NETFS_WRITEBACK_SINGLE
case NETFS_WRITEBACK_SINGLE:
[NETFS_WRITEBACK_SINGLE] = "W1",
wreq = netfs_create_write_req(mapping, NULL, 0, NETFS_WRITEBACK_SINGLE);
origin == NETFS_WRITEBACK_SINGLE ||
EM(NETFS_WRITEBACK_SINGLE, "W1") \