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118 lines · 3.3 KiB

1/*
2 * super.c
3 *
4 * Copyright (C) 2001-2002 Will Dyson <[email protected]>
5 *
6 * Licensed under the GNU GPL. See the file COPYING for details.
7 *
8 */
9
10#include <linux/fs.h>
11#include <asm/page.h> /* for PAGE_SIZE */
12
13#include "befs.h"
14#include "super.h"
15
16/*
17 * befs_load_sb -- Read from disk and properly byteswap all the fields
18 * of the befs superblock
19 */
20int
21befs_load_sb(struct super_block *sb, befs_super_block *disk_sb)
22{
23 struct befs_sb_info *befs_sb = BEFS_SB(sb);
24
25 /* Check the byte order of the filesystem */
26 if (disk_sb->fs_byte_order == BEFS_BYTEORDER_NATIVE_LE)
27 befs_sb->byte_order = BEFS_BYTESEX_LE;
28 else if (disk_sb->fs_byte_order == BEFS_BYTEORDER_NATIVE_BE)
29 befs_sb->byte_order = BEFS_BYTESEX_BE;
30
31 befs_sb->magic1 = fs32_to_cpu(sb, disk_sb->magic1);
32 befs_sb->magic2 = fs32_to_cpu(sb, disk_sb->magic2);
33 befs_sb->magic3 = fs32_to_cpu(sb, disk_sb->magic3);
34 befs_sb->block_size = fs32_to_cpu(sb, disk_sb->block_size);
35 befs_sb->block_shift = fs32_to_cpu(sb, disk_sb->block_shift);
36 befs_sb->num_blocks = fs64_to_cpu(sb, disk_sb->num_blocks);
37 befs_sb->used_blocks = fs64_to_cpu(sb, disk_sb->used_blocks);
38 befs_sb->inode_size = fs32_to_cpu(sb, disk_sb->inode_size);
39
40 befs_sb->blocks_per_ag = fs32_to_cpu(sb, disk_sb->blocks_per_ag);
41 befs_sb->ag_shift = fs32_to_cpu(sb, disk_sb->ag_shift);
42 befs_sb->num_ags = fs32_to_cpu(sb, disk_sb->num_ags);
43
44 befs_sb->flags = fs32_to_cpu(sb, disk_sb->flags);
45
46 befs_sb->log_blocks = fsrun_to_cpu(sb, disk_sb->log_blocks);
47 befs_sb->log_start = fs64_to_cpu(sb, disk_sb->log_start);
48 befs_sb->log_end = fs64_to_cpu(sb, disk_sb->log_end);
49
50 befs_sb->root_dir = fsrun_to_cpu(sb, disk_sb->root_dir);
51 befs_sb->indices = fsrun_to_cpu(sb, disk_sb->indices);
52 befs_sb->nls = NULL;
53
54 return BEFS_OK;
55}
56
57int
58befs_check_sb(struct super_block *sb)
59{
60 struct befs_sb_info *befs_sb = BEFS_SB(sb);
61
62 /* Check magic headers of super block */
63 if ((befs_sb->magic1 != BEFS_SUPER_MAGIC1)
64 || (befs_sb->magic2 != BEFS_SUPER_MAGIC2)
65 || (befs_sb->magic3 != BEFS_SUPER_MAGIC3)) {
66 befs_error(sb, "invalid magic header");
67 return BEFS_ERR;
68 }
69
70 /*
71 * Check blocksize of BEFS.
72 *
73 * Blocksize of BEFS is 1024, 2048, 4096 or 8192.
74 */
75
76 if ((befs_sb->block_size != 1024)
77 && (befs_sb->block_size != 2048)
78 && (befs_sb->block_size != 4096)
79 && (befs_sb->block_size != 8192)) {
80 befs_error(sb, "invalid blocksize: %u", befs_sb->block_size);
81 return BEFS_ERR;
82 }
83
84 if (befs_sb->block_size > PAGE_SIZE) {
85 befs_error(sb, "blocksize(%u) cannot be larger "
86 "than system pagesize(%lu)", befs_sb->block_size,
87 PAGE_SIZE);
88 return BEFS_ERR;
89 }
90
91 /*
92 * block_shift and block_size encode the same information
93 * in different ways as a consistency check.
94 */
95
96 if ((1 << befs_sb->block_shift) != befs_sb->block_size) {
97 befs_error(sb, "block_shift disagrees with block_size. "
98 "Corruption likely.");
99 return BEFS_ERR;
100 }
101
102
103 /* ag_shift also encodes the same information as blocks_per_ag in a
104 * different way, non-fatal consistency check
105 */
106 if ((1 << befs_sb->ag_shift) != befs_sb->blocks_per_ag)
107 befs_error(sb, "ag_shift disagrees with blocks_per_ag.");
108
109 if (befs_sb->log_start != befs_sb->log_end ||
110 befs_sb->flags == BEFS_DIRTY) {
111 befs_error(sb, "Filesystem not clean! There are blocks in the "
112 "journal. You must boot into BeOS and mount this "
113 "volume to make it clean.");
114 return BEFS_ERR;
115 }
116
117 return BEFS_OK;
118}