| 1 | /* ffs_inode.c 3.2 %H% */ |
| 2 | |
| 3 | #include "../h/param.h" |
| 4 | #include "../h/systm.h" |
| 5 | #include "../h/mount.h" |
| 6 | #include "../h/dir.h" |
| 7 | #include "../h/user.h" |
| 8 | #include "../h/inode.h" |
| 9 | #include "../h/ino.h" |
| 10 | #include "../h/filsys.h" |
| 11 | #include "../h/conf.h" |
| 12 | #include "../h/buf.h" |
| 13 | #include "../h/inline.h" |
| 14 | |
| 15 | #define INOHSZ 63 |
| 16 | #define INOHASH(dev,ino) (((dev)+(ino))%INOHSZ) |
| 17 | short inohash[INOHSZ]; |
| 18 | short ifreel; |
| 19 | |
| 20 | /* |
| 21 | * Initialize hash links for inodes |
| 22 | * and build inode free list. |
| 23 | */ |
| 24 | ihinit() |
| 25 | { |
| 26 | register int i; |
| 27 | |
| 28 | ifreel = 0; |
| 29 | for (i = 0; i < NINODE - 1; i++) |
| 30 | inode[i].i_hlink = i+1; |
| 31 | inode[NINODE - 1].i_hlink = -1; |
| 32 | for (i = 0; i < INOHSZ; i++) |
| 33 | inohash[i] = -1; |
| 34 | } |
| 35 | |
| 36 | /* |
| 37 | * Find an inode if it is incore. |
| 38 | * This is the equivalent, for inodes, |
| 39 | * of ``incore'' in bio.c or ``pfind'' in subr.c. |
| 40 | */ |
| 41 | struct inode * |
| 42 | ifind(dev, ino) |
| 43 | dev_t dev; |
| 44 | ino_t ino; |
| 45 | { |
| 46 | register struct inode *ip; |
| 47 | |
| 48 | for (ip = &inode[inohash[INOHASH(dev,ino)]]; ip != &inode[-1]; |
| 49 | ip = &inode[ip->i_hlink]) |
| 50 | if (ino==ip->i_number && dev==ip->i_dev) |
| 51 | return (ip); |
| 52 | return ((struct inode *)0); |
| 53 | } |
| 54 | |
| 55 | /* |
| 56 | * Look up an inode by device,inumber. |
| 57 | * If it is in core (in the inode structure), |
| 58 | * honor the locking protocol. |
| 59 | * If it is not in core, read it in from the |
| 60 | * specified device. |
| 61 | * If the inode is mounted on, perform |
| 62 | * the indicated indirection. |
| 63 | * In all cases, a pointer to a locked |
| 64 | * inode structure is returned. |
| 65 | * |
| 66 | * printf warning: no inodes -- if the inode |
| 67 | * structure is full |
| 68 | * panic: no imt -- if the mounted file |
| 69 | * system is not in the mount table. |
| 70 | * "cannot happen" |
| 71 | */ |
| 72 | struct inode * |
| 73 | iget(dev, ino) |
| 74 | dev_t dev; |
| 75 | ino_t ino; |
| 76 | { |
| 77 | register struct inode *ip; |
| 78 | register struct mount *mp; |
| 79 | register struct buf *bp; |
| 80 | register struct dinode *dp; |
| 81 | register int slot; |
| 82 | |
| 83 | loop: |
| 84 | slot = INOHASH(dev, ino); |
| 85 | ip = &inode[inohash[slot]]; |
| 86 | while (ip != &inode[-1]) { |
| 87 | if(ino == ip->i_number && dev == ip->i_dev) { |
| 88 | if((ip->i_flag&ILOCK) != 0) { |
| 89 | ip->i_flag |= IWANT; |
| 90 | sleep((caddr_t)ip, PINOD); |
| 91 | goto loop; |
| 92 | } |
| 93 | if((ip->i_flag&IMOUNT) != 0) { |
| 94 | for(mp = &mount[0]; mp < &mount[NMOUNT]; mp++) |
| 95 | if(mp->m_inodp == ip) { |
| 96 | dev = mp->m_dev; |
| 97 | ino = ROOTINO; |
| 98 | goto loop; |
| 99 | } |
| 100 | panic("no imt"); |
| 101 | } |
| 102 | ip->i_count++; |
| 103 | ip->i_flag |= ILOCK; |
| 104 | return(ip); |
| 105 | } |
| 106 | ip = &inode[ip->i_hlink]; |
| 107 | } |
| 108 | if(ifreel < 0) { |
| 109 | printf("Inode table overflow\n"); |
| 110 | u.u_error = ENFILE; |
| 111 | return(NULL); |
| 112 | } |
| 113 | ip = &inode[ifreel]; |
| 114 | ifreel = ip->i_hlink; |
| 115 | ip->i_hlink = inohash[slot]; |
| 116 | inohash[slot] = ip - inode; |
| 117 | ip->i_dev = dev; |
| 118 | ip->i_number = ino; |
| 119 | ip->i_flag = ILOCK; |
| 120 | ip->i_count++; |
| 121 | ip->i_un.i_lastr = 0; |
| 122 | bp = bread(dev, itod(ino)); |
| 123 | /* |
| 124 | * Check I/O errors |
| 125 | */ |
| 126 | if((bp->b_flags&B_ERROR) != 0) { |
| 127 | brelse(bp); |
| 128 | iput(ip); |
| 129 | return(NULL); |
| 130 | } |
| 131 | dp = bp->b_un.b_dino; |
| 132 | dp += itoo(ino); |
| 133 | iexpand(ip, dp); |
| 134 | brelse(bp); |
| 135 | return(ip); |
| 136 | } |
| 137 | |
| 138 | iexpand(ip, dp) |
| 139 | register struct inode *ip; |
| 140 | register struct dinode *dp; |
| 141 | { |
| 142 | register char *p1, *p2; |
| 143 | register int i; |
| 144 | |
| 145 | ip->i_mode = dp->di_mode; |
| 146 | ip->i_nlink = dp->di_nlink; |
| 147 | ip->i_uid = dp->di_uid; |
| 148 | ip->i_gid = dp->di_gid; |
| 149 | ip->i_size = dp->di_size; |
| 150 | p1 = (char *)ip->i_un.i_addr; |
| 151 | p2 = (char *)dp->di_addr; |
| 152 | for(i=0; i<NADDR; i++) { |
| 153 | *p1++ = *p2++; |
| 154 | *p1++ = *p2++; |
| 155 | *p1++ = *p2++; |
| 156 | *p1++ = 0; |
| 157 | } |
| 158 | } |
| 159 | |
| 160 | /* |
| 161 | * Decrement reference count of |
| 162 | * an inode structure. |
| 163 | * On the last reference, |
| 164 | * write the inode out and if necessary, |
| 165 | * truncate and deallocate the file. |
| 166 | */ |
| 167 | iput(ip) |
| 168 | register struct inode *ip; |
| 169 | { |
| 170 | register int i, x; |
| 171 | register struct inode *jp; |
| 172 | |
| 173 | if(ip->i_count == 1) { |
| 174 | ip->i_flag |= ILOCK; |
| 175 | if(ip->i_nlink <= 0) { |
| 176 | itrunc(ip); |
| 177 | ip->i_mode = 0; |
| 178 | ip->i_flag |= IUPD|ICHG; |
| 179 | ifree(ip->i_dev, ip->i_number); |
| 180 | } |
| 181 | IUPDAT(ip, &time, &time); |
| 182 | prele(ip); |
| 183 | i = INOHASH(ip->i_dev, ip->i_number); |
| 184 | x = ip - inode; |
| 185 | if (inohash[i] == x) { |
| 186 | inohash[i] = ip->i_hlink; |
| 187 | } else { |
| 188 | for (jp = &inode[inohash[i]]; jp != &inode[-1]; |
| 189 | jp = &inode[jp->i_hlink]) |
| 190 | if (jp->i_hlink == x) { |
| 191 | jp->i_hlink = ip->i_hlink; |
| 192 | goto done; |
| 193 | } |
| 194 | panic("iput"); |
| 195 | } |
| 196 | done: |
| 197 | ip->i_hlink = ifreel; |
| 198 | ifreel = x; |
| 199 | ip->i_flag = 0; |
| 200 | ip->i_number = 0; |
| 201 | } else |
| 202 | prele(ip); |
| 203 | ip->i_count--; |
| 204 | } |
| 205 | |
| 206 | /* |
| 207 | * Check accessed and update flags on |
| 208 | * an inode structure. |
| 209 | * If any is on, update the inode |
| 210 | * with the current time. |
| 211 | */ |
| 212 | iupdat(ip, ta, tm) |
| 213 | register struct inode *ip; |
| 214 | time_t *ta, *tm; |
| 215 | { |
| 216 | register struct buf *bp; |
| 217 | struct dinode *dp; |
| 218 | register char *p1, *p2; |
| 219 | register int i; |
| 220 | |
| 221 | if((ip->i_flag&(IUPD|IACC|ICHG)) != 0) { |
| 222 | if(getfs(ip->i_dev)->s_ronly) |
| 223 | return; |
| 224 | bp = bread(ip->i_dev, itod(ip->i_number)); |
| 225 | if (bp->b_flags & B_ERROR) { |
| 226 | brelse(bp); |
| 227 | return; |
| 228 | } |
| 229 | dp = bp->b_un.b_dino; |
| 230 | dp += itoo(ip->i_number); |
| 231 | dp->di_mode = ip->i_mode; |
| 232 | dp->di_nlink = ip->i_nlink; |
| 233 | dp->di_uid = ip->i_uid; |
| 234 | dp->di_gid = ip->i_gid; |
| 235 | dp->di_size = ip->i_size; |
| 236 | p1 = (char *)dp->di_addr; |
| 237 | p2 = (char *)ip->i_un.i_addr; |
| 238 | for(i=0; i<NADDR; i++) { |
| 239 | *p1++ = *p2++; |
| 240 | *p1++ = *p2++; |
| 241 | *p1++ = *p2++; |
| 242 | if(*p2++ != 0 && (ip->i_mode&IFMT)!=IFMPC |
| 243 | && (ip->i_mode&IFMT)!=IFMPB) |
| 244 | printf("iaddress > 2^24\n"); |
| 245 | } |
| 246 | if(ip->i_flag&IACC) |
| 247 | dp->di_atime = *ta; |
| 248 | if(ip->i_flag&IUPD) |
| 249 | dp->di_mtime = *tm; |
| 250 | if(ip->i_flag&ICHG) |
| 251 | dp->di_ctime = time; |
| 252 | ip->i_flag &= ~(IUPD|IACC|ICHG); |
| 253 | bdwrite(bp); |
| 254 | } |
| 255 | } |
| 256 | |
| 257 | /* |
| 258 | * Free all the disk blocks associated |
| 259 | * with the specified inode structure. |
| 260 | * The blocks of the file are removed |
| 261 | * in reverse order. This FILO |
| 262 | * algorithm will tend to maintain |
| 263 | * a contiguous free list much longer |
| 264 | * than FIFO. |
| 265 | */ |
| 266 | itrunc(ip) |
| 267 | register struct inode *ip; |
| 268 | { |
| 269 | register i; |
| 270 | dev_t dev; |
| 271 | daddr_t bn; |
| 272 | |
| 273 | if (ip->i_vfdcnt) |
| 274 | panic("itrunc"); |
| 275 | i = ip->i_mode & IFMT; |
| 276 | if (i!=IFREG && i!=IFDIR) |
| 277 | return; |
| 278 | dev = ip->i_dev; |
| 279 | for(i=NADDR-1; i>=0; i--) { |
| 280 | bn = ip->i_un.i_addr[i]; |
| 281 | if(bn == (daddr_t)0) |
| 282 | continue; |
| 283 | ip->i_un.i_addr[i] = (daddr_t)0; |
| 284 | switch(i) { |
| 285 | |
| 286 | default: |
| 287 | free(dev, bn); |
| 288 | break; |
| 289 | |
| 290 | case NADDR-3: |
| 291 | tloop(dev, bn, 0, 0); |
| 292 | break; |
| 293 | |
| 294 | case NADDR-2: |
| 295 | tloop(dev, bn, 1, 0); |
| 296 | break; |
| 297 | |
| 298 | case NADDR-1: |
| 299 | tloop(dev, bn, 1, 1); |
| 300 | } |
| 301 | } |
| 302 | ip->i_size = 0; |
| 303 | ip->i_flag |= ICHG|IUPD; |
| 304 | } |
| 305 | |
| 306 | tloop(dev, bn, f1, f2) |
| 307 | dev_t dev; |
| 308 | daddr_t bn; |
| 309 | { |
| 310 | register i; |
| 311 | register struct buf *bp; |
| 312 | register daddr_t *bap; |
| 313 | daddr_t nb; |
| 314 | |
| 315 | bp = NULL; |
| 316 | for(i=NINDIR-1; i>=0; i--) { |
| 317 | if(bp == NULL) { |
| 318 | bp = bread(dev, bn); |
| 319 | if (bp->b_flags & B_ERROR) { |
| 320 | brelse(bp); |
| 321 | return; |
| 322 | } |
| 323 | bap = bp->b_un.b_daddr; |
| 324 | } |
| 325 | nb = bap[i]; |
| 326 | if(nb == (daddr_t)0) |
| 327 | continue; |
| 328 | if(f1) { |
| 329 | brelse(bp); |
| 330 | bp = NULL; |
| 331 | tloop(dev, nb, f2, 0); |
| 332 | } else |
| 333 | free(dev, nb); |
| 334 | } |
| 335 | if(bp != NULL) |
| 336 | brelse(bp); |
| 337 | free(dev, bn); |
| 338 | } |
| 339 | |
| 340 | /* |
| 341 | * Make a new file. |
| 342 | */ |
| 343 | struct inode * |
| 344 | maknode(mode) |
| 345 | { |
| 346 | register struct inode *ip; |
| 347 | |
| 348 | ip = ialloc(u.u_pdir->i_dev); |
| 349 | if(ip == NULL) { |
| 350 | iput(u.u_pdir); |
| 351 | return(NULL); |
| 352 | } |
| 353 | ip->i_flag |= IACC|IUPD|ICHG; |
| 354 | if((mode&IFMT) == 0) |
| 355 | mode |= IFREG; |
| 356 | ip->i_mode = mode & ~u.u_cmask; |
| 357 | ip->i_nlink = 1; |
| 358 | ip->i_uid = u.u_uid; |
| 359 | ip->i_gid = u.u_gid; |
| 360 | wdir(ip); |
| 361 | return(ip); |
| 362 | } |
| 363 | |
| 364 | /* |
| 365 | * Write a directory entry with |
| 366 | * parameters left as side effects |
| 367 | * to a call to namei. |
| 368 | */ |
| 369 | wdir(ip) |
| 370 | struct inode *ip; |
| 371 | { |
| 372 | |
| 373 | u.u_dent.d_ino = ip->i_number; |
| 374 | bcopy((caddr_t)u.u_dbuf, (caddr_t)u.u_dent.d_name, DIRSIZ); |
| 375 | u.u_count = sizeof(struct direct); |
| 376 | u.u_segflg = 1; |
| 377 | u.u_base = (caddr_t)&u.u_dent; |
| 378 | writei(u.u_pdir); |
| 379 | iput(u.u_pdir); |
| 380 | } |