2 * 10th edition 4K file system
15 #define VIFREG 0100000
16 #define VIFDIR 0040000
17 #define VIFCHR 0120000
18 #define VIFBLK 0160000
21 #define VROOT 2 /* root inode */
24 #define LINOPB (BLSIZE/sizeof(struct v10dinode))
25 #define LNINDIR (BLSIZE/sizeof(unsigned long))
28 unsigned char flags[2];
29 unsigned char nlinks[2];
32 unsigned char size[4];
33 unsigned char addr[40];
34 unsigned char atime[4];
35 unsigned char mtime[4];
36 unsigned char ctime[4];
46 Fileinf iget(int ino);
47 long bmap(Ram *r, long bno);
48 void getblk(Ram *r, long bno, char *buf);
57 tapefile = open(name, OREAD);
59 error("Can't open argument file");
60 if ((d=dirfstat(tapefile)) == nil)
79 char name[VNAMELEN+1];
82 for (i=0; i<r->ndata; i+=sizeof(struct v10dir)) {
84 cp = doread(r, i, BLSIZE);
85 dp = (struct v10dir *)(cp+i%BLSIZE);
86 ino = g2byte(dp->ino);
87 if (strcmp(dp->name, ".")==0 || strcmp(dp->name, "..")==0)
92 strncpy(name, dp->name, VNAMELEN);
93 name[VNAMELEN] = '\0';
113 doread(Ram *r, vlong off, long cnt)
115 static char buf[Maxbuf+BLSIZE];
121 error("count too large");
126 getblk(r, bno, &buf[i*BLSIZE]);
135 dowrite(Ram *r, char *buf, long off, long cnt)
137 USED(r); USED(buf); USED(off); USED(cnt);
149 * -- no sanity check for now
150 * -- magic inode-to-disk-block stuff here
157 struct v10dinode *dp;
161 seek(tapefile, BLSIZE*((ino-1)/LINOPB + VSUPERB + 1), 0);
162 if (read(tapefile, buf, BLSIZE) != BLSIZE)
163 error("Can't read inode");
164 dp = ((struct v10dinode *)buf) + ((ino-1)%LINOPB);
165 flags = g2byte(dp->flags);
166 f.size = g4byte(dp->size);
167 if ((flags&VFMT)==VIFCHR || (flags&VFMT)==VIFBLK)
169 f.data = emalloc(VNADDR*sizeof(long));
170 for (i = 0; i < VNADDR; i++)
171 ((long*)f.data)[i] = g3byte(dp->addr+3*i);
172 f.mode = flags & VMODE;
173 if ((flags&VFMT)==VIFDIR)
175 f.uid = g2byte(dp->uid);
176 f.gid = g2byte(dp->gid);
177 f.mdate = g4byte(dp->mtime);
182 getblk(Ram *r, long bno, char *buf)
186 if ((dbno = bmap(r, bno)) == 0) {
187 memset(buf, 0, BLSIZE);
190 if ((vlong)(dbno+1)*BLSIZE > tapelen) {
191 fprint(2, "read past end of tape: %lld\n", (vlong)dbno*BLSIZE);
192 memset(buf, 0, BLSIZE);
195 seek(tapefile, dbno*BLSIZE, 0);
196 if (readn(tapefile, buf, BLSIZE) != BLSIZE){
197 fprint(2, "readn at %lld: %r\n", (vlong)dbno*BLSIZE);
203 * logical to physical block
204 * only singly-indirect files for now
208 bmap(Ram *r, long bno)
210 unsigned char indbuf[LNINDIR][sizeof(long)];
213 return ((long*)r->data)[bno];
214 if (bno < VNADDR*LNINDIR) {
215 seek(tapefile, ((long *)r->data)[(bno-(VNADDR-3))/LNINDIR+(VNADDR-3)]*BLSIZE, 0);
216 if (read(tapefile, (char *)indbuf, BLSIZE) != BLSIZE)
218 return ((indbuf[(bno-(VNADDR-3))%LNINDIR][2]<<16) + (indbuf[(bno-(VNADDR-3))%LNINDIR][1]<<8)
219 + indbuf[(bno-(VNADDR-3))%LNINDIR][0]);