linux/fs/btrfs
Josef Bacik 9118264507 btrfs: stop partially refilling tickets when releasing space
btrfs_space_info_add_old_bytes is used when adding the extra space from
an existing reservation back into the space_info to be used by any
waiting tickets.  In order to keep us from overcommitting we check to
make sure that we can still use this space for our reserve ticket, and
if we cannot we'll simply subtract it from space_info->bytes_may_use.

However this is problematic, because it assumes that only changes to
bytes_may_use would affect our ability to make reservations.  Any
changes to bytes_reserved would be missed.  If we were unable to make a
reservation prior because of reserved space, but that reserved space was
free'd due to unlink or truncate and we were allowed to immediately
reclaim that metadata space we would still ENOSPC.

Consider the example where we create a file with a bunch of extents,
using up 2MiB of actual space for the new tree blocks.  Then we try to
make a reservation of 2MiB but we do not have enough space to make this
reservation.  The iput() occurs in another thread and we remove this
space, and since we did not write the blocks we simply do
space_info->bytes_reserved -= 2MiB.  We would never see this because we
do not check our space info used, we just try to re-use the freed
reservations.

To fix this problem, and to greatly simplify the wakeup code, do away
with this partial refilling nonsense.  Use
btrfs_space_info_add_old_bytes to subtract the reservation from
space_info->bytes_may_use, and then check the ticket against the total
used of the space_info the same way we do with the initial reservation
attempt.

This keeps the reservation logic consistent and solves the problem of
early ENOSPC in the case that we free up space in places other than
bytes_may_use and bytes_pinned.  Thanks,

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-09-09 14:59:18 +02:00
..
tests btrfs: stop clearing EXTENT_DIRTY in inode I/O tree 2019-09-09 14:59:17 +02:00
acl.c btrfs: cleanup btrfs_setxattr_trans and drop transaction parameter 2019-04-29 19:02:44 +02:00
async-thread.c btrfs: async-thread: convert defines to enums 2019-09-09 14:59:03 +02:00
async-thread.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
backref.c Btrfs: fix deadlock between fiemap and transaction commits 2019-07-30 18:25:12 +02:00
backref.h btrfs: fiemap: preallocate ulists for btrfs_check_shared 2019-07-01 13:34:53 +02:00
block-group.c btrfs: add space reservation tracepoint for reserved bytes 2019-09-09 14:59:17 +02:00
block-group.h btrfs: move struct io_ctl to free-space-cache.h 2019-09-09 14:59:15 +02:00
block-rsv.c btrfs: roll tracepoint into btrfs_space_info_update helper 2019-09-09 14:59:17 +02:00
block-rsv.h btrfs: migrate the global_block_rsv helpers to block-rsv.c 2019-07-02 12:30:55 +02:00
btrfs_inode.h btrfs: remove assumption about csum type form btrfs_print_data_csum_error() 2019-07-01 13:35:02 +02:00
check-integrity.c btrfs: reduce stack usage for btrfsic_process_written_block 2019-09-09 14:58:58 +02:00
check-integrity.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
compression.c btrfs: move cond_wake_up functions out of ctree 2019-09-09 14:59:15 +02:00
compression.h btrfs: compression: replace set_level callbacks by a common helper 2019-09-09 14:59:11 +02:00
ctree.c btrfs: tie extent buffer and it's token together 2019-09-09 14:59:16 +02:00
ctree.h btrfs: tie extent buffer and it's token together 2019-09-09 14:59:16 +02:00
delalloc-space.c btrfs: roll tracepoint into btrfs_space_info_update helper 2019-09-09 14:59:17 +02:00
delalloc-space.h btrfs: migrate the delalloc space stuff to it's own home 2019-07-04 17:26:17 +02:00
delayed-inode.c btrfs: move cond_wake_up functions out of ctree 2019-09-09 14:59:15 +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: rename the btrfs_calc_*_metadata_size helpers 2019-09-09 14:59:13 +02:00
delayed-ref.h btrfs: migrate the delayed refs rsv code 2019-07-04 17:26:17 +02:00
dev-replace.c btrfs: move cond_wake_up functions out of ctree 2019-09-09 14:59:15 +02:00
dev-replace.h btrfs: get fs_info from trans in btrfs_run_dev_replace 2019-04-29 19:02:43 +02:00
dir-item.c btrfs: remove unused parameter fs_info from btrfs_extend_item 2019-04-29 19:02:50 +02:00
disk-io.c btrfs: Detect unbalanced tree with empty leaf before crashing btree operations 2019-09-09 14:59:14 +02:00
disk-io.h btrfs: Make reada_tree_block_flagged private 2019-09-09 14:59:11 +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: stop clearing EXTENT_DIRTY in inode I/O tree 2019-09-09 14:59:17 +02:00
extent_io.h btrfs: Remove delalloc_end argument from extent_clear_unlock_delalloc 2019-09-09 14:58:59 +02:00
extent_map.c btrfs: assert extent map tree lock in add_extent_mapping 2019-09-09 14:59:00 +02:00
extent_map.h btrfs: Remove impossible condition from mergable_maps 2019-02-25 14:13:21 +01:00
extent-tree.c btrfs: roll tracepoint into btrfs_space_info_update helper 2019-09-09 14:59:17 +02:00
file-item.c btrfs: directly call into crypto framework for checksumming 2019-07-01 13:35:02 +02:00
file.c btrfs: stop clearing EXTENT_DIRTY in inode I/O tree 2019-09-09 14:59:17 +02:00
free-space-cache.c btrfs: stop clearing EXTENT_DIRTY in inode I/O tree 2019-09-09 14:59:17 +02:00
free-space-cache.h btrfs: move struct io_ctl to free-space-cache.h 2019-09-09 14:59:15 +02:00
free-space-tree.c btrfs: move basic block_group definitions to their own header 2019-09-09 14:59:03 +02:00
free-space-tree.h btrfs: move basic block_group definitions to their own header 2019-09-09 14:59:03 +02:00
inode-item.c btrfs: Make btrfs_find_name_in_ext_backref return struct btrfs_inode_extref 2019-09-09 14:59:16 +02:00
inode-map.c btrfs: rename the btrfs_calc_*_metadata_size helpers 2019-09-09 14:59:13 +02:00
inode-map.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
inode.c btrfs: stop clearing EXTENT_DIRTY in inode I/O tree 2019-09-09 14:59:17 +02:00
ioctl.c btrfs: stop clearing EXTENT_DIRTY in inode I/O tree 2019-09-09 14:59:17 +02:00
Kconfig btrfs: Fix build error while LIBCRC32C is module 2019-07-17 17:03:30 +02:00
locking.c btrfs: move cond_wake_up functions out of ctree 2019-09-09 14:59:15 +02:00
locking.h btrfs: Remove unused locking functions 2019-09-09 14:58:59 +02:00
lzo.c btrfs: compression: replace set_level callbacks by a common helper 2019-09-09 14:59:11 +02:00
Makefile btrfs: migrate the block group lookup code 2019-09-09 14:59:04 +02:00
misc.h btrfs: move math functions to misc.h 2019-09-09 14:59:15 +02:00
ordered-data.c btrfs: move cond_wake_up functions out of ctree 2019-09-09 14:59:15 +02:00
ordered-data.h btrfs: don't assume ordered sums to be 4 bytes 2019-07-01 13:35:00 +02:00
orphan.c btrfs: replace GPL boilerplate by SPDX -- sources 2018-04-12 16:29:51 +02:00
print-tree.c btrfs: switch extent_buffer write_locks from atomic to int 2019-07-02 12:30:47 +02:00
print-tree.h btrfs: print-tree: debugging output enhancement 2018-04-20 19:18:16 +02:00
props.c btrfs: rename the btrfs_calc_*_metadata_size helpers 2019-09-09 14:59:13 +02:00
props.h btrfs: delete unused function btrfs_set_prop_trans 2019-04-29 19:02:54 +02:00
qgroup.c btrfs: qgroup: Try our best to delete qgroup relations 2019-09-09 14:59:06 +02:00
qgroup.h btrfs: qgroup: Move reserved data accounting from btrfs_delayed_ref_head to btrfs_qgroup_extent_record 2019-02-25 14:13:39 +01:00
raid56.c btrfs: move private raid56 definitions from ctree.h 2019-09-09 14:59:15 +02:00
raid56.h btrfs: constify map parameter for nr_parity_stripes and nr_data_stripes 2019-07-01 13:34:58 +02:00
rcu-string.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
reada.c btrfs: Make reada_tree_block_flagged private 2019-09-09 14:59:11 +02:00
ref-verify.c Wimplicit-fallthrough patches for 5.2-rc1 2019-05-07 12:48:10 -07:00
ref-verify.h btrfs: ref-verify: Use btrfs_ref to refactor btrfs_ref_tree_mod() 2019-04-29 19:02:49 +02:00
relocation.c btrfs: move basic block_group definitions to their own header 2019-09-09 14:59:03 +02:00
root-tree.c btrfs: rename the btrfs_calc_*_metadata_size helpers 2019-09-09 14:59:13 +02:00
scrub.c btrfs: move basic block_group definitions to their own header 2019-09-09 14:59:03 +02:00
send.c btrfs: move functions for tree compare to send.c 2019-09-09 14:59:15 +02:00
send.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
space-info.c btrfs: stop partially refilling tickets when releasing space 2019-09-09 14:59:18 +02:00
space-info.h btrfs: roll tracepoint into btrfs_space_info_update helper 2019-09-09 14:59:17 +02:00
struct-funcs.c btrfs: tie extent buffer and it's token together 2019-09-09 14:59:16 +02:00
super.c btrfs: move sysfs declarations out of ctree.h 2019-09-09 14:59:06 +02:00
sysfs.c btrfs: sysfs: move helper macros to sysfs.c 2019-09-09 14:59:08 +02:00
sysfs.h btrfs: sysfs: move helper macros to sysfs.c 2019-09-09 14:59:08 +02:00
transaction.c btrfs: move cond_wake_up functions out of ctree 2019-09-09 14:59:15 +02:00
transaction.h Btrfs: fix deadlock between fiemap and transaction commits 2019-07-30 18:25:12 +02:00
tree-checker.c btrfs: Detect unbalanced tree with empty leaf before crashing btree operations 2019-09-09 14:59:14 +02:00
tree-checker.h btrfs: get fs_info from eb in btrfs_check_chunk_valid 2019-04-29 19:02:39 +02:00
tree-defrag.c btrfs: open code now trivial btrfs_set_lock_blocking 2019-02-25 14:13:27 +01:00
tree-log.c btrfs: tie extent buffer and it's token together 2019-09-09 14:59:16 +02:00
tree-log.h btrfs: get fs_info from trans in btrfs_set_log_full_commit 2019-04-29 19:02:41 +02:00
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 unused parameter fs_info from btrfs_extend_item 2019-04-29 19:02:50 +02:00
volumes.c btrfs: move dev_stats helpers to volumes.c 2019-09-09 14:59:16 +02:00
volumes.h btrfs: reset device stat using btrfs_dev_stat_set 2019-09-09 14:59:06 +02:00
xattr.c Btrfs: fix failure to persist compression property xattr deletion on fsync 2019-06-17 16:37:17 +02:00
xattr.h btrfs: cleanup btrfs_setxattr_trans and drop transaction parameter 2019-04-29 19:02:44 +02:00
zlib.c btrfs: compression: replace set_level callbacks by a common helper 2019-09-09 14:59:11 +02:00
zstd.c btrfs: move cond_wake_up functions out of ctree 2019-09-09 14:59:15 +02:00