[PATCH RESEND] btrfs: Fix exception handling in relocating_repair_kthread()

[Markus Elfring]

From: Markus Elfring <elfring@xxxxxxxxxxxxxxxxxxxxx>
Date: Wed, 22 Mar 2023 20:10:09 +0100

The label “out” was used to jump to another pointer check despite of
the detail in the implementation of the function
“relocating_repair_kthread” that it was determined already that
a corresponding variable contained a null pointer because of
a failed call of the function “btrfs_lookup_block_group”.

* Thus use more appropriate labels instead.

* Delete a redundant check.


This issue was detected by using the Coccinelle software.

Fixes: f7ef5287a63d ("btrfs: zoned: relocate block group to repair IO failure in zoned filesystems")
Signed-off-by: Markus Elfring <elfring@xxxxxxxxxxxxxxxxxxxxx>
---
 fs/btrfs/volumes.c | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 6d0124b6e79e..de11ad6c8740 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -8096,23 +8096,22 @@ static int relocating_repair_kthread(void *data)
 	/* Ensure block group still exists */
 	cache = btrfs_lookup_block_group(fs_info, target);
 	if (!cache)
-		goto out;
+		goto unlock;

 	if (!test_bit(BLOCK_GROUP_FLAG_RELOCATING_REPAIR, &cache->runtime_flags))
-		goto out;
+		goto put_block_group;

 	ret = btrfs_may_alloc_data_chunk(fs_info, target);
 	if (ret < 0)
-		goto out;
+		goto put_block_group;

 	btrfs_info(fs_info,
 		   "zoned: relocating block group %llu to repair IO failure",
 		   target);
 	ret = btrfs_relocate_chunk(fs_info, target);
-
-out:
-	if (cache)
-		btrfs_put_block_group(cache);
+put_block_group:
+	btrfs_put_block_group(cache);
+unlock:
 	mutex_unlock(&fs_info->reclaim_bgs_lock);
 	btrfs_exclop_finish(fs_info);
 	sb_end_write(fs_info->sb);
--
2.40.0