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
42 static inline void
43 vxfs_get_fshead(struct vxfs_oltfshead *fshp, struct vxfs_sb_info *infp)
44 {
45 BUG_ON(infp->vsi_fshino);
46 infp->vsi_fshino = fs32_to_cpu(infp, fshp->olt_fsino[0]);
47 }
48
49 static inline void
50 vxfs_get_ilist(struct vxfs_oltilist *ilistp, struct vxfs_sb_info *infp)
51 {
52 BUG_ON(infp->vsi_iext);
53 infp->vsi_iext = fs32_to_cpu(infp, ilistp->olt_iext[0]);
54 }
55
56 static inline u_long
57 vxfs_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 */
76 int
77 vxfs_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 bp = sb_bread(sbp, vxfs_oblock(sbp, infp->vsi_oltext, bsize));
85 if (!bp || !bp->b_data)
86 goto fail;
87
88 op = (struct vxfs_olt *)bp->b_data;
89 if (fs32_to_cpu(infp, op->olt_magic) != VXFS_OLT_MAGIC) {
90 printk(KERN_NOTICE "vxfs: ivalid olt magic number\n");
91 goto fail;
92 }
93
94 /*
95 * It is in theory possible that vsi_oltsize is > 1.
96 * I've not seen any such filesystem yet and I'm lazy.. --hch
97 */
98 if (infp->vsi_oltsize > 1) {
99 printk(KERN_NOTICE "vxfs: oltsize > 1 detected.\n");
100 printk(KERN_NOTICE "vxfs: please notify hch@infradead.org\n");
101 goto fail;
102 }
103
104 oaddr = bp->b_data + fs32_to_cpu(infp, op->olt_size);
105 eaddr = bp->b_data + (infp->vsi_oltsize * sbp->s_blocksize);
106
107 while (oaddr < eaddr) {
108 struct vxfs_oltcommon *ocp =
109 (struct vxfs_oltcommon *)oaddr;
110
111 switch (fs32_to_cpu(infp, ocp->olt_type)) {
112 case VXFS_OLT_FSHEAD:
113 vxfs_get_fshead((struct vxfs_oltfshead *)oaddr, infp);
114 break;
115 case VXFS_OLT_ILIST:
116 vxfs_get_ilist((struct vxfs_oltilist *)oaddr, infp);
117 break;
118 }
119
120 oaddr += fs32_to_cpu(infp, ocp->olt_size);
121 }
122
123 brelse(bp);
124 return (infp->vsi_fshino && infp->vsi_iext) ? 0 : -EINVAL;
125
126 fail:
127 brelse(bp);
128 return -EINVAL;
129 }