Commit | Line | Data |
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d99e8b3c KT |
1 | # |
2 | /* | |
3 | */ | |
4 | ||
5 | #include "../param.h" | |
6 | #include "../inode.h" | |
7 | #include "../user.h" | |
8 | #include "../buf.h" | |
9 | #include "../conf.h" | |
10 | #include "../systm.h" | |
11 | ||
12 | /* | |
13 | * Read the file corresponding to | |
14 | * the inode pointed at by the argument. | |
15 | * The actual read arguments are found | |
16 | * in the variables: | |
17 | * u_base core address for destination | |
18 | * u_offset byte offset in file | |
19 | * u_count number of bytes to read | |
20 | * u_segflg read to kernel/user | |
21 | */ | |
22 | readi(aip) | |
23 | struct inode *aip; | |
24 | { | |
25 | int *bp; | |
26 | int lbn, bn, on; | |
27 | register dn, n; | |
28 | register struct inode *ip; | |
29 | ||
30 | ip = aip; | |
31 | if(u.u_count == 0) | |
32 | return; | |
33 | ip->i_flag =| IACC; | |
34 | if((ip->i_mode&IFMT) == IFCHR) { | |
35 | (*cdevsw[ip->i_addr[0].d_major].d_read)(ip->i_addr[0]); | |
36 | return; | |
37 | } | |
38 | ||
39 | do { | |
40 | lbn = bn = lshift(u.u_offset, -9); | |
41 | on = u.u_offset[1] & 0777; | |
42 | n = min(512-on, u.u_count); | |
43 | if((ip->i_mode&IFMT) != IFBLK) { | |
44 | dn = dpcmp(ip->i_size0&0377, ip->i_size1, | |
45 | u.u_offset[0], u.u_offset[1]); | |
46 | if(dn <= 0) | |
47 | return; | |
48 | n = min(n, dn); | |
49 | if ((bn = bmap(ip, lbn)) == 0) | |
50 | return; | |
51 | dn = ip->i_dev; | |
52 | } else { | |
53 | dn = ip->i_addr[0]; | |
54 | rablock = bn+1; | |
55 | } | |
56 | if (ip->i_lastr+1 == lbn) | |
57 | bp = breada(dn, bn, rablock); | |
58 | else | |
59 | bp = bread(dn, bn); | |
60 | ip->i_lastr = lbn; | |
61 | iomove(bp, on, n, B_READ); | |
62 | brelse(bp); | |
63 | } while(u.u_error==0 && u.u_count!=0); | |
64 | } | |
65 | ||
66 | /* | |
67 | * Write the file corresponding to | |
68 | * the inode pointed at by the argument. | |
69 | * The actual write arguments are found | |
70 | * in the variables: | |
71 | * u_base core address for source | |
72 | * u_offset byte offset in file | |
73 | * u_count number of bytes to write | |
74 | * u_segflg write to kernel/user | |
75 | */ | |
76 | writei(aip) | |
77 | struct inode *aip; | |
78 | { | |
79 | int *bp; | |
80 | int n, on; | |
81 | register dn, bn; | |
82 | register struct inode *ip; | |
83 | ||
84 | ip = aip; | |
85 | ip->i_flag =| IACC|IUPD; | |
86 | if((ip->i_mode&IFMT) == IFCHR) { | |
87 | (*cdevsw[ip->i_addr[0].d_major].d_write)(ip->i_addr[0]); | |
88 | return; | |
89 | } | |
90 | if (u.u_count == 0) | |
91 | return; | |
92 | ||
93 | do { | |
94 | bn = lshift(u.u_offset, -9); | |
95 | on = u.u_offset[1] & 0777; | |
96 | n = min(512-on, u.u_count); | |
97 | if((ip->i_mode&IFMT) != IFBLK) { | |
98 | if ((bn = bmap(ip, bn)) == 0) | |
99 | return; | |
100 | dn = ip->i_dev; | |
101 | } else | |
102 | dn = ip->i_addr[0]; | |
103 | if(n == 512) | |
104 | bp = getblk(dn, bn); else | |
105 | bp = bread(dn, bn); | |
106 | iomove(bp, on, n, B_WRITE); | |
107 | if(u.u_error != 0) | |
108 | brelse(bp); else | |
109 | if ((u.u_offset[1]&0777)==0) | |
110 | bawrite(bp); else | |
111 | bdwrite(bp); | |
112 | if(dpcmp(ip->i_size0&0377, ip->i_size1, | |
113 | u.u_offset[0], u.u_offset[1]) < 0 && | |
114 | (ip->i_mode&(IFBLK&IFCHR)) == 0) { | |
115 | ip->i_size0 = u.u_offset[0]; | |
116 | ip->i_size1 = u.u_offset[1]; | |
117 | } | |
118 | ip->i_flag =| IUPD; | |
119 | } while(u.u_error==0 && u.u_count!=0); | |
120 | } | |
121 | ||
122 | /* | |
123 | * Return the logical maximum | |
124 | * of the 2 arguments. | |
125 | */ | |
126 | max(a, b) | |
127 | char *a, *b; | |
128 | { | |
129 | ||
130 | if(a > b) | |
131 | return(a); | |
132 | return(b); | |
133 | } | |
134 | ||
135 | /* | |
136 | * Return the logical minimum | |
137 | * of the 2 arguments. | |
138 | */ | |
139 | min(a, b) | |
140 | char *a, *b; | |
141 | { | |
142 | ||
143 | if(a < b) | |
144 | return(a); | |
145 | return(b); | |
146 | } | |
147 | ||
148 | /* | |
149 | * Move 'an' bytes at byte location | |
150 | * &bp->b_addr[o] to/from (flag) the | |
151 | * user/kernel (u.segflg) area starting at u.base. | |
152 | * Update all the arguments by the number | |
153 | * of bytes moved. | |
154 | * | |
155 | * There are 2 algorithms, | |
156 | * if source address, dest address and count | |
157 | * are all even in a user copy, | |
158 | * then the machine language copyin/copyout | |
159 | * is called. | |
160 | * If not, its done byte-by-byte with | |
161 | * cpass and passc. | |
162 | */ | |
163 | iomove(bp, o, an, flag) | |
164 | struct buf *bp; | |
165 | { | |
166 | register char *cp; | |
167 | register int n, t; | |
168 | ||
169 | n = an; | |
170 | cp = bp->b_addr + o; | |
171 | if(u.u_segflg==0 && ((n | cp | u.u_base)&01)==0) { | |
172 | if (flag==B_WRITE) | |
173 | cp = copyin(u.u_base, cp, n); | |
174 | else | |
175 | cp = copyout(cp, u.u_base, n); | |
176 | if (cp) { | |
177 | u.u_error = EFAULT; | |
178 | return; | |
179 | } | |
180 | u.u_base =+ n; | |
181 | dpadd(u.u_offset, n); | |
182 | u.u_count =- n; | |
183 | return; | |
184 | } | |
185 | if (flag==B_WRITE) { | |
186 | while(n--) { | |
187 | if ((t = cpass()) < 0) | |
188 | return; | |
189 | *cp++ = t; | |
190 | } | |
191 | } else | |
192 | while (n--) | |
193 | if(passc(*cp++) < 0) | |
194 | return; | |
195 | } |