From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: stable@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	patches@lists.linux.dev,
	Qu Wenruo <wqu@suse.com>,
	Johannes Thumshirn <johannes.thumshirn@wdc.com>,
	David Sterba <dsterba@suse.com>,
	Sasha Levin <sashal@kernel.org>
Subject: [PATCH 6.12 0621/1102] btrfs: zoned: finish active block group cleanup if call_zone_finish() fails
Date: Thu, 17 Sep 2026 16:09:24 +0100
Message-ID: <20260917151555.666561160@linuxfoundation.org>
In-Reply-To: <20260917151539.408551884@linuxfoundation.org>
References: <20260917151539.408551884@linuxfoundation.org>
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6.12-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Johannes Thumshirn <johannes.thumshirn@wdc.com>

[ Upstream commit a18a6b93a2843b9d103d3456bbd4b3f90282a379 ]

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
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/btrfs/zoned.c | 11 ++++-------
 1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/fs/btrfs/zoned.c b/fs/btrfs/zoned.c
index df7d75ef7ae3e..3503253511995 100644
--- a/fs/btrfs/zoned.c
+++ b/fs/btrfs/zoned.c
@@ -2559,16 +2559,13 @@ static int do_zone_finish(struct btrfs_block_group *block_group, bool fully_writ
 	down_read(&dev_replace->rwsem);
 	map = block_group->physical_map;
 	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);
@@ -2581,7 +2578,7 @@ 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)
-- 
2.53.0