diff --git a/fs/ocfs2/refcounttree.c b/fs/ocfs2/refcounttree.c
index 6a42c04ac0ab..46bbd315c39f 100644
--- a/fs/ocfs2/refcounttree.c
+++ b/fs/ocfs2/refcounttree.c
@@ -4852,7 +4852,7 @@ int ocfs2_reflink_remap_range(struct file *file_in,
 
 	ret = generic_remap_file_range_prep(file_in, pos_in, file_out, pos_out,
 			&len, remap_flags);
-	if (ret <= 0)
+	if (ret < 0 || len == 0)
 		goto out_unlock;
 
 	/* Lock out changes to the allocation maps and remap. */
diff --git a/fs/read_write.c b/fs/read_write.c
index e4d295d0d236..6b40a43edf18 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -1848,8 +1848,8 @@ out_error:
  * sense, and then flush all dirty data.  Caller must ensure that the
  * inodes have been locked against any other modifications.
  *
- * Returns: 0 for "nothing to clone", 1 for "something to clone", or
- * the usual negative error code.
+ * If there's an error, then the usual negative error code is returned.
+ * Otherwise returns 0 with *len set to the request length.
  */
 int generic_remap_file_range_prep(struct file *file_in, loff_t pos_in,
 				  struct file *file_out, loff_t pos_out,
@@ -1945,7 +1945,7 @@ int generic_remap_file_range_prep(struct file *file_in, loff_t pos_in,
 			return ret;
 	}
 
-	return 1;
+	return 0;
 }
 EXPORT_SYMBOL(generic_remap_file_range_prep);
 
diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c
index 3dbe5fb7e9c0..9b1ea42c81d1 100644
--- a/fs/xfs/xfs_reflink.c
+++ b/fs/xfs/xfs_reflink.c
@@ -1329,7 +1329,7 @@ xfs_reflink_remap_prep(
 
 	ret = generic_remap_file_range_prep(file_in, pos_in, file_out, pos_out,
 			len, remap_flags);
-	if (ret <= 0)
+	if (ret < 0 || *len == 0)
 		goto out_unlock;
 
 	/*
@@ -1409,7 +1409,7 @@ xfs_reflink_remap_range(
 	/* Prepare and then clone file data. */
 	ret = xfs_reflink_remap_prep(file_in, pos_in, file_out, pos_out,
 			&len, remap_flags);
-	if (ret <= 0)
+	if (ret < 0 || len == 0)
 		return ret;
 
 	trace_xfs_reflink_remap_range(src, pos_in, len, dest, pos_out);