linux/fs/btrfs
Josef Bacik fc1f91b923 btrfs: wait for actual caching progress during allocation
Recently we've been having mysterious hangs while running generic/475 on
the CI system.  This turned out to be something like this:

  Task 1
  dmsetup suspend --nolockfs
  -> __dm_suspend
   -> dm_wait_for_completion
    -> dm_wait_for_bios_completion
     -> Unable to complete because of IO's on a plug in Task 2

  Task 2
  wb_workfn
  -> wb_writeback
   -> blk_start_plug
    -> writeback_sb_inodes
     -> Infinite loop unable to make an allocation

  Task 3
  cache_block_group
  ->read_extent_buffer_pages
   ->Waiting for IO to complete that can't be submitted because Task 1
     suspended the DM device

The problem here is that we need Task 2 to be scheduled completely for
the blk plug to flush.  Normally this would happen, we normally wait for
the block group caching to finish (Task 3), and this schedule would
result in the block plug flushing.

However if there's enough free space available from the current caching
to satisfy the allocation we won't actually wait for the caching to
complete.  This check however just checks that we have enough space, not
that we can make the allocation.  In this particular case we were trying
to allocate 9MiB, and we had 10MiB of free space, but we didn't have
9MiB of contiguous space to allocate, and thus the allocation failed and
we looped.

We specifically don't cycle through the FFE loop until we stop finding
cached block groups because we don't want to allocate new block groups
just because we're caching, so we short circuit the normal loop once we
hit LOOP_CACHING_WAIT and we found a caching block group.

This is normally fine, except in this particular case where the caching
thread can't make progress because the DM device has been suspended.

Fix this by not only waiting for free space to >= the amount of space we
want to allocate, but also that we make some progress in caching from
the time we start waiting.  This will keep us from busy looping when the
caching is taking a while but still theoretically has enough space for
us to allocate from, and fixes this particular case by forcing us to
actually sleep and wait for forward progress, which will flush the plug.

With this fix we're no longer hanging with generic/475.

CC: stable@vger.kernel.org # 6.1+
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2023-08-10 16:44:14 +02:00
..
tests btrfs: drop gfp from parameter extent state helpers 2023-06-19 13:59:30 +02:00
accessors.c btrfs: add eb to btrfs_node_key_ptr_offset 2022-12-05 18:00:58 +01:00
accessors.h btrfs: add stack helpers for a few btrfs items 2022-12-05 18:00:58 +01:00
acl.c fs: port acl to mnt_idmap 2023-01-19 09:24:28 +01:00
acl.h fs: port ->set_acl() to pass mnt_idmap 2023-01-19 09:24:27 +01:00
async-thread.c btrfs: use alloc_ordered_workqueue() to create ordered workqueues 2023-06-19 13:59:30 +02:00
async-thread.h btrfs: use alloc_ordered_workqueue() to create ordered workqueues 2023-06-19 13:59:30 +02:00
backref.c btrfs: fix backref walking not returning all inode refs 2023-05-09 22:09:11 +02:00
backref.h btrfs: fix backref walking not returning all inode refs 2023-05-09 22:09:11 +02:00
bio.c btrfs: add an ordered_extent pointer to struct btrfs_bio 2023-06-19 13:59:36 +02:00
bio.h btrfs: add an ordered_extent pointer to struct btrfs_bio 2023-06-19 13:59:36 +02:00
block-group.c btrfs: wait for actual caching progress during allocation 2023-08-10 16:44:14 +02:00
block-group.h btrfs: wait for actual caching progress during allocation 2023-08-10 16:44:14 +02:00
block-rsv.c btrfs: account block group tree when calculating global reserve size 2023-07-20 19:22:54 +02:00
block-rsv.h btrfs: move btrfs_check_trunc_cache_free_space into block-rsv.c 2023-06-19 13:59:24 +02:00
btrfs_inode.h btrfs: tracepoints: also show actual number of the outstanding extents 2023-06-19 19:47:58 +02:00
check-integrity.c btrfs: rename __btrfs_map_block to btrfs_map_block 2023-06-19 13:59:34 +02:00
check-integrity.h btrfs: check-integrity: split submit_bio from btrfsic checking 2022-05-16 17:03:12 +02:00
compression.c btrfs: make btrfs_compressed_bioset static 2023-06-19 17:01:44 +02:00
compression.h btrfs: pass an ordered_extent to btrfs_submit_compressed_write 2023-06-19 13:59:36 +02:00
ctree.c btrfs: replace BUG_ON() at split_item() with proper error handling 2023-06-19 13:59:39 +02:00
ctree.h btrfs: do not BUG_ON() on tree mod log failures at btrfs_del_ptr() 2023-06-19 13:59:39 +02:00
defrag.c btrfs: drop gfp from parameter extent state helpers 2023-06-19 13:59:30 +02:00
defrag.h btrfs: move defrag related prototypes to their own header 2022-12-05 18:00:46 +01:00
delalloc-space.c btrfs: count extents before taking inode's spinlock when reserving metadata 2023-04-17 18:01:19 +02:00
delalloc-space.h btrfs: move delalloc space related prototypes to delalloc-space.h 2022-12-05 18:00:44 +01:00
delayed-inode.c btrfs: handle btrfs_del_item errors in __btrfs_update_delayed_inode 2023-03-06 19:28:19 +01:00
delayed-inode.h btrfs: extend btrfs_dir_item type to store encryption status 2022-12-05 18:00:43 +01:00
delayed-ref.c btrfs: use a single switch statement when initializing delayed ref head 2023-06-19 13:59:32 +02:00
delayed-ref.h btrfs: use bool type for delayed ref head fields that are used as booleans 2023-06-19 13:59:32 +02:00
dev-replace.c btrfs: rename __btrfs_map_block to btrfs_map_block 2023-06-19 13:59:34 +02:00
dev-replace.h btrfs: move dev-replace prototypes into dev-replace.h 2022-12-05 18:00:47 +01:00
dir-item.c btrfs: move dir-item prototypes into dir-item.h 2022-12-05 18:00:46 +01:00
dir-item.h btrfs: move dir-item prototypes into dir-item.h 2022-12-05 18:00:46 +01:00
discard.c btrfs: unexport btrfs_run_discard_work and make it static 2023-06-19 13:59:25 +02:00
discard.h btrfs: unexport btrfs_run_discard_work and make it static 2023-06-19 13:59:25 +02:00
disk-io.c btrfs: zoned: do not enable async discard 2023-07-20 19:18:14 +02:00
disk-io.h btrfs: use a separate end_io handler for read_extent_buffer 2023-06-19 13:59:27 +02:00
export.c btrfs: move super_block specific helpers into super.h 2022-12-05 18:00:47 +01:00
export.h btrfs: simplify generation check in btrfs_get_dentry 2022-12-05 18:00:41 +01:00
extent_io.c btrfs: use btrfs_finish_ordered_extent to complete buffered writes 2023-06-19 13:59:37 +02:00
extent_io.h btrfs: don't treat zoned writeback as being from an async helper thread 2023-06-19 13:59:35 +02:00
extent_map.c btrfs: pass the new logical address to split_extent_map 2023-06-19 13:59:33 +02:00
extent_map.h btrfs: pass the new logical address to split_extent_map 2023-06-19 13:59:33 +02:00
extent-io-tree.c btrfs: drop gfp from parameter extent state helpers 2023-06-19 13:59:30 +02:00
extent-io-tree.h btrfs: drop gfp from parameter extent state helpers 2023-06-19 13:59:30 +02:00
extent-tree.c btrfs: use bool type for delayed ref head fields that are used as booleans 2023-06-19 13:59:32 +02:00
extent-tree.h btrfs: remove level argument from btrfs_set_block_flags 2023-06-19 13:59:24 +02:00
file-item.c btrfs: use bbio->ordered in btrfs_csum_one_bio 2023-06-19 13:59:37 +02:00
file-item.h btrfs: optimize the logical to physical mapping for zoned writes 2023-06-19 13:59:32 +02:00
file.c btrfs: set FMODE_CAN_ODIRECT instead of a dummy direct_IO method 2023-06-19 13:59:38 +02:00
file.h btrfs: use cached state when looking for delalloc ranges with fiemap 2022-12-05 18:00:56 +01:00
free-space-cache.c btrfs: move btrfs_check_trunc_cache_free_space into block-rsv.c 2023-06-19 13:59:24 +02:00
free-space-cache.h btrfs: move btrfs_check_trunc_cache_free_space into block-rsv.c 2023-06-19 13:59:24 +02:00
free-space-tree.c btrfs: remove BUG_ON()'s in add_new_free_space() 2023-07-24 18:06:05 +02:00
free-space-tree.h btrfs: make clear_cache mount option to rebuild FST without disabling it 2023-05-10 14:51:27 +02:00
fs.c btrfs: sysfs: update fs features directory asynchronously 2023-02-13 17:50:35 +01:00
fs.h btrfs: add comment to struct btrfs_fs_info::dirty_cowonly_roots 2023-06-19 20:14:44 +02:00
inode-item.c btrfs: remove obsolete delayed ref throttling logic when truncating items 2023-04-17 18:01:19 +02:00
inode-item.h btrfs: move split_flags/combine_flags helpers to inode-item.h 2023-06-19 13:59:25 +02:00
inode.c btrfs: fix ordered extent split error handling in btrfs_dio_submit_io 2023-07-18 03:14:01 +02:00
ioctl.c btrfs: trigger orphan inode cleanup during START_SYNC ioctl 2023-06-19 13:59:26 +02:00
ioctl.h fs: port ->fileattr_set() to pass mnt_idmap 2023-01-19 09:24:27 +01:00
Kconfig block: make blkcg_punt_bio_submit optional 2023-04-17 18:01:22 +02:00
locking.c btrfs: add block-group tree to lockdep classes 2023-06-19 13:59:35 +02:00
locking.h btrfs: locking: use atomic for DREW lock writers 2023-04-17 18:01:17 +02:00
lru_cache.c btrfs: send: cache utimes operations for directories if possible 2023-02-15 19:38:50 +01:00
lru_cache.h btrfs: remove btrfs_lru_cache_is_full() inline function 2023-04-17 18:01:18 +02:00
lzo.c btrfs: disable allocation warnings for compression workspaces 2023-06-19 13:59:34 +02:00
Makefile btrfs: send: genericize the backref cache to allow it to be reused 2023-02-13 17:50:35 +01:00
messages.c btrfs: print assertion failure report and stack trace from the same line 2023-06-19 13:59:31 +02:00
messages.h btrfs: print assertion failure report and stack trace from the same line 2023-06-19 13:59:31 +02:00
misc.h btrfs: export bitmap_test_range_all_{set,zero} 2023-06-19 13:59:22 +02:00
ordered-data.c btrfs: add a btrfs_finish_ordered_extent helper 2023-06-19 13:59:37 +02:00
ordered-data.h btrfs: add a btrfs_finish_ordered_extent helper 2023-06-19 13:59:37 +02:00
orphan.c btrfs: move orphan prototypes into orphan.h 2022-12-05 18:00:47 +01:00
orphan.h btrfs: move orphan prototypes into orphan.h 2022-12-05 18:00:47 +01:00
print-tree.c btrfs: print-tree: pass const extent buffer pointer 2023-06-19 13:59:22 +02:00
print-tree.h btrfs: print-tree: pass const extent buffer pointer 2023-06-19 13:59:22 +02:00
props.c btrfs: move super_block specific helpers into super.h 2022-12-05 18:00:47 +01:00
props.h btrfs: make module init/exit match their sequence 2022-12-05 18:00:40 +01:00
qgroup.c btrfs: fix warning when putting transaction with qgroups enabled after abort 2023-07-18 03:14:11 +02:00
qgroup.h btrfs: sink gfp_t parameter to btrfs_qgroup_trace_extent 2022-12-05 18:00:43 +01:00
raid56.c btrfs: raid56: always verify the P/Q contents for scrub 2023-07-18 03:13:15 +02:00
raid56.h btrfs: scrub: use recovered data stripes as cache to avoid unnecessary read 2023-06-19 13:59:24 +02:00
rcu-string.h btrfs: replace strncpy() with strscpy() 2022-12-05 18:00:59 +01:00
ref-verify.c btrfs: move accessor helpers into accessors.h 2022-12-05 18:00:42 +01:00
ref-verify.h btrfs: ref-verify: Use btrfs_ref to refactor btrfs_ref_tree_mod() 2019-04-29 19:02:49 +02:00
reflink.c btrfs: pass btrfs_inode to btrfs_inode_unlock 2022-12-05 18:00:53 +01:00
reflink.h Btrfs: move all reflink implementation code into its own file 2020-03-23 17:01:54 +01:00
relocation.c btrfs: pass an ordered_extent to btrfs_reloc_clone_csums 2023-06-19 13:59:36 +02:00
relocation.h btrfs: pass an ordered_extent to btrfs_reloc_clone_csums 2023-06-19 13:59:36 +02:00
root-tree.c btrfs: move orphan prototypes into orphan.h 2022-12-05 18:00:47 +01:00
root-tree.h btrfs: move root tree prototypes to their own header 2022-12-05 18:00:44 +01:00
scrub.c btrfs: scrub: remove btrfs_fs_info::scrub_wr_completion_workers 2023-06-19 13:59:40 +02:00
scrub.h btrfs: scrub: remove scrub_bio structure 2023-04-17 18:01:24 +02:00
send.c btrfs: send: do not BUG_ON() on unexpected symlink data extent 2023-06-19 13:59:39 +02:00
send.h btrfs: send add define for v2 buffer size 2022-12-05 18:00:41 +01:00
space-info.c btrfs: add helper to calculate space for delayed references 2023-04-17 18:01:19 +02:00
space-info.h btrfs: update documentation for BTRFS_RESERVE_FLUSH_EVICT flush method 2023-04-17 18:01:18 +02:00
subpage.c btrfs: stop setting PageError in the data I/O path 2023-06-19 13:59:35 +02:00
subpage.h btrfs: stop setting PageError in the data I/O path 2023-06-19 13:59:35 +02:00
super.c btrfs: remove hipri_workers workqueue 2023-06-19 13:59:23 +02:00
super.h btrfs: move super_block specific helpers into super.h 2022-12-05 18:00:47 +01:00
sysfs.c btrfs: sysfs: relax bg_reclaim_threshold for debugging purposes 2023-04-17 18:01:18 +02:00
sysfs.h btrfs: sysfs: update fs features directory asynchronously 2023-02-13 17:50:35 +01:00
transaction.c btrfs: check for commit error at btrfs_attach_transaction_barrier() 2023-07-26 13:57:47 +02:00
transaction.h btrfs: don't hold an extra reference for redirtied buffers 2023-06-19 13:59:26 +02:00
tree-checker.c btrfs: move split_flags/combine_flags helpers to inode-item.h 2023-06-19 13:59:25 +02:00
tree-checker.h btrfs: move btrfs_verify_level_key into tree-checker.c 2023-06-19 13:59:25 +02:00
tree-log.c btrfs: do not BUG_ON() when dropping inode items from log root 2023-06-19 13:59:39 +02:00
tree-log.h btrfs: change for_rename argument of btrfs_record_unlink_dir() to bool 2023-06-19 13:59:26 +02:00
tree-mod-log.c btrfs: avoid tree mod log ENOMEM failures when we don't need to log 2023-06-19 13:59:38 +02:00
tree-mod-log.h btrfs: fix SPDX comment in tree-mod-log.h 2022-12-05 18:00:48 +01:00
ulist.c btrfs: constify ulist parameter of ulist_next() 2022-12-05 18:00:50 +01:00
ulist.h btrfs: constify ulist parameter of ulist_next() 2022-12-05 18:00:50 +01:00
uuid-tree.c btrfs: move uuid tree prototypes to uuid-tree.h 2022-12-05 18:00:46 +01:00
uuid-tree.h btrfs: move uuid tree prototypes to uuid-tree.h 2022-12-05 18:00:46 +01:00
verity.c fsverity: pass pos and size to ->write_merkle_tree_block 2023-01-01 15:46:48 -08:00
verity.h btrfs: move verity prototypes into verity.h 2022-12-05 18:00:47 +01:00
volumes.c btrfs: be a bit more careful when setting mirror_num_ret in btrfs_map_block 2023-07-11 17:32:14 +02:00
volumes.h btrfs: open code btrfs_map_sblock 2023-06-19 13:59:34 +02:00
xattr.c fs: drop unused posix acl handlers 2023-03-06 09:57:12 +01:00
xattr.h btrfs: cleanup btrfs_setxattr_trans and drop transaction parameter 2019-04-29 19:02:44 +02:00
zlib.c btrfs: disable allocation warnings for compression workspaces 2023-06-19 13:59:34 +02:00
zoned.c btrfs: zoned: do not enable async discard 2023-07-20 19:18:14 +02:00
zoned.h btrfs: defer splitting of ordered extents until I/O completion 2023-06-19 13:59:33 +02:00
zstd.c btrfs: disable allocation warnings for compression workspaces 2023-06-19 13:59:34 +02:00