This source file includes following definitions.
- xshort
- xint
- main
- wsect
- winode
- rinode
- rsect
- ialloc
- balloc
- iappend
- die
1 #include <stdio.h>
2 #include <unistd.h>
3 #include <stdlib.h>
4 #include <string.h>
5 #include <fcntl.h>
6 #include <assert.h>
7
8 #define stat xv6_stat
9 #include "kernel/types.h"
10 #include "kernel/fs.h"
11 #include "kernel/stat.h"
12 #include "kernel/param.h"
13
14 #ifndef static_assert
15 #define static_assert(a, b) do { switch (0) case 0: case (a): ; } while (0)
16 #endif
17
18 #define NINODES 200
19
20
21
22
23 int nbitmap = FSSIZE/(BSIZE*8) + 1;
24 int ninodeblocks = NINODES / IPB + 1;
25 int nlog = LOGSIZE;
26 int nmeta;
27 int nblocks;
28
29 int fsfd;
30 struct superblock sb;
31 char zeroes[BSIZE];
32 uint freeinode = 1;
33 uint freeblock;
34
35
36 void balloc(int);
37 void wsect(uint, void*);
38 void winode(uint, struct dinode*);
39 void rinode(uint inum, struct dinode *ip);
40 void rsect(uint sec, void *buf);
41 uint ialloc(ushort type);
42 void iappend(uint inum, void *p, int n);
43 void die(const char *);
44
45
46 ushort
47 xshort(ushort x)
48 {
49 ushort y;
50 uchar *a = (uchar*)&y;
51 a[0] = x;
52 a[1] = x >> 8;
53 return y;
54 }
55
56 uint
57 xint(uint x)
58 {
59 uint y;
60 uchar *a = (uchar*)&y;
61 a[0] = x;
62 a[1] = x >> 8;
63 a[2] = x >> 16;
64 a[3] = x >> 24;
65 return y;
66 }
67
68 int
69 main(int argc, char *argv[])
70 {
71 int i, cc, fd;
72 uint rootino, inum, off;
73 struct dirent de;
74 char buf[BSIZE];
75 struct dinode din;
76
77
78 static_assert(sizeof(int) == 4, "Integers must be 4 bytes!");
79
80 if(argc < 2){
81 fprintf(stderr, "Usage: mkfs fs.img files...\n");
82 exit(1);
83 }
84
85 assert((BSIZE % sizeof(struct dinode)) == 0);
86 assert((BSIZE % sizeof(struct dirent)) == 0);
87
88 fsfd = open(argv[1], O_RDWR|O_CREAT|O_TRUNC, 0666);
89 if(fsfd < 0)
90 die(argv[1]);
91
92
93 nmeta = 2 + nlog + ninodeblocks + nbitmap;
94 nblocks = FSSIZE - nmeta;
95
96 sb.magic = FSMAGIC;
97 sb.size = xint(FSSIZE);
98 sb.nblocks = xint(nblocks);
99 sb.ninodes = xint(NINODES);
100 sb.nlog = xint(nlog);
101 sb.logstart = xint(2);
102 sb.inodestart = xint(2+nlog);
103 sb.bmapstart = xint(2+nlog+ninodeblocks);
104
105 printf("nmeta %d (boot, super, log blocks %u inode blocks %u, bitmap blocks %u) blocks %d total %d\n",
106 nmeta, nlog, ninodeblocks, nbitmap, nblocks, FSSIZE);
107
108 freeblock = nmeta;
109
110 for(i = 0; i < FSSIZE; i++)
111 wsect(i, zeroes);
112
113 memset(buf, 0, sizeof(buf));
114 memmove(buf, &sb, sizeof(sb));
115 wsect(1, buf);
116
117 rootino = ialloc(T_DIR);
118 assert(rootino == ROOTINO);
119
120 bzero(&de, sizeof(de));
121 de.inum = xshort(rootino);
122 strcpy(de.name, ".");
123 iappend(rootino, &de, sizeof(de));
124
125 bzero(&de, sizeof(de));
126 de.inum = xshort(rootino);
127 strcpy(de.name, "..");
128 iappend(rootino, &de, sizeof(de));
129
130 for(i = 2; i < argc; i++){
131
132 char *shortname;
133 if(strncmp(argv[i], "user/", 5) == 0)
134 shortname = argv[i] + 5;
135 else
136 shortname = argv[i];
137
138 assert(index(shortname, '/') == 0);
139
140 if((fd = open(argv[i], 0)) < 0)
141 die(argv[i]);
142
143
144
145
146
147 if(shortname[0] == '_')
148 shortname += 1;
149
150 inum = ialloc(T_FILE);
151
152 bzero(&de, sizeof(de));
153 de.inum = xshort(inum);
154 strncpy(de.name, shortname, DIRSIZ);
155 iappend(rootino, &de, sizeof(de));
156
157 while((cc = read(fd, buf, sizeof(buf))) > 0)
158 iappend(inum, buf, cc);
159
160 close(fd);
161 }
162
163
164 rinode(rootino, &din);
165 off = xint(din.size);
166 off = ((off/BSIZE) + 1) * BSIZE;
167 din.size = xint(off);
168 winode(rootino, &din);
169
170 balloc(freeblock);
171
172 exit(0);
173 }
174
175 void
176 wsect(uint sec, void *buf)
177 {
178 if(lseek(fsfd, sec * BSIZE, 0) != sec * BSIZE)
179 die("lseek");
180 if(write(fsfd, buf, BSIZE) != BSIZE)
181 die("write");
182 }
183
184 void
185 winode(uint inum, struct dinode *ip)
186 {
187 char buf[BSIZE];
188 uint bn;
189 struct dinode *dip;
190
191 bn = IBLOCK(inum, sb);
192 rsect(bn, buf);
193 dip = ((struct dinode*)buf) + (inum % IPB);
194 *dip = *ip;
195 wsect(bn, buf);
196 }
197
198 void
199 rinode(uint inum, struct dinode *ip)
200 {
201 char buf[BSIZE];
202 uint bn;
203 struct dinode *dip;
204
205 bn = IBLOCK(inum, sb);
206 rsect(bn, buf);
207 dip = ((struct dinode*)buf) + (inum % IPB);
208 *ip = *dip;
209 }
210
211 void
212 rsect(uint sec, void *buf)
213 {
214 if(lseek(fsfd, sec * BSIZE, 0) != sec * BSIZE)
215 die("lseek");
216 if(read(fsfd, buf, BSIZE) != BSIZE)
217 die("read");
218 }
219
220 uint
221 ialloc(ushort type)
222 {
223 uint inum = freeinode++;
224 struct dinode din;
225
226 bzero(&din, sizeof(din));
227 din.type = xshort(type);
228 din.nlink = xshort(1);
229 din.size = xint(0);
230 winode(inum, &din);
231 return inum;
232 }
233
234 void
235 balloc(int used)
236 {
237 uchar buf[BSIZE];
238 int i;
239
240 printf("balloc: first %d blocks have been allocated\n", used);
241 assert(used < BSIZE*8);
242 bzero(buf, BSIZE);
243 for(i = 0; i < used; i++){
244 buf[i/8] = buf[i/8] | (0x1 << (i%8));
245 }
246 printf("balloc: write bitmap block at sector %d\n", sb.bmapstart);
247 wsect(sb.bmapstart, buf);
248 }
249
250 #define min(a, b) ((a) < (b) ? (a) : (b))
251
252 void
253 iappend(uint inum, void *xp, int n)
254 {
255 char *p = (char*)xp;
256 uint fbn, off, n1;
257 struct dinode din;
258 char buf[BSIZE];
259 uint indirect[NINDIRECT];
260 uint x;
261
262 rinode(inum, &din);
263 off = xint(din.size);
264
265 while(n > 0){
266 fbn = off / BSIZE;
267 assert(fbn < MAXFILE);
268 if(fbn < NDIRECT){
269 if(xint(din.addrs[fbn]) == 0){
270 din.addrs[fbn] = xint(freeblock++);
271 }
272 x = xint(din.addrs[fbn]);
273 } else {
274 if(xint(din.addrs[NDIRECT]) == 0){
275 din.addrs[NDIRECT] = xint(freeblock++);
276 }
277 rsect(xint(din.addrs[NDIRECT]), (char*)indirect);
278 if(indirect[fbn - NDIRECT] == 0){
279 indirect[fbn - NDIRECT] = xint(freeblock++);
280 wsect(xint(din.addrs[NDIRECT]), (char*)indirect);
281 }
282 x = xint(indirect[fbn-NDIRECT]);
283 }
284 n1 = min(n, (fbn + 1) * BSIZE - off);
285 rsect(x, buf);
286 bcopy(p, buf + off - (fbn * BSIZE), n1);
287 wsect(x, buf);
288 n -= n1;
289 off += n1;
290 p += n1;
291 }
292 din.size = xint(off);
293 winode(inum, &din);
294 }
295
296 void
297 die(const char *s)
298 {
299 perror(s);
300 exit(1);
301 }