[apple/libc.git] / gen / FreeBSD / opendir.c

/*-
 * Copyright (c) 1983, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)opendir.c	8.8 (Berkeley) 5/1/95";
#endif /* LIBC_SCCS and not lint */
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");

#include "namespace.h"
#include <sys/param.h>
#include <sys/mount.h>
#include <sys/stat.h>

#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <pthread.h>
#include "un-namespace.h"

#include "telldir.h"

static DIR * __opendir_common(int, int, bool);

/*
 * Open a directory.
 */
DIR *
opendir(const char *name)
{

	return (__opendir2(name, DTF_HIDEW|DTF_NODUP));
}

/*
 * Open a directory with existing file descriptor.
 */
DIR *
fdopendir(int fd)
{
	struct stat statb;

	/* Check that fd is associated with a directory. */
	if (_fstat(fd, &statb) != 0)
		return (NULL);
	if (!S_ISDIR(statb.st_mode)) {
		errno = ENOTDIR;
		return (NULL);
	}
	/* Make sure CLOEXEC is set on the fd */
	if (_fcntl(fd, F_SETFD, FD_CLOEXEC) == -1)
		return (NULL);
	return (__opendir_common(fd, DTF_HIDEW|DTF_NODUP, true));
}

DIR *
__opendir2(const char *name, int flags)
{
	int fd;
	DIR *dir;
	int saved_errno;

	if ((flags & (__DTF_READALL | __DTF_SKIPREAD)) != 0)
		return (NULL);
	if ((fd = _open(name,
	    O_RDONLY | O_NONBLOCK | O_DIRECTORY | O_CLOEXEC)) == -1)
		return (NULL);

	dir = __opendir_common(fd, flags, false);
	if (dir == NULL) {
		saved_errno = errno;
		_close(fd);
		errno = saved_errno;
	}
	return (dir);
}

static int
opendir_compar(const void *p1, const void *p2)
{

	return (strcmp((*(const struct dirent **)p1)->d_name,
	    (*(const struct dirent **)p2)->d_name));
}

/*
 * For a directory at the top of a unionfs stack, the entire directory's
 * contents are read and cached locally until the next call to rewinddir().
 * For the fdopendir() case, the initial seek position must be preserved.
 * For rewinddir(), the full directory should always be re-read from the
 * beginning.
 *
 * If an error occurs, the existing buffer and state of 'dirp' is left
 * unchanged.
 */
bool
_filldir(DIR *dirp, bool use_current_pos)
{
	struct dirent **dpv;
	char *buf, *ddptr, *ddeptr;
	off_t pos;
	int fd2, incr, len, n, saved_errno, space;
	
	len = 0;
	space = 0;
	buf = NULL;
	ddptr = NULL;

	/*
	 * Use the system page size if that is a multiple of DIRBLKSIZ.
	 * Hopefully this can be a big win someday by allowing page
	 * trades to user space to be done by _getdirentries().
	 */
	incr = getpagesize();
	if ((incr % DIRBLKSIZ) != 0) 
		incr = DIRBLKSIZ;

	/*
	 * The strategy here is to read all the directory
	 * entries into a buffer, sort the buffer, and
	 * remove duplicate entries by setting the inode
	 * number to zero.
	 *
	 * We reopen the directory because _getdirentries()
	 * on a MNT_UNION mount modifies the open directory,
	 * making it refer to the lower directory after the
	 * upper directory's entries are exhausted.
	 * This would otherwise break software that uses
	 * the directory descriptor for fchdir or *at
	 * functions, such as fts.c.
	 */
	if ((fd2 = openat(dirp->dd_fd, ".", O_RDONLY | O_CLOEXEC)) == -1)
		return (false);

	if (use_current_pos) {
		pos = lseek(dirp->dd_fd, 0, SEEK_CUR);
		if (pos == -1 || lseek(fd2, pos, SEEK_SET) == -1) {
			saved_errno = errno;
			_close(fd2);
			errno = saved_errno;
			return (false);
		}
	}

	do {
		/*
		 * Always make at least DIRBLKSIZ bytes
		 * available to _getdirentries
		 */
		if (space < DIRBLKSIZ) {
			space += incr;
			len += incr;
			buf = reallocf(buf, len);
			if (buf == NULL) {
				saved_errno = errno;
				_close(fd2);
				errno = saved_errno;
				return (false);
			}
			ddptr = buf + (len - space);
		}

#if __DARWIN_64_BIT_INO_T
		n = (int)__getdirentries64(fd2, ddptr, space, &dirp->dd_td->seekoff);
#else /* !__DARWIN_64_BIT_INO_T */
		n = _getdirentries(fd2, ddptr, space, &dirp->dd_seek);
#endif /* __DARWIN_64_BIT_INO_T */
		if (n > 0) {
			ddptr += n;
			space -= n;
		}
		if (n < 0) {
			saved_errno = errno;
			_close(fd2);
			errno = saved_errno;
			return (false);
		}
	} while (n > 0);
	_close(fd2);

	ddeptr = ddptr;

	/*
	 * There is now a buffer full of (possibly) duplicate
	 * names.
	 */
	dirp->dd_buf = buf;

	/*
	 * Go round this loop twice...
	 *
	 * Scan through the buffer, counting entries.
	 * On the second pass, save pointers to each one.
	 * Then sort the pointers and remove duplicate names.
	 */
	for (dpv = NULL;;) {
		n = 0;
		ddptr = buf;
		while (ddptr < ddeptr) {
			struct dirent *dp;

			dp = (struct dirent *) ddptr;
			if ((long)dp & 03L)
				break;
			if ((dp->d_reclen <= 0) ||
			    (dp->d_reclen > (ddeptr + 1 - ddptr)))
				break;
			ddptr += dp->d_reclen;
			if (dp->d_fileno) {
				if (dpv)
					dpv[n] = dp;
				n++;
			}
		}

		if (dpv) {
			struct dirent *xp;

			/*
			 * This sort must be stable.
			 */
			mergesort(dpv, n, sizeof(*dpv), opendir_compar);

			dpv[n] = NULL;
			xp = NULL;

			/*
			 * Scan through the buffer in sort order,
			 * zapping the inode number of any
			 * duplicate names.
			 */
			for (n = 0; dpv[n]; n++) {
				struct dirent *dp = dpv[n];

				if ((xp == NULL) ||
				    strcmp(dp->d_name, xp->d_name)) {
					xp = dp;
				} else {
					dp->d_fileno = 0;
				}
				if (dp->d_type == DT_WHT &&
				    (dirp->dd_flags & DTF_HIDEW))
					dp->d_fileno = 0;
			}

			free(dpv);
			break;
		} else {
			dpv = malloc((n+1) * sizeof(struct dirent *));
			if (dpv == NULL)
				break;
		}
	}

	dirp->dd_len = len;
	dirp->dd_size = ddptr - dirp->dd_buf;
	return (true);
}


/*
 * Common routine for opendir(3), __opendir2(3) and fdopendir(3).
 */
static DIR *
__opendir_common(int fd, int flags, bool use_current_pos)
{
	DIR *dirp;
	int incr;
	int saved_errno;
	int unionstack;

	if ((dirp = malloc(sizeof(DIR) + sizeof(struct _telldir))) == NULL)
		return (NULL);

	dirp->dd_buf = NULL;
	dirp->dd_fd = fd;
	dirp->dd_flags = flags;
	dirp->dd_loc = 0;
	dirp->dd_lock = (pthread_mutex_t)PTHREAD_MUTEX_INITIALIZER;
	dirp->dd_td = (struct _telldir *)((char *)dirp + sizeof(DIR));
	LIST_INIT(&dirp->dd_td->td_locq);
	dirp->dd_td->td_loccnt = 0;

	/*
	 * Use the system page size if that is a multiple of DIRBLKSIZ.
	 * Hopefully this can be a big win someday by allowing page
	 * trades to user space to be done by _getdirentries().
	 */
	incr = getpagesize();
	if ((incr % DIRBLKSIZ) != 0) 
		incr = DIRBLKSIZ;

	/*
	 * Determine whether this directory is the top of a union stack.
	 */
	if (flags & DTF_NODUP) {
		struct statfs sfb;

		if (_fstatfs(fd, &sfb) < 0)
			goto fail;
		unionstack = !strcmp(sfb.f_fstypename, "unionfs")
		    || (sfb.f_flags & MNT_UNION);
	} else {
		unionstack = 0;
	}

	if (unionstack) {
		if (!_filldir(dirp, use_current_pos))
			goto fail;
		dirp->dd_flags |= __DTF_READALL;
	} else {
		dirp->dd_len = incr;
		dirp->dd_buf = malloc(dirp->dd_len);
		if (dirp->dd_buf == NULL)
			goto fail;
		if (use_current_pos) {
			/*
			 * Read the first batch of directory entries
			 * to prime dd_seek.  This also checks if the
			 * fd passed to fdopendir() is a directory.
			 */
#if __DARWIN_64_BIT_INO_T
			dirp->dd_size = (long)__getdirentries64(dirp->dd_fd,
			    dirp->dd_buf, dirp->dd_len, &dirp->dd_td->seekoff);
#else /* !__DARWIN_64_BIT_INO_T */
			dirp->dd_size = _getdirentries(dirp->dd_fd,
			    dirp->dd_buf, dirp->dd_len, &dirp->dd_seek);
#endif /* __DARWIN_64_BIT_INO_T */
			if (dirp->dd_size < 0) {
				if (errno == EINVAL)
					errno = ENOTDIR;
				goto fail;
			}
			dirp->dd_flags |= __DTF_SKIPREAD;
		} else {
			dirp->dd_size = 0;
#if __DARWIN_64_BIT_INO_T
			dirp->dd_td->seekoff = 0;
#else /* !__DARWIN_64_BIT_INO_T */
			dirp->dd_seek = 0;
#endif /* __DARWIN_64_BIT_INO_T */
		}
	}

	return (dirp);

fail:
	saved_errno = errno;
	free(dirp->dd_buf);
	free(dirp);
	errno = saved_errno;
	return (NULL);
}
Commit	Line	Data
1f2f436a	1	/*-
e9ce8d39 A	2	* Copyright (c) 1983, 1993
	3	* The Regents of the University of California. All rights reserved.
	4	*
	5	* Redistribution and use in source and binary forms, with or without
	6	* modification, are permitted provided that the following conditions
	7	* are met:
	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.
e9ce8d39 A	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.
	16	*
	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
	27	* SUCH DAMAGE.
	28	*/
	29
9385eb3d A	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>
23e20b00	34	__FBSDID("$FreeBSD$");
e9ce8d39	35
9385eb3d	36	#include "namespace.h"
e9ce8d39 A	37	#include <sys/param.h>
	38	#include <sys/mount.h>
	39	#include <sys/stat.h>
	40
	41	#include <dirent.h>
	42	#include <errno.h>
	43	#include <fcntl.h>
	44	#include <stdlib.h>
e9ce8d39	45	#include <string.h>
9385eb3d	46	#include <unistd.h>
ad3c9f2a	47	#include <pthread.h>
9385eb3d A	48	#include "un-namespace.h"
	49
	50	#include "telldir.h"
23e20b00	51
b061a43b	52	static DIR * __opendir_common(int, int, bool);
23e20b00	53
9385eb3d A	54	/*
	55	* Open a directory.
	56	*/
	57	DIR *
1f2f436a	58	opendir(const char *name)
9385eb3d A	59	{
	60
	61	return (__opendir2(name, DTF_HIDEW\|DTF_NODUP));
	62	}
e9ce8d39	63
23e20b00 A	64	/*
	65	* Open a directory with existing file descriptor.
	66	*/
	67	DIR *
	68	fdopendir(int fd)
	69	{
	70	struct stat statb;
	71
	72	/* Check that fd is associated with a directory. */
	73	if (_fstat(fd, &statb) != 0)
	74	return (NULL);
	75	if (!S_ISDIR(statb.st_mode)) {
	76	errno = ENOTDIR;
	77	return (NULL);
	78	}
b061a43b	79	/* Make sure CLOEXEC is set on the fd */
23e20b00 A	80	if (_fcntl(fd, F_SETFD, FD_CLOEXEC) == -1)
23e20b00 A	81	return (NULL);
b061a43b	82	return (__opendir_common(fd, DTF_HIDEW\|DTF_NODUP, true));
23e20b00 A	83	}
23e20b00 A	84
9385eb3d	85	DIR *
1f2f436a	86	__opendir2(const char *name, int flags)
e9ce8d39	87	{
e9ce8d39	88	int fd;
b061a43b A	89	DIR *dir;
b061a43b A	90	int saved_errno;
23e20b00	91
b061a43b A	92	if ((flags & (__DTF_READALL \| __DTF_SKIPREAD)) != 0)
b061a43b A	93	return (NULL);
23e20b00 A	94	if ((fd = _open(name,
	95	O_RDONLY \| O_NONBLOCK \| O_DIRECTORY \| O_CLOEXEC)) == -1)
	96	return (NULL);
	97
b061a43b A	98	dir = __opendir_common(fd, flags, false);
	99	if (dir == NULL) {
	100	saved_errno = errno;
	101	_close(fd);
	102	errno = saved_errno;
	103	}
	104	return (dir);
23e20b00 A	105	}
	106
	107	static int
	108	opendir_compar(const void p1, const void p2)
	109	{
	110
	111	return (strcmp(((const struct dirent *)p1)->d_name,
	112	((const struct dirent *)p2)->d_name));
	113	}
	114
b061a43b A	115	/*
	116	* For a directory at the top of a unionfs stack, the entire directory's
	117	* contents are read and cached locally until the next call to rewinddir().
	118	* For the fdopendir() case, the initial seek position must be preserved.
	119	* For rewinddir(), the full directory should always be re-read from the
	120	* beginning.
	121	*
	122	* If an error occurs, the existing buffer and state of 'dirp' is left
	123	* unchanged.
	124	*/
	125	bool
	126	_filldir(DIR *dirp, bool use_current_pos)
	127	{
	128	struct dirent **dpv;
	129	char buf, ddptr, *ddeptr;
	130	off_t pos;
	131	int fd2, incr, len, n, saved_errno, space;
	132
	133	len = 0;
	134	space = 0;
	135	buf = NULL;
	136	ddptr = NULL;
	137
	138	/*
	139	* Use the system page size if that is a multiple of DIRBLKSIZ.
	140	* Hopefully this can be a big win someday by allowing page
	141	* trades to user space to be done by _getdirentries().
	142	*/
	143	incr = getpagesize();
	144	if ((incr % DIRBLKSIZ) != 0)
	145	incr = DIRBLKSIZ;
	146
	147	/*
	148	* The strategy here is to read all the directory
	149	* entries into a buffer, sort the buffer, and
	150	* remove duplicate entries by setting the inode
	151	* number to zero.
	152	*
	153	* We reopen the directory because _getdirentries()
	154	* on a MNT_UNION mount modifies the open directory,
	155	* making it refer to the lower directory after the
	156	* upper directory's entries are exhausted.
	157	* This would otherwise break software that uses
	158	* the directory descriptor for fchdir or *at
	159	* functions, such as fts.c.
	160	*/
	161	if ((fd2 = openat(dirp->dd_fd, ".", O_RDONLY \| O_CLOEXEC)) == -1)
	162	return (false);
	163
	164	if (use_current_pos) {
	165	pos = lseek(dirp->dd_fd, 0, SEEK_CUR);
	166	if (pos == -1 \|\| lseek(fd2, pos, SEEK_SET) == -1) {
	167	saved_errno = errno;
	168	_close(fd2);
	169	errno = saved_errno;
	170	return (false);
	171	}
	172	}
	173
	174	do {
	175	/*
	176	* Always make at least DIRBLKSIZ bytes
	177	* available to _getdirentries
	178	*/
179	if (space < DIRBLKSIZ) {
180	space += incr;
181	len += incr;
182	buf = reallocf(buf, len);
183	if (buf == NULL) {
184	saved_errno = errno;
185	_close(fd2);
186	errno = saved_errno;
187	return (false);
188	}
189	ddptr = buf + (len - space);
190	}
191
192	#if __DARWIN_64_BIT_INO_T
193	n = (int)__getdirentries64(fd2, ddptr, space, &dirp->dd_td->seekoff);
194	#else /* !__DARWIN_64_BIT_INO_T */
195	n = _getdirentries(fd2, ddptr, space, &dirp->dd_seek);
196	#endif /* __DARWIN_64_BIT_INO_T */
197	if (n > 0) {
198	ddptr += n;
199	space -= n;
200	}
201	if (n < 0) {
202	saved_errno = errno;
203	_close(fd2);
204	errno = saved_errno;
205	return (false);
206	}
207	} while (n > 0);
208	_close(fd2);
209
210	ddeptr = ddptr;
211
212	/*
213	* There is now a buffer full of (possibly) duplicate
214	* names.
215	*/
216	dirp->dd_buf = buf;
217
218	/*
219	* Go round this loop twice...
220	*
221	* Scan through the buffer, counting entries.
222	* On the second pass, save pointers to each one.
223	* Then sort the pointers and remove duplicate names.
224	*/
225	for (dpv = NULL;;) {
226	n = 0;
227	ddptr = buf;
228	while (ddptr < ddeptr) {
229	struct dirent *dp;
230
231	dp = (struct dirent *) ddptr;
232	if ((long)dp & 03L)
233	break;
234	if ((dp->d_reclen <= 0) \|\|
235	(dp->d_reclen > (ddeptr + 1 - ddptr)))
236	break;
237	ddptr += dp->d_reclen;
238	if (dp->d_fileno) {
239	if (dpv)
240	dpv[n] = dp;
241	n++;
242	}
243	}
244
245	if (dpv) {
246	struct dirent *xp;
247
248	/*
249	* This sort must be stable.
250	*/
251	mergesort(dpv, n, sizeof(*dpv), opendir_compar);
252
253	dpv[n] = NULL;
254	xp = NULL;
255
256	/*
257	* Scan through the buffer in sort order,
258	* zapping the inode number of any
259	* duplicate names.
260	*/
261	for (n = 0; dpv[n]; n++) {
262	struct dirent *dp = dpv[n];
263
264	if ((xp == NULL) \|\|
265	strcmp(dp->d_name, xp->d_name)) {
266	xp = dp;
267	} else {
268	dp->d_fileno = 0;
269	}
270	if (dp->d_type == DT_WHT &&
271	(dirp->dd_flags & DTF_HIDEW))
272	dp->d_fileno = 0;
273	}
274
275	free(dpv);
276	break;
277	} else {
278	dpv = malloc((n+1) * sizeof(struct dirent *));
279	if (dpv == NULL)
280	break;
281	}
282	}
283
284	dirp->dd_len = len;
285	dirp->dd_size = ddptr - dirp->dd_buf;
286	return (true);
287	}
288
289
23e20b00 A	290	/*
	291	* Common routine for opendir(3), __opendir2(3) and fdopendir(3).
	292	*/
	293	static DIR *
b061a43b	294	__opendir_common(int fd, int flags, bool use_current_pos)
23e20b00 A	295	{
23e20b00 A	296	DIR *dirp;
e9ce8d39	297	int incr;
9385eb3d	298	int saved_errno;
e9ce8d39	299	int unionstack;
e9ce8d39	300
23e20b00	301	if ((dirp = malloc(sizeof(DIR) + sizeof(struct _telldir))) == NULL)
e9ce8d39	302	return (NULL);
9385eb3d	303
b061a43b A	304	dirp->dd_buf = NULL;
	305	dirp->dd_fd = fd;
	306	dirp->dd_flags = flags;
	307	dirp->dd_loc = 0;
	308	dirp->dd_lock = (pthread_mutex_t)PTHREAD_MUTEX_INITIALIZER;
3d9156a7	309	dirp->dd_td = (struct _telldir )((char )dirp + sizeof(DIR));
9385eb3d A	310	LIST_INIT(&dirp->dd_td->td_locq);
9385eb3d A	311	dirp->dd_td->td_loccnt = 0;
e9ce8d39 A	312
e9ce8d39 A	313	/*
9385eb3d	314	* Use the system page size if that is a multiple of DIRBLKSIZ.
e9ce8d39	315	* Hopefully this can be a big win someday by allowing page
9385eb3d	316	* trades to user space to be done by _getdirentries().
e9ce8d39	317	*/
9385eb3d A	318	incr = getpagesize();
9385eb3d A	319	if ((incr % DIRBLKSIZ) != 0)
e9ce8d39 A	320	incr = DIRBLKSIZ;
	321
	322	/*
	323	* Determine whether this directory is the top of a union stack.
	324	*/
	325	if (flags & DTF_NODUP) {
	326	struct statfs sfb;
	327
9385eb3d A	328	if (_fstatfs(fd, &sfb) < 0)
9385eb3d A	329	goto fail;
23e20b00 A	330	unionstack = !strcmp(sfb.f_fstypename, "unionfs")
23e20b00 A	331	\|\| (sfb.f_flags & MNT_UNION);
e9ce8d39 A	332	} else {
	333	unionstack = 0;
	334	}
	335
	336	if (unionstack) {
b061a43b A	337	if (!_filldir(dirp, use_current_pos))
	338	goto fail;
	339	dirp->dd_flags \|= __DTF_READALL;
	340	} else {
	341	dirp->dd_len = incr;
	342	dirp->dd_buf = malloc(dirp->dd_len);
	343	if (dirp->dd_buf == NULL)
	344	goto fail;
	345	if (use_current_pos) {
e9ce8d39	346	/*
b061a43b A	347	* Read the first batch of directory entries
	348	* to prime dd_seek. This also checks if the
	349	* fd passed to fdopendir() is a directory.
e9ce8d39	350	*/
ad3c9f2a	351	#if __DARWIN_64_BIT_INO_T
b061a43b A	352	dirp->dd_size = (long)__getdirentries64(dirp->dd_fd,
b061a43b A	353	dirp->dd_buf, dirp->dd_len, &dirp->dd_td->seekoff);
ad3c9f2a	354	#else /* !__DARWIN_64_BIT_INO_T */
b061a43b A	355	dirp->dd_size = _getdirentries(dirp->dd_fd,
b061a43b A	356	dirp->dd_buf, dirp->dd_len, &dirp->dd_seek);
ad3c9f2a	357	#endif /* __DARWIN_64_BIT_INO_T */
b061a43b A	358	if (dirp->dd_size < 0) {
	359	if (errno == EINVAL)
	360	errno = ENOTDIR;
	361	goto fail;
e9ce8d39	362	}
b061a43b A	363	dirp->dd_flags \|= __DTF_SKIPREAD;
	364	} else {
	365	dirp->dd_size = 0;
ad3c9f2a	366	#if __DARWIN_64_BIT_INO_T
b061a43b	367	dirp->dd_td->seekoff = 0;
ad3c9f2a	368	#else /* !__DARWIN_64_BIT_INO_T */
b061a43b	369	dirp->dd_seek = 0;
ad3c9f2a	370	#endif /* __DARWIN_64_BIT_INO_T */
b061a43b	371	}
e9ce8d39 A	372	}
e9ce8d39 A	373
e9ce8d39	374	return (dirp);
e9ce8d39	375
9385eb3d A	376	fail:
9385eb3d A	377	saved_errno = errno;
b061a43b	378	free(dirp->dd_buf);
9385eb3d	379	free(dirp);
9385eb3d A	380	errno = saved_errno;
9385eb3d A	381	return (NULL);
e9ce8d39	382	}