pud_request
error = pud_request(bp->b_dev, pc_rw, allocsize, PUD_REQ_BDEV,
error = pud_request(dev, pc_read, allocsize,
error = pud_request(dev, pc_write, allocsize,
return pud_request(dev, &pc_oc, sizeof(pc_oc), class, type);
error = pud_request(dev, pc_ioctl, allocsize, class, type);
int pud_request(dev_t, void *, size_t, int, int);