Commit | Line | Data |
---|---|---|
200a8f27 BJ |
1 | /* ufs_disksubr.c 3.1 %H% */ |
2 | ||
3 | /* | |
4 | * generalized seek sort for disk | |
5 | */ | |
6 | ||
7 | #include "../h/param.h" | |
8 | #include "../h/systm.h" | |
9 | #include "../h/buf.h" | |
10 | ||
11 | #define b_cylin b_resid | |
12 | ||
13 | disksort(dp, bp) | |
14 | register struct buf *dp, *bp; | |
15 | { | |
16 | register struct buf *ap; | |
17 | struct buf *tp; | |
18 | ||
19 | ap = dp->b_actf; | |
20 | if(ap == NULL) { | |
21 | dp->b_actf = bp; | |
22 | dp->b_actl = bp; | |
23 | bp->av_forw = NULL; | |
24 | return; | |
25 | } | |
26 | tp = NULL; | |
27 | for(; ap != NULL; ap = ap->av_forw) { | |
28 | if ((bp->b_flags&B_READ) && (ap->b_flags&B_READ) == 0) { | |
29 | if (tp == NULL) | |
30 | tp = ap; | |
31 | break; | |
32 | } | |
33 | if ((bp->b_flags&B_READ) == 0 && (ap->b_flags&B_READ)) | |
34 | continue; | |
35 | if(ap->b_cylin <= bp->b_cylin) | |
36 | if(tp == NULL || ap->b_cylin >= tp->b_cylin) | |
37 | tp = ap; | |
38 | } | |
39 | if(tp == NULL) | |
40 | tp = dp->b_actl; | |
41 | bp->av_forw = tp->av_forw; | |
42 | tp->av_forw = bp; | |
43 | if(tp == dp->b_actl) | |
44 | dp->b_actl = bp; | |
45 | } |