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