1 /* lfs_inode.c 4.29 82/10/19 */ 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 #ifdef QUOTA 13 #include "../h/quota.h" 14 #endif 15 #include "../h/kernel.h" 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&ILOCKED) != 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 |= ILOCKED; 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 = ILOCKED; 172 ip->i_count++; 173 ip->i_lastr = 0; 174 bp = bread(dev, fsbtodb(fs, itod(fs, ino)), (int)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 & ILOCKED) == 0) 226 panic("iput"); 227 iunlock(ip); 228 irele(ip); 229 } 230 231 irele(ip) 232 register struct inode *ip; 233 { 234 int mode; 235 236 if (ip->i_count == 1) { 237 ip->i_flag |= ILOCKED; 238 if (ip->i_nlink <= 0) { 239 itrunc(ip, 0); 240 mode = ip->i_mode; 241 ip->i_mode = 0; 242 ip->i_rdev = 0; 243 ip->i_flag |= IUPD|ICHG; 244 ifree(ip, ip->i_number, mode); 245 #ifdef QUOTA 246 chkiq(ip->i_dev, ip, ip->i_uid, 0); 247 dqrele(ip->i_dquot); 248 ip->i_dquot = NODQUOT; 249 #endif 250 } 251 IUPDAT(ip, &time, &time, 0); 252 iunlock(ip); 253 ip->i_flag = 0; 254 /* 255 * Put the inode on the end of the free list. 256 * Possibly in some cases it would be better to 257 * put the inode at the head of the free list, 258 * (eg: where i_mode == 0 || i_number == 0) 259 * but I will think about that later .. kre 260 * (i_number is rarely 0 - only after an i/o error in iget, 261 * where i_mode == 0, the inode will probably be wanted 262 * again soon for an ialloc, so possibly we should keep it) 263 */ 264 if (ifreeh) { 265 *ifreet = ip; 266 ip->i_freeb = ifreet; 267 } else { 268 ifreeh = ip; 269 ip->i_freeb = &ifreeh; 270 } 271 ip->i_freef = NULL; 272 ifreet = &ip->i_freef; 273 } 274 ip->i_count--; 275 } 276 277 /* 278 * Check accessed and update flags on 279 * an inode structure. 280 * If any is on, update the inode 281 * with the current time. 282 * If waitfor is given, then must insure 283 * i/o order so wait for write to complete. 284 */ 285 iupdat(ip, ta, tm, waitfor) 286 register struct inode *ip; 287 struct timeval *ta, *tm; 288 int waitfor; 289 { 290 register struct buf *bp; 291 struct dinode *dp; 292 register struct fs *fp; 293 294 fp = ip->i_fs; 295 if ((ip->i_flag & (IUPD|IACC|ICHG)) != 0) { 296 if (fp->fs_ronly) 297 return; 298 bp = bread(ip->i_dev, fsbtodb(fp, itod(fp, ip->i_number)), 299 (int)fp->fs_bsize); 300 if (bp->b_flags & B_ERROR) { 301 brelse(bp); 302 return; 303 } 304 if (ip->i_flag&IACC) 305 ip->i_atime = ta->tv_sec; 306 if (ip->i_flag&IUPD) 307 ip->i_mtime = tm->tv_sec; 308 if (ip->i_flag&ICHG) 309 ip->i_ctime = time.tv_sec; 310 ip->i_flag &= ~(IUPD|IACC|ICHG); 311 dp = bp->b_un.b_dino + itoo(fp, ip->i_number); 312 dp->di_ic = ip->i_ic; 313 if (waitfor) 314 bwrite(bp); 315 else 316 bdwrite(bp); 317 } 318 } 319 320 /* 321 * Truncate the inode ip to at most 322 * length size. Free affected disk 323 * blocks -- the blocks of the file 324 * are removed in reverse order. 325 */ 326 itrunc(ip, length) 327 register struct inode *ip; 328 register int length; 329 { 330 register i; 331 daddr_t bn; 332 struct inode itmp; 333 register struct fs *fs; 334 #ifdef QUOTA 335 register long cnt = 0; 336 long tloop(); 337 #endif 338 /* 339 * Only plain files, directories and symbolic 340 * links contain blocks. 341 */ 342 i = ip->i_mode & IFMT; 343 if (i != IFREG && i != IFDIR && i != IFLNK) 344 return; 345 if (ip->i_size <= length) 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 = length; 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 fs = ip->i_fs; 367 /* 368 * release double indirect block first 369 */ 370 bn = ip->i_ib[NIADDR-1]; 371 if (bn != (daddr_t)0) { 372 ip->i_ib[NIADDR - 1] = (daddr_t)0; 373 #ifdef QUOTA 374 cnt += 375 #endif 376 tloop(ip, bn, 1); 377 } 378 /* 379 * release single indirect blocks second 380 */ 381 for (i = NIADDR - 2; i >= 0; i--) { 382 bn = ip->i_ib[i]; 383 if (bn != (daddr_t)0) { 384 ip->i_ib[i] = (daddr_t)0; 385 #ifdef QUOTA 386 cnt += 387 #endif 388 tloop(ip, bn, 0); 389 } 390 } 391 /* 392 * finally release direct blocks 393 */ 394 for (i = NDADDR - 1; i>=0; i--) { 395 bn = ip->i_db[i]; 396 if (bn == (daddr_t)0) 397 continue; 398 ip->i_db[i] = (daddr_t)0; 399 #ifndef QUOTA 400 fre(ip, bn, (off_t)blksize(fs, ip, i)); 401 #else 402 fre(ip, bn, size = (off_t)blksize(fs, ip, i)); 403 cnt += size / DEV_BSIZE; 404 #endif 405 } 406 ip->i_size = 0; 407 /* 408 * Inode was written and flags updated above. 409 * No need to modify flags here. 410 */ 411 #ifdef QUOTA 412 (void) chkdq(ip, -cnt, 0); 413 #endif 414 } 415 416 #ifdef QUOTA 417 long 418 #endif 419 tloop(ip, bn, indflg) 420 register struct inode *ip; 421 daddr_t bn; 422 int indflg; 423 { 424 register i; 425 register struct buf *bp; 426 register daddr_t *bap; 427 register struct fs *fs; 428 daddr_t nb; 429 #ifdef QUOTA 430 register long cnt = 0; 431 #endif 432 433 bp = NULL; 434 fs = ip->i_fs; 435 for (i = NINDIR(fs) - 1; i >= 0; i--) { 436 if (bp == NULL) { 437 bp = bread(ip->i_dev, fsbtodb(fs, bn), 438 (int)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, (int)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, (int)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 /* 528 * Lock an inode. If its already locked, set the WANT bit and sleep. 529 */ 530 ilock(ip) 531 register struct inode *ip; 532 { 533 534 ILOCK(ip); 535 } 536 537 /* 538 * Unlock an inode. If WANT bit is on, wakeup. 539 */ 540 iunlock(ip) 541 register struct inode *ip; 542 { 543 544 IUNLOCK(ip); 545 } 546