scrub task waits
for all the worker tasks to complete (also done at scrub_stripe()).

So make sure GFP_NOFS is used for the memory allocations because at any
time a scrub pause request can happen from another task that started to
commit a transaction.

Fixes: 58c4e17384 ("btrfs: scrub: use GFP_KERNEL on the submission path")
CC: stable@vger.kernel.org # 4.6+
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-12-17 14:51:41 +01:00
..
tests btrfs: use EXPORT_FOR_TESTS for conditionally exported functions 2018-12-17 14:51:37 +01:00
acl.c btrfs: remove unnecessary curly braces in btrfs_get_acl 2018-08-06 13:12:41 +02:00
async-thread.c btrfs: replace GPL boilerplate by SPDX -- sources 2018-04-12 16:29:51 +02:00
async-thread.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
backref.c btrfs: Remove needless tree locking in iterate_inode_extrefs 2018-12-17 14:51:30 +01:00
backref.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
btrfs_inode.h btrfs: use tagged writepage to mitigate livelock of snapshot 2018-12-17 14:51:33 +01:00
check-integrity.c btrfs: Remove fsid/metadata_fsid fields from btrfs_info 2018-12-17 14:51:37 +01:00
check-integrity.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
compression.c btrfs: Remove unused extent_state argument from btrfs_writepage_endio_finish_ordered 2018-12-17 14:51:32 +01:00
compression.h btrfs: compression: Add linux/sizes.h for compression.h 2018-05-29 18:13:00 +02:00
ctree.c btrfs: Remove fsid/metadata_fsid fields from btrfs_info 2018-12-17 14:51:37 +01:00
ctree.h btrfs: Remove fsid/metadata_fsid fields from btrfs_info 2018-12-17 14:51:37 +01:00
dedupe.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
delayed-inode.c Btrfs: kill btrfs_clear_path_blocking 2018-10-15 17:23:38 +02:00
delayed-inode.h Btrfs: delayed-inode: use rb_first_cached for ins_root and del_root 2018-10-15 17:23:33 +02:00
delayed-ref.c btrfs: delayed-ref: extract find_first_ref_head from find_ref_head 2018-10-17 19:21:00 +02:00
delayed-ref.h btrfs: delayed-ref: pass delayed_refs directly to btrfs_delayed_ref_lock 2018-10-15 17:23:41 +02:00
dev-replace.c btrfs: don't report user-requested cancel as an error 2018-12-17 14:51:36 +01:00
dev-replace.h btrfs: mark btrfs_dev_replace_start as static 2018-12-17 14:51:34 +01:00
dir-item.c btrfs: Remove root parameter from btrfs_insert_dir_item 2018-10-15 17:23:25 +02:00
disk-io.c btrfs: Remove extent_io_ops::readpage_io_failed_hook 2018-12-17 14:51:41 +01:00
disk-io.h btrfs: unify end_io callbacks of async_submit_bio 2018-08-06 13:12:55 +02:00
export.c btrfs: Remove 'objectid' member from struct btrfs_root 2018-10-15 17:23:25 +02:00
export.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
extent_io.c btrfs: Remove extent_io_ops::readpage_io_failed_hook 2018-12-17 14:51:41 +01:00
extent_io.h btrfs: Remove extent_io_ops::readpage_io_failed_hook 2018-12-17 14:51:41 +01:00
extent_map.c Btrfs: extent_map: use rb_first_cached 2018-10-15 17:23:33 +02:00
extent_map.h Btrfs: extent_map: use rb_first_cached 2018-10-15 17:23:33 +02:00
extent-tree.c Btrfs: allow clear_extent_dirty() to receive a cached extent state record 2018-12-17 14:51:38 +01:00
file-item.c btrfs: replace btrfs_io_bio::end_io with a simple helper 2018-12-17 14:51:40 +01:00
file.c Btrfs: remove no longer used io_err from btrfs_log_ctx 2018-12-17 14:51:31 +01:00
free-space-cache.c Btrfs: fix deadlock on tree root leaf when finding free extent 2018-11-06 16:42:32 +01:00
free-space-cache.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
free-space-tree.c btrfs: use EXPORT_FOR_TESTS for conditionally exported functions 2018-12-17 14:51:37 +01:00
free-space-tree.h btrfs: Remove fs_info argument from add_to_free_space_tree 2018-05-28 18:07:36 +02:00
inode-item.c btrfs: replace GPL boilerplate by SPDX -- sources 2018-04-12 16:29:51 +02:00
inode-map.c btrfs: prune unused includes 2018-08-06 13:12:43 +02:00
inode-map.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
inode.c btrfs: Remove extent_io_ops::readpage_io_failed_hook 2018-12-17 14:51:41 +01:00
ioctl.c btrfs: Remove fsid/metadata_fsid fields from btrfs_info 2018-12-17 14:51:37 +01:00
Kconfig btrfs: add SPDX header to Kconfig 2018-04-12 16:29:55 +02:00
locking.c btrfs: replace waitqueue_actvie with cond_wake_up 2018-05-28 18:23:09 +02:00
locking.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
lzo.c btrfs: lzo: Harden inline lzo compressed extent decompression 2018-05-30 16:46:43 +02:00
Makefile btrfs: Remove custom crc32c init code 2018-03-26 15:09:39 +02:00
math.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
ordered-data.c Btrfs: remove no longer used stuff for tracking pending ordered extents 2018-12-17 14:51:25 +01:00
ordered-data.h Btrfs: remove no longer used stuff for tracking pending ordered extents 2018-12-17 14:51:25 +01:00
orphan.c btrfs: replace GPL boilerplate by SPDX -- sources 2018-04-12 16:29:51 +02:00
print-tree.c btrfs: annotate unlikely branches after V0 extent type removal 2018-08-06 13:12:41 +02:00
print-tree.h btrfs: print-tree: debugging output enhancement 2018-04-20 19:18:16 +02:00
props.c btrfs: property: Set incompat flag if lzo/zstd compression is set 2018-05-17 14:18:25 +02:00
props.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
qgroup.c Btrfs: fix deadlock when enabling quotas due to concurrent snapshot creation 2018-12-17 14:51:39 +01:00
qgroup.h btrfs: qgroup: Avoid calling qgroup functions if qgroup is not enabled 2018-10-15 17:23:40 +02:00
raid56.c btrfs: raid56: catch errors from full_stripe_write 2018-08-06 13:12:45 +02:00
raid56.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
rcu-string.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
reada.c btrfs: prune unused includes 2018-08-06 13:12:43 +02:00
ref-verify.c btrfs: Remove 'objectid' member from struct btrfs_root 2018-10-15 17:23:25 +02:00
ref-verify.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
relocation.c btrfs: add helper to describe block group flags 2018-12-17 14:51:39 +01:00
root-tree.c btrfs: Remove fs_info from btrfs_add_root_ref 2018-08-06 13:13:00 +02:00
scrub.c Btrfs: fix deadlock with memory reclaim during scrub 2018-12-17 14:51:41 +01:00
send.c Btrfs: send, fix infinite loop due to directory rename dependencies 2018-11-21 17:03:50 +01:00
send.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
struct-funcs.c btrfs: prune unused includes 2018-08-06 13:12:43 +02:00
super.c btrfs: Remove fsid/metadata_fsid fields from btrfs_info 2018-12-17 14:51:37 +01:00
sysfs.c btrfs: Add sysfs support for metadata_uuid feature 2018-12-17 14:51:37 +01:00
sysfs.h btrfs: sysfs: Use enum/define value for feature array definitions 2018-05-28 18:23:39 +02:00
transaction.c Btrfs: remove no longer used stuff for tracking pending ordered extents 2018-12-17 14:51:25 +01:00
transaction.h Btrfs: remove no longer used stuff for tracking pending ordered extents 2018-12-17 14:51:25 +01:00
tree-checker.c btrfs: tree-checker: Don't check max block group size as current max chunk size limit is unreliable 2018-12-04 15:05:30 +01:00
tree-checker.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
tree-defrag.c btrfs: replace GPL boilerplate by SPDX -- sources 2018-04-12 16:29:51 +02:00
tree-log.c Btrfs: simpler and more efficient cleanup of a log tree's extent io tree 2018-12-17 14:51:31 +01:00
tree-log.h Btrfs: remove no longer used io_err from btrfs_log_ctx 2018-12-17 14:51:31 +01:00
ulist.c btrfs: replace GPL boilerplate by SPDX -- sources 2018-04-12 16:29:51 +02:00
ulist.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
uuid-tree.c btrfs: Remove fs_info argument from btrfs_uuid_tree_rem 2018-05-30 16:46:53 +02:00
volumes.c btrfs: balance: print to system log when balance ends or is paused 2018-12-17 14:51:39 +01:00
volumes.h btrfs: remove btrfs_bio_end_io_t 2018-12-17 14:51:40 +01:00
xattr.c btrfs: replace GPL boilerplate by SPDX -- sources 2018-04-12 16:29:51 +02:00
xattr.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
zlib.c btrfs: replace GPL boilerplate by SPDX -- sources 2018-04-12 16:29:51 +02:00
zstd.c btrfs: replace GPL boilerplate by SPDX -- sources 2018-04-12 16:29:51 +02:00