/* fsusage.c -- return space usage of mounted filesystems
   Copyright (C) 1991, 1992 Free Software Foundation, Inc.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2, or (at your option)
   any later version.

   This program 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 General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */

#include <sys/types.h>
#include "fsusage.h"

int statfs ();

#if defined (STATFS_OSF1)	/* DEC Alpha running OSF/1 */
#  include <sys/mount.h>
#endif

#if defined(STAT_STATFS2_BSIZE) && !defined(_IBMR2) /* 4.3BSD, SunOS 4, HP-UX, AIX PS/2.  */
#include <sys/vfs.h>
#endif

#ifdef STAT_STATFS2_FSIZE	/* 4.4BSD.  */
#include <sys/mount.h>
#endif

#ifdef STAT_STATFS2_FS_DATA	/* Ultrix.  */
#include <sys/param.h>
#include <sys/mount.h>
#endif

#ifdef STAT_READ		/* SVR2.  */
#include <sys/param.h>
#include <sys/filsys.h>
#include <fcntl.h>
#endif

#if defined(STAT_STATFS4) || (defined(_AIX) && defined(_IBMR2)) /* SVR3, Dynix, Irix, AIX RS6000.  */
#include <sys/statfs.h>
#endif

#if defined(_AIX) && defined(_I386) /* AIX PS/2.  */
#include <sys/stat.h>
#include <sys/dustat.h>
#endif

#ifdef STAT_STATVFS		/* SVR4.  */
#include <sys/statvfs.h>
int statvfs ();
#endif

/* Return the number of TOSIZE-byte blocks used by
   BLOCKS FROMSIZE-byte blocks, rounding up.  */

static long
adjust_blocks (blocks, fromsize, tosize)
     long blocks;
     int fromsize, tosize;
{
  if (fromsize == tosize)	/* E.g., from 512 to 512.  */
    return blocks;
  else if (fromsize > tosize)	/* E.g., from 2048 to 512.  */
    return blocks * (fromsize / tosize);
  else				/* E.g., from 256 to 512.  */
    return (blocks + 1) / (tosize / fromsize);
}

/* Fill in the fields of FSP with information about space usage for
   the filesystem on which PATH resides.
   DISK is the device on which PATH is mounted, for space-getting
   methods that need to know it.
   Return 0 if successful, -1 if not. */

int
get_fs_usage (path, disk, fsp)
     char *path, *disk;
     struct fs_usage *fsp;
{
#if defined (STATFS_OSF1)
  struct statfs fsd;

  if (statfs (path, &fsd, sizeof (struct statfs)) != 0)
    return (-1);
#define convert_blocks(b) adjust_blocks ((b),fsd.f_fsize, 512)
#endif /* STATFS_OSF1 */

#ifdef STAT_STATFS2_FS_DATA	/* Ultrix.  */
  struct fs_data fsd;

  if (statfs (path, &fsd) != 1)
    return -1;
#define convert_blocks(b) adjust_blocks ((b), 1024, 512)
  fsp->fsu_blocks = convert_blocks (fsd.fd_req.btot);
  fsp->fsu_bfree = convert_blocks (fsd.fd_req.bfree);
  fsp->fsu_bavail = convert_blocks (fsd.fd_req.bfreen);
  fsp->fsu_files = fsd.fd_req.gtot;
  fsp->fsu_ffree = fsd.fd_req.gfree;
#endif

#ifdef STAT_READ		/* SVR2.  */
#ifndef SUPERBOFF
#define SUPERBOFF (SUPERB * 512)
#endif
  struct filsys fsd;
  int fd;

  fd = open (disk, O_RDONLY);
  if (fd < 0)
    return -1;
  lseek (fd, (long) SUPERBOFF, 0);
  if (read (fd, (char *) &fsd, sizeof fsd) != sizeof fsd)
    {
      close (fd);
      return -1;
    }
  close (fd);
#define convert_blocks(b) adjust_blocks ((b), (fsd.s_type == Fs2b ? 1024 : 512), 512)
  fsp->fsu_blocks = convert_blocks (fsd.s_fsize);
  fsp->fsu_bfree = convert_blocks (fsd.s_tfree);
  fsp->fsu_bavail = convert_blocks (fsd.s_tfree);
  fsp->fsu_files = (fsd.s_isize - 2) * INOPB * (fsd.s_type == Fs2b ? 2 : 1);
  fsp->fsu_ffree = fsd.s_tinode;
#endif

#ifdef STAT_STATFS2_BSIZE	/* 4.3BSD, SunOS 4, HP-UX, AIX.  */
  struct statfs fsd;

  if (statfs (path, &fsd) < 0)
    return -1;
#define convert_blocks(b) adjust_blocks ((b), fsd.f_bsize, 512)
#endif

#ifdef STAT_STATFS2_FSIZE	/* 4.4BSD.  */
  struct statfs fsd;

  if (statfs (path, &fsd) < 0)
    return -1;
#define convert_blocks(b) adjust_blocks ((b), fsd.f_fsize, 512)
#endif

#ifdef STAT_STATFS4		/* SVR3, Dynix, Irix.  */
  struct statfs fsd;

  if (statfs (path, &fsd, sizeof fsd, 0) < 0)
    return -1;
  /* Empirically, the block counts on most SVR3 and SVR3-derived
     systems seem to always be in terms of 512-byte blocks,
     no matter what value f_bsize has.  */
#define convert_blocks(b) (b)
#ifndef _SEQUENT_		/* _SEQUENT_ is DYNIX/ptx.  */
#ifndef DOLPHIN			/* DOLPHIN 3.8.alfa/7.18 has f_bavail */
#define f_bavail f_bfree
#endif
#endif
#endif

#ifdef STAT_STATVFS		/* SVR4.  */
  struct statvfs fsd;

  if (statvfs (path, &fsd) < 0)
    return -1;
  /* f_frsize isn't guaranteed to be supported.  */
#define convert_blocks(b) \
  adjust_blocks ((b), fsd.f_frsize ? fsd.f_frsize : fsd.f_bsize, 512)
#endif

#if !defined(STAT_STATFS2_FS_DATA) && !defined(STAT_READ) /* !Ultrix && !SVR2.  */
  fsp->fsu_blocks = convert_blocks (fsd.f_blocks);
  fsp->fsu_bfree = convert_blocks (fsd.f_bfree);
  fsp->fsu_bavail = convert_blocks (fsd.f_bavail);
  fsp->fsu_files = fsd.f_files;
  fsp->fsu_ffree = fsd.f_ffree;
#endif

  return 0;
}

#if defined(_AIX) && defined(_I386)
/* AIX PS/2 does not supply statfs.  */

int
statfs (path, fsb)
     char *path;
     struct statfs *fsb;
{
  struct stat stats;
  struct dustat fsd;

  if (stat (path, &stats))
    return -1;
  if (dustat (stats.st_dev, 0, &fsd, sizeof (fsd)))
    return -1;
  fsb->f_type   = 0;
  fsb->f_bsize  = fsd.du_bsize;
  fsb->f_blocks = fsd.du_fsize - fsd.du_isize;
  fsb->f_bfree  = fsd.du_tfree;
  fsb->f_bavail = fsd.du_tfree;
  fsb->f_files  = (fsd.du_isize - 2) * fsd.du_inopb;
  fsb->f_ffree  = fsd.du_tinode;
  fsb->f_fsid.val[0] = fsd.du_site;
  fsb->f_fsid.val[1] = fsd.du_pckno;
  return 0;
}
#endif /* _AIX && _I386 */