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/stat.h> 44 #include <sys/time.h> 45 46 #include <assert.h> 47 #include <errno.h> 48 #include <fcntl.h> 49 #include <stdio.h> 50 #include <dirent.h> 51 #include <stdlib.h> 52 #include <string.h> 53 #include <unistd.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 free_nodes(root); 337 } 338 339 static void 340 apply_specdir(const char *dir, NODE *specnode, fsnode *dirnode, int speconly) 341 { 342 char path[MAXPATHLEN + 1]; 343 NODE *curnode; 344 fsnode *curfsnode; 345 346 assert(specnode != NULL); 347 assert(dirnode != NULL); 348 349 if (debug & DEBUG_APPLY_SPECFILE) 350 printf("apply_specdir: %s %p %p\n", dir, specnode, dirnode); 351 352 if (specnode->type != F_DIR) 353 errx(1, "Specfile node `%s/%s' is not a directory", 354 dir, specnode->name); 355 if (dirnode->type != S_IFDIR) 356 errx(1, "Directory node `%s/%s' is not a directory", 357 dir, dirnode->name); 358 359 apply_specentry(dir, specnode, dirnode); 360 361 /* Remove any filesystem nodes not found in specfile */ 362 /* XXX inefficient. This is O^2 in each dir and it would 363 * have been better never to have walked this part of the tree 364 * to begin with 365 */ 366 if (speconly) { 367 fsnode *next; 368 assert(dirnode->name[0] == '.' && dirnode->name[1] == '\0'); 369 for (curfsnode = dirnode->next; curfsnode != NULL; curfsnode = next) { 370 next = curfsnode->next; 371 for (curnode = specnode->child; curnode != NULL; 372 curnode = curnode->next) { 373 if (strcmp(curnode->name, curfsnode->name) == 0) 374 break; 375 } 376 if (curnode == NULL) { 377 if (debug & DEBUG_APPLY_SPECONLY) { 378 printf("apply_specdir: trimming %s/%s %p\n", dir, curfsnode->name, curfsnode); 379 } 380 free_fsnodes(curfsnode); 381 } 382 } 383 } 384 385 /* now walk specnode->child matching up with dirnode */ 386 for (curnode = specnode->child; curnode != NULL; 387 curnode = curnode->next) { 388 if (debug & DEBUG_APPLY_SPECENTRY) 389 printf("apply_specdir: spec %s\n", 390 curnode->name); 391 for (curfsnode = dirnode->next; curfsnode != NULL; 392 curfsnode = curfsnode->next) { 393 #if 0 /* too verbose for now */ 394 if (debug & DEBUG_APPLY_SPECENTRY) 395 printf("apply_specdir: dirent %s\n", 396 curfsnode->name); 397 #endif 398 if (strcmp(curnode->name, curfsnode->name) == 0) 399 break; 400 } 401 if (snprintf(path, sizeof(path), "%s/%s", 402 dir, curnode->name) >= sizeof(path)) 403 errx(1, "Pathname too long."); 404 if (curfsnode == NULL) { /* need new entry */ 405 struct stat stbuf; 406 407 /* 408 * don't add optional spec entries 409 * that lack an existing fs entry 410 */ 411 if ((curnode->flags & F_OPT) && 412 lstat(path, &stbuf) == -1) 413 continue; 414 415 /* check that enough info is provided */ 416 #define NODETEST(t, m) \ 417 if (!(t)) \ 418 errx(1, "`%s': %s not provided", path, m) 419 NODETEST(curnode->flags & F_TYPE, "type"); 420 NODETEST(curnode->flags & F_MODE, "mode"); 421 /* XXX: require F_TIME ? */ 422 NODETEST(curnode->flags & F_GID || 423 curnode->flags & F_GNAME, "group"); 424 NODETEST(curnode->flags & F_UID || 425 curnode->flags & F_UNAME, "user"); 426 /* if (curnode->type == F_BLOCK || curnode->type == F_CHAR) 427 NODETEST(curnode->flags & F_DEV, 428 "device number");*/ 429 #undef NODETEST 430 431 if (debug & DEBUG_APPLY_SPECFILE) 432 printf("apply_specdir: adding %s\n", 433 curnode->name); 434 /* build minimal fsnode */ 435 memset(&stbuf, 0, sizeof(stbuf)); 436 stbuf.st_mode = nodetoino(curnode->type); 437 stbuf.st_nlink = 1; 438 stbuf.st_mtime = stbuf.st_atime = 439 stbuf.st_ctime = start_time.tv_sec; 440 #if HAVE_STRUCT_STAT_ST_MTIMENSEC 441 stbuf.st_mtimensec = stbuf.st_atimensec = 442 stbuf.st_ctimensec = start_time.tv_nsec; 443 #endif 444 curfsnode = create_fsnode(".", ".", curnode->name, 445 &stbuf); 446 curfsnode->parent = dirnode->parent; 447 curfsnode->first = dirnode; 448 curfsnode->next = dirnode->next; 449 dirnode->next = curfsnode; 450 if (curfsnode->type == S_IFDIR) { 451 /* for dirs, make "." entry as well */ 452 curfsnode->child = create_fsnode(".", ".", ".", 453 &stbuf); 454 curfsnode->child->parent = curfsnode; 455 curfsnode->child->first = curfsnode->child; 456 } 457 if (curfsnode->type == S_IFLNK) { 458 assert(curnode->slink != NULL); 459 /* for symlinks, copy the target */ 460 if ((curfsnode->symlink = 461 strdup(curnode->slink)) == NULL) 462 err(1, "Memory allocation error"); 463 } 464 } 465 apply_specentry(dir, curnode, curfsnode); 466 if (curnode->type == F_DIR) { 467 if (curfsnode->type != S_IFDIR) 468 errx(1, "`%s' is not a directory", path); 469 assert (curfsnode->child != NULL); 470 apply_specdir(path, curnode, curfsnode->child, speconly); 471 } 472 } 473 } 474 475 static void 476 apply_specentry(const char *dir, NODE *specnode, fsnode *dirnode) 477 { 478 479 assert(specnode != NULL); 480 assert(dirnode != NULL); 481 482 if (nodetoino(specnode->type) != dirnode->type) 483 errx(1, "`%s/%s' type mismatch: specfile %s, tree %s", 484 dir, specnode->name, inode_type(nodetoino(specnode->type)), 485 inode_type(dirnode->type)); 486 487 if (debug & DEBUG_APPLY_SPECENTRY) 488 printf("apply_specentry: %s/%s\n", dir, dirnode->name); 489 490 #define ASEPRINT(t, b, o, n) \ 491 if (debug & DEBUG_APPLY_SPECENTRY) \ 492 printf("\t\t\tchanging %s from " b " to " b "\n", \ 493 t, o, n) 494 495 if (specnode->flags & (F_GID | F_GNAME)) { 496 ASEPRINT("gid", "%d", 497 dirnode->inode->st.st_gid, specnode->st_gid); 498 dirnode->inode->st.st_gid = specnode->st_gid; 499 } 500 if (specnode->flags & F_MODE) { 501 ASEPRINT("mode", "%#o", 502 dirnode->inode->st.st_mode & ALLPERMS, specnode->st_mode); 503 dirnode->inode->st.st_mode &= ~ALLPERMS; 504 dirnode->inode->st.st_mode |= (specnode->st_mode & ALLPERMS); 505 } 506 /* XXX: ignoring F_NLINK for now */ 507 if (specnode->flags & F_SIZE) { 508 ASEPRINT("size", "%lld", 509 (long long)dirnode->inode->st.st_size, 510 (long long)specnode->st_size); 511 dirnode->inode->st.st_size = specnode->st_size; 512 } 513 if (specnode->flags & F_SLINK) { 514 assert(dirnode->symlink != NULL); 515 assert(specnode->slink != NULL); 516 ASEPRINT("symlink", "%s", dirnode->symlink, specnode->slink); 517 free(dirnode->symlink); 518 if ((dirnode->symlink = strdup(specnode->slink)) == NULL) 519 err(1, "Memory allocation error"); 520 } 521 if (specnode->flags & F_TIME) { 522 ASEPRINT("time", "%ld", 523 (long)dirnode->inode->st.st_mtime, 524 (long)specnode->st_mtimespec.tv_sec); 525 dirnode->inode->st.st_mtime = specnode->st_mtimespec.tv_sec; 526 dirnode->inode->st.st_atime = specnode->st_mtimespec.tv_sec; 527 dirnode->inode->st.st_ctime = start_time.tv_sec; 528 #if HAVE_STRUCT_STAT_ST_MTIMENSEC 529 dirnode->inode->st.st_mtimensec = specnode->st_mtimespec.tv_nsec; 530 dirnode->inode->st.st_atimensec = specnode->st_mtimespec.tv_nsec; 531 dirnode->inode->st.st_ctimensec = start_time.tv_nsec; 532 #endif 533 } 534 if (specnode->flags & (F_UID | F_UNAME)) { 535 ASEPRINT("uid", "%d", 536 dirnode->inode->st.st_uid, specnode->st_uid); 537 dirnode->inode->st.st_uid = specnode->st_uid; 538 } 539 #if HAVE_STRUCT_STAT_ST_FLAGS 540 if (specnode->flags & F_FLAGS) { 541 ASEPRINT("flags", "%#lX", 542 (unsigned long)dirnode->inode->st.st_flags, 543 (unsigned long)specnode->st_flags); 544 dirnode->inode->st.st_flags = specnode->st_flags; 545 } 546 #endif 547 /* if (specnode->flags & F_DEV) { 548 ASEPRINT("rdev", "%#llx", 549 (unsigned long long)dirnode->inode->st.st_rdev, 550 (unsigned long long)specnode->st_rdev); 551 dirnode->inode->st.st_rdev = specnode->st_rdev; 552 }*/ 553 #undef ASEPRINT 554 555 dirnode->flags |= FSNODE_F_HASSPEC; 556 } 557 558 559 /* 560 * dump_fsnodes -- 561 * dump the fsnodes from `cur' 562 */ 563 void 564 dump_fsnodes(fsnode *root) 565 { 566 fsnode *cur; 567 char path[MAXPATHLEN + 1]; 568 569 printf("dump_fsnodes: %s %p\n", root->path, root); 570 for (cur = root; cur != NULL; cur = cur->next) { 571 if (snprintf(path, sizeof(path), "%s/%s", cur->path, 572 cur->name) >= (int)sizeof(path)) 573 errx(1, "Pathname too long."); 574 575 if (debug & DEBUG_DUMP_FSNODES_VERBOSE) 576 printf("cur=%8p parent=%8p first=%8p ", 577 cur, cur->parent, cur->first); 578 printf("%7s: %s", inode_type(cur->type), path); 579 if (S_ISLNK(cur->type)) { 580 assert(cur->symlink != NULL); 581 printf(" -> %s", cur->symlink); 582 } else { 583 assert (cur->symlink == NULL); 584 } 585 if (cur->inode->nlink > 1) 586 printf(", nlinks=%d", cur->inode->nlink); 587 putchar('\n'); 588 589 if (cur->child) { 590 assert (cur->type == S_IFDIR); 591 dump_fsnodes(cur->child); 592 } 593 } 594 printf("dump_fsnodes: finished %s/%s\n", root->path, root->name); 595 } 596 597 598 /* 599 * inode_type -- 600 * for a given inode type `mode', return a descriptive string. 601 * for most cases, uses inotype() from mtree/misc.c 602 */ 603 const char * 604 inode_type(mode_t mode) 605 { 606 if (S_ISREG(mode)) 607 return ("file"); 608 if (S_ISLNK(mode)) 609 return ("symlink"); 610 if (S_ISDIR(mode)) 611 return ("dir"); 612 if (S_ISLNK(mode)) 613 return ("link"); 614 if (S_ISFIFO(mode)) 615 return ("fifo"); 616 if (S_ISSOCK(mode)) 617 return ("socket"); 618 /* XXX should not happen but handle them */ 619 if (S_ISCHR(mode)) 620 return ("char"); 621 if (S_ISBLK(mode)) 622 return ("block"); 623 return ("unknown"); 624 } 625 626 627 /* 628 * link_check -- 629 * return pointer to fsinode matching `entry's st_ino & st_dev if it exists, 630 * otherwise add `entry' to table and return NULL 631 */ 632 /* This was borrowed from du.c and tweaked to keep an fsnode 633 * pointer instead. -- dbj@netbsd.org 634 */ 635 fsinode * 636 link_check(fsinode *entry) 637 { 638 static struct entry { 639 fsinode *data; 640 } *htable; 641 static int htshift; /* log(allocated size) */ 642 static int htmask; /* allocated size - 1 */ 643 static int htused; /* 2*number of insertions */ 644 int h, h2; 645 uint64_t tmp; 646 /* this constant is (1<<64)/((1+sqrt(5))/2) 647 * aka (word size)/(golden ratio) 648 */ 649 const uint64_t HTCONST = 11400714819323198485ULL; 650 const int HTBITS = 64; 651 652 /* Never store zero in hashtable */ 653 assert(entry); 654 655 /* Extend hash table if necessary, keep load under 0.5 */ 656 if (htused<<1 >= htmask) { 657 struct entry *ohtable; 658 659 if (!htable) 660 htshift = 10; /* starting hashtable size */ 661 else 662 htshift++; /* exponential hashtable growth */ 663 664 htmask = (1 << htshift) - 1; 665 htused = 0; 666 667 ohtable = htable; 668 htable = calloc(htmask+1, sizeof(*htable)); 669 if (!htable) 670 err(1, "Memory allocation error"); 671 672 /* populate newly allocated hashtable */ 673 if (ohtable) { 674 int i; 675 for (i = 0; i <= htmask>>1; i++) 676 if (ohtable[i].data) 677 link_check(ohtable[i].data); 678 free(ohtable); 679 } 680 } 681 682 /* multiplicative hashing */ 683 tmp = entry->st.st_dev; 684 tmp <<= HTBITS>>1; 685 tmp |= entry->st.st_ino; 686 tmp *= HTCONST; 687 h = tmp >> (HTBITS - htshift); 688 h2 = 1 | ( tmp >> (HTBITS - (htshift<<1) - 1)); /* must be odd */ 689 690 /* open address hashtable search with double hash probing */ 691 while (htable[h].data) { 692 if ((htable[h].data->st.st_ino == entry->st.st_ino) && 693 (htable[h].data->st.st_dev == entry->st.st_dev)) { 694 return htable[h].data; 695 } 696 h = (h + h2) & htmask; 697 } 698 699 /* Insert the current entry into hashtable */ 700 htable[h].data = entry; 701 htused++; 702 return NULL; 703 } 704