minix/lib/nbsd_libc/gen/initdir.c
Gianluca Guida b87af1c325 Fix stat, add fstat and other NBSD libc fixes.
This patch changes the NBSD libc stat implemenation and adds
fstat (and headers), taken from current libc.
It also adds weaks alias to functions in the resolver that
were removed from public use in NetBSD but that are still
used by Minix, and fixes a NetBSD non-REENTRANT bug in
in gen/initdir.c.
2011-03-04 22:31:31 +00:00

284 lines
6.9 KiB
C

/* $NetBSD: initdir.c,v 1.1 2010/09/26 02:26:59 yamt Exp $ */
/*
* 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.
* 3. 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.
*/
#include <sys/cdefs.h>
#if defined(LIBC_SCCS) && !defined(lint)
__RCSID("$NetBSD: initdir.c,v 1.1 2010/09/26 02:26:59 yamt Exp $");
#endif /* LIBC_SCCS and not lint */
#include "namespace.h"
#ifdef __minix
/* NetBSD BUG on !_REENTRANT */
#include <sys/cdefs.h>
#include <sys/featuretest.h>
#include <sys/types.h>
#endif
#include "reentrant.h"
#include "extern.h"
#include <sys/param.h>
#include <assert.h>
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "dirent_private.h"
#define MAXITERATIONS 100
int
_initdir(DIR *dirp, int fd, const char *name)
{
int flags = dirp->dd_flags;
int pagesz;
int incr;
/*
* If the machine's page size is an exact multiple of DIRBLKSIZ,
* use a buffer that is cluster boundary aligned.
* Hopefully this can be a big win someday by allowing page trades
* to user space to be done by getdents()
*/
if (((pagesz = getpagesize()) % DIRBLKSIZ) == 0)
incr = pagesz;
else
incr = DIRBLKSIZ;
if ((flags & DTF_REWIND) && name == NULL) {
return EINVAL;
}
if ((flags & __DTF_READALL) != 0) {
size_t len;
size_t space;
char *buf, *nbuf;
char *ddptr;
char *ddeptr;
int n;
struct dirent **dpv;
int i;
/*
* The strategy here for directories on top of a union stack
* is to read all the directory entries into a buffer, sort
* the buffer, and remove duplicate entries by setting the
* inode number to zero.
*
* For directories on an NFS mounted filesystem, we try
* to get a consistent snapshot by trying until we have
* successfully read all of the directory without errors
* (i.e. 'bad cookie' errors from the server because
* the directory was modified). These errors should not
* happen often, but need to be dealt with.
*/
i = 0;
retry:
len = 0;
space = 0;
buf = 0;
ddptr = 0;
do {
/*
* Always make at least DIRBLKSIZ bytes
* available to getdents
*/
if (space < DIRBLKSIZ) {
space += incr;
len += incr;
nbuf = realloc(buf, len);
if (nbuf == NULL) {
dirp->dd_buf = buf;
return errno;
}
buf = nbuf;
ddptr = buf + (len - space);
}
dirp->dd_seek = lseek(fd, (off_t)0, SEEK_CUR);
n = getdents(fd, ddptr, space);
/*
* For NFS: EINVAL means a bad cookie error
* from the server. Keep trying to get a
* consistent view, in this case this means
* starting all over again.
*/
if (n == -1 && errno == EINVAL &&
(flags & __DTF_RETRY_ON_BADCOOKIE) != 0) {
free(buf);
lseek(fd, (off_t)0, SEEK_SET);
if (++i > MAXITERATIONS)
return EINVAL;
goto retry;
}
if (n > 0) {
ddptr += n;
space -= n;
}
} while (n > 0);
ddeptr = ddptr;
/*
* Re-open the directory.
* This has the effect of rewinding back to the
* top of the union stack and is needed by
* programs which plan to fchdir to a descriptor
* which has also been read -- see fts.c.
*/
if (flags & DTF_REWIND) {
(void) close(fd);
if ((fd = open(name, O_RDONLY)) == -1 ||
fcntl(fd, F_SETFD, FD_CLOEXEC) == -1) {
dirp->dd_buf = buf;
return errno;
}
}
/*
* 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.
*/
if ((flags & DTF_NODUP) != 0) {
for (dpv = 0;;) {
for (n = 0, ddptr = buf; ddptr < ddeptr;) {
struct dirent *dp;
dp = (struct dirent *)(void *)ddptr;
if ((long)dp & _DIRENT_ALIGN(dp))
break;
/*
* d_reclen is unsigned,
* so no need to compare <= 0
*/
if (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, (size_t)n, sizeof(*dpv),
alphasort);
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;
#ifndef __minix
if (dp->d_type == DT_WHT &&
(flags & DTF_HIDEW))
dp->d_fileno = 0;
#endif
}
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;
} else {
dirp->dd_len = incr;
dirp->dd_buf = malloc((size_t)dirp->dd_len);
if (dirp->dd_buf == NULL)
return errno;
dirp->dd_seek = 0;
flags &= ~DTF_REWIND;
}
dirp->dd_loc = 0;
dirp->dd_fd = fd;
dirp->dd_flags = flags;
/*
* Set up seek point for rewinddir.
*/
(void)_telldir_unlocked(dirp);
return 0;
}
void
_finidir(DIR *dirp)
{
struct dirpos *poslist;
free(dirp->dd_buf);
/* free seekdir/telldir storage */
for (poslist = dirp->dd_internal; poslist; ) {
struct dirpos *nextpos = poslist->dp_next;
free(poslist);
poslist = nextpos;
}
dirp->dd_internal = NULL;
}