Commit | Line | Data |
---|---|---|
dca9bb95 | 1 | /* vm_swap.c 6.5 85/05/22 */ |
013037be | 2 | |
94368568 JB |
3 | #include "param.h" |
4 | #include "systm.h" | |
5 | #include "buf.h" | |
6 | #include "conf.h" | |
7 | #include "dir.h" | |
8 | #include "user.h" | |
9 | #include "inode.h" | |
10 | #include "map.h" | |
11 | #include "uio.h" | |
12 | #include "file.h" | |
013037be BJ |
13 | |
14 | struct buf rswbuf; | |
15 | /* | |
16 | * Indirect driver for multi-controller paging. | |
17 | */ | |
18 | swstrategy(bp) | |
19 | register struct buf *bp; | |
20 | { | |
21 | int sz, off, seg; | |
22 | dev_t dev; | |
23 | ||
b9ee5d20 BJ |
24 | #ifdef GENERIC |
25 | /* | |
26 | * A mini-root gets copied into the front of the swap | |
27 | * and we run over top of the swap area just long | |
28 | * enough for us to do a mkfs and restor of the real | |
29 | * root (sure beats rewriting standalone restor). | |
30 | */ | |
8c5046eb | 31 | #define MINIROOTSIZE 4096 |
b9ee5d20 BJ |
32 | if (rootdev == dumpdev) |
33 | bp->b_blkno += MINIROOTSIZE; | |
34 | #endif | |
ca1f746a | 35 | sz = howmany(bp->b_bcount, DEV_BSIZE); |
d668d9ba | 36 | if (bp->b_blkno+sz > nswap) { |
013037be BJ |
37 | bp->b_flags |= B_ERROR; |
38 | iodone(bp); | |
39 | return; | |
40 | } | |
d668d9ba SL |
41 | if (nswdev > 1) { |
42 | off = bp->b_blkno % dmmax; | |
43 | if (off+sz > dmmax) { | |
44 | bp->b_flags |= B_ERROR; | |
45 | iodone(bp); | |
46 | return; | |
47 | } | |
48 | seg = bp->b_blkno / dmmax; | |
49 | dev = swdevt[seg % nswdev].sw_dev; | |
50 | seg /= nswdev; | |
51 | bp->b_blkno = seg*dmmax + off; | |
52 | } else | |
53 | dev = swdevt[0].sw_dev; | |
013037be BJ |
54 | bp->b_dev = dev; |
55 | if (dev == 0) | |
56 | panic("swstrategy"); | |
57 | (*bdevsw[major(dev)].d_strategy)(bp); | |
58 | } | |
59 | ||
5699bf69 BJ |
60 | swread(dev, uio) |
61 | dev_t dev; | |
62 | struct uio *uio; | |
013037be BJ |
63 | { |
64 | ||
30c36259 | 65 | return (physio(swstrategy, &rswbuf, dev, B_READ, minphys, uio)); |
013037be BJ |
66 | } |
67 | ||
5699bf69 BJ |
68 | swwrite(dev, uio) |
69 | dev_t dev; | |
70 | struct uio *uio; | |
013037be BJ |
71 | { |
72 | ||
30c36259 | 73 | return (physio(swstrategy, &rswbuf, dev, B_WRITE, minphys, uio)); |
013037be BJ |
74 | } |
75 | ||
76 | /* | |
77 | * System call swapon(name) enables swapping on device name, | |
78 | * which must be in the swdevsw. Return EBUSY | |
79 | * if already swapping on this device. | |
80 | */ | |
2dfa06c1 | 81 | swapon() |
013037be | 82 | { |
2dfa06c1 SL |
83 | struct a { |
84 | char *name; | |
715baff1 | 85 | } *uap = (struct a *)u.u_ap; |
013037be BJ |
86 | register struct inode *ip; |
87 | dev_t dev; | |
88 | register struct swdevt *sp; | |
715baff1 | 89 | register struct nameidata *ndp = &u.u_nd; |
013037be | 90 | |
dca9bb95 KM |
91 | if (!suser()) |
92 | return; | |
715baff1 KM |
93 | ndp->ni_nameiop = LOOKUP | FOLLOW; |
94 | ndp->ni_segflg = UIO_USERSPACE; | |
95 | ndp->ni_dirp = uap->name; | |
96 | ip = namei(ndp); | |
013037be BJ |
97 | if (ip == NULL) |
98 | return; | |
99 | if ((ip->i_mode&IFMT) != IFBLK) { | |
100 | u.u_error = ENOTBLK; | |
101 | iput(ip); | |
102 | return; | |
103 | } | |
76e9203a | 104 | dev = (dev_t)ip->i_rdev; |
013037be BJ |
105 | iput(ip); |
106 | if (major(dev) >= nblkdev) { | |
107 | u.u_error = ENXIO; | |
108 | return; | |
109 | } | |
ae0ffeb1 | 110 | for (sp = &swdevt[0]; sp->sw_dev; sp++) |
013037be BJ |
111 | if (sp->sw_dev == dev) { |
112 | if (sp->sw_freed) { | |
113 | u.u_error = EBUSY; | |
114 | return; | |
115 | } | |
116 | swfree(sp - swdevt); | |
117 | return; | |
118 | } | |
ae0ffeb1 | 119 | u.u_error = EINVAL; |
013037be BJ |
120 | } |
121 | ||
122 | /* | |
123 | * Swfree(index) frees the index'th portion of the swap map. | |
124 | * Each of the nswdev devices provides 1/nswdev'th of the swap | |
d668d9ba | 125 | * space, which is laid out with blocks of dmmax pages circularly |
013037be BJ |
126 | * among the devices. |
127 | */ | |
128 | swfree(index) | |
129 | int index; | |
130 | { | |
131 | register swblk_t vsbase; | |
39d536e6 | 132 | register long blk; |
e438ed8e | 133 | dev_t dev; |
d668d9ba SL |
134 | register swblk_t dvbase; |
135 | register int nblks; | |
013037be | 136 | |
e438ed8e BJ |
137 | dev = swdevt[index].sw_dev; |
138 | (*bdevsw[major(dev)].d_open)(dev, FREAD|FWRITE); | |
013037be | 139 | swdevt[index].sw_freed = 1; |
d668d9ba SL |
140 | nblks = swdevt[index].sw_nblks; |
141 | for (dvbase = 0; dvbase < nblks; dvbase += dmmax) { | |
142 | blk = nblks - dvbase; | |
143 | if ((vsbase = index*dmmax + dvbase*nswdev) >= nswap) | |
144 | panic("swfree"); | |
145 | if (blk > dmmax) | |
146 | blk = dmmax; | |
013037be BJ |
147 | if (vsbase == 0) { |
148 | /* | |
149 | * Can't free a block starting at 0 in the swapmap | |
c84ff1f9 | 150 | * but need some space for argmap so use 1/2 this |
013037be BJ |
151 | * hunk which needs special treatment anyways. |
152 | */ | |
153 | argdev = swdevt[0].sw_dev; | |
e438ed8e BJ |
154 | rminit(argmap, (long)(blk/2-ctod(CLSIZE)), |
155 | (long)ctod(CLSIZE), "argmap", ARGMAPSIZE); | |
c84ff1f9 BJ |
156 | /* |
157 | * First of all chunks... initialize the swapmap | |
158 | * the second half of the hunk. | |
159 | */ | |
a29f7995 BJ |
160 | rminit(swapmap, (long)blk/2, (long)blk/2, |
161 | "swap", nswapmap); | |
013037be | 162 | } else |
c84ff1f9 | 163 | rmfree(swapmap, blk, vsbase); |
013037be BJ |
164 | } |
165 | } |