1 /* $NetBSD: walk.c,v 1.33 2023/12/28 12:13:55 tsutsui 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 #if HAVE_NBTOOL_CONFIG_H 39 #include "nbtool_config.h" 40 #endif 41 42 #include <sys/cdefs.h> 43 #if defined(__RCSID) && !defined(__lint) 44 __RCSID("$NetBSD: walk.c,v 1.33 2023/12/28 12:13:55 tsutsui Exp $"); 45 #endif /* !__lint */ 46 47 #include <sys/param.h> 48 #include <sys/stat.h> 49 50 #include <assert.h> 51 #include <errno.h> 52 #include <fcntl.h> 53 #include <stdio.h> 54 #include <dirent.h> 55 #include <stdlib.h> 56 #include <string.h> 57 #include <unistd.h> 58 #include <util.h> 59 60 #include "makefs.h" 61 #include "mtree.h" 62 63 static void apply_specdir(const char *, NODE *, fsnode *, int); 64 static void apply_specentry(const char *, NODE *, fsnode *); 65 static fsnode *create_fsnode(const char *, const char *, const char *, 66 struct stat *); 67 static fsinode *link_check(fsinode *); 68 69 70 /* 71 * walk_dir -- 72 * build a tree of fsnodes from `root' and `dir', with a parent 73 * fsnode of `parent' (which may be NULL for the root of the tree). 74 * append the tree to a fsnode of `join' if it is not NULL. 75 * each "level" is a directory, with the "." entry guaranteed to be 76 * at the start of the list, and without ".." entries. 77 */ 78 fsnode * 79 walk_dir(const char *root, const char *dir, fsnode *parent, fsnode *join, 80 int replace, int follow) 81 { 82 fsnode *first, *cur, *prev, *last; 83 DIR *dirp; 84 struct dirent *dent; 85 char path[MAXPATHLEN + 1]; 86 struct stat stbuf; 87 char *name, *rp; 88 int dot, len; 89 90 assert(root != NULL); 91 assert(dir != NULL); 92 93 len = snprintf(path, sizeof(path), "%s/%s", root, dir); 94 if (len >= (int)sizeof(path)) 95 errx(EXIT_FAILURE, "Pathname too long."); 96 if (debug & DEBUG_WALK_DIR) 97 printf("walk_dir: %s %p\n", path, parent); 98 if ((dirp = opendir(path)) == NULL) 99 err(EXIT_FAILURE, "Can't opendir `%s'", path); 100 rp = path + strlen(root) + 1; 101 if (join != NULL) { 102 first = cur = join; 103 while (cur->next != NULL) 104 cur = cur->next; 105 prev = last = cur; 106 } else 107 last = first = prev = NULL; 108 while ((dent = readdir(dirp)) != NULL) { 109 name = dent->d_name; 110 dot = 0; 111 if (name[0] == '.') 112 switch (name[1]) { 113 case '\0': /* "." */ 114 if (join != NULL) 115 continue; 116 dot = 1; 117 break; 118 case '.': /* ".." */ 119 if (name[2] == '\0') 120 continue; 121 /* FALLTHROUGH */ 122 default: 123 dot = 0; 124 } 125 if (debug & DEBUG_WALK_DIR_NODE) 126 printf("scanning %s/%s/%s\n", root, dir, name); 127 if (snprintf(path + len, sizeof(path) - len, "/%s", name) >= 128 (int)sizeof(path) - len) 129 errx(EXIT_FAILURE, "Pathname too long."); 130 if (follow) { 131 if (stat(path, &stbuf) == -1) 132 err(EXIT_FAILURE, "Can't stat `%s'", path); 133 } else { 134 if (lstat(path, &stbuf) == -1) 135 err(EXIT_FAILURE, "Can't lstat `%s'", path); 136 } 137 #ifdef S_ISSOCK 138 if (S_ISSOCK(stbuf.st_mode & S_IFMT)) { 139 if (debug & DEBUG_WALK_DIR_NODE) 140 printf(" skipping socket %s\n", path); 141 continue; 142 } 143 #endif 144 145 if (join != NULL) { 146 cur = join->next; 147 for (;;) { 148 if (cur == NULL || strcmp(cur->name, name) == 0) 149 break; 150 if (cur == last) { 151 cur = NULL; 152 break; 153 } 154 cur = cur->next; 155 } 156 if (cur != NULL) { 157 if (S_ISDIR(cur->type) && 158 S_ISDIR(stbuf.st_mode)) { 159 if (debug & DEBUG_WALK_DIR_NODE) 160 printf("merging %s with %p\n", 161 path, cur->child); 162 cur->child = walk_dir(root, rp, cur, 163 cur->child, replace, follow); 164 continue; 165 } 166 if (!replace) 167 errx(EXIT_FAILURE, 168 "Can't merge %s `%s' with " 169 "existing %s", 170 inode_type(stbuf.st_mode), path, 171 inode_type(cur->type)); 172 else { 173 if (debug & DEBUG_WALK_DIR_NODE) 174 printf("replacing %s %s\n", 175 inode_type(stbuf.st_mode), 176 path); 177 if (cur == join->next) 178 join->next = cur->next; 179 else { 180 fsnode *p; 181 for (p = join->next; 182 p->next != cur; p = p->next) 183 continue; 184 p->next = cur->next; 185 } 186 free(cur); 187 } 188 } 189 } 190 191 cur = create_fsnode(root, dir, name, &stbuf); 192 cur->parent = parent; 193 if (dot) { 194 /* ensure "." is at the start of the list */ 195 cur->next = first; 196 first = cur; 197 if (! prev) 198 prev = cur; 199 cur->first = first; 200 } else { /* not "." */ 201 if (prev) 202 prev->next = cur; 203 prev = cur; 204 if (!first) 205 first = cur; 206 cur->first = first; 207 if (S_ISDIR(cur->type)) { 208 cur->child = walk_dir(root, rp, cur, NULL, 209 replace, follow); 210 continue; 211 } 212 } 213 if (stbuf.st_nlink > 1) { 214 fsinode *curino; 215 216 curino = link_check(cur->inode); 217 if (curino != NULL) { 218 free(cur->inode); 219 cur->inode = curino; 220 cur->inode->nlink++; 221 if (debug & DEBUG_WALK_DIR_LINKCHECK) 222 printf("link_check: found [%llu, %llu]\n", 223 (unsigned long long)curino->st.st_dev, 224 (unsigned long long)curino->st.st_ino); 225 } 226 } 227 if (S_ISLNK(cur->type)) { 228 char slink[PATH_MAX+1]; 229 int llen; 230 231 llen = readlink(path, slink, sizeof(slink) - 1); 232 if (llen == -1) 233 err(EXIT_FAILURE, "Readlink `%s'", path); 234 slink[llen] = '\0'; 235 cur->symlink = estrdup(slink); 236 } 237 } 238 assert(first != NULL); 239 if (join == NULL) 240 for (cur = first->next; cur != NULL; cur = cur->next) 241 cur->first = first; 242 if (closedir(dirp) == -1) 243 err(EXIT_FAILURE, "Can't closedir `%s/%s'", root, dir); 244 return (first); 245 } 246 247 static fsnode * 248 create_fsnode(const char *root, const char *path, const char *name, 249 struct stat *stbuf) 250 { 251 fsnode *cur; 252 253 cur = ecalloc(1, sizeof(*cur)); 254 cur->path = estrdup(path); 255 cur->name = estrdup(name); 256 cur->inode = ecalloc(1, sizeof(*cur->inode)); 257 cur->root = root; 258 cur->type = stbuf->st_mode & S_IFMT; 259 cur->inode->nlink = 1; 260 cur->inode->st = *stbuf; 261 if (stampst.st_ino) { 262 cur->inode->st.st_atime = stampst.st_atime; 263 cur->inode->st.st_mtime = stampst.st_mtime; 264 cur->inode->st.st_ctime = stampst.st_ctime; 265 #if HAVE_STRUCT_STAT_ST_MTIMENSEC 266 cur->inode->st.st_atimensec = stampst.st_atimensec; 267 cur->inode->st.st_mtimensec = stampst.st_mtimensec; 268 cur->inode->st.st_ctimensec = stampst.st_ctimensec; 269 #endif 270 #if HAVE_STRUCT_STAT_BIRTHTIME 271 cur->inode->st.st_birthtime = stampst.st_birthtime; 272 cur->inode->st.st_birthtimensec = stampst.st_birthtimensec; 273 #endif 274 } 275 return (cur); 276 } 277 278 /* 279 * free_fsnodes -- 280 * Removes node from tree and frees it and all of 281 * its descendents. 282 */ 283 void 284 free_fsnodes(fsnode *node) 285 { 286 fsnode *cur, *next; 287 288 assert(node != NULL); 289 290 /* for ".", start with actual parent node */ 291 if (node->first == node) { 292 assert(node->name[0] == '.' && node->name[1] == '\0'); 293 if (node->parent) { 294 assert(node->parent->child == node); 295 node = node->parent; 296 } 297 } 298 299 /* Find ourselves in our sibling list and unlink */ 300 if (node->first != node) { 301 for (cur = node->first; cur->next; cur = cur->next) { 302 if (cur->next == node) { 303 cur->next = node->next; 304 node->next = NULL; 305 break; 306 } 307 } 308 } 309 310 for (cur = node; cur != NULL; cur = next) { 311 next = cur->next; 312 if (cur->child) { 313 cur->child->parent = NULL; 314 free_fsnodes(cur->child); 315 } 316 if (cur->inode->nlink-- == 1) 317 free(cur->inode); 318 if (cur->symlink) 319 free(cur->symlink); 320 free(cur->path); 321 free(cur->name); 322 free(cur); 323 } 324 } 325 326 /* 327 * apply_specfile -- 328 * read in the mtree(8) specfile, and apply it to the tree 329 * at dir,parent. parameters in parent on equivalent types 330 * will be changed to those found in specfile, and missing 331 * entries will be added. 332 */ 333 void 334 apply_specfile(const char *specfile, const char *dir, fsnode *parent, int speconly) 335 { 336 struct timeval start; 337 FILE *fp; 338 NODE *root; 339 340 assert(specfile != NULL); 341 assert(parent != NULL); 342 343 if (debug & DEBUG_APPLY_SPECFILE) 344 printf("apply_specfile: %s, %s %p\n", specfile, dir, parent); 345 346 /* read in the specfile */ 347 if ((fp = fopen(specfile, "r")) == NULL) 348 err(EXIT_FAILURE, "Can't open `%s'", specfile); 349 TIMER_START(start); 350 root = spec(fp); 351 TIMER_RESULTS(start, "spec"); 352 if (fclose(fp) == EOF) 353 err(EXIT_FAILURE, "Can't close `%s'", specfile); 354 355 /* perform some sanity checks */ 356 if (root == NULL) 357 errx(EXIT_FAILURE, 358 "Specfile `%s' did not contain a tree", specfile); 359 assert(strcmp(root->name, ".") == 0); 360 assert(root->type == F_DIR); 361 362 /* merge in the changes */ 363 apply_specdir(dir, root, parent, speconly); 364 365 free_nodes(root); 366 } 367 368 static void 369 apply_specdir(const char *dir, NODE *specnode, fsnode *dirnode, int speconly) 370 { 371 char path[MAXPATHLEN + 1]; 372 NODE *curnode; 373 fsnode *curfsnode; 374 375 assert(specnode != NULL); 376 assert(dirnode != NULL); 377 378 if (debug & DEBUG_APPLY_SPECFILE) 379 printf("apply_specdir: %s %p %p\n", dir, specnode, dirnode); 380 381 if (specnode->type != F_DIR) 382 errx(EXIT_FAILURE, "Specfile node `%s/%s' is not a directory", 383 dir, specnode->name); 384 if (dirnode->type != S_IFDIR) 385 errx(EXIT_FAILURE, "Directory node `%s/%s' is not a directory", 386 dir, dirnode->name); 387 388 apply_specentry(dir, specnode, dirnode); 389 390 /* Remove any filesystem nodes not found in specfile */ 391 /* XXX inefficient. This is O^2 in each dir and it would 392 * have been better never to have walked this part of the tree 393 * to begin with 394 */ 395 if (speconly) { 396 fsnode *next; 397 assert(dirnode->name[0] == '.' && dirnode->name[1] == '\0'); 398 for (curfsnode = dirnode->next; curfsnode != NULL; curfsnode = next) { 399 next = curfsnode->next; 400 for (curnode = specnode->child; curnode != NULL; 401 curnode = curnode->next) { 402 if (strcmp(curnode->name, curfsnode->name) == 0) 403 break; 404 } 405 if (curnode == NULL) { 406 if (debug & DEBUG_APPLY_SPECONLY) { 407 printf("apply_specdir: trimming %s/%s %p\n", dir, curfsnode->name, curfsnode); 408 } 409 free_fsnodes(curfsnode); 410 } 411 } 412 } 413 414 /* now walk specnode->child matching up with dirnode */ 415 for (curnode = specnode->child; curnode != NULL; 416 curnode = curnode->next) { 417 if (debug & DEBUG_APPLY_SPECENTRY) 418 printf("apply_specdir: spec %s\n", 419 curnode->name); 420 for (curfsnode = dirnode->next; curfsnode != NULL; 421 curfsnode = curfsnode->next) { 422 #if 0 /* too verbose for now */ 423 if (debug & DEBUG_APPLY_SPECENTRY) 424 printf("apply_specdir: dirent %s\n", 425 curfsnode->name); 426 #endif 427 if (strcmp(curnode->name, curfsnode->name) == 0) 428 break; 429 } 430 if ((size_t)snprintf(path, sizeof(path), "%s/%s", 431 dir, curnode->name) >= sizeof(path)) 432 errx(EXIT_FAILURE, "Pathname too long."); 433 if (curfsnode == NULL) { /* need new entry */ 434 struct stat stbuf; 435 436 /* 437 * don't add optional spec entries 438 * that lack an existing fs entry 439 */ 440 if ((curnode->flags & F_OPT) && 441 lstat(path, &stbuf) == -1) 442 continue; 443 444 /* check that enough info is provided */ 445 #define NODETEST(t, m) \ 446 if (!(t)) \ 447 errx(EXIT_FAILURE, \ 448 "`%s': %s not provided", path, m) 449 NODETEST(curnode->flags & F_TYPE, "type"); 450 NODETEST(curnode->flags & F_MODE, "mode"); 451 /* XXX: require F_TIME ? */ 452 NODETEST(curnode->flags & F_GID || 453 curnode->flags & F_GNAME, "group"); 454 NODETEST(curnode->flags & F_UID || 455 curnode->flags & F_UNAME, "user"); 456 if (curnode->type == F_BLOCK || curnode->type == F_CHAR) 457 NODETEST(curnode->flags & F_DEV, 458 "device number"); 459 #undef NODETEST 460 461 if (debug & DEBUG_APPLY_SPECFILE) 462 printf("apply_specdir: adding %s\n", 463 curnode->name); 464 /* build minimal fsnode */ 465 memset(&stbuf, 0, sizeof(stbuf)); 466 stbuf.st_mode = nodetoino(curnode->type); 467 stbuf.st_nlink = 1; 468 stbuf.st_mtime = stbuf.st_atime = 469 stbuf.st_ctime = start_time.tv_sec; 470 #if HAVE_STRUCT_STAT_ST_MTIMENSEC 471 stbuf.st_mtimensec = stbuf.st_atimensec = 472 stbuf.st_ctimensec = start_time.tv_nsec; 473 #endif 474 curfsnode = create_fsnode(".", ".", curnode->name, 475 &stbuf); 476 curfsnode->parent = dirnode->parent; 477 curfsnode->first = dirnode; 478 curfsnode->next = dirnode->next; 479 dirnode->next = curfsnode; 480 if (curfsnode->type == S_IFDIR) { 481 /* for dirs, make "." entry as well */ 482 curfsnode->child = create_fsnode(".", ".", ".", 483 &stbuf); 484 curfsnode->child->parent = curfsnode; 485 curfsnode->child->first = curfsnode->child; 486 } 487 if (curfsnode->type == S_IFLNK) { 488 assert(curnode->slink != NULL); 489 /* for symlinks, copy the target */ 490 curfsnode->symlink = estrdup(curnode->slink); 491 } 492 } 493 apply_specentry(dir, curnode, curfsnode); 494 if (curnode->type == F_DIR) { 495 if (curfsnode->type != S_IFDIR) 496 errx(EXIT_FAILURE, 497 "`%s' is not a directory", path); 498 assert (curfsnode->child != NULL); 499 apply_specdir(path, curnode, curfsnode->child, speconly); 500 } 501 } 502 } 503 504 static void 505 apply_specentry(const char *dir, NODE *specnode, fsnode *dirnode) 506 { 507 508 assert(specnode != NULL); 509 assert(dirnode != NULL); 510 511 if (nodetoino(specnode->type) != dirnode->type) 512 errx(EXIT_FAILURE, 513 "`%s/%s' type mismatch: specfile %s, tree %s", 514 dir, specnode->name, inode_type(nodetoino(specnode->type)), 515 inode_type(dirnode->type)); 516 517 if (debug & DEBUG_APPLY_SPECENTRY) 518 printf("apply_specentry: %s/%s\n", dir, dirnode->name); 519 520 #define ASEPRINT(t, b, o, n) \ 521 if (debug & DEBUG_APPLY_SPECENTRY) \ 522 printf("\t\t\tchanging %s from " b " to " b "\n", \ 523 t, o, n) 524 525 if (specnode->flags & (F_GID | F_GNAME)) { 526 ASEPRINT("gid", "%d", 527 dirnode->inode->st.st_gid, specnode->st_gid); 528 dirnode->inode->st.st_gid = specnode->st_gid; 529 } 530 if (specnode->flags & F_MODE) { 531 ASEPRINT("mode", "%#o", 532 dirnode->inode->st.st_mode & ALLPERMS, specnode->st_mode); 533 dirnode->inode->st.st_mode &= ~ALLPERMS; 534 dirnode->inode->st.st_mode |= (specnode->st_mode & ALLPERMS); 535 } 536 /* XXX: ignoring F_NLINK for now */ 537 if (specnode->flags & F_SIZE) { 538 ASEPRINT("size", "%lld", 539 (long long)dirnode->inode->st.st_size, 540 (long long)specnode->st_size); 541 dirnode->inode->st.st_size = specnode->st_size; 542 } 543 if (specnode->flags & F_SLINK) { 544 assert(dirnode->symlink != NULL); 545 assert(specnode->slink != NULL); 546 ASEPRINT("symlink", "%s", dirnode->symlink, specnode->slink); 547 free(dirnode->symlink); 548 dirnode->symlink = estrdup(specnode->slink); 549 } 550 if (specnode->flags & F_TIME) { 551 ASEPRINT("time", "%ld", 552 (long)dirnode->inode->st.st_mtime, 553 (long)specnode->st_mtimespec.tv_sec); 554 dirnode->inode->st.st_mtime = specnode->st_mtimespec.tv_sec; 555 dirnode->inode->st.st_atime = specnode->st_mtimespec.tv_sec; 556 dirnode->inode->st.st_ctime = start_time.tv_sec; 557 #if HAVE_STRUCT_STAT_ST_MTIMENSEC 558 dirnode->inode->st.st_mtimensec = specnode->st_mtimespec.tv_nsec; 559 dirnode->inode->st.st_atimensec = specnode->st_mtimespec.tv_nsec; 560 dirnode->inode->st.st_ctimensec = start_time.tv_nsec; 561 #endif 562 } 563 if (specnode->flags & (F_UID | F_UNAME)) { 564 ASEPRINT("uid", "%d", 565 dirnode->inode->st.st_uid, specnode->st_uid); 566 dirnode->inode->st.st_uid = specnode->st_uid; 567 } 568 #if HAVE_STRUCT_STAT_ST_FLAGS 569 if (specnode->flags & F_FLAGS) { 570 ASEPRINT("flags", "%#lX", 571 (unsigned long)dirnode->inode->st.st_flags, 572 (unsigned long)specnode->st_flags); 573 dirnode->inode->st.st_flags = specnode->st_flags; 574 } 575 #endif 576 if (specnode->flags & F_DEV) { 577 ASEPRINT("rdev", "%#llx", 578 (unsigned long long)dirnode->inode->st.st_rdev, 579 (unsigned long long)specnode->st_rdev); 580 dirnode->inode->st.st_rdev = specnode->st_rdev; 581 } 582 #undef ASEPRINT 583 584 dirnode->flags |= FSNODE_F_HASSPEC; 585 } 586 587 588 /* 589 * dump_fsnodes -- 590 * dump the fsnodes from `cur' 591 */ 592 void 593 dump_fsnodes(fsnode *root) 594 { 595 fsnode *cur; 596 char path[MAXPATHLEN + 1]; 597 598 printf("dump_fsnodes: %s %p\n", root->path, root); 599 for (cur = root; cur != NULL; cur = cur->next) { 600 if (snprintf(path, sizeof(path), "%s/%s", cur->path, 601 cur->name) >= (int)sizeof(path)) 602 errx(EXIT_FAILURE, "Pathname too long."); 603 604 if (debug & DEBUG_DUMP_FSNODES_VERBOSE) 605 printf("cur=%8p parent=%8p first=%8p ", 606 cur, cur->parent, cur->first); 607 printf("%7s: %s", inode_type(cur->type), path); 608 if (S_ISLNK(cur->type)) { 609 assert(cur->symlink != NULL); 610 printf(" -> %s", cur->symlink); 611 } else { 612 assert (cur->symlink == NULL); 613 } 614 if (cur->inode->nlink > 1) 615 printf(", nlinks=%d", cur->inode->nlink); 616 putchar('\n'); 617 618 if (cur->child) { 619 assert (cur->type == S_IFDIR); 620 dump_fsnodes(cur->child); 621 } 622 } 623 printf("dump_fsnodes: finished %s/%s\n", root->path, root->name); 624 } 625 626 627 /* 628 * inode_type -- 629 * for a given inode type `mode', return a descriptive string. 630 * for most cases, uses inotype() from mtree/misc.c 631 */ 632 const char * 633 inode_type(mode_t mode) 634 { 635 636 if (S_ISLNK(mode)) 637 return ("symlink"); /* inotype() returns "link"... */ 638 return (inotype(mode)); 639 } 640 641 642 /* 643 * link_check -- 644 * return pointer to fsinode matching `entry's st_ino & st_dev if it exists, 645 * otherwise add `entry' to table and return NULL 646 */ 647 /* This was borrowed from du.c and tweaked to keep an fsnode 648 * pointer instead. -- dbj@netbsd.org 649 */ 650 static fsinode * 651 link_check(fsinode *entry) 652 { 653 static struct entry { 654 fsinode *data; 655 } *htable; 656 static int htshift; /* log(allocated size) */ 657 static int htmask; /* allocated size - 1 */ 658 static int htused; /* 2*number of insertions */ 659 int h, h2; 660 uint64_t tmp; 661 /* this constant is (1<<64)/((1+sqrt(5))/2) 662 * aka (word size)/(golden ratio) 663 */ 664 const uint64_t HTCONST = 11400714819323198485ULL; 665 const int HTBITS = 64; 666 667 /* Never store zero in hashtable */ 668 assert(entry); 669 670 /* Extend hash table if necessary, keep load under 0.5 */ 671 if (htused<<1 >= htmask) { 672 struct entry *ohtable; 673 674 if (!htable) 675 htshift = 10; /* starting hashtable size */ 676 else 677 htshift++; /* exponential hashtable growth */ 678 679 htmask = (1 << htshift) - 1; 680 htused = 0; 681 682 ohtable = htable; 683 htable = ecalloc(htmask+1, sizeof(*htable)); 684 /* populate newly allocated hashtable */ 685 if (ohtable) { 686 int i; 687 for (i = 0; i <= htmask>>1; i++) 688 if (ohtable[i].data) 689 link_check(ohtable[i].data); 690 free(ohtable); 691 } 692 } 693 694 /* multiplicative hashing */ 695 tmp = entry->st.st_dev; 696 tmp <<= HTBITS>>1; 697 tmp |= entry->st.st_ino; 698 tmp *= HTCONST; 699 h = tmp >> (HTBITS - htshift); 700 h2 = 1 | ( tmp >> (HTBITS - (htshift<<1) - 1)); /* must be odd */ 701 702 /* open address hashtable search with double hash probing */ 703 while (htable[h].data) { 704 if ((htable[h].data->st.st_ino == entry->st.st_ino) && 705 (htable[h].data->st.st_dev == entry->st.st_dev)) { 706 return htable[h].data; 707 } 708 h = (h + h2) & htmask; 709 } 710 711 /* Insert the current entry into hashtable */ 712 htable[h].data = entry; 713 htused++; 714 return NULL; 715 } 716