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 cp = 0; 76 for (i=0; i<r->ndata; i+=sizeof(struct v6dir)) { 77 if (i%BLSIZE==0) 78 cp = doread(r, i, BLSIZE); 79 dp = (struct v6dir *)(cp+i%BLSIZE); 80 ino = dp->ino[0] + (dp->ino[1]<<8); 81 if (strcmp(dp->name, ".")==0 || strcmp(dp->name, "..")==0) 82 continue; 83 if (ino==0) 84 continue; 85 f = iget(ino); 86 strncpy(name, dp->name, V6NAMELEN); 87 name[V6NAMELEN+1] = '\0'; 88 f.name = name; 89 popfile(r, f); 90 } 91 r->replete = 1; 92 } 93 94 void 95 dotrunc(Ram *r) 96 { 97 USED(r); 98 } 99 100 void 101 docreate(Ram *r) 102 { 103 USED(r); 104 } 105 106 char * 107 doread(Ram *r, long off, long cnt) 108 { 109 static char buf[Maxbuf+BLSIZE]; 110 int bno, i; 111 112 bno = off/BLSIZE; 113 off -= bno*BLSIZE; 114 if (cnt>Maxbuf) 115 error("count too large"); 116 if (off) 117 cnt += off; 118 i = 0; 119 while (cnt>0) { 120 getblk(r, bno, &buf[i*BLSIZE]); 121 cnt -= BLSIZE; 122 bno++; 123 i++; 124 } 125 return buf; 126 } 127 128 void 129 dowrite(Ram *r, char *buf, long off, long cnt) 130 { 131 USED(r); USED(buf); USED(off); USED(cnt); 132 } 133 134 int 135 dopermw(Ram *r) 136 { 137 USED(r); 138 return 0; 139 } 140 141 /* 142 * fetch an i-node 143 * -- no sanity check for now 144 * -- magic inode-to-disk-block stuff here 145 */ 146 147 Fileinf 148 iget(int ino) 149 { 150 char buf[BLSIZE]; 151 struct v6dinode *dp; 152 long flags, i; 153 Fileinf f; 154 155 seek(tapefile, BLSIZE*((ino-1)/LINOPB + V6SUPERB + 1), 0); 156 if (read(tapefile, buf, BLSIZE) != BLSIZE) 157 error("Can't read inode"); 158 dp = ((struct v6dinode *)buf) + ((ino-1)%LINOPB); 159 flags = (dp->flags[1]<<8) + dp->flags[0]; 160 f.size = (dp->hisize << 16) + (dp->losize[1]<<8) + dp->losize[0]; 161 if ((flags&V6FMT)==V6IFCHR || (flags&V6FMT)==V6IFBLK) 162 f.size = 0; 163 f.addr = emalloc(V6NADDR*sizeof(ushort)); 164 for (i = 0; i < V6NADDR; i++) 165 ((ushort*)f.addr)[i] = (dp->addr[i][1]<<8) + dp->addr[i][0]; 166 f.mode = flags & V6MODE; 167 if ((flags&V6FMT)==V6IFDIR) 168 f.mode |= DMDIR; 169 f.uid = dp->uid; 170 f.gid = dp->gid; 171 f.mdate = (dp->mtime[2]<<0) + (dp->mtime[3]<<8) 172 +(dp->mtime[0]<<16) + (dp->mtime[1]<<24); 173 return f; 174 } 175 176 void 177 getblk(Ram *r, long bno, char *buf) 178 { 179 long dbno; 180 181 if ((dbno = bmap(r, bno)) == 0) { 182 memset(buf, 0, BLSIZE); 183 return; 184 } 185 seek(tapefile, dbno*BLSIZE, 0); 186 if (read(tapefile, buf, BLSIZE) != BLSIZE) 187 error("bad read"); 188 } 189 190 /* 191 * logical to physical block 192 * only singly-indirect files for now 193 */ 194 195 long 196 bmap(Ram *r, long bno) 197 { 198 unsigned char indbuf[LNINDIR][2]; 199 200 if (r->ndata <= V6NADDR*BLSIZE) { /* assume size predicts largeness of file */ 201 if (bno < V6NADDR) 202 return ((ushort*)r->data)[bno]; 203 return 0; 204 } 205 if (bno < V6NADDR*LNINDIR) { 206 seek(tapefile, ((ushort *)r->data)[bno/LNINDIR]*BLSIZE, 0); 207 if (read(tapefile, (char *)indbuf, BLSIZE) != BLSIZE) 208 return 0; 209 return ((indbuf[bno%LNINDIR][1]<<8) + indbuf[bno%LNINDIR][0]); 210 } 211 return 0; 212 } 213