From: Naohiro Aota naota@elisp.net
commit 93463ff7b54626f8276c0bd3d3f968fbf8d5d380 upstream.
When a filesystem is read-only, we cannot reclaim a block group as it cannot rewrite the data. Just bail out in that case.
Note that it can drop block groups in this case. As we did sb_start_write(), read-only filesystem means we got a fatal error and forced read-only. There is no chance to reclaim them again.
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 | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-)
--- a/fs/btrfs/block-group.c +++ b/fs/btrfs/block-group.c @@ -1798,8 +1798,15 @@ void btrfs_reclaim_bgs_work(struct work_ } spin_unlock(&bg->lock);
- /* Get out fast, in case we're unmounting the filesystem */ - if (btrfs_fs_closing(fs_info)) { + /* + * Get out fast, in case we're read-only or unmounting the + * filesystem. It is OK to drop block groups from the list even + * for the read-only case. As we did sb_start_write(), + * "mount -o remount,ro" won't happen and read-only filesystem + * means it is forced read-only due to a fatal error. So, it + * never gets back to read-write to let us reclaim again. + */ + if (btrfs_need_cleaner_sleep(fs_info)) { up_write(&space_info->groups_sem); goto next; }