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