diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index f1fbf903bf9b491ef4e489946d6f7b5c7d8fe03e..a44ca6a4feffc1af73ef74813b38c849934a5fbf 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -843,7 +843,10 @@ static noinline int cow_file_range(struct inode *inode,
 	struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
 	int ret = 0;
 
-	BUG_ON(btrfs_is_free_space_inode(inode));
+	if (btrfs_is_free_space_inode(inode)) {
+		WARN_ON_ONCE(1);
+		return -EINVAL;
+	}
 
 	num_bytes = ALIGN(end - start + 1, blocksize);
 	num_bytes = max(blocksize,  num_bytes);