| 1 | /* lfs_inode.c 4.22 82/08/03 */ |
| 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/fs.h" |
| 10 | #include "../h/conf.h" |
| 11 | #include "../h/buf.h" |
| 12 | #include "../h/inline.h" |
| 13 | #ifdef QUOTA |
| 14 | #include "../h/quota.h" |
| 15 | #endif |
| 16 | |
| 17 | #define INOHSZ 63 |
| 18 | #if ((INOHSZ&(INOHSZ-1)) == 0) |
| 19 | #define INOHASH(dev,ino) (((dev)+(ino))&(INOHSZ-1)) |
| 20 | #else |
| 21 | #define INOHASH(dev,ino) (((dev)+(ino))%INOHSZ) |
| 22 | #endif |
| 23 | |
| 24 | union ihead { /* inode LRU cache, Chris Maltby */ |
| 25 | union ihead *ih_head[2]; |
| 26 | struct inode *ih_chain[2]; |
| 27 | } ihead[INOHSZ]; |
| 28 | |
| 29 | struct inode *ifreeh, **ifreet; |
| 30 | |
| 31 | /* |
| 32 | * Initialize hash links for inodes |
| 33 | * and build inode free list. |
| 34 | */ |
| 35 | ihinit() |
| 36 | { |
| 37 | register int i; |
| 38 | register struct inode *ip = inode; |
| 39 | register union ihead *ih = ihead; |
| 40 | |
| 41 | for (i = INOHSZ; --i >= 0; ih++) { |
| 42 | ih->ih_head[0] = ih; |
| 43 | ih->ih_head[1] = ih; |
| 44 | } |
| 45 | ifreeh = ip; |
| 46 | ifreet = &ip->i_freef; |
| 47 | ip->i_freeb = &ifreeh; |
| 48 | ip->i_forw = ip; |
| 49 | ip->i_back = ip; |
| 50 | for (i = ninode; --i > 0; ) { |
| 51 | ++ip; |
| 52 | ip->i_forw = ip; |
| 53 | ip->i_back = ip; |
| 54 | *ifreet = ip; |
| 55 | ip->i_freeb = ifreet; |
| 56 | ifreet = &ip->i_freef; |
| 57 | } |
| 58 | ip->i_freef = NULL; |
| 59 | } |
| 60 | |
| 61 | #ifdef notdef |
| 62 | /* |
| 63 | * Find an inode if it is incore. |
| 64 | * This is the equivalent, for inodes, |
| 65 | * of ``incore'' in bio.c or ``pfind'' in subr.c. |
| 66 | */ |
| 67 | struct inode * |
| 68 | ifind(dev, ino) |
| 69 | dev_t dev; |
| 70 | ino_t ino; |
| 71 | { |
| 72 | register struct inode *ip; |
| 73 | register union ihead *ih; |
| 74 | |
| 75 | ih = &ihead[INOHASH(dev, ino)]; |
| 76 | for (ip = ih->ih_chain[0]; ip != (struct inode *)ih; ip = ip->i_forw) |
| 77 | if (ino==ip->i_number && dev==ip->i_dev) |
| 78 | return (ip); |
| 79 | return ((struct inode *)0); |
| 80 | } |
| 81 | #endif notdef |
| 82 | |
| 83 | /* |
| 84 | * Look up an inode by device,inumber. |
| 85 | * If it is in core (in the inode structure), |
| 86 | * honor the locking protocol. |
| 87 | * If it is not in core, read it in from the |
| 88 | * specified device. |
| 89 | * If the inode is mounted on, perform |
| 90 | * the indicated indirection. |
| 91 | * In all cases, a pointer to a locked |
| 92 | * inode structure is returned. |
| 93 | * |
| 94 | * panic: no imt -- if the mounted file |
| 95 | * system is not in the mount table. |
| 96 | * "cannot happen" |
| 97 | */ |
| 98 | struct inode * |
| 99 | iget(dev, fs, ino) |
| 100 | dev_t dev; |
| 101 | register struct fs *fs; |
| 102 | ino_t ino; |
| 103 | { |
| 104 | register struct inode *ip; |
| 105 | register union ihead *ih; |
| 106 | register struct mount *mp; |
| 107 | register struct buf *bp; |
| 108 | register struct dinode *dp; |
| 109 | register struct inode *iq; |
| 110 | |
| 111 | loop: |
| 112 | if (getfs(dev) != fs) |
| 113 | panic("iget: bad fs"); |
| 114 | ih = &ihead[INOHASH(dev, ino)]; |
| 115 | for (ip = ih->ih_chain[0]; ip != (struct inode *)ih; ip = ip->i_forw) |
| 116 | if (ino == ip->i_number && dev == ip->i_dev) { |
| 117 | if ((ip->i_flag&ILOCK) != 0) { |
| 118 | ip->i_flag |= IWANT; |
| 119 | sleep((caddr_t)ip, PINOD); |
| 120 | goto loop; |
| 121 | } |
| 122 | if ((ip->i_flag&IMOUNT) != 0) { |
| 123 | for (mp = &mount[0]; mp < &mount[NMOUNT]; mp++) |
| 124 | if(mp->m_inodp == ip) { |
| 125 | dev = mp->m_dev; |
| 126 | fs = mp->m_bufp->b_un.b_fs; |
| 127 | ino = ROOTINO; |
| 128 | goto loop; |
| 129 | } |
| 130 | panic("no imt"); |
| 131 | } |
| 132 | if (ip->i_count == 0) { /* ino on free list */ |
| 133 | if (iq = ip->i_freef) |
| 134 | iq->i_freeb = ip->i_freeb; |
| 135 | else |
| 136 | ifreet = ip->i_freeb; |
| 137 | *ip->i_freeb = iq; |
| 138 | ip->i_freef = NULL; |
| 139 | ip->i_freeb = NULL; |
| 140 | } |
| 141 | ip->i_count++; |
| 142 | ip->i_flag |= ILOCK; |
| 143 | return(ip); |
| 144 | } |
| 145 | |
| 146 | if ((ip = ifreeh) == NULL) { |
| 147 | tablefull("inode"); |
| 148 | u.u_error = ENFILE; |
| 149 | return(NULL); |
| 150 | } |
| 151 | if (iq = ip->i_freef) |
| 152 | iq->i_freeb = &ifreeh; |
| 153 | ifreeh = iq; |
| 154 | ip->i_freef = NULL; |
| 155 | ip->i_freeb = NULL; |
| 156 | /* |
| 157 | * Now to take inode off the hash chain it was on |
| 158 | * (initially, or after an iflush, it is on a "hash chain" |
| 159 | * consisting entirely of itself, and pointed to by no-one, |
| 160 | * but that doesn't matter), and put it on the chain for |
| 161 | * its new (ino, dev) pair |
| 162 | */ |
| 163 | remque(ip); |
| 164 | insque(ip, ih); |
| 165 | #ifdef QUOTA |
| 166 | dqrele(ip->i_dquot); |
| 167 | #endif |
| 168 | ip->i_dev = dev; |
| 169 | ip->i_fs = fs; |
| 170 | ip->i_number = ino; |
| 171 | ip->i_flag = ILOCK; |
| 172 | ip->i_count++; |
| 173 | ip->i_lastr = 0; |
| 174 | bp = bread(dev, fsbtodb(fs, itod(fs, ino)), fs->fs_bsize); |
| 175 | /* |
| 176 | * Check I/O errors |
| 177 | */ |
| 178 | if ((bp->b_flags&B_ERROR) != 0) { |
| 179 | brelse(bp); |
| 180 | /* |
| 181 | * the inode doesn't contain anything useful, so it would |
| 182 | * be misleading to leave it on its hash chain. |
| 183 | * 'iput' will take care of putting it back on the free list. |
| 184 | */ |
| 185 | remque(ip); |
| 186 | ip->i_forw = ip; |
| 187 | ip->i_back = ip; |
| 188 | /* |
| 189 | * we also loose its inumber, just in case (as iput |
| 190 | * doesn't do that any more) - but as it isn't on its |
| 191 | * hash chain, I doubt if this is really necessary .. kre |
| 192 | * (probably the two methods are interchangable) |
| 193 | */ |
| 194 | ip->i_number = 0; |
| 195 | #ifdef QUOTA |
| 196 | ip->i_dquot = NODQUOT; |
| 197 | #endif |
| 198 | iput(ip); |
| 199 | return(NULL); |
| 200 | } |
| 201 | dp = bp->b_un.b_dino; |
| 202 | dp += itoo(fs, ino); |
| 203 | ip->i_ic = dp->di_ic; |
| 204 | brelse(bp); |
| 205 | #ifdef QUOTA |
| 206 | if (ip->i_mode == 0) |
| 207 | ip->i_dquot = NODQUOT; |
| 208 | else |
| 209 | ip->i_dquot = inoquota(ip); |
| 210 | #endif |
| 211 | return (ip); |
| 212 | } |
| 213 | |
| 214 | /* |
| 215 | * Decrement reference count of |
| 216 | * an inode structure. |
| 217 | * On the last reference, |
| 218 | * write the inode out and if necessary, |
| 219 | * truncate and deallocate the file. |
| 220 | */ |
| 221 | iput(ip) |
| 222 | register struct inode *ip; |
| 223 | { |
| 224 | |
| 225 | if ((ip->i_flag & ILOCK) == 0) |
| 226 | panic("iput"); |
| 227 | iunlock(ip); |
| 228 | irele(ip); |
| 229 | } |
| 230 | |
| 231 | irele(ip) |
| 232 | register struct inode *ip; |
| 233 | { |
| 234 | register int i, x; |
| 235 | register struct inode *jp; |
| 236 | int mode; |
| 237 | |
| 238 | if (ip->i_count == 1) { |
| 239 | ip->i_flag |= ILOCK; |
| 240 | if (ip->i_nlink <= 0) { |
| 241 | itrunc(ip); |
| 242 | mode = ip->i_mode; |
| 243 | ip->i_mode = 0; |
| 244 | ip->i_rdev = 0; |
| 245 | ip->i_flag |= IUPD|ICHG; |
| 246 | ifree(ip, ip->i_number, mode); |
| 247 | #ifdef QUOTA |
| 248 | chkiq(ip->i_dev, ip, ip->i_uid, 0); |
| 249 | dqrele(ip->i_dquot); |
| 250 | ip->i_dquot = NODQUOT; |
| 251 | #endif |
| 252 | } |
| 253 | IUPDAT(ip, &time, &time, 0); |
| 254 | iunlock(ip); |
| 255 | ip->i_flag = 0; |
| 256 | /* |
| 257 | * Put the inode on the end of the free list. |
| 258 | * Possibly in some cases it would be better to |
| 259 | * put the inode at the head of the free list, |
| 260 | * (eg: where i_mode == 0 || i_number == 0) |
| 261 | * but I will think about that later .. kre |
| 262 | * (i_number is rarely 0 - only after an i/o error in iget, |
| 263 | * where i_mode == 0, the inode will probably be wanted |
| 264 | * again soon for an ialloc, so possibly we should keep it) |
| 265 | */ |
| 266 | if (ifreeh) { |
| 267 | *ifreet = ip; |
| 268 | ip->i_freeb = ifreet; |
| 269 | } else { |
| 270 | ifreeh = ip; |
| 271 | ip->i_freeb = &ifreeh; |
| 272 | } |
| 273 | ip->i_freef = NULL; |
| 274 | ifreet = &ip->i_freef; |
| 275 | } |
| 276 | ip->i_count--; |
| 277 | } |
| 278 | |
| 279 | /* |
| 280 | * Check accessed and update flags on |
| 281 | * an inode structure. |
| 282 | * If any is on, update the inode |
| 283 | * with the current time. |
| 284 | * If waitfor is given, then must insure |
| 285 | * i/o order so wait for write to complete. |
| 286 | */ |
| 287 | iupdat(ip, ta, tm, waitfor) |
| 288 | register struct inode *ip; |
| 289 | time_t *ta, *tm; |
| 290 | int waitfor; |
| 291 | { |
| 292 | register struct buf *bp; |
| 293 | struct dinode *dp; |
| 294 | register struct fs *fp; |
| 295 | |
| 296 | fp = ip->i_fs; |
| 297 | if ((ip->i_flag & (IUPD|IACC|ICHG)) != 0) { |
| 298 | if (fp->fs_ronly) |
| 299 | return; |
| 300 | bp = bread(ip->i_dev, fsbtodb(fp, itod(fp, ip->i_number)), |
| 301 | fp->fs_bsize); |
| 302 | if (bp->b_flags & B_ERROR) { |
| 303 | brelse(bp); |
| 304 | return; |
| 305 | } |
| 306 | if (ip->i_flag&IACC) |
| 307 | ip->i_atime = *ta; |
| 308 | if (ip->i_flag&IUPD) |
| 309 | ip->i_mtime = *tm; |
| 310 | if (ip->i_flag&ICHG) |
| 311 | ip->i_ctime = time; |
| 312 | ip->i_flag &= ~(IUPD|IACC|ICHG); |
| 313 | dp = bp->b_un.b_dino + itoo(fp, ip->i_number); |
| 314 | dp->di_ic = ip->i_ic; |
| 315 | if (waitfor) |
| 316 | bwrite(bp); |
| 317 | else |
| 318 | bdwrite(bp); |
| 319 | } |
| 320 | } |
| 321 | |
| 322 | /* |
| 323 | * Free all the disk blocks associated |
| 324 | * with the specified inode structure. |
| 325 | * The blocks of the file are removed |
| 326 | * in reverse order. |
| 327 | */ |
| 328 | itrunc(ip) |
| 329 | register struct inode *ip; |
| 330 | { |
| 331 | register i; |
| 332 | dev_t dev; |
| 333 | daddr_t bn; |
| 334 | struct inode itmp; |
| 335 | register struct fs *fs; |
| 336 | #ifdef QUOTA |
| 337 | register long cnt = 0; |
| 338 | long tloop(); |
| 339 | #endif |
| 340 | /* |
| 341 | * Only plain files, directories and symbolic |
| 342 | * links contain blocks. |
| 343 | */ |
| 344 | i = ip->i_mode & IFMT; |
| 345 | if (i != IFREG && i != IFDIR && i != IFLNK) |
| 346 | return; |
| 347 | |
| 348 | /* |
| 349 | * Clean inode on disk before freeing blocks |
| 350 | * to insure no duplicates if system crashes. |
| 351 | */ |
| 352 | itmp = *ip; |
| 353 | itmp.i_size = 0; |
| 354 | for (i = 0; i < NDADDR; i++) |
| 355 | itmp.i_db[i] = 0; |
| 356 | for (i = 0; i < NIADDR; i++) |
| 357 | itmp.i_ib[i] = 0; |
| 358 | itmp.i_flag |= ICHG|IUPD; |
| 359 | iupdat(&itmp, &time, &time, 1); |
| 360 | ip->i_flag &= ~(IUPD|IACC|ICHG); |
| 361 | |
| 362 | /* |
| 363 | * Now return blocks to free list... if machine |
| 364 | * crashes, they will be harmless MISSING blocks. |
| 365 | */ |
| 366 | dev = ip->i_dev; |
| 367 | fs = ip->i_fs; |
| 368 | /* |
| 369 | * release double indirect block first |
| 370 | */ |
| 371 | bn = ip->i_ib[NIADDR-1]; |
| 372 | if (bn != (daddr_t)0) { |
| 373 | ip->i_ib[NIADDR - 1] = (daddr_t)0; |
| 374 | #ifdef QUOTA |
| 375 | cnt += |
| 376 | #endif |
| 377 | tloop(ip, bn, 1); |
| 378 | } |
| 379 | /* |
| 380 | * release single indirect blocks second |
| 381 | */ |
| 382 | for (i = NIADDR - 2; i >= 0; i--) { |
| 383 | bn = ip->i_ib[i]; |
| 384 | if (bn != (daddr_t)0) { |
| 385 | ip->i_ib[i] = (daddr_t)0; |
| 386 | #ifdef QUOTA |
| 387 | cnt += |
| 388 | #endif |
| 389 | tloop(ip, bn, 0); |
| 390 | } |
| 391 | } |
| 392 | /* |
| 393 | * finally release direct blocks |
| 394 | */ |
| 395 | for (i = NDADDR - 1; i>=0; i--) { |
| 396 | register size; |
| 397 | |
| 398 | bn = ip->i_db[i]; |
| 399 | if (bn == (daddr_t)0) |
| 400 | continue; |
| 401 | ip->i_db[i] = (daddr_t)0; |
| 402 | fre(ip, bn, size = (off_t)blksize(fs, ip, i)); |
| 403 | #ifdef QUOTA |
| 404 | cnt += size / DEV_BSIZE; |
| 405 | #endif |
| 406 | } |
| 407 | ip->i_size = 0; |
| 408 | /* |
| 409 | * Inode was written and flags updated above. |
| 410 | * No need to modify flags here. |
| 411 | */ |
| 412 | #ifdef QUOTA |
| 413 | (void) chkdq(ip, -cnt, 0); |
| 414 | #endif |
| 415 | } |
| 416 | |
| 417 | #ifdef QUOTA |
| 418 | long |
| 419 | #endif |
| 420 | tloop(ip, bn, indflg) |
| 421 | register struct inode *ip; |
| 422 | daddr_t bn; |
| 423 | int indflg; |
| 424 | { |
| 425 | register i; |
| 426 | register struct buf *bp; |
| 427 | register daddr_t *bap; |
| 428 | register struct fs *fs; |
| 429 | daddr_t nb; |
| 430 | #ifdef QUOTA |
| 431 | register long cnt = 0; |
| 432 | #endif |
| 433 | |
| 434 | bp = NULL; |
| 435 | fs = ip->i_fs; |
| 436 | for (i = NINDIR(fs) - 1; i >= 0; i--) { |
| 437 | if (bp == NULL) { |
| 438 | bp = bread(ip->i_dev, fsbtodb(fs, bn), fs->fs_bsize); |
| 439 | if (bp->b_flags & B_ERROR) { |
| 440 | brelse(bp); |
| 441 | return; |
| 442 | } |
| 443 | bap = bp->b_un.b_daddr; |
| 444 | } |
| 445 | nb = bap[i]; |
| 446 | if (nb == (daddr_t)0) |
| 447 | continue; |
| 448 | if (indflg) { |
| 449 | #ifdef QUOTA |
| 450 | cnt += |
| 451 | #endif |
| 452 | tloop(ip, nb, 0); |
| 453 | } else { |
| 454 | fre(ip, nb, fs->fs_bsize); |
| 455 | #ifdef QUOTA |
| 456 | cnt += fs->fs_bsize / DEV_BSIZE; |
| 457 | #endif |
| 458 | } |
| 459 | } |
| 460 | if (bp != NULL) |
| 461 | brelse(bp); |
| 462 | fre(ip, bn, fs->fs_bsize); |
| 463 | #ifdef QUOTA |
| 464 | cnt += fs->fs_bsize / DEV_BSIZE; |
| 465 | return(cnt); |
| 466 | #endif |
| 467 | } |
| 468 | |
| 469 | /* |
| 470 | * remove any inodes in the inode cache belonging to dev |
| 471 | * |
| 472 | * There should not be any active ones, return error if any are found |
| 473 | * (nb: this is a user error, not a system err) |
| 474 | * |
| 475 | * Also, count the references to dev by block devices - this really |
| 476 | * has nothing to do with the object of the procedure, but as we have |
| 477 | * to scan the inode table here anyway, we might as well get the |
| 478 | * extra benefit. |
| 479 | * |
| 480 | * this is called from sumount()/sys3.c when dev is being unmounted |
| 481 | */ |
| 482 | #ifdef QUOTA |
| 483 | iflush(dev, iq) |
| 484 | dev_t dev; |
| 485 | struct inode *iq; |
| 486 | #else |
| 487 | iflush(dev) |
| 488 | dev_t dev; |
| 489 | #endif |
| 490 | { |
| 491 | register struct inode *ip; |
| 492 | register open = 0; |
| 493 | |
| 494 | for (ip = inode; ip < inodeNINODE; ip++) { |
| 495 | #ifdef QUOTA |
| 496 | if (ip != iq && ip->i_dev == dev) |
| 497 | #else |
| 498 | if (ip->i_dev == dev) |
| 499 | #endif |
| 500 | if (ip->i_count) |
| 501 | return(-1); |
| 502 | else { |
| 503 | remque(ip); |
| 504 | ip->i_forw = ip; |
| 505 | ip->i_back = ip; |
| 506 | /* |
| 507 | * as i_count == 0, the inode was on the free |
| 508 | * list already, just leave it there, it will |
| 509 | * fall off the bottom eventually. We could |
| 510 | * perhaps move it to the head of the free |
| 511 | * list, but as umounts are done so |
| 512 | * infrequently, we would gain very little, |
| 513 | * while making the code bigger. |
| 514 | */ |
| 515 | #ifdef QUOTA |
| 516 | dqrele(ip->i_dquot); |
| 517 | ip->i_dquot = NODQUOT; |
| 518 | #endif |
| 519 | } |
| 520 | else if (ip->i_count && (ip->i_mode&IFMT)==IFBLK && |
| 521 | ip->i_rdev == dev) |
| 522 | open++; |
| 523 | } |
| 524 | return (open); |
| 525 | } |
| 526 | |
| 527 | #ifdef ilock |
| 528 | #undef ilock |
| 529 | #endif |
| 530 | #ifdef iunlock |
| 531 | #undef iunlock |
| 532 | #endif |
| 533 | /* |
| 534 | * Lock an inode. If its already locked, set the WANT bit and sleep. |
| 535 | */ |
| 536 | ilock(ip) |
| 537 | register struct inode *ip; |
| 538 | { |
| 539 | |
| 540 | while (ip->i_flag&ILOCK) { |
| 541 | ip->i_flag |= IWANT; |
| 542 | sleep((caddr_t)ip, PINOD); |
| 543 | } |
| 544 | ip->i_flag |= ILOCK; |
| 545 | } |
| 546 | |
| 547 | /* |
| 548 | * Unlock an inode. If WANT bit is on, wakeup. |
| 549 | */ |
| 550 | iunlock(ip) |
| 551 | register struct inode *ip; |
| 552 | { |
| 553 | |
| 554 | ip->i_flag &= ~ILOCK; |
| 555 | if (ip->i_flag&IWANT) { |
| 556 | ip->i_flag &= ~IWANT; |
| 557 | wakeup((caddr_t)ip); |
| 558 | } |
| 559 | } |