SEEK_DATA does require more than just return, actually.

Signed-off-by: Rich Ercolani <rincebrain@gmail.com>

module/zfs/zfs_vnops.c

@@ -65,7 +65,6 @@
  */
 int zfs_bclone_enabled = 1;
 
-
 /*
  * When set zfs_clone_range() waits for dirty data to be written to disk.
  * This allows the clone operation to reliably succeed when a file is modified
@@ -182,6 +181,10 @@ zfs_holey(znode_t *zp, ulong_t cmd, loff_t *off)
 		/*
 		 * F_SEEK_DATA, not modifying *off is "data here"
 		 */
+		else if (cmd == F_SEEK_DATA)
+			if (*off >= zp->z_size)
+				return (ENXIO);
+
 		return (0);
 	}