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| author | Johannes Thumshirn <johannes.thumshirn@wdc.com> | 2021-04-19 16:41:02 +0900 |
|---|---|---|
| committer | David Sterba <dsterba@suse.com> | 2021-04-20 20:46:31 +0200 |
| commit | 18bb8bbf13c1839b43c9e09e76d397b753989af2 (patch) | |
| tree | 129cbdd4389bbaa1dc598da8a40138729f26f77b /fs/btrfs/disk-io.c | |
| parent | f33720657d29d6b7282dd2e5e8634e0a39ad372e (diff) | |
| download | linux-18bb8bbf13c1839b43c9e09e76d397b753989af2.tar.bz2 | |
btrfs: zoned: automatically reclaim zones
When a file gets deleted on a zoned file system, the space freed is not
returned back into the block group's free space, but is migrated to
zone_unusable.
As this zone_unusable space is behind the current write pointer it is not
possible to use it for new allocations. In the current implementation a
zone is reset once all of the block group's space is accounted as zone
unusable.
This behaviour can lead to premature ENOSPC errors on a busy file system.
Instead of only reclaiming the zone once it is completely unusable,
kick off a reclaim job once the amount of unusable bytes exceeds a user
configurable threshold between 51% and 100%. It can be set per mounted
filesystem via the sysfs tunable bg_reclaim_threshold which is set to 75%
by default.
Similar to reclaiming unused block groups, these dirty block groups are
added to a to_reclaim list and then on a transaction commit, the reclaim
process is triggered but after we deleted unused block groups, which will
free space for the relocation process.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs/btrfs/disk-io.c')
| -rw-r--r-- | fs/btrfs/disk-io.c | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index e52b89ad0a61..c9a3036c23bf 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -1898,6 +1898,13 @@ static int cleaner_kthread(void *arg) * unused block groups. */ btrfs_delete_unused_bgs(fs_info); + + /* + * Reclaim block groups in the reclaim_bgs list after we deleted + * all unused block_groups. This possibly gives us some more free + * space. + */ + btrfs_reclaim_bgs(fs_info); sleep: clear_and_wake_up_bit(BTRFS_FS_CLEANER_RUNNING, &fs_info->flags); if (kthread_should_park()) @@ -2886,6 +2893,7 @@ void btrfs_init_fs_info(struct btrfs_fs_info *fs_info) INIT_LIST_HEAD(&fs_info->space_info); INIT_LIST_HEAD(&fs_info->tree_mod_seq_list); INIT_LIST_HEAD(&fs_info->unused_bgs); + INIT_LIST_HEAD(&fs_info->reclaim_bgs); #ifdef CONFIG_BTRFS_DEBUG INIT_LIST_HEAD(&fs_info->allocated_roots); INIT_LIST_HEAD(&fs_info->allocated_ebs); @@ -2974,6 +2982,9 @@ void btrfs_init_fs_info(struct btrfs_fs_info *fs_info) fs_info->swapfile_pins = RB_ROOT; fs_info->send_in_progress = 0; + + fs_info->bg_reclaim_threshold = BTRFS_DEFAULT_RECLAIM_THRESH; + INIT_WORK(&fs_info->reclaim_bgs_work, btrfs_reclaim_bgs_work); } static int init_mount_fs_info(struct btrfs_fs_info *fs_info, struct super_block *sb) @@ -4332,6 +4343,8 @@ void __cold close_ctree(struct btrfs_fs_info *fs_info) cancel_work_sync(&fs_info->async_data_reclaim_work); cancel_work_sync(&fs_info->preempt_reclaim_work); + cancel_work_sync(&fs_info->reclaim_bgs_work); + /* Cancel or finish ongoing discard work */ btrfs_discard_cleanup(fs_info); |