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