lib/libc/gen/getmntinfo.c

   1 /*      $NetBSD: getmntinfo.c,v 1.17 2012/03/20 16:36:05 matt Exp $     */
   2
   3 /*
   4  * Copyright (c) 1989, 1993
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   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.
  18  *
  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.
  30  */
  31
  32 #include <sys/cdefs.h>
  33 #if defined(LIBC_SCCS) && !defined(lint)
  34 #if 0
  35 static char sccsid[] = "@(#)getmntinfo.c        8.1 (Berkeley) 6/4/93";
  36 #else
  37 __RCSID("$NetBSD: getmntinfo.c,v 1.17 2012/03/20 16:36:05 matt Exp $");
  38 #endif
  39 #endif /* LIBC_SCCS and not lint */
  40
  41 #include "namespace.h"
  42 #include <sys/param.h>
  43 #include <sys/ucred.h>
  44 #include <sys/mount.h>
  45
  46 #include <assert.h>
  47 #include <errno.h>
  48 #include <stdlib.h>
  49
  50 /*
  51  * Return information about mounted filesystems.
  52  */
  53 int
  54 getmntinfo(struct statvfs **mntbufp, int flags)
  55 {
  56         static struct statvfs *mntbuf;
  57         static int mntsize;
  58         static size_t bufsize;
  59
  60         _DIAGASSERT(mntbufp != NULL);
  61
  62         if (mntsize <= 0 &&
  63             (mntsize = getvfsstat(NULL, (size_t)0, MNT_NOWAIT)) == -1)
  64                 return (0);
  65         if (bufsize > 0 &&
  66             (mntsize = getvfsstat(mntbuf, bufsize, flags)) == -1)
  67                 return (0);
  68         while (bufsize <= mntsize * sizeof(struct statvfs)) {
  69                 if (mntbuf)
  70                         free(mntbuf);
  71                 bufsize = (mntsize + 1) * sizeof(struct statvfs);
  72                 if ((mntbuf = malloc(bufsize)) == NULL)
  73                         return (0);
  74                 if ((mntsize = getvfsstat(mntbuf, bufsize, flags)) == -1)
  75                         return (0);
  76         }
  77         *mntbufp = mntbuf;
  78         return (mntsize);
  79 }