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 */
24 int
befs_load_sb(struct super_block * sb,befs_super_block * disk_sb)25 befs_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
59 int
befs_check_sb(struct super_block * sb)60 befs_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