1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (c) 2000-2001 Christoph Hellwig.
4 */
5
6 /*
7 * Veritas filesystem driver - object location table support.
8 */
9 #include <linux/fs.h>
10 #include <linux/buffer_head.h>
11 #include <linux/kernel.h>
12
13 #include "vxfs.h"
14 #include "vxfs_olt.h"
15 #include "vxfs_extern.h"
16
17
18 static inline void
19 vxfs_get_fshead(struct vxfs_oltfshead *fshp, struct vxfs_sb_info *infp)
20 {
21 BUG_ON(infp->vsi_fshino);
22 infp->vsi_fshino = fs32_to_cpu(infp, fshp->olt_fsino[0]);
23 }
24
25 static inline void
26 vxfs_get_ilist(struct vxfs_oltilist *ilistp, struct vxfs_sb_info *infp)
27 {
28 BUG_ON(infp->vsi_iext);
29 infp->vsi_iext = fs32_to_cpu(infp, ilistp->olt_iext[0]);
30 }
31
32 static inline u_long
33 vxfs_oblock(struct super_block *sbp, daddr_t block, u_long bsize)
34 {
35 BUG_ON(sbp->s_blocksize % bsize);
36 return (block * (sbp->s_blocksize / bsize));
37 }
38
39
40 /**
41 * vxfs_read_olt - read olt
42 * @sbp: superblock of the filesystem
43 * @bsize: blocksize of the filesystem
44 *
45 * Description:
46 * vxfs_read_olt reads the olt of the filesystem described by @sbp
47 * into main memory and does some basic setup.
48 *
49 * Returns:
50 * Zero on success, else a negative error code.
51 */
52 int
53 vxfs_read_olt(struct super_block *sbp, u_long bsize)
54 {
55 struct vxfs_sb_info *infp = VXFS_SBI(sbp);
56 struct buffer_head *bp;
57 struct vxfs_olt *op;
58 char *oaddr, *eaddr;
59
60 bp = sb_bread(sbp, vxfs_oblock(sbp, infp->vsi_oltext, bsize));
61 if (!bp || !bp->b_data)
62 goto fail;
63
64 op = (struct vxfs_olt *)bp->b_data;
65 if (fs32_to_cpu(infp, op->olt_magic) != VXFS_OLT_MAGIC) {
66 printk(KERN_NOTICE "vxfs: ivalid olt magic number\n");
67 goto fail;
68 }
69
70 /*
71 * It is in theory possible that vsi_oltsize is > 1.
72 * I've not seen any such filesystem yet and I'm lazy.. --hch
73 */
74 if (infp->vsi_oltsize > 1) {
75 printk(KERN_NOTICE "vxfs: oltsize > 1 detected.\n");
76 printk(KERN_NOTICE "vxfs: please notify hch@infradead.org\n");
77 goto fail;
78 }
79
80 oaddr = bp->b_data + fs32_to_cpu(infp, op->olt_size);
81 eaddr = bp->b_data + (infp->vsi_oltsize * sbp->s_blocksize);
82
83 while (oaddr < eaddr) {
84 struct vxfs_oltcommon *ocp =
85 (struct vxfs_oltcommon *)oaddr;
86
87 switch (fs32_to_cpu(infp, ocp->olt_type)) {
88 case VXFS_OLT_FSHEAD:
89 vxfs_get_fshead((struct vxfs_oltfshead *)oaddr, infp);
90 break;
91 case VXFS_OLT_ILIST:
92 vxfs_get_ilist((struct vxfs_oltilist *)oaddr, infp);
93 break;
94 }
95
96 oaddr += fs32_to_cpu(infp, ocp->olt_size);
97 }
98
99 brelse(bp);
100 return (infp->vsi_fshino && infp->vsi_iext) ? 0 : -EINVAL;
101
102 fail:
103 brelse(bp);
104 return -EINVAL;
105 }
106
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