linux-stable/fs/btrfs
Josef Bacik 81e75ac74e btrfs: account for new extents being deleted in total_bytes_pinned
My recent patch set "A variety of lock contention fixes", found here

https://lore.kernel.org/linux-btrfs/cover.1608319304.git.josef@toxicpanda.com/
(Tracked in https://github.com/btrfs/linux/issues/86)

that reduce lock contention on the extent root by running delayed refs
less often resulted in a regression in generic/371.  This test
fallocate()'s the fs until it's full, deletes all the files, and then
tries to fallocate() until full again.

Before these patches we would run all of the delayed refs during
flushing, and then would commit the transaction because we had plenty of
pinned space to recover in order to allocate.  However my patches made
it so we weren't running the delayed refs as aggressively, which meant
that we appeared to have less pinned space when we were deciding to
commit the transaction.

We use the space_info->total_bytes_pinned to approximate how much space
we have pinned.  It's approximate because if we remove a reference to an
extent we may free it, but there may be more references to it than we
know of at that point, but we account it as pinned at the creation time,
and then it's properly accounted when the delayed ref runs.

The way we account for pinned space is if the
delayed_ref_head->total_ref_mod is < 0, because that is clearly a
freeing option.  However there is another case, and that is where
->total_ref_mod == 0 && ->must_insert_reserved == 1.

When we allocate a new extent, we have ->total_ref_mod == 1 and we have
->must_insert_reserved == 1.  This is used to indicate that it is a
brand new extent and will need to have its extent entry added before we
modify any references on the delayed ref head.  But if we subsequently
remove that extent reference, our ->total_ref_mod will be 0, and that
space will be pinned and freed.  Accounting for this case properly
allows for generic/371 to pass with my delayed refs patches applied.

It's important to note that this problem exists without the referenced
patches, it just was uncovered by them.

CC: stable@vger.kernel.org # 5.10
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2021-02-08 22:58:55 +01:00
..
tests btrfs: tests: initialize test inodes location 2020-12-18 14:59:49 +01:00
Kconfig btrfs: switch to iomap for direct IO 2020-10-07 12:06:57 +02:00
Makefile btrfs: enable W=1 checks for btrfs 2021-02-08 22:58:55 +01:00
acl.c
async-thread.c Btrfs: fix crash during unmount due to race with delayed inode workers 2020-03-23 17:01:51 +01:00
async-thread.h Btrfs: fix crash during unmount due to race with delayed inode workers 2020-03-23 17:01:51 +01:00
backref.c btrfs: document btrfs_check_shared parameters 2021-02-08 22:58:54 +01:00
backref.h btrfs: rename BTRFS_ROOT_REF_COWS to BTRFS_ROOT_SHAREABLE 2020-05-25 11:25:35 +02:00
block-group.c btrfs: handle space_info::total_bytes_pinned inside the delayed ref itself 2021-02-08 22:58:55 +01:00
block-group.h btrfs: load free space cache asynchronously 2020-12-08 15:54:03 +01:00
block-rsv.c btrfs: introduce mount option rescue=ignorebadroots 2020-12-08 15:53:41 +01:00
block-rsv.h btrfs: Remove __ prefix from btrfs_block_rsv_release 2020-03-23 17:01:55 +01:00
btrfs_inode.h btrfs: make btrfs_dio_private::bytes u32 2021-02-08 22:58:51 +01:00
check-integrity.c btrfs: drop casts of bio bi_sector 2020-12-09 19:16:05 +01:00
check-integrity.h btrfs: remove btrfsic_submit_bh() 2020-03-23 17:01:39 +01:00
compression.c btrfs: refactor btrfs_lookup_bio_sums to handle out-of-order bvecs 2020-12-09 19:16:11 +01:00
compression.h btrfs: compression: move declarations to header 2020-10-07 12:06:55 +02:00
ctree.c btrfs: allow error injection for btrfs_search_slot and btrfs_cow_block 2021-02-08 22:58:50 +01:00
ctree.h btrfs: make btrfs_start_delalloc_root's nr argument a long 2021-02-08 22:58:51 +01:00
delalloc-space.c btrfs: fix parameter description of btrfs_inode_rsv_release/btrfs_delalloc_release_space 2021-02-08 22:58:54 +01:00
delalloc-space.h btrfs: make btrfs_delalloc_reserve_space take btrfs_inode 2020-07-27 12:55:36 +02:00
delayed-inode.c btrfs: make btrfs_delayed_update_inode take btrfs_inode 2020-12-08 15:54:10 +01:00
delayed-inode.h btrfs: make btrfs_delayed_update_inode take btrfs_inode 2020-12-08 15:54:10 +01:00
delayed-ref.c btrfs: account for new extents being deleted in total_bytes_pinned 2021-02-08 22:58:55 +01:00
delayed-ref.h btrfs: handle space_info::total_bytes_pinned inside the delayed ref itself 2021-02-08 22:58:55 +01:00
dev-replace.c btrfs: make btrfs_start_delalloc_root's nr argument a long 2021-02-08 22:58:51 +01:00
dev-replace.h btrfs: add __pure attribute to functions 2019-11-18 12:46:52 +01:00
dir-item.c btrfs: locking: rip out path->leave_spinning 2020-12-08 15:54:02 +01:00
discard.c btrfs: document now parameter of peek_discard_list 2021-02-08 22:58:53 +01:00
discard.h btrfs: cleanup btrfs_discard_update_discardable usage 2020-12-08 15:54:02 +01:00
disk-io.c btrfs: make btrfs_root::free_objectid hold the next available objectid 2021-02-08 22:58:50 +01:00
disk-io.h btrfs: rename btrfs_find_free_objectid to btrfs_get_free_objectid 2021-02-08 22:58:49 +01:00
export.c btrfs: locking: rip out path->leave_spinning 2020-12-08 15:54:02 +01:00
export.h btrfs: export helpers for subvolume name/id resolution 2020-03-23 17:01:42 +01:00
extent-io-tree.h btrfs: use fixed width int type for extent_state::state 2020-12-08 15:54:13 +01:00
extent-tree.c btrfs: account for new extents being deleted in total_bytes_pinned 2021-02-08 22:58:55 +01:00
extent_io.c btrfs: fix parameter description for functions in extent_io.c 2021-02-08 22:58:54 +01:00
extent_io.h btrfs: update num_extent_pages to support subpage sized extent buffer 2020-12-09 19:16:10 +01:00
extent_map.c btrfs: fix parameter description of btrfs_add_extent_mapping 2021-02-08 22:58:53 +01:00
extent_map.h btrfs: remove extent_map::bdev 2019-11-18 23:43:44 +01:00
file-item.c btrfs: fix function description formats in file-item.c 2021-02-08 22:58:53 +01:00
file.c btrfs: update comment for btrfs_dirty_pages 2021-02-08 22:58:52 +01:00
free-space-cache.c btrfs: improve parameter description for __btrfs_write_out_cache 2021-02-08 22:58:53 +01:00
free-space-cache.h btrfs: remove free space items when disabling space cache v1 2020-12-09 19:16:09 +01:00
free-space-tree.c btrfs: fix possible free space tree corruption with online conversion 2021-01-25 18:44:37 +01:00
free-space-tree.h btrfs: rename btrfs_block_group_cache 2019-11-18 17:51:51 +01:00
inode-item.c btrfs: locking: rip out path->leave_spinning 2020-12-08 15:54:02 +01:00
inode.c btrfs: fix description format of fs_info of btrfs_wait_on_delayed_iputs 2021-02-08 22:58:54 +01:00
ioctl.c btrfs: make btrfs_start_delalloc_root's nr argument a long 2021-02-08 22:58:51 +01:00
locking.c btrfs: remove the recurse parameter from __btrfs_tree_read_lock 2020-12-08 15:54:09 +01:00
locking.h btrfs: remove the recurse parameter from __btrfs_tree_read_lock 2020-12-08 15:54:09 +01:00
lzo.c btrfs: compression: inline free_workspace 2019-11-18 12:46:59 +01:00
misc.h btrfs: rename tree_entry to rb_simple_node and export it 2020-05-25 11:25:19 +02:00
ordered-data.c btrfs: rework the order of btrfs_ordered_extent::flags 2021-02-08 22:58:52 +01:00
ordered-data.h btrfs: rework the order of btrfs_ordered_extent::flags 2021-02-08 22:58:52 +01:00
orphan.c
print-tree.c btrfs: print the actual offset in btrfs_root_name 2021-01-07 17:25:05 +01:00
print-tree.h btrfs: print the actual offset in btrfs_root_name 2021-01-07 17:25:05 +01:00
props.c btrfs: simplify iget helpers 2020-05-25 11:25:37 +02:00
props.h
qgroup.c btrfs: fix transaction leak and crash after RO remount caused by qgroup rescan 2020-12-18 14:59:57 +01:00
qgroup.h btrfs: qgroup: export qgroups in sysfs 2020-07-27 12:55:37 +02:00
raid56.c btrfs: remove redundant NULL check before kvfree 2021-02-08 22:58:52 +01:00
raid56.h
rcu-string.h btrfs: rcu-string: Replace zero-length array with flexible-array member 2020-03-23 17:01:53 +01:00
reada.c btrfs: pass the owner_root and level to alloc_extent_buffer 2020-12-08 15:54:07 +01:00
ref-verify.c btrfs: ref-verify: make sure owner is set for all refs 2021-02-08 22:58:50 +01:00
ref-verify.h
reflink.c btrfs: fix deadlock when cloning inline extent and low on free metadata space 2020-12-18 14:49:50 +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: keep track of the root owner for relocation reads 2021-02-08 22:58:52 +01:00
root-tree.c btrfs: qgroup: fix qgroup meta rsv leak for subvolume operations 2020-10-07 12:12:13 +02:00
scrub.c btrfs: scrub: allow scrub to work with subpage sectorsize 2020-12-09 19:16:11 +01:00
send.c btrfs: send: remove stale code when checking for shared extents 2021-02-08 22:58:51 +01:00
send.h btrfs: send: avoid copying file data 2020-10-07 12:13:17 +02:00
space-info.c btrfs: fix parameter description in space-info.c 2021-02-08 22:58:54 +01:00
space-info.h btrfs: handle space_info::total_bytes_pinned inside the delayed ref itself 2021-02-08 22:58:55 +01:00
struct-funcs.c btrfs: handle sectorsize < PAGE_SIZE case for extent buffer accessors 2020-12-09 19:16:10 +01:00
super.c btrfs: run delayed iputs when remounting RO to avoid leaking them 2020-12-18 15:00:08 +01:00
sysfs.c for-5.11/block-2020-12-14 2020-12-16 12:57:51 -08:00
sysfs.h btrfs: split and refactor btrfs_sysfs_remove_devices_dir 2020-10-07 12:12:21 +02:00
transaction.c btrfs: rename btrfs_find_free_objectid to btrfs_get_free_objectid 2021-02-08 22:58:49 +01:00
transaction.h btrfs: return bool from btrfs_should_end_transaction 2020-12-08 15:54:16 +01:00
tree-checker.c btrfs: tree-checker: check if chunk item end overflows 2021-01-07 17:25:05 +01:00
tree-checker.h
tree-defrag.c btrfs: locking: remove all the blocking helpers 2020-12-08 15:54:01 +01:00
tree-log.c btrfs: rename btrfs_find_highest_objectid to btrfs_init_root_free_objectid 2021-02-08 22:58:49 +01:00
tree-log.h btrfs: make fast fsyncs wait only for writeback 2020-10-07 12:06:56 +02:00
ulist.c
ulist.h
uuid-tree.c btrfs: remove unnecessary casts in printk 2020-12-08 15:53:52 +01:00
volumes.c btrfs: consolidate btrfs_previous_item ret val handling in btrfs_shrink_device 2021-02-08 22:58:51 +01:00
volumes.h btrfs: fix lockdep warning due to seqcount_mutex on 32bit arch 2021-01-25 18:44:50 +01:00
xattr.c btrfs: skip unnecessary searches for xattrs when logging an inode 2020-12-08 15:54:12 +01:00
xattr.h
zlib.c btrfs: use larger zlib buffer for s390 hardware compression 2020-01-31 10:30:40 -08:00
zoned.c btrfs: zoned: remove unused variable in btrfs_sb_log_location_bdev 2021-02-08 22:58:54 +01:00
zoned.h btrfs: implement log-structured superblock for ZONED mode 2020-12-09 19:16:04 +01:00
zstd.c btrfs: compression: inline free_workspace 2019-11-18 12:46:59 +01:00