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];
45 Fileinf iget(int ino);
46 long bmap(Ram *r, long bno);
47 void getblk(Ram *r, long bno, char *buf);
55 tapefile = open(name, OREAD);
57 error("Can't open argument file");
73 char name[VNAMELEN+1];
76 for (i=0; i<r->ndata; i+=sizeof(struct v10dir)) {
78 cp = doread(r, i, BLSIZE);
79 dp = (struct v10dir *)(cp+i%BLSIZE);
80 ino = g2byte(dp->ino);
81 if (strcmp(dp->name, ".")==0 || strcmp(dp->name, "..")==0)
86 strncpy(name, dp->name, VNAMELEN);
87 name[VNAMELEN] = '\0';
107 doread(Ram *r, vlong off, long cnt)
109 static char buf[Maxbuf+BLSIZE];
115 error("count too large");
120 getblk(r, bno, &buf[i*BLSIZE]);
129 dowrite(Ram *r, char *buf, long off, long cnt)
131 USED(r); USED(buf); USED(off); USED(cnt);
143 * -- no sanity check for now
144 * -- magic inode-to-disk-block stuff here
151 struct v10dinode *dp;
155 memset(&f, 0, sizeof f);
156 seek(tapefile, BLSIZE*((ino-1)/LINOPB + VSUPERB + 1), 0);
157 if (read(tapefile, buf, BLSIZE) != BLSIZE)
158 error("Can't read inode");
159 dp = ((struct v10dinode *)buf) + ((ino-1)%LINOPB);
160 flags = g2byte(dp->flags);
161 f.size = g4byte(dp->size);
162 if ((flags&VFMT)==VIFCHR || (flags&VFMT)==VIFBLK)
164 f.data = emalloc(VNADDR*sizeof(long));
165 for (i = 0; i < VNADDR; i++)
166 ((long*)f.data)[i] = g3byte(dp->addr+3*i);
167 f.mode = flags & VMODE;
168 if ((flags&VFMT)==VIFDIR)
170 f.uid = g2byte(dp->uid);
171 f.gid = g2byte(dp->gid);
172 f.mdate = g4byte(dp->mtime);
177 getblk(Ram *r, long bno, char *buf)
181 if ((dbno = bmap(r, bno)) == 0) {
182 memset(buf, 0, BLSIZE);
185 seek(tapefile, dbno*BLSIZE, 0);
186 if (read(tapefile, buf, BLSIZE) != BLSIZE)
191 * logical to physical block
192 * only singly-indirect files for now
196 bmap(Ram *r, long bno)
198 unsigned char indbuf[LNINDIR][sizeof(long)];
201 return ((long*)r->data)[bno];
202 if (bno < VNADDR*LNINDIR) {
203 seek(tapefile, ((long *)r->data)[(bno-(VNADDR-3))/LNINDIR+(VNADDR-3)]*BLSIZE, 0);
204 if (read(tapefile, (char *)indbuf, BLSIZE) != BLSIZE)
206 return ((indbuf[(bno-(VNADDR-3))%LNINDIR][2]<<16) + (indbuf[(bno-(VNADDR-3))%LNINDIR][1]<<8)
207 + indbuf[(bno-(VNADDR-3))%LNINDIR][0]);