From: Naohiro Aota naota@elisp.net
commit a9f189716cf15913c453299d72f69c51a9b0f86b upstream.
An unused block group is easy to remove to free up space and should be reclaimed fast. Such block group can often already be a target of the reclaim process. As we check list_empty(&bg->bg_list), we keep it in the reclaim list. That block group is never reclaimed until the file system is filled e.g. up to 75%.
Instead, we can move unused block group to the unused list and delete it fast.
Fixes: 18bb8bbf13c1 ("btrfs: zoned: automatically reclaim zones") CC: stable@vger.kernel.org # 5.15+ Reviewed-by: Filipe Manana fdmanana@suse.com Reviewed-by: Johannes Thumshirn johannes.thumshirn@wdc.com Signed-off-by: Naohiro Aota naohiro.aota@wdc.com Signed-off-by: David Sterba dsterba@suse.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/btrfs/block-group.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
--- a/fs/btrfs/block-group.c +++ b/fs/btrfs/block-group.c @@ -1640,11 +1640,14 @@ void btrfs_mark_bg_unused(struct btrfs_b { struct btrfs_fs_info *fs_info = bg->fs_info;
+ trace_btrfs_add_unused_block_group(bg); spin_lock(&fs_info->unused_bgs_lock); if (list_empty(&bg->bg_list)) { btrfs_get_block_group(bg); - trace_btrfs_add_unused_block_group(bg); list_add_tail(&bg->bg_list, &fs_info->unused_bgs); + } else { + /* Pull out the block group from the reclaim_bgs list. */ + list_move_tail(&bg->bg_list, &fs_info->unused_bgs); } spin_unlock(&fs_info->unused_bgs_lock); }