btrfs: reset RO counter on block group if we fail to relocate

With the automatic block group reclaim code we will preemptively try to
mark the block group RO before we start the relocation.  We do this to
make sure we should actually try to relocate the block group.

However if we hit an error during the actual relocation we won't clean
up our RO counter and the block group will remain RO.  This was observed
internally with file systems reporting less space available from df when
we had failed background relocations.

Fix this by doing the dec_ro in the error case.

Fixes: 18bb8bbf13c1 ("btrfs: zoned: automatically reclaim zones")
CC: stable@vger.kernel.org # 5.15+
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/block-group.c b/fs/btrfs/block-group.c
index c3aecfb0a71d2b199800f8f97ebb4a7bf646306a..993aca2f1e1812d4f7849bbe01357a32c38ab057 100644 (file)
--- a/fs/btrfs/block-group.c
+++ b/fs/btrfs/block-group.c
@@ -1640,9 +1640,11 @@ void btrfs_reclaim_bgs_work(struct work_struct *work)
                                div64_u64(zone_unusable * 100, bg->length));
                trace_btrfs_reclaim_block_group(bg);
                ret = btrfs_relocate_chunk(fs_info, bg->start);
-               if (ret)
+               if (ret) {
+                       btrfs_dec_block_group_ro(bg);
                        btrfs_err(fs_info, "error relocating chunk %llu",
                                  bg->start);
+               }
 
 next:
                btrfs_put_block_group(bg);