1/*
2 * Copyright (c) 2000-2001 Christoph Hellwig.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions, and the following disclaimer,
10 *    without modification.
11 * 2. The name of the author may not be used to endorse or promote products
12 *    derived from this software without specific prior written permission.
13 *
14 * Alternatively, this software may be distributed under the terms of the
15 * GNU General Public License ("GPL").
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
21 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30/*
31 * Veritas filesystem driver - object location table support.
32 */
33#include <linux/fs.h>
34#include <linux/buffer_head.h>
35#include <linux/kernel.h>
36
37#include "vxfs.h"
38#include "vxfs_olt.h"
39#include "vxfs_extern.h"
40
41
42static inline void
43vxfs_get_fshead(struct vxfs_oltfshead *fshp, struct vxfs_sb_info *infp)
44{
45	BUG_ON(infp->vsi_fshino);
46	infp->vsi_fshino = fshp->olt_fsino[0];
47}
48
49static inline void
50vxfs_get_ilist(struct vxfs_oltilist *ilistp, struct vxfs_sb_info *infp)
51{
52	BUG_ON(infp->vsi_iext);
53	infp->vsi_iext = ilistp->olt_iext[0];
54}
55
56static inline u_long
57vxfs_oblock(struct super_block *sbp, daddr_t block, u_long bsize)
58{
59	BUG_ON(sbp->s_blocksize % bsize);
60	return (block * (sbp->s_blocksize / bsize));
61}
62
63
64/**
65 * vxfs_read_olt - read olt
66 * @sbp:	superblock of the filesystem
67 * @bsize:	blocksize of the filesystem
68 *
69 * Description:
70 *   vxfs_read_olt reads the olt of the filesystem described by @sbp
71 *   into main memory and does some basic setup.
72 *
73 * Returns:
74 *   Zero on success, else a negative error code.
75 */
76int
77vxfs_read_olt(struct super_block *sbp, u_long bsize)
78{
79	struct vxfs_sb_info	*infp = VXFS_SBI(sbp);
80	struct buffer_head	*bp;
81	struct vxfs_olt		*op;
82	char			*oaddr, *eaddr;
83
84
85	bp = sb_bread(sbp, vxfs_oblock(sbp, infp->vsi_oltext, bsize));
86	if (!bp || !bp->b_data)
87		goto fail;
88
89	op = (struct vxfs_olt *)bp->b_data;
90	if (op->olt_magic != VXFS_OLT_MAGIC) {
91		printk(KERN_NOTICE "vxfs: ivalid olt magic number\n");
92		goto fail;
93	}
94
95	/*
96	 * It is in theory possible that vsi_oltsize is > 1.
97	 * I've not seen any such filesystem yet and I'm lazy..  --hch
98	 */
99	if (infp->vsi_oltsize > 1) {
100		printk(KERN_NOTICE "vxfs: oltsize > 1 detected.\n");
101		printk(KERN_NOTICE "vxfs: please notify hch@infradead.org\n");
102		goto fail;
103	}
104
105	oaddr = bp->b_data + op->olt_size;
106	eaddr = bp->b_data + (infp->vsi_oltsize * sbp->s_blocksize);
107
108	while (oaddr < eaddr) {
109		struct vxfs_oltcommon	*ocp =
110			(struct vxfs_oltcommon *)oaddr;
111
112		switch (ocp->olt_type) {
113		case VXFS_OLT_FSHEAD:
114			vxfs_get_fshead((struct vxfs_oltfshead *)oaddr, infp);
115			break;
116		case VXFS_OLT_ILIST:
117			vxfs_get_ilist((struct vxfs_oltilist *)oaddr, infp);
118			break;
119		}
120
121		oaddr += ocp->olt_size;
122	}
123
124	brelse(bp);
125	return 0;
126
127fail:
128	brelse(bp);
129	return -EINVAL;
130}
131