ext2fs_df.c revision 1.12 
1/*	$OpenBSD: ext2fs_df.c,v 1.12 2015/01/16 06:39:31 deraadt Exp $	*/
2
3/*
4 * This file is substantially derived from src/sys/ufs/ext2fs/ext2fs_vfsops.c:e2fs_statfs().
5 * That file's copyright is applied here.
6 */
7
8/* Modified for EXT2FS on NetBSD by Manuel Bouyer, April 1997 */
9
10/*
11 * Copyright (c) 1989, 1991, 1993, 1994
12 *      The Regents of the University of California.  All rights reserved.
13 *
14 * Redistribution and use in source and binary forms, with or without
15 * modification, are permitted provided that the following conditions
16 * are met:
17 * 1. Redistributions of source code must retain the above copyright
18 *      notice, this list of conditions and the following disclaimer.
19 * 2. Redistributions in binary form must reproduce the above copyright
20 *      notice, this list of conditions and the following disclaimer in the
21 *      documentation and/or other materials provided with the distribution.
22 * 3. Neither the name of the University nor the names of its contributors
23 *      may be used to endorse or promote products derived from this software
24 *      without specific prior written permission.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 * SUCH DAMAGE.
37 *
38 *	@(#)ffs_vfsops.c	8.14 (Berkeley) 11/28/94
39 */
40
41#include <sys/types.h>
42#include <sys/mount.h>
43#include <ufs/ext2fs/ext2fs.h>
44#include <ufs/ext2fs/ext2fs_dinode.h>
45#include <unistd.h>
46#include <stdlib.h>
47#include <string.h>
48#include <fcntl.h>
49#include <fstab.h>
50
51int		e2fs_df(int, char *, struct statfs *);
52
53extern int	bread(int, off_t, void *, int);
54extern char	*getmntpt(char *);
55
56static union {
57	struct ext2fs ie_fs;
58	char dummy[SBSIZE];
59} sb;
60#define sblock sb.ie_fs
61
62int
63e2fs_df(int rfd, char *file, struct statfs *sfsp)
64{
65	char *mntpt;
66	u_int32_t overhead, overhead_per_group;
67	int32_t	ncg, ngdb, ipb, itpg;
68
69	if (bread(rfd, (off_t)SBOFF, &sblock, SBSIZE) == 0) {
70		return (-1);
71	}
72	if ((sblock.e2fs_magic != E2FS_MAGIC) ||
73	    (sblock.e2fs_rev != E2FS_REV0 && sblock.e2fs_rev != E2FS_REV1)) {
74		return (-1);
75	}
76	sfsp->f_flags = 0;	/* The fs is not mapped, so no flags */
77	sfsp->f_bsize = 1024 << sblock.e2fs_log_bsize;
78	sfsp->f_iosize = 1024 << sblock.e2fs_log_bsize;
79
80	ipb = sfsp->f_bsize / sizeof(struct ext2fs_dinode);
81	itpg = sblock.e2fs_ipg/ipb;
82
83	ncg = howmany(sblock.e2fs_bcount - sblock.e2fs_first_dblock,
84		sblock.e2fs_bpg);
85	ngdb = howmany(ncg, sfsp->f_bsize / sizeof(struct ext2_gd));
86	overhead_per_group = 1 /* super block */ +
87					ngdb +
88					1 /* block bitmap */ +
89					1 /* inode bitmap */ +
90					itpg;
91	overhead = sblock.e2fs_first_dblock + ncg * overhead_per_group;
92
93	sfsp->f_blocks = sblock.e2fs_bcount - overhead;
94	sfsp->f_bfree = sblock.e2fs_fbcount;
95	sfsp->f_bavail = sfsp->f_bfree - sblock.e2fs_rbcount;
96	sfsp->f_files = sblock.e2fs_icount;
97	sfsp->f_ffree = sblock.e2fs_ficount;
98	sfsp->f_fsid.val[0] = 0;
99	sfsp->f_fsid.val[1] = 0;
100	if ((mntpt = getmntpt(file)) == 0)
101		mntpt = "";
102	memmove(&sfsp->f_mntonname[0], mntpt, MNAMELEN);
103	memmove(&sfsp->f_mntfromname[0], file, MNAMELEN);
104	strlcpy(sfsp->f_fstypename, MOUNT_EXT2FS, MFSNAMELEN);
105	return (0);
106}
107