sl_status
if (slot.sl_status == SL_NONE)
slotp->sl_status = SL_NONE;
if (error == ENOENT && slotp->sl_status == SL_NONE) {
slotp->sl_status = SL_EXTEND;
if (slotp->sl_status == SL_NONE) {
slotp->sl_status = SL_FOUND;
enum {SL_NONE, SL_FOUND, SL_EXTEND} sl_status; /* slot status */
sizeof (struct sl_status),
zss->sl_mstat = allocb(sizeof (struct sl_status), BPRI_MED);
struct sl_status *mstat;
mstat = (struct sl_status *)mp->b_wptr;
mp->b_wptr += sizeof (struct sl_status);