[PATCH 5.15 015/244] btrfs: reset RO counter on block group if we fail to relocate

Greg Kroah-Hartman
2022-08-23T09:36:43Z

From: Josef Bacik <josef@toxicpanda.com>

commit 74944c873602a3ed8d16ff7af3f64af80c0f9dac upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
fs/btrfs/block-group.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

--- a/fs/btrfs/block-group.c
+++ b/fs/btrfs/block-group.c
@@ -1575,9 +1575,11 @@ void btrfs_reclaim_bgs_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);