sysdeps/unix/sysv/linux/internal_statvfs.c

   1 /* Copyright (C) 1998, 1999, 2000 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1998.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Library General Public License as
   7    published by the Free Software Foundation; either version 2 of the
   8    License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Library General Public License for more details.
  14
  15    You should have received a copy of the GNU Library General Public
  16    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  17    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  18    Boston, MA 02111-1307, USA.  */
  19
  20   /* Now fill in the fields we have information for.  */
  21   buf->f_bsize = fsbuf.f_bsize;
  22   /* Linux does not support f_frsize, so set it to the full block size.  */
  23   buf->f_frsize = fsbuf.f_bsize;
  24   buf->f_blocks = fsbuf.f_blocks;
  25   buf->f_bfree = fsbuf.f_bfree;
  26   buf->f_bavail = fsbuf.f_bavail;
  27   buf->f_files = fsbuf.f_files;
  28   buf->f_ffree = fsbuf.f_ffree;
  29   buf->f_fsid = fsbuf.f_fsid;
  30   buf->f_namemax = fsbuf.f_namelen;
  31   memset (buf->f_spare, '\0', 6 * sizeof (int));
  32
  33   /* What remains to do is to fill the fields f_favail and f_flag.  */
  34
  35   /* XXX I have no idea how to compute f_favail.  Any idea???  */
  36   buf->f_favail = buf->f_ffree;
  37
  38   /* Determining the flags is tricky.  We have to read /proc/mounts or
  39      the /etc/mtab file and search for the entry which matches the given
  40      file.  The way we can test for matching filesystem is using the
  41      device number.  */
  42   buf->f_flag = 0;
  43   if (STAT (&st) >= 0)
  44     {
  45       int save_errno = errno;
  46       struct mntent mntbuf;
  47       FILE *mtab;
  48
  49       mtab = __setmntent ("/proc/mounts", "r");
  50       if (mtab == NULL)
  51         mtab = __setmntent (_PATH_MOUNTED, "r");
  52
  53       if (mtab != NULL)
  54         {
  55           char tmpbuf[1024];
  56
  57           while (__getmntent_r (mtab, &mntbuf, tmpbuf, sizeof (tmpbuf)))
  58             {
  59               struct stat fsst;
  60
  61               /* Find out about the device the current entry is for.  */
  62               if (stat (mntbuf.mnt_dir, &fsst) >= 0
  63                   && st.st_dev == fsst.st_dev)
  64                 {
  65                   /* Bingo, we found the entry for the device FD is on.
  66                      Now interpret the option string.  */
  67                   char *cp = mntbuf.mnt_opts;
  68                   char *opt;
  69
  70                   while ((opt = strsep (&cp, ",")) != NULL)
  71                     if (strcmp (opt, "ro") == 0)
  72                       buf->f_flag |= ST_RDONLY;
  73                     else if (strcmp (opt, "nosuid") == 0)
  74                       buf->f_flag |= ST_NOSUID;
  75                     else if (strcmp (opt, "noexec") == 0)
  76                       buf->f_flag |= ST_NOEXEC;
  77                     else if (strcmp (opt, "nodev") == 0)
  78                       buf->f_flag |= ST_NODEV;
  79                     else if (strcmp (opt, "sync") == 0)
  80                       buf->f_flag |= ST_SYNCHRONOUS;
  81                     else if (strcmp (opt, "mand") == 0)
  82                       buf->f_flag |= ST_MANDLOCK;
  83                     else if (strcmp (opt, "noatime") == 0)
  84                       buf->f_flag |= ST_NOATIME;
  85                     else if (strcmp (opt, "nodiratime") == 0)
  86                       buf->f_flag |= ST_NODIRATIME;
  87
  88                   /* We can stop looking for more entries.  */
  89                   break;
  90                 }
  91             }
  92
  93           /* Close the file.  */
  94           __endmntent (mtab);
  95         }
  96
  97       __set_errno (save_errno);
  98     }