Commit | Line | Data |
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d668d9ba | 1 | /* vm_swap.c 4.18 83/05/18 */ |
013037be BJ |
2 | |
3 | #include "../h/param.h" | |
4 | #include "../h/systm.h" | |
5 | #include "../h/buf.h" | |
6 | #include "../h/conf.h" | |
7 | #include "../h/dir.h" | |
8 | #include "../h/user.h" | |
9 | #include "../h/inode.h" | |
10 | #include "../h/map.h" | |
5699bf69 | 11 | #include "../h/uio.h" |
ca1f746a | 12 | #include "../h/file.h" |
4f083fd7 | 13 | #include "../h/nami.h" |
013037be BJ |
14 | |
15 | struct buf rswbuf; | |
16 | /* | |
17 | * Indirect driver for multi-controller paging. | |
18 | */ | |
19 | swstrategy(bp) | |
20 | register struct buf *bp; | |
21 | { | |
22 | int sz, off, seg; | |
23 | dev_t dev; | |
24 | ||
b9ee5d20 BJ |
25 | #ifdef GENERIC |
26 | /* | |
27 | * A mini-root gets copied into the front of the swap | |
28 | * and we run over top of the swap area just long | |
29 | * enough for us to do a mkfs and restor of the real | |
30 | * root (sure beats rewriting standalone restor). | |
31 | */ | |
8c5046eb | 32 | #define MINIROOTSIZE 4096 |
b9ee5d20 BJ |
33 | if (rootdev == dumpdev) |
34 | bp->b_blkno += MINIROOTSIZE; | |
35 | #endif | |
ca1f746a | 36 | sz = howmany(bp->b_bcount, DEV_BSIZE); |
d668d9ba | 37 | if (bp->b_blkno+sz > nswap) { |
013037be BJ |
38 | bp->b_flags |= B_ERROR; |
39 | iodone(bp); | |
40 | return; | |
41 | } | |
d668d9ba SL |
42 | if (nswdev > 1) { |
43 | off = bp->b_blkno % dmmax; | |
44 | if (off+sz > dmmax) { | |
45 | bp->b_flags |= B_ERROR; | |
46 | iodone(bp); | |
47 | return; | |
48 | } | |
49 | seg = bp->b_blkno / dmmax; | |
50 | dev = swdevt[seg % nswdev].sw_dev; | |
51 | seg /= nswdev; | |
52 | bp->b_blkno = seg*dmmax + off; | |
53 | } else | |
54 | dev = swdevt[0].sw_dev; | |
013037be BJ |
55 | bp->b_dev = dev; |
56 | if (dev == 0) | |
57 | panic("swstrategy"); | |
58 | (*bdevsw[major(dev)].d_strategy)(bp); | |
59 | } | |
60 | ||
5699bf69 BJ |
61 | swread(dev, uio) |
62 | dev_t dev; | |
63 | struct uio *uio; | |
013037be BJ |
64 | { |
65 | ||
30c36259 | 66 | return (physio(swstrategy, &rswbuf, dev, B_READ, minphys, uio)); |
013037be BJ |
67 | } |
68 | ||
5699bf69 BJ |
69 | swwrite(dev, uio) |
70 | dev_t dev; | |
71 | struct uio *uio; | |
013037be BJ |
72 | { |
73 | ||
30c36259 | 74 | return (physio(swstrategy, &rswbuf, dev, B_WRITE, minphys, uio)); |
013037be BJ |
75 | } |
76 | ||
77 | /* | |
78 | * System call swapon(name) enables swapping on device name, | |
79 | * which must be in the swdevsw. Return EBUSY | |
80 | * if already swapping on this device. | |
81 | */ | |
2dfa06c1 | 82 | swapon() |
013037be | 83 | { |
2dfa06c1 SL |
84 | struct a { |
85 | char *name; | |
86 | }; | |
013037be BJ |
87 | register struct inode *ip; |
88 | dev_t dev; | |
89 | register struct swdevt *sp; | |
90 | ||
4f083fd7 | 91 | ip = namei(uchar, LOOKUP, 1); |
013037be BJ |
92 | if (ip == NULL) |
93 | return; | |
94 | if ((ip->i_mode&IFMT) != IFBLK) { | |
95 | u.u_error = ENOTBLK; | |
96 | iput(ip); | |
97 | return; | |
98 | } | |
76e9203a | 99 | dev = (dev_t)ip->i_rdev; |
013037be BJ |
100 | iput(ip); |
101 | if (major(dev) >= nblkdev) { | |
102 | u.u_error = ENXIO; | |
103 | return; | |
104 | } | |
105 | /* | |
106 | * Search starting at second table entry, | |
107 | * since first (primary swap area) is freed at boot. | |
108 | */ | |
109 | for (sp = &swdevt[1]; sp->sw_dev; sp++) | |
110 | if (sp->sw_dev == dev) { | |
111 | if (sp->sw_freed) { | |
112 | u.u_error = EBUSY; | |
113 | return; | |
114 | } | |
115 | swfree(sp - swdevt); | |
116 | return; | |
117 | } | |
118 | u.u_error = ENODEV; | |
119 | } | |
120 | ||
121 | /* | |
122 | * Swfree(index) frees the index'th portion of the swap map. | |
123 | * Each of the nswdev devices provides 1/nswdev'th of the swap | |
d668d9ba | 124 | * space, which is laid out with blocks of dmmax pages circularly |
013037be BJ |
125 | * among the devices. |
126 | */ | |
127 | swfree(index) | |
128 | int index; | |
129 | { | |
130 | register swblk_t vsbase; | |
39d536e6 | 131 | register long blk; |
e438ed8e | 132 | dev_t dev; |
d668d9ba SL |
133 | register swblk_t dvbase; |
134 | register int nblks; | |
013037be | 135 | |
e438ed8e BJ |
136 | dev = swdevt[index].sw_dev; |
137 | (*bdevsw[major(dev)].d_open)(dev, FREAD|FWRITE); | |
013037be | 138 | swdevt[index].sw_freed = 1; |
d668d9ba SL |
139 | nblks = swdevt[index].sw_nblks; |
140 | for (dvbase = 0; dvbase < nblks; dvbase += dmmax) { | |
141 | blk = nblks - dvbase; | |
142 | if ((vsbase = index*dmmax + dvbase*nswdev) >= nswap) | |
143 | panic("swfree"); | |
144 | if (blk > dmmax) | |
145 | blk = dmmax; | |
013037be BJ |
146 | if (vsbase == 0) { |
147 | /* | |
148 | * Can't free a block starting at 0 in the swapmap | |
c84ff1f9 | 149 | * but need some space for argmap so use 1/2 this |
013037be BJ |
150 | * hunk which needs special treatment anyways. |
151 | */ | |
152 | argdev = swdevt[0].sw_dev; | |
e438ed8e BJ |
153 | rminit(argmap, (long)(blk/2-ctod(CLSIZE)), |
154 | (long)ctod(CLSIZE), "argmap", ARGMAPSIZE); | |
c84ff1f9 BJ |
155 | /* |
156 | * First of all chunks... initialize the swapmap | |
157 | * the second half of the hunk. | |
158 | */ | |
a29f7995 BJ |
159 | rminit(swapmap, (long)blk/2, (long)blk/2, |
160 | "swap", nswapmap); | |
013037be | 161 | } else |
c84ff1f9 | 162 | rmfree(swapmap, blk, vsbase); |
013037be BJ |
163 | } |
164 | } |