[PATCH 5.4 36/77] btrfs: fix silent failure when deleting root reference

[Greg Kroah-Hartman]

From: Filipe Manana <fdmanana@xxxxxxxx>

commit 47bf225a8d2cccb15f7e8d4a1ed9b757dd86afd7 upstream.

At btrfs_del_root_ref(), if btrfs_search_slot() returns an error, we end
up returning from the function with a value of 0 (success). This happens
because the function returns the value stored in the variable 'err',
which is 0, while the error value we got from btrfs_search_slot() is
stored in the 'ret' variable.

So fix it by setting 'err' with the error value.

Fixes: 8289ed9f93bef2 ("btrfs: replace the BUG_ON in btrfs_del_root_ref with proper error handling")
CC: stable@xxxxxxxxxxxxxxx # 5.16+
Reviewed-by: Qu Wenruo <wqu@xxxxxxxx>
Signed-off-by: Filipe Manana <fdmanana@xxxxxxxx>
Reviewed-by: David Sterba <dsterba@xxxxxxxx>
Signed-off-by: David Sterba <dsterba@xxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 fs/btrfs/root-tree.c |    5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

--- a/fs/btrfs/root-tree.c
+++ b/fs/btrfs/root-tree.c
@@ -371,9 +371,10 @@ int btrfs_del_root_ref(struct btrfs_tran
 	key.offset = ref_id;
 again:
 	ret = btrfs_search_slot(trans, tree_root, &key, path, -1, 1);
-	if (ret < 0)
+	if (ret < 0) {
+		err = ret;
 		goto out;
-	if (ret == 0) {
+	} else if (ret == 0) {
 		leaf = path->nodes[0];
 		ref = btrfs_item_ptr(leaf, path->slots[0],
 				     struct btrfs_root_ref);