opendir change: refinement
[minix.git] / lib / libc / gen / opendir.c
blob2229dfdefa71fb5d7d542def89c0141cd31ae73e
1 /* $NetBSD: opendir.c,v 1.38 2011/10/15 23:00:01 christos Exp $ */
3 /*
4 * Copyright (c) 1983, 1993
5 * The Regents of the University of California. All rights reserved.
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
32 #include <sys/cdefs.h>
33 #if defined(LIBC_SCCS) && !defined(lint)
34 #if 0
35 static char sccsid[] = "@(#)opendir.c 8.7 (Berkeley) 12/10/94";
36 #else
37 __RCSID("$NetBSD: opendir.c,v 1.38 2011/10/15 23:00:01 christos Exp $");
38 #endif
39 #endif /* LIBC_SCCS and not lint */
41 #include "namespace.h"
42 #include "reentrant.h"
44 #ifdef __minix
45 #include <sys/cdefs.h>
46 #include <sys/types.h>
48 #if !defined(O_CLOEXEC)
49 #define O_CLOEXEC 0
50 #endif
52 #endif
54 #include "extern.h"
56 #include <sys/param.h>
57 #include <sys/mount.h>
58 #include <sys/stat.h>
60 #include <assert.h>
61 #include <dirent.h>
62 #include <errno.h>
63 #include <fcntl.h>
64 #include <stdlib.h>
65 #include <string.h>
66 #include <unistd.h>
68 #include "dirent_private.h"
70 static DIR *__opendir_common(int, const char *, int);
72 __weak_alias(fdopendir,_fdopendir)
74 #if defined(__weak_alias) && defined(__minix)
75 __weak_alias(opendir,__opendir230)
76 #endif
79 * Open a directory.
81 DIR *
82 opendir(const char *name)
85 _DIAGASSERT(name != NULL);
87 return (__opendir2(name, DTF_HIDEW|DTF_NODUP));
90 DIR *
91 __opendir2(const char *name, int flags)
93 int fd;
95 if ((fd = open(name, O_RDONLY | O_NONBLOCK | O_CLOEXEC)) == -1)
96 return NULL;
97 #if defined(__minix)
98 if (fcntl(fd, F_SETFD, FD_CLOEXEC) == -1) {
99 close(fd);
100 return NULL;
102 #endif /* defined(__minix) */
104 return __opendir_common(fd, name, flags);
107 #ifndef __LIBC12_SOURCE__
108 DIR *
109 _fdopendir(int fd)
111 if (fcntl(fd, F_SETFD, FD_CLOEXEC) == -1)
112 return NULL;
114 return __opendir_common(fd, NULL, DTF_HIDEW|DTF_NODUP);
116 #endif
118 static DIR *
119 __opendir_common(int fd, const char *name, int flags)
121 DIR *dirp = NULL;
122 int serrno;
123 struct stat sb;
124 #ifndef __minix
125 struct statvfs sfb;
126 #endif
127 int error;
129 if (fstat(fd, &sb) || !S_ISDIR(sb.st_mode)) {
130 errno = ENOTDIR;
131 goto error;
133 if ((dirp = malloc(sizeof(*dirp))) == NULL)
134 goto error;
135 dirp->dd_buf = NULL;
136 dirp->dd_internal = NULL;
137 #ifdef _REENTRANT
138 if (__isthreaded) {
139 if ((dirp->dd_lock = malloc(sizeof(mutex_t))) == NULL)
140 goto error;
141 mutex_init((mutex_t *)dirp->dd_lock, NULL);
143 #endif
146 * Tweak flags for the underlying filesystem.
149 #ifdef __minix
150 /* MOUNT_UNION and MOUNT_NFS not supported */
151 flags &= ~DTF_NODUP;
152 #else
153 if (fstatvfs1(fd, &sfb, ST_NOWAIT) < 0)
154 goto error;
155 if ((flags & DTF_NODUP) != 0) {
156 if (!strncmp(sfb.f_fstypename, MOUNT_UNION,
157 sizeof(sfb.f_fstypename)) ||
158 (sfb.f_flag & MNT_UNION) != 0) {
159 flags |= __DTF_READALL;
160 } else {
161 flags &= ~DTF_NODUP;
164 if (!strncmp(sfb.f_fstypename, MOUNT_NFS, sizeof(sfb.f_fstypename))) {
165 flags |= __DTF_READALL | __DTF_RETRY_ON_BADCOOKIE;
167 #endif
169 dirp->dd_flags = flags;
170 error = _initdir(dirp, fd, name);
171 if (error) {
172 errno = error;
173 goto error;
176 return (dirp);
177 error:
178 serrno = errno;
179 if (dirp != NULL) {
180 #ifdef _REENTRANT
181 if (__isthreaded) {
182 mutex_destroy((mutex_t *)dirp->dd_lock);
183 free(dirp->dd_lock);
185 #endif
186 free(dirp->dd_buf);
188 free(dirp);
189 if (fd != -1)
190 (void)close(fd);
191 errno = serrno;
192 return NULL;