[PATCH] btrfs: don't clobber errors in add_remap_tree_entries()

[PATCH] btrfs: don't clobber errors in add_remap_tree_entries()

[Mark Harmstone]

From: Mark Harmstone <maharmstone@fb.com>

In add_remap_tree_entries(), we only process a certain number of entries
at a time, meaning we may need to loop.

But because we weren't checking the return value of btrfs_insert_empty_items()
within the loop, this meant that if the last iteration of the loop
succeeded but a previous iteration failed, we were erroneously returning
0.

Fix this by breaking the loop early if btrfs_insert_empty_items() fails.

Fixes: b56f35560b82 ("btrfs: handle setting up relocation of block group with remap-tree")
Signed-off-by: Mark Harmstone <mark@harmstone.com>
---
 fs/btrfs/relocation.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
index ad433b7ca919aa..a7cf5d9cf1de0d 100644
--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -3876,7 +3876,7 @@ static int add_remap_tree_entries(struct btrfs_trans_handle *trans, struct btrfs
 		ret = btrfs_insert_empty_items(trans, fs_info->remap_root, path, &batch);
 		btrfs_release_path(path);
 
-		if (num_entries <= max_items)
+		if (ret || num_entries <= max_items)
 			break;
 
 		num_entries -= max_items;
-- 
2.52.0

Re: [PATCH] btrfs: don't clobber errors in add_remap_tree_entries()

[David Sterba]

On Wed, Apr 08, 2026 at 02:13:20PM +0100, Mark Harmstone wrote:
> From: Mark Harmstone <maharmstone@fb.com>
> 
> In add_remap_tree_entries(), we only process a certain number of entries
> at a time, meaning we may need to loop.
> 
> But because we weren't checking the return value of btrfs_insert_empty_items()
> within the loop, this meant that if the last iteration of the loop
> succeeded but a previous iteration failed, we were erroneously returning
> 0.
> 
> Fix this by breaking the loop early if btrfs_insert_empty_items() fails.
> 
> Fixes: b56f35560b82 ("btrfs: handle setting up relocation of block group with remap-tree")
> Signed-off-by: Mark Harmstone <mark@harmstone.com>

Reviewed-by: David Sterba <dsterba@suse.com>