Btrfs: fix copy_items() return value when logging an inode

From: Filipe Manana <[email protected]>

When logging an inode, at tree-log.c:copy_items(), if we call btrfs_next_leaf() at the loop which checks for the need to log holes, we need to make sure copy_items() returns the value 1 to its caller and not 0 (on success). This is because the path the caller passed was released and is now different from what is was before, and the caller expects a return value of 0 to mean both success and that the path has not changed, while a return value of 1 means both success and signals the caller that it can not reuse the path, it has to perform another tree search.

Even though this is a case that should not be triggered on normal circumstances or very rare at least, its consequences can be very unpredictable (especially when replaying a log tree).

---
 fs/btrfs/tree-log.c | 1 +
 1 file changed, 1 insertion(+)

index 1d738ff5c41b..abd9fd81cd1c 100644
@@ -3960,6 +3960,7 @@ static noinline int copy_items(struct btrfs_trans_handle *trans,
 			ASSERT(ret == 0);
 			src = src_path->nodes[0];
 			i = 0;
+			need_find_last_extent = true;
 		}
 
 		btrfs_item_key_to_cpu(src, &key, i);

2.11.0