UNLIMITED_IODEVS
nr_iodevs = df ? df->if_max_iodevs : UNLIMITED_IODEVS;
if (nr_iodevs == UNLIMITED_IODEVS)
df.if_max_iodevs = UNLIMITED_IODEVS;
(count && (df.if_max_iodevs == UNLIMITED_IODEVS)))