/*
 * 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 "system.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 */
