1 /* 2 * old (V6 and before) PDP-11 Unix filesystem 3 */ 4 #include <u.h> 5 #include <libc.h> 6 #include <auth.h> 7 #include <fcall.h> 8 #include "tapefs.h" 9 10 /* 11 * v6 disk inode 12 */ 13 #define V6NADDR 8 14 #define V6FMT 0160000 15 #define V6IFREG 0100000 16 #define V6IFDIR 0140000 17 #define V6IFCHR 0120000 18 #define V6IFBLK 0160000 19 #define V6MODE 0777 20 #define V6LARGE 010000 21 #define V6SUPERB 1 22 #define V6ROOT 1 /* root inode */ 23 #define V6NAMELEN 14 24 #define BLSIZE 512 25 #define LINOPB (BLSIZE/sizeof(struct v6dinode)) 26 #define LNINDIR (BLSIZE/sizeof(unsigned short)) 27 28 struct v6dinode { 29 unsigned char flags[2]; 30 unsigned char nlinks; 31 unsigned char uid; 32 unsigned char gid; 33 unsigned char hisize; 34 unsigned char losize[2]; 35 unsigned char addr[V6NADDR][2]; 36 unsigned char atime[4]; /* pdp-11 order */ 37 unsigned char mtime[4]; /* pdp-11 order */ 38 }; 39 40 struct v6dir { 41 uchar ino[2]; 42 char name[V6NAMELEN]; 43 }; 44 45 int tapefile; 46 Fileinf iget(int ino); 47 long bmap(Ram *r, long bno); 48 void getblk(Ram *r, long bno, char *buf); 49 50 void 51 populate(char *name) 52 { 53 Fileinf f; 54 55 replete = 0; 56 tapefile = open(name, OREAD); 57 if (tapefile<0) 58 error("Can't open argument file"); 59 f = iget(V6ROOT); 60 ram->perm = f.mode; 61 ram->mtime = f.mdate; 62 ram->data = f.addr; 63 ram->ndata = f.size; 64 } 65 66 void 67 popdir(Ram *r) 68 { 69 int i, ino; 70 char *cp; 71 struct v6dir *dp; 72 Fileinf f; 73 char name[V6NAMELEN+1]; 74 75 for (i=0; i<r->ndata; i+=sizeof(struct v6dir)) { 76 if (i%BLSIZE==0) 77 cp = doread(r, i, BLSIZE); 78 dp = (struct v6dir *)(cp+i%BLSIZE); 79 ino = dp->ino[0] + (dp->ino[1]<<8); 80 if (strcmp(dp->name, ".")==0 || strcmp(dp->name, "..")==0) 81 continue; 82 if (ino==0) 83 continue; 84 f = iget(ino); 85 strncpy(name, dp->name, V6NAMELEN); 86 name[V6NAMELEN+1] = '\0'; 87 f.name = name; 88 popfile(r, f); 89 } 90 r->replete = 1; 91 } 92 93 void 94 dotrunc(Ram *r) 95 { 96 USED(r); 97 } 98 99 void 100 docreate(Ram *r) 101 { 102 USED(r); 103 } 104 105 char * 106 doread(Ram *r, long off, long cnt) 107 { 108 static char buf[MAXFDATA+BLSIZE]; 109 int bno, i; 110 111 bno = off/BLSIZE; 112 off -= bno*BLSIZE; 113 if (cnt>MAXFDATA) 114 error("count too large"); 115 if (off) 116 cnt += BLSIZE-off; 117 i = 0; 118 while (cnt>0) { 119 getblk(r, bno, &buf[i*BLSIZE]); 120 cnt -= BLSIZE; 121 bno++; 122 i++; 123 } 124 return buf; 125 } 126 127 void 128 dowrite(Ram *r, char *buf, long off, long cnt) 129 { 130 USED(r); USED(buf); USED(off); USED(cnt); 131 } 132 133 int 134 dopermw(Ram *r) 135 { 136 USED(r); 137 return 0; 138 } 139 140 /* 141 * fetch an i-node 142 * -- no sanity check for now 143 * -- magic inode-to-disk-block stuff here 144 */ 145 146 Fileinf 147 iget(int ino) 148 { 149 char buf[BLSIZE]; 150 struct v6dinode *dp; 151 long flags, i; 152 Fileinf f; 153 154 seek(tapefile, BLSIZE*((ino-1)/LINOPB + V6SUPERB + 1), 0); 155 if (read(tapefile, buf, BLSIZE) != BLSIZE) 156 error("Can't read inode"); 157 dp = ((struct v6dinode *)buf) + ((ino-1)%LINOPB); 158 flags = (dp->flags[1]<<8) + dp->flags[0]; 159 f.size = (dp->hisize << 16) + (dp->losize[1]<<8) + dp->losize[0]; 160 if ((flags&V6FMT)==V6IFCHR || (flags&V6FMT)==V6IFBLK) 161 f.size = 0; 162 f.addr = emalloc(V6NADDR*sizeof(ushort)); 163 for (i = 0; i < V6NADDR; i++) 164 ((ushort*)f.addr)[i] = (dp->addr[i][1]<<8) + dp->addr[i][0]; 165 f.mode = flags & V6MODE; 166 if ((flags&V6FMT)==V6IFDIR) 167 f.mode |= CHDIR; 168 f.uid = dp->uid; 169 f.gid = dp->gid; 170 f.mdate = (dp->mtime[2]<<0) + (dp->mtime[3]<<8) 171 +(dp->mtime[0]<<16) + (dp->mtime[1]<<24); 172 return f; 173 } 174 175 void 176 getblk(Ram *r, long bno, char *buf) 177 { 178 long dbno; 179 180 if ((dbno = bmap(r, bno)) == 0) { 181 memset(buf, 0, BLSIZE); 182 return; 183 } 184 seek(tapefile, dbno*BLSIZE, 0); 185 if (read(tapefile, buf, BLSIZE) != BLSIZE) 186 error("bad read"); 187 } 188 189 /* 190 * logical to physical block 191 * only singly-indirect files for now 192 */ 193 194 long 195 bmap(Ram *r, long bno) 196 { 197 unsigned char indbuf[LNINDIR][2]; 198 199 if (r->ndata < V6NADDR*BLSIZE) { /* assume size predicts largeness of file */ 200 if (bno < V6NADDR) 201 return ((ushort*)r->data)[bno]; 202 return 0; 203 } 204 if (bno < V6NADDR*LNINDIR) { 205 seek(tapefile, ((ushort *)r->data)[bno/LNINDIR]*BLSIZE, 0); 206 if (read(tapefile, (char *)indbuf, BLSIZE) != BLSIZE) 207 return 0; 208 return ((indbuf[bno%LNINDIR][1]<<8) + indbuf[bno%LNINDIR][0]); 209 } 210 return 0; 211 } 212