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| author | Johannes Thumshirn <johannes.thumshirn@wdc.com> | 2021-04-19 09:41:02 +0200 |
|---|---|---|
| committer | David Sterba <dsterba@suse.com> | 2021-04-20 20:46:31 +0200 |
| commit | 18bb8bbf13c1839b43c9e09e76d397b753989af2 (patch) | |
| tree | 129cbdd4389bbaa1dc598da8a40138729f26f77b /fs/btrfs/volumes.h | |
| parent | btrfs: rename delete_unused_bgs_mutex to reclaim_bgs_lock (diff) | |
| download | linux-18bb8bbf13c1839b43c9e09e76d397b753989af2.tar.xz linux-18bb8bbf13c1839b43c9e09e76d397b753989af2.zip | |
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/volumes.h')
| -rw-r--r-- | fs/btrfs/volumes.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h index d4c3e0dd32b8..9c0d84e5ec06 100644 --- a/fs/btrfs/volumes.h +++ b/fs/btrfs/volumes.h @@ -484,6 +484,7 @@ void btrfs_describe_block_groups(u64 flags, char *buf, u32 size_buf); int btrfs_resume_balance_async(struct btrfs_fs_info *fs_info); int btrfs_recover_balance(struct btrfs_fs_info *fs_info); int btrfs_pause_balance(struct btrfs_fs_info *fs_info); +int btrfs_relocate_chunk(struct btrfs_fs_info *fs_info, u64 chunk_offset); int btrfs_cancel_balance(struct btrfs_fs_info *fs_info); int btrfs_create_uuid_tree(struct btrfs_fs_info *fs_info); int btrfs_uuid_scan_kthread(void *data); |