1 /* $NetBSD: walk.c,v 1.24 2008/12/28 21:51:46 christos Exp $ */ 2 3 /* 4 * Copyright (c) 2001 Wasabi Systems, Inc. 5 * All rights reserved. 6 * 7 * Written by Luke Mewburn for Wasabi Systems, Inc. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 3. All advertising materials mentioning features or use of this software 18 * must display the following acknowledgement: 19 * This product includes software developed for the NetBSD Project by 20 * Wasabi Systems, Inc. 21 * 4. The name of Wasabi Systems, Inc. may not be used to endorse 22 * or promote products derived from this software without specific prior 23 * written permission. 24 * 25 * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND 26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 27 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 28 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL WASABI SYSTEMS, INC 29 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 30 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 31 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 32 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 33 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 34 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 35 * POSSIBILITY OF SUCH DAMAGE. 36 */ 37 38 39 #include <sys/cdefs.h> 40 __FBSDID("$FreeBSD$"); 41 42 #include <sys/param.h> 43 44 #include <assert.h> 45 #include <errno.h> 46 #include <fcntl.h> 47 #include <stdio.h> 48 #include <dirent.h> 49 #include <stdlib.h> 50 #include <string.h> 51 #include <unistd.h> 52 #include <sys/stat.h> 53 54 #include "makefs.h" 55 #include "mtree.h" 56 #include "extern.h" 57 58 static void apply_specdir(const char *, NODE *, fsnode *, int); 59 static void apply_specentry(const char *, NODE *, fsnode *); 60 static fsnode *create_fsnode(const char *, const char *, const char *, 61 struct stat *); 62 63 64 /* 65 * walk_dir -- 66 * build a tree of fsnodes from `root' and `dir', with a parent 67 * fsnode of `parent' (which may be NULL for the root of the tree). 68 * append the tree to a fsnode of `join' if it is not NULL. 69 * each "level" is a directory, with the "." entry guaranteed to be 70 * at the start of the list, and without ".." entries. 71 */ 72 fsnode * 73 walk_dir(const char *root, const char *dir, fsnode *parent, fsnode *join) 74 { 75 fsnode *first, *cur, *prev, *last; 76 DIR *dirp; 77 struct dirent *dent; 78 char path[MAXPATHLEN + 1]; 79 struct stat stbuf; 80 char *name, *rp; 81 int dot, len; 82 83 assert(root != NULL); 84 assert(dir != NULL); 85 86 len = snprintf(path, sizeof(path), "%s/%s", root, dir); 87 if (len >= (int)sizeof(path)) 88 errx(1, "Pathname too long."); 89 if (debug & DEBUG_WALK_DIR) 90 printf("walk_dir: %s %p\n", path, parent); 91 if ((dirp = opendir(path)) == NULL) 92 err(1, "Can't opendir `%s'", path); 93 rp = path + strlen(root) + 1; 94 if (join != NULL) { 95 first = cur = join; 96 while (cur->next != NULL) 97 cur = cur->next; 98 prev = cur; 99 } else 100 first = prev = NULL; 101 last = prev; 102 while ((dent = readdir(dirp)) != NULL) { 103 name = dent->d_name; 104 dot = 0; 105 if (name[0] == '.') 106 switch (name[1]) { 107 case '\0': /* "." */ 108 if (join != NULL) 109 continue; 110 dot = 1; 111 break; 112 case '.': /* ".." */ 113 if (name[2] == '\0') 114 continue; 115 /* FALLTHROUGH */ 116 default: 117 dot = 0; 118 } 119 if (debug & DEBUG_WALK_DIR_NODE) 120 printf("scanning %s/%s/%s\n", root, dir, name); 121 if (snprintf(path + len, sizeof(path) - len, "/%s", name) >= 122 (int)sizeof(path) - len) 123 errx(1, "Pathname too long."); 124 if (lstat(path, &stbuf) == -1) 125 err(1, "Can't lstat `%s'", path); 126 #ifdef S_ISSOCK 127 if (S_ISSOCK(stbuf.st_mode & S_IFMT)) { 128 if (debug & DEBUG_WALK_DIR_NODE) 129 printf(" skipping socket %s\n", path); 130 continue; 131 } 132 #endif 133 134 if (join != NULL) { 135 cur = join->next; 136 for (;;) { 137 if (cur == NULL || strcmp(cur->name, name) == 0) 138 break; 139 if (cur == last) { 140 cur = NULL; 141 break; 142 } 143 cur = cur->next; 144 } 145 if (cur != NULL) { 146 if (S_ISDIR(cur->type) && 147 S_ISDIR(stbuf.st_mode)) { 148 if (debug & DEBUG_WALK_DIR_NODE) 149 printf("merging %s with %p\n", 150 path, cur->child); 151 cur->child = walk_dir(root, rp, cur, 152 cur->child); 153 continue; 154 } 155 errx(1, "Can't merge %s `%s' with existing %s", 156 inode_type(stbuf.st_mode), path, 157 inode_type(cur->type)); 158 } 159 } 160 161 cur = create_fsnode(root, dir, name, &stbuf); 162 cur->parent = parent; 163 if (dot) { 164 /* ensure "." is at the start of the list */ 165 cur->next = first; 166 first = cur; 167 if (! prev) 168 prev = cur; 169 cur->first = first; 170 } else { /* not "." */ 171 if (prev) 172 prev->next = cur; 173 prev = cur; 174 if (!first) 175 first = cur; 176 cur->first = first; 177 if (S_ISDIR(cur->type)) { 178 cur->child = walk_dir(root, rp, cur, NULL); 179 continue; 180 } 181 } 182 if (stbuf.st_nlink > 1) { 183 fsinode *curino; 184 185 curino = link_check(cur->inode); 186 if (curino != NULL) { 187 free(cur->inode); 188 cur->inode = curino; 189 cur->inode->nlink++; 190 if (debug & DEBUG_WALK_DIR_LINKCHECK) 191 printf("link_check: found [%llu, %llu]\n", 192 (unsigned long long)curino->st.st_dev, 193 (unsigned long long)curino->st.st_ino); 194 } 195 } 196 if (S_ISLNK(cur->type)) { 197 char slink[PATH_MAX+1]; 198 int llen; 199 200 llen = readlink(path, slink, sizeof(slink) - 1); 201 if (llen == -1) 202 err(1, "Readlink `%s'", path); 203 slink[llen] = '\0'; 204 if ((cur->symlink = strdup(slink)) == NULL) 205 err(1, "Memory allocation error"); 206 } 207 } 208 assert(first != NULL); 209 if (join == NULL) 210 for (cur = first->next; cur != NULL; cur = cur->next) 211 cur->first = first; 212 if (closedir(dirp) == -1) 213 err(1, "Can't closedir `%s/%s'", root, dir); 214 return (first); 215 } 216 217 static fsnode * 218 create_fsnode(const char *root, const char *path, const char *name, 219 struct stat *stbuf) 220 { 221 fsnode *cur; 222 223 if ((cur = calloc(1, sizeof(fsnode))) == NULL || 224 (cur->path = strdup(path)) == NULL || 225 (cur->name = strdup(name)) == NULL || 226 (cur->inode = calloc(1, sizeof(fsinode))) == NULL) 227 err(1, "Memory allocation error"); 228 cur->root = root; 229 cur->type = stbuf->st_mode & S_IFMT; 230 cur->inode->nlink = 1; 231 cur->inode->st = *stbuf; 232 return (cur); 233 } 234 235 /* 236 * free_fsnodes -- 237 * Removes node from tree and frees it and all of 238 * its descendants. 239 */ 240 void 241 free_fsnodes(fsnode *node) 242 { 243 fsnode *cur, *next; 244 245 assert(node != NULL); 246 247 /* for ".", start with actual parent node */ 248 if (node->first == node) { 249 assert(node->name[0] == '.' && node->name[1] == '\0'); 250 if (node->parent) { 251 assert(node->parent->child == node); 252 node = node->parent; 253 } 254 } 255 256 /* Find ourselves in our sibling list and unlink */ 257 if (node->first != node) { 258 for (cur = node->first; cur->next; cur = cur->next) { 259 if (cur->next == node) { 260 cur->next = node->next; 261 node->next = NULL; 262 break; 263 } 264 } 265 } 266 267 for (cur = node; cur != NULL; cur = next) { 268 next = cur->next; 269 if (cur->child) { 270 cur->child->parent = NULL; 271 free_fsnodes(cur->child); 272 } 273 if (cur->inode->nlink-- == 1) 274 free(cur->inode); 275 if (cur->symlink) 276 free(cur->symlink); 277 free(cur->path); 278 free(cur->name); 279 free(cur); 280 } 281 } 282 283 /* 284 * apply_specfile -- 285 * read in the mtree(8) specfile, and apply it to the tree 286 * at dir,parent. parameters in parent on equivalent types 287 * will be changed to those found in specfile, and missing 288 * entries will be added. 289 */ 290 void 291 apply_specfile(const char *specfile, const char *dir, fsnode *parent, int speconly) 292 { 293 struct timeval start; 294 FILE *fp; 295 NODE *root; 296 297 assert(specfile != NULL); 298 assert(parent != NULL); 299 300 if (debug & DEBUG_APPLY_SPECFILE) 301 printf("apply_specfile: %s, %s %p\n", specfile, dir, parent); 302 303 /* read in the specfile */ 304 if ((fp = fopen(specfile, "r")) == NULL) 305 err(1, "Can't open `%s'", specfile); 306 TIMER_START(start); 307 root = mtree_readspec(fp); 308 TIMER_RESULTS(start, "spec"); 309 if (fclose(fp) == EOF) 310 err(1, "Can't close `%s'", specfile); 311 312 /* perform some sanity checks */ 313 if (root == NULL) 314 errx(1, "Specfile `%s' did not contain a tree", specfile); 315 assert(strcmp(root->name, ".") == 0); 316 assert(root->type == F_DIR); 317 318 /* merge in the changes */ 319 apply_specdir(dir, root, parent, speconly); 320 321 } 322 323 static u_int 324 nodetoino(u_int type) 325 { 326 327 switch (type) { 328 case F_BLOCK: 329 return S_IFBLK; 330 case F_CHAR: 331 return S_IFCHR; 332 case F_DIR: 333 return S_IFDIR; 334 case F_FIFO: 335 return S_IFIFO; 336 case F_FILE: 337 return S_IFREG; 338 case F_LINK: 339 return S_IFLNK; 340 case F_SOCK: 341 return S_IFSOCK; 342 default: 343 printf("unknown type %d", type); 344 abort(); 345 } 346 /* NOTREACHED */ 347 } 348 349 350 static void 351 apply_specdir(const char *dir, NODE *specnode, fsnode *dirnode, int speconly) 352 { 353 char path[MAXPATHLEN + 1]; 354 NODE *curnode; 355 fsnode *curfsnode; 356 357 assert(specnode != NULL); 358 assert(dirnode != NULL); 359 360 if (debug & DEBUG_APPLY_SPECFILE) 361 printf("apply_specdir: %s %p %p\n", dir, specnode, dirnode); 362 363 if (specnode->type != F_DIR) 364 errx(1, "Specfile node `%s/%s' is not a directory", 365 dir, specnode->name); 366 if (dirnode->type != S_IFDIR) 367 errx(1, "Directory node `%s/%s' is not a directory", 368 dir, dirnode->name); 369 370 apply_specentry(dir, specnode, dirnode); 371 372 /* Remove any filesystem nodes not found in specfile */ 373 /* XXX inefficient. This is O^2 in each dir and it would 374 * have been better never to have walked this part of the tree 375 * to begin with 376 */ 377 if (speconly) { 378 fsnode *next; 379 assert(dirnode->name[0] == '.' && dirnode->name[1] == '\0'); 380 for (curfsnode = dirnode->next; curfsnode != NULL; curfsnode = next) { 381 next = curfsnode->next; 382 for (curnode = specnode->child; curnode != NULL; 383 curnode = curnode->next) { 384 if (strcmp(curnode->name, curfsnode->name) == 0) 385 break; 386 } 387 if (curnode == NULL) { 388 if (debug & DEBUG_APPLY_SPECONLY) { 389 printf("apply_specdir: trimming %s/%s %p\n", dir, curfsnode->name, curfsnode); 390 } 391 free_fsnodes(curfsnode); 392 } 393 } 394 } 395 396 /* now walk specnode->child matching up with dirnode */ 397 for (curnode = specnode->child; curnode != NULL; 398 curnode = curnode->next) { 399 if (debug & DEBUG_APPLY_SPECENTRY) 400 printf("apply_specdir: spec %s\n", 401 curnode->name); 402 for (curfsnode = dirnode->next; curfsnode != NULL; 403 curfsnode = curfsnode->next) { 404 #if 0 /* too verbose for now */ 405 if (debug & DEBUG_APPLY_SPECENTRY) 406 printf("apply_specdir: dirent %s\n", 407 curfsnode->name); 408 #endif 409 if (strcmp(curnode->name, curfsnode->name) == 0) 410 break; 411 } 412 if (snprintf(path, sizeof(path), "%s/%s", 413 dir, curnode->name) >= sizeof(path)) 414 errx(1, "Pathname too long."); 415 if (curfsnode == NULL) { /* need new entry */ 416 struct stat stbuf; 417 418 /* 419 * don't add optional spec entries 420 * that lack an existing fs entry 421 */ 422 if ((curnode->flags & F_OPT) && 423 lstat(path, &stbuf) == -1) 424 continue; 425 426 /* check that enough info is provided */ 427 #define NODETEST(t, m) \ 428 if (!(t)) \ 429 errx(1, "`%s': %s not provided", path, m) 430 NODETEST(curnode->flags & F_TYPE, "type"); 431 NODETEST(curnode->flags & F_MODE, "mode"); 432 /* XXX: require F_TIME ? */ 433 NODETEST(curnode->flags & F_GID || 434 curnode->flags & F_GNAME, "group"); 435 NODETEST(curnode->flags & F_UID || 436 curnode->flags & F_UNAME, "user"); 437 /* if (curnode->type == F_BLOCK || curnode->type == F_CHAR) 438 NODETEST(curnode->flags & F_DEV, 439 "device number");*/ 440 #undef NODETEST 441 442 if (debug & DEBUG_APPLY_SPECFILE) 443 printf("apply_specdir: adding %s\n", 444 curnode->name); 445 /* build minimal fsnode */ 446 memset(&stbuf, 0, sizeof(stbuf)); 447 stbuf.st_mode = nodetoino(curnode->type); 448 stbuf.st_nlink = 1; 449 stbuf.st_mtime = stbuf.st_atime = 450 stbuf.st_ctime = start_time.tv_sec; 451 #if HAVE_STRUCT_STAT_ST_MTIMENSEC 452 stbuf.st_mtimensec = stbuf.st_atimensec = 453 stbuf.st_ctimensec = start_time.tv_nsec; 454 #endif 455 curfsnode = create_fsnode(".", ".", curnode->name, 456 &stbuf); 457 curfsnode->parent = dirnode->parent; 458 curfsnode->first = dirnode; 459 curfsnode->next = dirnode->next; 460 dirnode->next = curfsnode; 461 if (curfsnode->type == S_IFDIR) { 462 /* for dirs, make "." entry as well */ 463 curfsnode->child = create_fsnode(".", ".", ".", 464 &stbuf); 465 curfsnode->child->parent = curfsnode; 466 curfsnode->child->first = curfsnode->child; 467 } 468 if (curfsnode->type == S_IFLNK) { 469 assert(curnode->slink != NULL); 470 /* for symlinks, copy the target */ 471 if ((curfsnode->symlink = 472 strdup(curnode->slink)) == NULL) 473 err(1, "Memory allocation error"); 474 } 475 } 476 apply_specentry(dir, curnode, curfsnode); 477 if (curnode->type == F_DIR) { 478 if (curfsnode->type != S_IFDIR) 479 errx(1, "`%s' is not a directory", path); 480 assert (curfsnode->child != NULL); 481 apply_specdir(path, curnode, curfsnode->child, speconly); 482 } 483 } 484 } 485 486 static void 487 apply_specentry(const char *dir, NODE *specnode, fsnode *dirnode) 488 { 489 490 assert(specnode != NULL); 491 assert(dirnode != NULL); 492 493 if (nodetoino(specnode->type) != dirnode->type) 494 errx(1, "`%s/%s' type mismatch: specfile %s, tree %s", 495 dir, specnode->name, inode_type(nodetoino(specnode->type)), 496 inode_type(dirnode->type)); 497 498 if (debug & DEBUG_APPLY_SPECENTRY) 499 printf("apply_specentry: %s/%s\n", dir, dirnode->name); 500 501 #define ASEPRINT(t, b, o, n) \ 502 if (debug & DEBUG_APPLY_SPECENTRY) \ 503 printf("\t\t\tchanging %s from " b " to " b "\n", \ 504 t, o, n) 505 506 if (specnode->flags & (F_GID | F_GNAME)) { 507 ASEPRINT("gid", "%d", 508 dirnode->inode->st.st_gid, specnode->st_gid); 509 dirnode->inode->st.st_gid = specnode->st_gid; 510 } 511 if (specnode->flags & F_MODE) { 512 ASEPRINT("mode", "%#o", 513 dirnode->inode->st.st_mode & ALLPERMS, specnode->st_mode); 514 dirnode->inode->st.st_mode &= ~ALLPERMS; 515 dirnode->inode->st.st_mode |= (specnode->st_mode & ALLPERMS); 516 } 517 /* XXX: ignoring F_NLINK for now */ 518 if (specnode->flags & F_SIZE) { 519 ASEPRINT("size", "%lld", 520 (long long)dirnode->inode->st.st_size, 521 (long long)specnode->st_size); 522 dirnode->inode->st.st_size = specnode->st_size; 523 } 524 if (specnode->flags & F_SLINK) { 525 assert(dirnode->symlink != NULL); 526 assert(specnode->slink != NULL); 527 ASEPRINT("symlink", "%s", dirnode->symlink, specnode->slink); 528 free(dirnode->symlink); 529 if ((dirnode->symlink = strdup(specnode->slink)) == NULL) 530 err(1, "Memory allocation error"); 531 } 532 if (specnode->flags & F_TIME) { 533 ASEPRINT("time", "%ld", 534 (long)dirnode->inode->st.st_mtime, 535 (long)specnode->st_mtimespec.tv_sec); 536 dirnode->inode->st.st_mtime = specnode->st_mtimespec.tv_sec; 537 dirnode->inode->st.st_atime = specnode->st_mtimespec.tv_sec; 538 dirnode->inode->st.st_ctime = start_time.tv_sec; 539 #if HAVE_STRUCT_STAT_ST_MTIMENSEC 540 dirnode->inode->st.st_mtimensec = specnode->st_mtimespec.tv_nsec; 541 dirnode->inode->st.st_atimensec = specnode->st_mtimespec.tv_nsec; 542 dirnode->inode->st.st_ctimensec = start_time.tv_nsec; 543 #endif 544 } 545 if (specnode->flags & (F_UID | F_UNAME)) { 546 ASEPRINT("uid", "%d", 547 dirnode->inode->st.st_uid, specnode->st_uid); 548 dirnode->inode->st.st_uid = specnode->st_uid; 549 } 550 #if HAVE_STRUCT_STAT_ST_FLAGS 551 if (specnode->flags & F_FLAGS) { 552 ASEPRINT("flags", "%#lX", 553 (unsigned long)dirnode->inode->st.st_flags, 554 (unsigned long)specnode->st_flags); 555 dirnode->inode->st.st_flags = specnode->st_flags; 556 } 557 #endif 558 /* if (specnode->flags & F_DEV) { 559 ASEPRINT("rdev", "%#llx", 560 (unsigned long long)dirnode->inode->st.st_rdev, 561 (unsigned long long)specnode->st_rdev); 562 dirnode->inode->st.st_rdev = specnode->st_rdev; 563 }*/ 564 #undef ASEPRINT 565 566 dirnode->flags |= FSNODE_F_HASSPEC; 567 } 568 569 570 /* 571 * dump_fsnodes -- 572 * dump the fsnodes from `cur' 573 */ 574 void 575 dump_fsnodes(fsnode *root) 576 { 577 fsnode *cur; 578 char path[MAXPATHLEN + 1]; 579 580 printf("dump_fsnodes: %s %p\n", root->path, root); 581 for (cur = root; cur != NULL; cur = cur->next) { 582 if (snprintf(path, sizeof(path), "%s/%s", cur->path, 583 cur->name) >= (int)sizeof(path)) 584 errx(1, "Pathname too long."); 585 586 if (debug & DEBUG_DUMP_FSNODES_VERBOSE) 587 printf("cur=%8p parent=%8p first=%8p ", 588 cur, cur->parent, cur->first); 589 printf("%7s: %s", inode_type(cur->type), path); 590 if (S_ISLNK(cur->type)) { 591 assert(cur->symlink != NULL); 592 printf(" -> %s", cur->symlink); 593 } else { 594 assert (cur->symlink == NULL); 595 } 596 if (cur->inode->nlink > 1) 597 printf(", nlinks=%d", cur->inode->nlink); 598 putchar('\n'); 599 600 if (cur->child) { 601 assert (cur->type == S_IFDIR); 602 dump_fsnodes(cur->child); 603 } 604 } 605 printf("dump_fsnodes: finished %s/%s\n", root->path, root->name); 606 } 607 608 609 /* 610 * inode_type -- 611 * for a given inode type `mode', return a descriptive string. 612 * for most cases, uses inotype() from mtree/misc.c 613 */ 614 const char * 615 inode_type(mode_t mode) 616 { 617 if (S_ISREG(mode)) 618 return ("file"); 619 if (S_ISLNK(mode)) 620 return ("symlink"); 621 if (S_ISDIR(mode)) 622 return ("dir"); 623 if (S_ISLNK(mode)) 624 return ("link"); 625 if (S_ISFIFO(mode)) 626 return ("fifo"); 627 if (S_ISSOCK(mode)) 628 return ("socket"); 629 /* XXX should not happen but handle them */ 630 if (S_ISCHR(mode)) 631 return ("char"); 632 if (S_ISBLK(mode)) 633 return ("block"); 634 return ("unknown"); 635 } 636 637 638 /* 639 * link_check -- 640 * return pointer to fsinode matching `entry's st_ino & st_dev if it exists, 641 * otherwise add `entry' to table and return NULL 642 */ 643 /* This was borrowed from du.c and tweaked to keep an fsnode 644 * pointer instead. -- dbj@netbsd.org 645 */ 646 fsinode * 647 link_check(fsinode *entry) 648 { 649 static struct entry { 650 fsinode *data; 651 } *htable; 652 static int htshift; /* log(allocated size) */ 653 static int htmask; /* allocated size - 1 */ 654 static int htused; /* 2*number of insertions */ 655 int h, h2; 656 uint64_t tmp; 657 /* this constant is (1<<64)/((1+sqrt(5))/2) 658 * aka (word size)/(golden ratio) 659 */ 660 const uint64_t HTCONST = 11400714819323198485ULL; 661 const int HTBITS = 64; 662 663 /* Never store zero in hashtable */ 664 assert(entry); 665 666 /* Extend hash table if necessary, keep load under 0.5 */ 667 if (htused<<1 >= htmask) { 668 struct entry *ohtable; 669 670 if (!htable) 671 htshift = 10; /* starting hashtable size */ 672 else 673 htshift++; /* exponential hashtable growth */ 674 675 htmask = (1 << htshift) - 1; 676 htused = 0; 677 678 ohtable = htable; 679 htable = calloc(htmask+1, sizeof(*htable)); 680 if (!htable) 681 err(1, "Memory allocation error"); 682 683 /* populate newly allocated hashtable */ 684 if (ohtable) { 685 int i; 686 for (i = 0; i <= htmask>>1; i++) 687 if (ohtable[i].data) 688 link_check(ohtable[i].data); 689 free(ohtable); 690 } 691 } 692 693 /* multiplicative hashing */ 694 tmp = entry->st.st_dev; 695 tmp <<= HTBITS>>1; 696 tmp |= entry->st.st_ino; 697 tmp *= HTCONST; 698 h = tmp >> (HTBITS - htshift); 699 h2 = 1 | ( tmp >> (HTBITS - (htshift<<1) - 1)); /* must be odd */ 700 701 /* open address hashtable search with double hash probing */ 702 while (htable[h].data) { 703 if ((htable[h].data->st.st_ino == entry->st.st_ino) && 704 (htable[h].data->st.st_dev == entry->st.st_dev)) { 705 return htable[h].data; 706 } 707 h = (h + h2) & htmask; 708 } 709 710 /* Insert the current entry into hashtable */ 711 htable[h].data = entry; 712 htused++; 713 return NULL; 714 } 715