Commit | Line | Data |
---|---|---|
da7c5cc6 | 1 | /* |
0880b18e | 2 | * Copyright (c) 1982, 1986 Regents of the University of California. |
da7c5cc6 KM |
3 | * All rights reserved. The Berkeley software License Agreement |
4 | * specifies the terms and conditions for redistribution. | |
5 | * | |
0880b18e | 6 | * @(#)vm_swap.c 7.1 (Berkeley) %G% |
da7c5cc6 | 7 | */ |
013037be | 8 | |
94368568 JB |
9 | #include "param.h" |
10 | #include "systm.h" | |
11 | #include "buf.h" | |
12 | #include "conf.h" | |
13 | #include "dir.h" | |
14 | #include "user.h" | |
15 | #include "inode.h" | |
16 | #include "map.h" | |
17 | #include "uio.h" | |
18 | #include "file.h" | |
013037be BJ |
19 | |
20 | struct buf rswbuf; | |
21 | /* | |
22 | * Indirect driver for multi-controller paging. | |
23 | */ | |
24 | swstrategy(bp) | |
25 | register struct buf *bp; | |
26 | { | |
27 | int sz, off, seg; | |
28 | dev_t dev; | |
29 | ||
b9ee5d20 BJ |
30 | #ifdef GENERIC |
31 | /* | |
32 | * A mini-root gets copied into the front of the swap | |
33 | * and we run over top of the swap area just long | |
34 | * enough for us to do a mkfs and restor of the real | |
35 | * root (sure beats rewriting standalone restor). | |
36 | */ | |
8c5046eb | 37 | #define MINIROOTSIZE 4096 |
b9ee5d20 BJ |
38 | if (rootdev == dumpdev) |
39 | bp->b_blkno += MINIROOTSIZE; | |
40 | #endif | |
ca1f746a | 41 | sz = howmany(bp->b_bcount, DEV_BSIZE); |
d668d9ba | 42 | if (bp->b_blkno+sz > nswap) { |
013037be BJ |
43 | bp->b_flags |= B_ERROR; |
44 | iodone(bp); | |
45 | return; | |
46 | } | |
d668d9ba SL |
47 | if (nswdev > 1) { |
48 | off = bp->b_blkno % dmmax; | |
49 | if (off+sz > dmmax) { | |
50 | bp->b_flags |= B_ERROR; | |
51 | iodone(bp); | |
52 | return; | |
53 | } | |
54 | seg = bp->b_blkno / dmmax; | |
55 | dev = swdevt[seg % nswdev].sw_dev; | |
56 | seg /= nswdev; | |
57 | bp->b_blkno = seg*dmmax + off; | |
58 | } else | |
59 | dev = swdevt[0].sw_dev; | |
013037be BJ |
60 | bp->b_dev = dev; |
61 | if (dev == 0) | |
62 | panic("swstrategy"); | |
63 | (*bdevsw[major(dev)].d_strategy)(bp); | |
64 | } | |
65 | ||
5699bf69 BJ |
66 | swread(dev, uio) |
67 | dev_t dev; | |
68 | struct uio *uio; | |
013037be BJ |
69 | { |
70 | ||
30c36259 | 71 | return (physio(swstrategy, &rswbuf, dev, B_READ, minphys, uio)); |
013037be BJ |
72 | } |
73 | ||
5699bf69 BJ |
74 | swwrite(dev, uio) |
75 | dev_t dev; | |
76 | struct uio *uio; | |
013037be BJ |
77 | { |
78 | ||
30c36259 | 79 | return (physio(swstrategy, &rswbuf, dev, B_WRITE, minphys, uio)); |
013037be BJ |
80 | } |
81 | ||
82 | /* | |
83 | * System call swapon(name) enables swapping on device name, | |
84 | * which must be in the swdevsw. Return EBUSY | |
85 | * if already swapping on this device. | |
86 | */ | |
2dfa06c1 | 87 | swapon() |
013037be | 88 | { |
2dfa06c1 SL |
89 | struct a { |
90 | char *name; | |
715baff1 | 91 | } *uap = (struct a *)u.u_ap; |
013037be BJ |
92 | register struct inode *ip; |
93 | dev_t dev; | |
94 | register struct swdevt *sp; | |
715baff1 | 95 | register struct nameidata *ndp = &u.u_nd; |
013037be | 96 | |
dca9bb95 KM |
97 | if (!suser()) |
98 | return; | |
715baff1 KM |
99 | ndp->ni_nameiop = LOOKUP | FOLLOW; |
100 | ndp->ni_segflg = UIO_USERSPACE; | |
101 | ndp->ni_dirp = uap->name; | |
102 | ip = namei(ndp); | |
013037be BJ |
103 | if (ip == NULL) |
104 | return; | |
105 | if ((ip->i_mode&IFMT) != IFBLK) { | |
106 | u.u_error = ENOTBLK; | |
107 | iput(ip); | |
108 | return; | |
109 | } | |
76e9203a | 110 | dev = (dev_t)ip->i_rdev; |
013037be BJ |
111 | iput(ip); |
112 | if (major(dev) >= nblkdev) { | |
113 | u.u_error = ENXIO; | |
114 | return; | |
115 | } | |
ae0ffeb1 | 116 | for (sp = &swdevt[0]; sp->sw_dev; sp++) |
013037be BJ |
117 | if (sp->sw_dev == dev) { |
118 | if (sp->sw_freed) { | |
119 | u.u_error = EBUSY; | |
120 | return; | |
121 | } | |
122 | swfree(sp - swdevt); | |
123 | return; | |
124 | } | |
ae0ffeb1 | 125 | u.u_error = EINVAL; |
013037be BJ |
126 | } |
127 | ||
128 | /* | |
129 | * Swfree(index) frees the index'th portion of the swap map. | |
130 | * Each of the nswdev devices provides 1/nswdev'th of the swap | |
d668d9ba | 131 | * space, which is laid out with blocks of dmmax pages circularly |
013037be BJ |
132 | * among the devices. |
133 | */ | |
134 | swfree(index) | |
135 | int index; | |
136 | { | |
137 | register swblk_t vsbase; | |
39d536e6 | 138 | register long blk; |
e438ed8e | 139 | dev_t dev; |
d668d9ba SL |
140 | register swblk_t dvbase; |
141 | register int nblks; | |
013037be | 142 | |
e438ed8e BJ |
143 | dev = swdevt[index].sw_dev; |
144 | (*bdevsw[major(dev)].d_open)(dev, FREAD|FWRITE); | |
013037be | 145 | swdevt[index].sw_freed = 1; |
d668d9ba SL |
146 | nblks = swdevt[index].sw_nblks; |
147 | for (dvbase = 0; dvbase < nblks; dvbase += dmmax) { | |
148 | blk = nblks - dvbase; | |
149 | if ((vsbase = index*dmmax + dvbase*nswdev) >= nswap) | |
150 | panic("swfree"); | |
151 | if (blk > dmmax) | |
152 | blk = dmmax; | |
013037be BJ |
153 | if (vsbase == 0) { |
154 | /* | |
155 | * Can't free a block starting at 0 in the swapmap | |
c84ff1f9 | 156 | * but need some space for argmap so use 1/2 this |
013037be BJ |
157 | * hunk which needs special treatment anyways. |
158 | */ | |
159 | argdev = swdevt[0].sw_dev; | |
e438ed8e BJ |
160 | rminit(argmap, (long)(blk/2-ctod(CLSIZE)), |
161 | (long)ctod(CLSIZE), "argmap", ARGMAPSIZE); | |
c84ff1f9 BJ |
162 | /* |
163 | * First of all chunks... initialize the swapmap | |
164 | * the second half of the hunk. | |
165 | */ | |
a29f7995 BJ |
166 | rminit(swapmap, (long)blk/2, (long)blk/2, |
167 | "swap", nswapmap); | |
013037be | 168 | } else |
c84ff1f9 | 169 | rmfree(swapmap, blk, vsbase); |
013037be BJ |
170 | } |
171 | } |