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