2 * Copyright (c) 1983, 1993
3 * The Regents of the University of California. All rights reserved.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 4. Neither the name of the University nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 #if defined(LIBC_SCCS) && !defined(lint)
31 static char sccsid[] = "@(#)opendir.c 8.8 (Berkeley) 5/1/95";
32 #endif /* LIBC_SCCS and not lint */
33 #include <sys/cdefs.h>
34 __FBSDID("$FreeBSD$");
36 #include "namespace.h"
37 #include <sys/param.h>
38 #include <sys/mount.h>
47 #include "un-namespace.h"
58 return (__opendir2(name, DTF_HIDEW|DTF_NODUP));
62 __opendir2(name, flags)
74 * stat() before _open() because opening of special files may be
75 * harmful. _fstat() after open because the file may have changed.
77 if (stat(name, &statb) != 0)
79 if (!S_ISDIR(statb.st_mode)) {
83 if ((fd = _open(name, O_RDONLY | O_NONBLOCK)) == -1)
86 if (_fstat(fd, &statb) != 0)
88 if (!S_ISDIR(statb.st_mode)) {
92 if (_fcntl(fd, F_SETFD, FD_CLOEXEC) == -1 ||
93 (dirp = malloc(sizeof(DIR) + sizeof(struct _telldir))) == NULL)
96 dirp->dd_td = (struct _telldir *)((char *)dirp + sizeof(DIR));
97 LIST_INIT(&dirp->dd_td->td_locq);
98 dirp->dd_td->td_loccnt = 0;
101 * Use the system page size if that is a multiple of DIRBLKSIZ.
102 * Hopefully this can be a big win someday by allowing page
103 * trades to user space to be done by _getdirentries().
105 incr = getpagesize();
106 if ((incr % DIRBLKSIZ) != 0)
110 * Determine whether this directory is the top of a union stack.
112 if (flags & DTF_NODUP) {
115 if (_fstatfs(fd, &sfb) < 0)
117 unionstack = !strcmp(sfb.f_fstypename, "unionfs")
118 || (sfb.f_flags & MNT_UNION);
133 * The strategy here is to read all the directory
134 * entries into a buffer, sort the buffer, and
135 * remove duplicate entries by setting the inode
141 * Always make at least DIRBLKSIZ bytes
142 * available to _getdirentries
144 if (space < DIRBLKSIZ) {
147 buf = reallocf(buf, len);
150 ddptr = buf + (len - space);
153 n = _getdirentries(fd, ddptr, space, &dirp->dd_seek);
161 flags |= __DTF_READALL;
164 * Re-open the directory.
165 * This has the effect of rewinding back to the
166 * top of the union stack and is needed by
167 * programs which plan to fchdir to a descriptor
168 * which has also been read -- see fts.c.
170 if (flags & DTF_REWIND) {
172 if ((fd = _open(name, O_RDONLY)) == -1) {
182 * There is now a buffer full of (possibly) duplicate
188 * Go round this loop twice...
190 * Scan through the buffer, counting entries.
191 * On the second pass, save pointers to each one.
192 * Then sort the pointers and remove duplicate names.
197 while (ddptr < ddeptr) {
200 dp = (struct dirent *) ddptr;
203 if ((dp->d_reclen <= 0) ||
204 (dp->d_reclen > (ddeptr + 1 - ddptr)))
206 ddptr += dp->d_reclen;
218 * This sort must be stable.
220 mergesort(dpv, n, sizeof(*dpv), alphasort);
226 * Scan through the buffer in sort order,
227 * zapping the inode number of any
230 for (n = 0; dpv[n]; n++) {
231 struct dirent *dp = dpv[n];
234 strcmp(dp->d_name, xp->d_name)) {
239 if (dp->d_type == DT_WHT &&
247 dpv = malloc((n+1) * sizeof(struct dirent *));
254 dirp->dd_size = ddptr - dirp->dd_buf;
258 dirp->dd_buf = malloc(dirp->dd_len);
259 if (dirp->dd_buf == NULL)
262 flags &= ~DTF_REWIND;
267 dirp->dd_flags = flags;
268 dirp->dd_lock = NULL;
271 * Set up seek point for rewinddir.
273 dirp->dd_rewind = telldir(dirp);