void
rewinddir(DIR *dirp)
{
if (__isthreaded)
_pthread_mutex_lock(&dirp->dd_lock);
dirp->dd_flags &= ~__DTF_SKIPREAD; /* current contents are invalid */
if (dirp->dd_flags & __DTF_READALL)
_filldir(dirp, false);
else {
(void) lseek(dirp->dd_fd, 0, SEEK_SET);
dirp->dd_seek = 0;
}
dirp->dd_loc = 0;
_reclaim_telldir(dirp);
if (__isthreaded)
_pthread_mutex_unlock(&dirp->dd_lock);
}
/*
* 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 = NULL;
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.
*/
dirp->dd_size = _getdirentries(dirp->dd_fd,
dirp->dd_buf, dirp->dd_len, &dirp->dd_seek);
if (dirp->dd_size < 0) {
if (errno == EINVAL)
errno = ENOTDIR;
goto fail;
}
dirp->dd_flags |= __DTF_SKIPREAD;
} else {
dirp->dd_size = 0;
dirp->dd_seek = 0;
}
}
return (dirp);
fail:
saved_errno = errno;
free(dirp->dd_buf);
free(dirp);
errno = saved_errno;
return (NULL);
}