1 /* $NetBSD: walk.c,v 1.24 2008/12/28 21:51:46 christos Exp $ */ 2 3 /* 4 * SPDX-License-Identifier: BSD-4-Clause 5 * 6 * Copyright (c) 2001 Wasabi Systems, Inc. 7 * All rights reserved. 8 * 9 * Written by Luke Mewburn for Wasabi Systems, Inc. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. All advertising materials mentioning features or use of this software 20 * must display the following acknowledgement: 21 * This product includes software developed for the NetBSD Project by 22 * Wasabi Systems, Inc. 23 * 4. The name of Wasabi Systems, Inc. may not be used to endorse 24 * or promote products derived from this software without specific prior 25 * written permission. 26 * 27 * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND 28 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 29 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 30 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL WASABI SYSTEMS, INC 31 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 32 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 33 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 34 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 35 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 36 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 37 * POSSIBILITY OF SUCH DAMAGE. 38 * 39 * $FreeBSD: head/usr.sbin/makefs/walk.c 326276 2017-11-27 15:37:16Z pfg $ 40 */ 41 42 43 #include <sys/param.h> 44 #include <sys/stat.h> 45 #include <sys/time.h> 46 47 #include <assert.h> 48 #include <errno.h> 49 #include <fcntl.h> 50 #include <stdio.h> 51 #include <dirent.h> 52 #include <stdlib.h> 53 #include <string.h> 54 #include <unistd.h> 55 56 #include "makefs.h" 57 #include "mtree.h" 58 #include "extern.h" 59 60 static void apply_specdir(const char *, NODE *, fsnode *, int); 61 static void apply_specentry(const char *, NODE *, fsnode *); 62 static fsnode *create_fsnode(const char *, const char *, const char *, 63 struct stat *); 64 65 66 /* 67 * walk_dir -- 68 * build a tree of fsnodes from `root' and `dir', with a parent 69 * fsnode of `parent' (which may be NULL for the root of the tree). 70 * append the tree to a fsnode of `join' if it is not NULL. 71 * each "level" is a directory, with the "." entry guaranteed to be 72 * at the start of the list, and without ".." entries. 73 */ 74 fsnode * 75 walk_dir(const char *root, const char *dir, fsnode *parent, fsnode *join) 76 { 77 fsnode *first, *cur, *prev, *last; 78 DIR *dirp; 79 struct dirent *dent; 80 char path[MAXPATHLEN + 1]; 81 struct stat stbuf; 82 char *name, *rp; 83 size_t len; 84 int dot; 85 86 assert(root != NULL); 87 assert(dir != NULL); 88 89 len = snprintf(path, sizeof(path), "%s/%s", root, dir); 90 if (len >= sizeof(path)) 91 errx(1, "Pathname too long."); 92 if (debug & DEBUG_WALK_DIR) 93 printf("walk_dir: %s %p\n", path, parent); 94 if ((dirp = opendir(path)) == NULL) 95 err(1, "Can't opendir `%s'", path); 96 rp = path + strlen(root) + 1; 97 if (join != NULL) { 98 first = cur = join; 99 while (cur->next != NULL) 100 cur = cur->next; 101 prev = cur; 102 } else 103 first = prev = NULL; 104 last = prev; 105 while ((dent = readdir(dirp)) != NULL) { 106 name = dent->d_name; 107 dot = 0; 108 if (name[0] == '.') 109 switch (name[1]) { 110 case '\0': /* "." */ 111 if (join != NULL) 112 continue; 113 dot = 1; 114 break; 115 case '.': /* ".." */ 116 if (name[2] == '\0') 117 continue; 118 /* FALLTHROUGH */ 119 default: 120 dot = 0; 121 } 122 if (debug & DEBUG_WALK_DIR_NODE) 123 printf("scanning %s/%s/%s\n", root, dir, name); 124 if ((size_t)snprintf(path + len, sizeof(path) - len, "/%s", 125 name) >= sizeof(path) - len) 126 errx(1, "Pathname too long."); 127 if (lstat(path, &stbuf) == -1) 128 err(1, "Can't lstat `%s'", path); 129 #ifdef S_ISSOCK 130 if (S_ISSOCK(stbuf.st_mode & S_IFMT)) { 131 if (debug & DEBUG_WALK_DIR_NODE) 132 printf(" skipping socket %s\n", path); 133 continue; 134 } 135 #endif 136 137 if (join != NULL) { 138 cur = join->next; 139 for (;;) { 140 if (cur == NULL || strcmp(cur->name, name) == 0) 141 break; 142 if (cur == last) { 143 cur = NULL; 144 break; 145 } 146 cur = cur->next; 147 } 148 if (cur != NULL) { 149 if (S_ISDIR(cur->type) && 150 S_ISDIR(stbuf.st_mode)) { 151 if (debug & DEBUG_WALK_DIR_NODE) 152 printf("merging %s with %p\n", 153 path, cur->child); 154 cur->child = walk_dir(root, rp, cur, 155 cur->child); 156 continue; 157 } 158 errx(1, "Can't merge %s `%s' with existing %s", 159 inode_type(stbuf.st_mode), path, 160 inode_type(cur->type)); 161 } 162 } 163 164 cur = create_fsnode(root, dir, name, &stbuf); 165 cur->parent = parent; 166 if (dot) { 167 /* ensure "." is at the start of the list */ 168 cur->next = first; 169 first = cur; 170 if (! prev) 171 prev = cur; 172 cur->first = first; 173 } else { /* not "." */ 174 if (prev) 175 prev->next = cur; 176 prev = cur; 177 if (!first) 178 first = cur; 179 cur->first = first; 180 if (S_ISDIR(cur->type)) { 181 cur->child = walk_dir(root, rp, cur, NULL); 182 continue; 183 } 184 } 185 if (stbuf.st_nlink > 1) { 186 fsinode *curino; 187 188 curino = link_check(cur->inode); 189 if (curino != NULL) { 190 free(cur->inode); 191 cur->inode = curino; 192 cur->inode->nlink++; 193 if (debug & DEBUG_WALK_DIR_LINKCHECK) 194 printf("link_check: found [%llu, %llu]\n", 195 (unsigned long long)curino->st.st_dev, 196 (unsigned long long)curino->st.st_ino); 197 } 198 } 199 if (S_ISLNK(cur->type)) { 200 char slink[PATH_MAX+1]; 201 int llen; 202 203 llen = readlink(path, slink, sizeof(slink) - 1); 204 if (llen == -1) 205 err(1, "Readlink `%s'", path); 206 slink[llen] = '\0'; 207 cur->symlink = estrdup(slink); 208 } 209 } 210 assert(first != NULL); 211 if (join == NULL) 212 for (cur = first->next; cur != NULL; cur = cur->next) 213 cur->first = first; 214 if (closedir(dirp) == -1) 215 err(1, "Can't closedir `%s/%s'", root, dir); 216 return (first); 217 } 218 219 static fsnode * 220 create_fsnode(const char *root, const char *path, const char *name, 221 struct stat *stbuf) 222 { 223 fsnode *cur; 224 225 cur = ecalloc(1, sizeof(*cur)); 226 cur->path = estrdup(path); 227 cur->name = estrdup(name); 228 cur->inode = ecalloc(1, sizeof(*cur->inode)); 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 ((size_t)snprintf(path, sizeof(path), "%s/%s", dir, 402 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 curfsnode->symlink = estrdup(curnode->slink); 461 } 462 } 463 apply_specentry(dir, curnode, curfsnode); 464 if (curnode->type == F_DIR) { 465 if (curfsnode->type != S_IFDIR) 466 errx(1, "`%s' is not a directory", path); 467 assert (curfsnode->child != NULL); 468 apply_specdir(path, curnode, curfsnode->child, speconly); 469 } 470 } 471 } 472 473 static void 474 apply_specentry(const char *dir, NODE *specnode, fsnode *dirnode) 475 { 476 477 assert(specnode != NULL); 478 assert(dirnode != NULL); 479 480 if (nodetoino(specnode->type) != dirnode->type) 481 errx(1, "`%s/%s' type mismatch: specfile %s, tree %s", 482 dir, specnode->name, inode_type(nodetoino(specnode->type)), 483 inode_type(dirnode->type)); 484 485 if (debug & DEBUG_APPLY_SPECENTRY) 486 printf("apply_specentry: %s/%s\n", dir, dirnode->name); 487 488 #define ASEPRINT(t, b, o, n) \ 489 if (debug & DEBUG_APPLY_SPECENTRY) \ 490 printf("\t\t\tchanging %s from " b " to " b "\n", \ 491 t, o, n) 492 493 if (specnode->flags & (F_GID | F_GNAME)) { 494 ASEPRINT("gid", "%d", 495 dirnode->inode->st.st_gid, specnode->st_gid); 496 dirnode->inode->st.st_gid = specnode->st_gid; 497 } 498 if (specnode->flags & F_MODE) { 499 ASEPRINT("mode", "%#o", 500 dirnode->inode->st.st_mode & ALLPERMS, specnode->st_mode); 501 dirnode->inode->st.st_mode &= ~ALLPERMS; 502 dirnode->inode->st.st_mode |= (specnode->st_mode & ALLPERMS); 503 } 504 /* XXX: ignoring F_NLINK for now */ 505 if (specnode->flags & F_SIZE) { 506 ASEPRINT("size", "%lld", 507 (long long)dirnode->inode->st.st_size, 508 (long long)specnode->st_size); 509 dirnode->inode->st.st_size = specnode->st_size; 510 } 511 if (specnode->flags & F_SLINK) { 512 assert(dirnode->symlink != NULL); 513 assert(specnode->slink != NULL); 514 ASEPRINT("symlink", "%s", dirnode->symlink, specnode->slink); 515 free(dirnode->symlink); 516 dirnode->symlink = estrdup(specnode->slink); 517 } 518 if (specnode->flags & F_TIME) { 519 ASEPRINT("time", "%ld", 520 (long)dirnode->inode->st.st_mtime, 521 (long)specnode->st_mtimespec.tv_sec); 522 dirnode->inode->st.st_mtime = specnode->st_mtimespec.tv_sec; 523 dirnode->inode->st.st_atime = specnode->st_mtimespec.tv_sec; 524 dirnode->inode->st.st_ctime = start_time.tv_sec; 525 #if HAVE_STRUCT_STAT_ST_MTIMENSEC 526 dirnode->inode->st.st_mtimensec = specnode->st_mtimespec.tv_nsec; 527 dirnode->inode->st.st_atimensec = specnode->st_mtimespec.tv_nsec; 528 dirnode->inode->st.st_ctimensec = start_time.tv_nsec; 529 #endif 530 } 531 if (specnode->flags & (F_UID | F_UNAME)) { 532 ASEPRINT("uid", "%d", 533 dirnode->inode->st.st_uid, specnode->st_uid); 534 dirnode->inode->st.st_uid = specnode->st_uid; 535 } 536 #if HAVE_STRUCT_STAT_ST_FLAGS 537 if (specnode->flags & F_FLAGS) { 538 ASEPRINT("flags", "%#lX", 539 (unsigned long)dirnode->inode->st.st_flags, 540 (unsigned long)specnode->st_flags); 541 dirnode->inode->st.st_flags = specnode->st_flags; 542 } 543 #endif 544 /* if (specnode->flags & F_DEV) { 545 ASEPRINT("rdev", "%#llx", 546 (unsigned long long)dirnode->inode->st.st_rdev, 547 (unsigned long long)specnode->st_rdev); 548 dirnode->inode->st.st_rdev = specnode->st_rdev; 549 }*/ 550 #undef ASEPRINT 551 552 dirnode->flags |= FSNODE_F_HASSPEC; 553 } 554 555 556 /* 557 * dump_fsnodes -- 558 * dump the fsnodes from `cur' 559 */ 560 void 561 dump_fsnodes(fsnode *root) 562 { 563 fsnode *cur; 564 char path[MAXPATHLEN + 1]; 565 566 printf("dump_fsnodes: %s %p\n", root->path, root); 567 for (cur = root; cur != NULL; cur = cur->next) { 568 if (snprintf(path, sizeof(path), "%s/%s", cur->path, 569 cur->name) >= (int)sizeof(path)) 570 errx(1, "Pathname too long."); 571 572 if (debug & DEBUG_DUMP_FSNODES_VERBOSE) 573 printf("cur=%8p parent=%8p first=%8p ", 574 cur, cur->parent, cur->first); 575 printf("%7s: %s", inode_type(cur->type), path); 576 if (S_ISLNK(cur->type)) { 577 assert(cur->symlink != NULL); 578 printf(" -> %s", cur->symlink); 579 } else { 580 assert (cur->symlink == NULL); 581 } 582 if (cur->inode->nlink > 1) 583 printf(", nlinks=%d", cur->inode->nlink); 584 putchar('\n'); 585 586 if (cur->child) { 587 assert (cur->type == S_IFDIR); 588 dump_fsnodes(cur->child); 589 } 590 } 591 printf("dump_fsnodes: finished %s/%s\n", root->path, root->name); 592 } 593 594 595 /* 596 * inode_type -- 597 * for a given inode type `mode', return a descriptive string. 598 * for most cases, uses inotype() from mtree/misc.c 599 */ 600 const char * 601 inode_type(mode_t mode) 602 { 603 if (S_ISREG(mode)) 604 return ("file"); 605 if (S_ISLNK(mode)) 606 return ("symlink"); 607 if (S_ISDIR(mode)) 608 return ("dir"); 609 if (S_ISLNK(mode)) 610 return ("link"); 611 if (S_ISFIFO(mode)) 612 return ("fifo"); 613 if (S_ISSOCK(mode)) 614 return ("socket"); 615 /* XXX should not happen but handle them */ 616 if (S_ISCHR(mode)) 617 return ("char"); 618 if (S_ISBLK(mode)) 619 return ("block"); 620 return ("unknown"); 621 } 622 623 624 /* 625 * link_check -- 626 * return pointer to fsinode matching `entry's st_ino & st_dev if it exists, 627 * otherwise add `entry' to table and return NULL 628 */ 629 /* This was borrowed from du.c and tweaked to keep an fsnode 630 * pointer instead. -- dbj@netbsd.org 631 */ 632 fsinode * 633 link_check(fsinode *entry) 634 { 635 static struct entry { 636 fsinode *data; 637 } *htable; 638 static int htshift; /* log(allocated size) */ 639 static int htmask; /* allocated size - 1 */ 640 static int htused; /* 2*number of insertions */ 641 int h, h2; 642 uint64_t tmp; 643 /* this constant is (1<<64)/((1+sqrt(5))/2) 644 * aka (word size)/(golden ratio) 645 */ 646 const uint64_t HTCONST = 11400714819323198485ULL; 647 const int HTBITS = 64; 648 649 /* Never store zero in hashtable */ 650 assert(entry); 651 652 /* Extend hash table if necessary, keep load under 0.5 */ 653 if (htused<<1 >= htmask) { 654 struct entry *ohtable; 655 656 if (!htable) 657 htshift = 10; /* starting hashtable size */ 658 else 659 htshift++; /* exponential hashtable growth */ 660 661 htmask = (1 << htshift) - 1; 662 htused = 0; 663 664 ohtable = htable; 665 htable = ecalloc(htmask+1, sizeof(*htable)); 666 /* populate newly allocated hashtable */ 667 if (ohtable) { 668 int i; 669 for (i = 0; i <= htmask>>1; i++) 670 if (ohtable[i].data) 671 link_check(ohtable[i].data); 672 free(ohtable); 673 } 674 } 675 676 /* multiplicative hashing */ 677 tmp = entry->st.st_dev; 678 tmp <<= HTBITS>>1; 679 tmp |= entry->st.st_ino; 680 tmp *= HTCONST; 681 h = tmp >> (HTBITS - htshift); 682 h2 = 1 | ( tmp >> (HTBITS - (htshift<<1) - 1)); /* must be odd */ 683 684 /* open address hashtable search with double hash probing */ 685 while (htable[h].data) { 686 if ((htable[h].data->st.st_ino == entry->st.st_ino) && 687 (htable[h].data->st.st_dev == entry->st.st_dev)) { 688 return htable[h].data; 689 } 690 h = (h + h2) & htmask; 691 } 692 693 /* Insert the current entry into hashtable */ 694 htable[h].data = entry; 695 htused++; 696 return NULL; 697 } 698