Root/fs/befs/super.c

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

Archive Download this file



interactive