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
vxfs_get_fshead(struct vxfs_oltfshead * fshp,struct vxfs_sb_info * infp)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
vxfs_get_ilist(struct vxfs_oltilist * ilistp,struct vxfs_sb_info * infp)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
vxfs_oblock(struct super_block * sbp,daddr_t block,u_long bsize)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
vxfs_read_olt(struct super_block * sbp,u_long bsize)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 }
130