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
18static inline void
19vxfs_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
25static inline void
26vxfs_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
32static inline u_long
33vxfs_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 */
52int
53vxfs_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
102fail:
103	brelse(bp);
104	return -EINVAL;
105}
106