2.11BSD#431 - /usr/src/sys/sys/ufs_dsort.c

   1: /*
   2:  * Copyright (c) 1986 Regents of the University of California.
   3:  * All rights reserved.  The Berkeley software License Agreement
   4:  * specifies the terms and conditions for redistribution.
   5:  *
   6:  *	@(#)ufs_dsort.c	1.1 (2.10BSD Berkeley) 12/1/86
   7:  */
   8: 
   9: /*
  10:  * generalized seek sort for disk
  11:  */
  12: 
  13: #include "param.h"
  14: #include "systm.h"
  15: #include "buf.h"
  16: #include "dk.h"
  17: 
  18: disksort(dp, bp)
  19:     register struct buf *dp, *bp;
  20: {
  21:     register struct buf *ap;
  22:     struct buf *tp;
  23: 
  24:     ap = dp->b_actf;
  25:     if (ap == NULL) {
  26:         dp->b_actf = bp;
  27:         dp->b_actl = bp;
  28:         bp->av_forw = NULL;
  29:         return;
  30:     }
  31:     tp = NULL;
  32:     for (; ap != NULL; ap = ap->av_forw) {
  33:         if ((bp->b_flags&B_READ) && (ap->b_flags&B_READ) == 0) {
  34:             if (tp == NULL)
  35:                 tp = ap;
  36:             break;
  37:         }
  38:         if ((bp->b_flags&B_READ) == 0 && (ap->b_flags&B_READ))
  39:             continue;
  40:         if (ap->b_cylin <= bp->b_cylin)
  41:             if (tp == NULL || ap->b_cylin >= tp->b_cylin)
  42:                 tp = ap;
  43:     }
  44:     if (tp == NULL)
  45:         tp = dp->b_actl;
  46:     bp->av_forw = tp->av_forw;
  47:     tp->av_forw = bp;
  48:     if (tp == dp->b_actl)
  49:         dp->b_actl = bp;
  50: }
  51: 
  52: #ifdef UCB_METER
  53: /*
  54:  * Allocate iostat disk monitoring slots for a driver.  If slots already
  55:  * allocated (*dkn >= 0) or not enough slots left to satisfy request simply
  56:  * ignore it.
  57:  */
  58: dk_alloc(dkn, slots, name, wps)
  59:     int *dkn;   /* pointer to number for iostat */
  60:     int slots;  /* number of iostat slots requested */
  61:     char *name; /* name of device */
  62:     long wps;   /* words per second transfer rate */
  63: {
  64:     int i;
  65:     register char **np;
  66:     register int *up;
  67:     register long *wp;
  68: 
  69:     if (*dkn < 0 && dk_n + slots <= DK_NDRIVE) {
  70:         /*
  71: 		 * Allocate and initialize the slots
  72: 		 */
  73:         *dkn = dk_n;
  74:         np = &dk_name[dk_n];
  75:         up = &dk_unit[dk_n];
  76:         wp = &dk_wps[dk_n];
  77:         dk_n += slots;
  78: 
  79:         for (i = 0; i < slots; i++) {
  80:             *np++ = name;
  81:             *up++ = i;
  82:             *wp++ = wps;
  83:         }
  84:     }
  85: }
  86: #endif /* UCB_METER */

Defined functions