aboutsummaryrefslogtreecommitdiffstats
path: root/fs/freevxfs/vxfs_olt.c
blob: 76a0708ae9789b018335a4fc4bec6a789eb330f3 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
/*
 * Copyright (c) 2000-2001 Christoph Hellwig.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions, and the following disclaimer,
 *    without modification.
 * 2. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * Alternatively, this software may be distributed under the terms of the
 * GNU General Public License ("GPL").
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

/* 
 * Veritas filesystem driver - object location table support.
 */
#include <linux/fs.h>
#include <linux/buffer_head.h>
#include <linux/kernel.h>

#include "vxfs.h"
#include "vxfs_olt.h"
#include "vxfs_extern.h"


static inline void
vxfs_get_fshead(struct vxfs_oltfshead *fshp, struct vxfs_sb_info *infp)
{
	if (infp->vsi_fshino)
		BUG();
	infp->vsi_fshino = fshp->olt_fsino[0];
}

static inline void
vxfs_get_ilist(struct vxfs_oltilist *ilistp, struct vxfs_sb_info *infp)
{
	if (infp->vsi_iext)
		BUG();
	infp->vsi_iext = ilistp->olt_iext[0]; 
}

static inline u_long
vxfs_oblock(struct super_block *sbp, daddr_t block, u_long bsize)
{
	if (sbp->s_blocksize % bsize)
		BUG();
	return (block * (sbp->s_blocksize / bsize));
}


/**
 * vxfs_read_olt - read olt
 * @sbp:	superblock of the filesystem
 * @bsize:	blocksize of the filesystem
 *
 * Description:
 *   vxfs_read_olt reads the olt of the filesystem described by @sbp
 *   into main memory and does some basic setup.
 *
 * Returns:
 *   Zero on success, else a negative error code.
 */
int
vxfs_read_olt(struct super_block *sbp, u_long bsize)
{
	struct vxfs_sb_info	*infp = VXFS_SBI(sbp);
	struct buffer_head	*bp;
	struct vxfs_olt		*op;
	char			*oaddr, *eaddr;


	bp = sb_bread(sbp, vxfs_oblock(sbp, infp->vsi_oltext, bsize));
	if (!bp || !bp->b_data)
		goto fail;

	op = (struct vxfs_olt *)bp->b_data;
	if (op->olt_magic != VXFS_OLT_MAGIC) {
		printk(KERN_NOTICE "vxfs: ivalid olt magic number\n");
		goto fail;
	}

	/*
	 * It is in theory possible that vsi_oltsize is > 1.
	 * I've not seen any such filesystem yet and I'm lazy..  --hch
	 */
	if (infp->vsi_oltsize > 1) {
		printk(KERN_NOTICE "vxfs: oltsize > 1 detected.\n");
		printk(KERN_NOTICE "vxfs: please notify hch@infradead.org\n");
		goto fail;
	}

	oaddr = bp->b_data + op->olt_size;
	eaddr = bp->b_data + (infp->vsi_oltsize * sbp->s_blocksize);

	while (oaddr < eaddr) {
		struct vxfs_oltcommon	*ocp =
			(struct vxfs_oltcommon *)oaddr;
		
		switch (ocp->olt_type) {
		case VXFS_OLT_FSHEAD:
			vxfs_get_fshead((struct vxfs_oltfshead *)oaddr, infp);
			break;
		case VXFS_OLT_ILIST:
			vxfs_get_ilist((struct vxfs_oltilist *)oaddr, infp);
			break;
		}

		oaddr += ocp->olt_size;
	}

	brelse(bp);
	return 0;

fail:
	brelse(bp);
	return -EINVAL;
}