valid_cl
assert(valid_cl(fat, head));
valid_cl(fat, next_cl);
while (valid_cl(fat, current_cl)) {
if (!valid_cl(fat, cl)) {
if (!valid_cl(fat, cl)) {
static inline bool valid_cl(struct fat_descriptor *, cl_t);
return (valid_cl(fat, cl));
} else if (!valid_cl(fat, nextcl) && nextcl < CLUST_RSRVD) {
} else if (valid_cl(fat, nextcl)) {