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 * 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}
119