[PATCH] btrfs: zoned: finish active block group cleanup if call_zone_finish() fails

do_zone_finish() clears BLOCK_GROUP_FLAG_ZONE_IS_ACTIVE before finishing
the zones. If call_zone_finish() then fails it returned early, leaving the
now inactive block group on fs_info->zone_active_bgs, leaking its
reference, the BTRFS_FS_NEED_ZONE_FINISH waiters are never woken, and as
its alloc_offset equals the zone capacity btrfs_zone_finish_one_bg() keeps
selecting it, spinning btrfs_zoned_activate_one_bg().

Fall through to the cleanup on failure too and return the error, but keep
the block group read-only as its zones are left inconsistent.

Fixes: d70cbdda75da ("btrfs: zoned: consolidate zone finish functions")
Link: https://sashiko.dev/#/patchset/20260818100037.1366563-1-johannes.thumshirn%40wdc.com
Signed-off-by: Johannes Thumshirn <[email protected]>
---
 fs/btrfs/zoned.c | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/fs/btrfs/zoned.c b/fs/btrfs/zoned.c
index 82c2394dd43c..9d448cdd60c4 100644
--- a/fs/btrfs/zoned.c
+++ b/fs/btrfs/zoned.c
@@ -2628,14 +2628,12 @@ static int do_zone_finish(struct btrfs_block_group *block_group, bool fully_writ
 	for (i = 0; i < map->num_stripes; i++) {
 
 		ret = call_zone_finish(block_group, &map->stripes[i]);
-		if (ret) {
-			up_read(&dev_replace->rwsem);
-			return ret;
-		}
+		if (ret)
+			break;
 	}
 	up_read(&dev_replace->rwsem);
 
-	if (!fully_written)
+	if (!ret && !fully_written)
 		btrfs_dec_block_group_ro(block_group);
 
 	spin_lock(&fs_info->zone_active_bgs_lock);
@@ -2648,7 +2646,7 @@ static int do_zone_finish(struct btrfs_block_group *block_group, bool fully_writ
 
 	clear_and_wake_up_bit(BTRFS_FS_NEED_ZONE_FINISH, &fs_info->flags);
 
-	return 0;
+	return ret;
 }
 
 int btrfs_zone_finish(struct btrfs_block_group *block_group)
-- 
2.55.0