uclibc-ng/libc/misc/statfs/internal_statvfs.c

/* Copyright (C) 1998, 1999, 2000, 2001 Free Software Foundation, Inc.
   This file is part of the GNU C Library.
   Contributed by Ulrich Drepper <drepper@cygnus.com>, 1998.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, see
   <http://www.gnu.org/licenses/>.  */

/* The kernel hints us if the f_flags is valid  */
#define ST_VALID 0x0020

  /* Now fill in the fields we have information for.  */
  buf->f_bsize = fsbuf.f_bsize;
#ifdef _STATFS_F_FRSIZE
  buf->f_frsize = fsbuf.f_frsize;
#else
  /* No support for f_frsize so set it to the full block size.  */
  buf->f_frsize = fsbuf.f_bsize;
#endif
  buf->f_blocks = fsbuf.f_blocks;
  buf->f_bfree = fsbuf.f_bfree;
  buf->f_bavail = fsbuf.f_bavail;
  buf->f_files = fsbuf.f_files;
  buf->f_ffree = fsbuf.f_ffree;
  if (sizeof (buf->f_fsid) == sizeof (fsbuf.f_fsid))
    buf->f_fsid = (fsbuf.f_fsid.__val[0]
		   | ((unsigned long long int) fsbuf.f_fsid.__val[1]
		      << (8 * (sizeof (buf->f_fsid)
			       - sizeof (fsbuf.f_fsid.__val[0])))));
  else
    /* We cannot help here.  The statvfs element is not large enough to
       contain both words of the statfs f_fsid field.  */
    buf->f_fsid = fsbuf.f_fsid.__val[0];
#ifdef _STATVFSBUF_F_UNUSED
  buf->__f_unused = 0;
#endif
  buf->f_namemax = fsbuf.f_namelen;
  memset (buf->__f_spare, '\0', sizeof(buf->__f_spare));
  /* XXX I have no idea how to compute f_favail.  Any idea???  */
  buf->f_favail = buf->f_ffree;

  /* Determining the flags is tricky.  We have to read /proc/mounts or
     the /etc/mtab file and search for the entry which matches the given
     file.  The way we can test for matching filesystem is using the
     device number.  */
  buf->f_flag = 0;
  if (STAT (&st) >= 0
#ifdef _STATFS_F_FLAGS
	  && (fsbuf.f_flags & ST_VALID) == 0
#endif
	 ) {
	  int save_errno = errno;
	  struct mntent mntbuf;
	  FILE *mtab;

	  mtab = setmntent ("/proc/mounts", "r");
	  if (mtab == NULL)
		mtab = setmntent (_PATH_MOUNTED, "r");
	  if (mtab != NULL) {
		char tmpbuf[1024];

		while (getmntent_r (mtab, &mntbuf, tmpbuf, sizeof (tmpbuf))) {
		  struct stat fsst;

		  /* Find out about the device the current entry is for.  */
		  if (stat (mntbuf.mnt_dir, &fsst) >= 0
			  && st.st_dev == fsst.st_dev) {
			  /* Bingo, we found the entry for the device FD is on.
				 Now interpret the option string.  */
			  char *cp = mntbuf.mnt_opts;
			  char *opt;

			  while ((opt = strsep (&cp, ",")) != NULL)
				if (strcmp (opt, "ro") == 0)
				  buf->f_flag |= ST_RDONLY;
				else if (strcmp (opt, "nosuid") == 0)
				  buf->f_flag |= ST_NOSUID;
#ifdef __USE_GNU
				else if (strcmp (opt, "noexec") == 0)
				  buf->f_flag |= ST_NOEXEC;
				else if (strcmp (opt, "nodev") == 0)
				  buf->f_flag |= ST_NODEV;
				else if (strcmp (opt, "sync") == 0)
				  buf->f_flag |= ST_SYNCHRONOUS;
				else if (strcmp (opt, "mand") == 0)
				  buf->f_flag |= ST_MANDLOCK;
				else if (strcmp (opt, "noatime") == 0)
				  buf->f_flag |= ST_NOATIME;
				else if (strcmp (opt, "nodiratime") == 0)
				  buf->f_flag |= ST_NODIRATIME;
				else if (strcmp (opt, "relatime") == 0)
				  buf->f_flag |= ST_RELATIME;
#endif
			  /* We can stop looking for more entries.  */
			  break;
		  }
		}
		/* Close the file.  */
		endmntent (mtab);
	  }
	  __set_errno (save_errno);
  }
#ifdef _STATFS_F_FLAGS
	else
	  buf->f_flag = fsbuf.f_flags ^ ST_VALID;
#endif