DTFS_CTOF
df = DTFS_CTOF(pn);
struct dtfs_file *df = DTFS_CTOF(targ);
df_targ = DTFS_CTOF(pn_tfile);
struct dtfs_file *df = DTFS_CTOF(opc);
struct dtfs_file *df = DTFS_CTOF(opc);
struct dtfs_file *df = DTFS_CTOF(opc);
struct dtfs_file *df = DTFS_CTOF(opc);