blob: 62aaf3e3126a6c18bb45abf5c48040393223b178 [file] [log] [blame]
Kai Bankett5d026c72012-02-17 05:59:20 +01001/*
2 * QNX6 file system, Linux implementation.
3 *
4 * Version : 1.0.0
5 *
6 * History :
7 *
8 * 01-02-2012 by Kai Bankett (chaosman@ontika.net) : first release.
9 *
10 */
11
12#include <linux/buffer_head.h>
13#include <linux/slab.h>
14#include <linux/crc32.h>
15#include "qnx6.h"
16
17static void qnx6_mmi_copy_sb(struct qnx6_super_block *qsb,
18 struct qnx6_mmi_super_block *sb)
19{
20 qsb->sb_magic = sb->sb_magic;
21 qsb->sb_checksum = sb->sb_checksum;
22 qsb->sb_serial = sb->sb_serial;
23 qsb->sb_blocksize = sb->sb_blocksize;
24 qsb->sb_num_inodes = sb->sb_num_inodes;
25 qsb->sb_free_inodes = sb->sb_free_inodes;
26 qsb->sb_num_blocks = sb->sb_num_blocks;
27 qsb->sb_free_blocks = sb->sb_free_blocks;
28
29 /* the rest of the superblock is the same */
30 memcpy(&qsb->Inode, &sb->Inode, sizeof(sb->Inode));
31 memcpy(&qsb->Bitmap, &sb->Bitmap, sizeof(sb->Bitmap));
32 memcpy(&qsb->Longfile, &sb->Longfile, sizeof(sb->Longfile));
33}
34
35struct qnx6_super_block *qnx6_mmi_fill_super(struct super_block *s, int silent)
36{
37 struct buffer_head *bh1, *bh2 = NULL;
38 struct qnx6_mmi_super_block *sb1, *sb2;
39 struct qnx6_super_block *qsb = NULL;
40 struct qnx6_sb_info *sbi;
41 __u64 offset;
42
43 /* Check the superblock signatures
44 start with the first superblock */
45 bh1 = sb_bread(s, 0);
46 if (!bh1) {
Fabian Fredericke6c32612014-08-08 14:23:05 -070047 pr_err("Unable to read first mmi superblock\n");
Kai Bankett5d026c72012-02-17 05:59:20 +010048 return NULL;
49 }
50 sb1 = (struct qnx6_mmi_super_block *)bh1->b_data;
51 sbi = QNX6_SB(s);
52 if (fs32_to_cpu(sbi, sb1->sb_magic) != QNX6_SUPER_MAGIC) {
53 if (!silent) {
Fabian Fredericke6c32612014-08-08 14:23:05 -070054 pr_err("wrong signature (magic) in superblock #1.\n");
Kai Bankett5d026c72012-02-17 05:59:20 +010055 goto out;
56 }
57 }
58
59 /* checksum check - start at byte 8 and end at byte 512 */
60 if (fs32_to_cpu(sbi, sb1->sb_checksum) !=
61 crc32_be(0, (char *)(bh1->b_data + 8), 504)) {
Fabian Fredericke6c32612014-08-08 14:23:05 -070062 pr_err("superblock #1 checksum error\n");
Kai Bankett5d026c72012-02-17 05:59:20 +010063 goto out;
64 }
65
66 /* calculate second superblock blocknumber */
67 offset = fs32_to_cpu(sbi, sb1->sb_num_blocks) + QNX6_SUPERBLOCK_AREA /
68 fs32_to_cpu(sbi, sb1->sb_blocksize);
69
70 /* set new blocksize */
71 if (!sb_set_blocksize(s, fs32_to_cpu(sbi, sb1->sb_blocksize))) {
Fabian Fredericke6c32612014-08-08 14:23:05 -070072 pr_err("unable to set blocksize\n");
Kai Bankett5d026c72012-02-17 05:59:20 +010073 goto out;
74 }
75 /* blocksize invalidates bh - pull it back in */
76 brelse(bh1);
77 bh1 = sb_bread(s, 0);
78 if (!bh1)
79 goto out;
80 sb1 = (struct qnx6_mmi_super_block *)bh1->b_data;
81
82 /* read second superblock */
83 bh2 = sb_bread(s, offset);
84 if (!bh2) {
Fabian Fredericke6c32612014-08-08 14:23:05 -070085 pr_err("unable to read the second superblock\n");
Kai Bankett5d026c72012-02-17 05:59:20 +010086 goto out;
87 }
88 sb2 = (struct qnx6_mmi_super_block *)bh2->b_data;
89 if (fs32_to_cpu(sbi, sb2->sb_magic) != QNX6_SUPER_MAGIC) {
90 if (!silent)
Fabian Fredericke6c32612014-08-08 14:23:05 -070091 pr_err("wrong signature (magic) in superblock #2.\n");
Kai Bankett5d026c72012-02-17 05:59:20 +010092 goto out;
93 }
94
95 /* checksum check - start at byte 8 and end at byte 512 */
96 if (fs32_to_cpu(sbi, sb2->sb_checksum)
97 != crc32_be(0, (char *)(bh2->b_data + 8), 504)) {
Fabian Fredericke6c32612014-08-08 14:23:05 -070098 pr_err("superblock #1 checksum error\n");
Kai Bankett5d026c72012-02-17 05:59:20 +010099 goto out;
100 }
101
102 qsb = kmalloc(sizeof(*qsb), GFP_KERNEL);
103 if (!qsb) {
Fabian Fredericke6c32612014-08-08 14:23:05 -0700104 pr_err("unable to allocate memory.\n");
Kai Bankett5d026c72012-02-17 05:59:20 +0100105 goto out;
106 }
107
108 if (fs64_to_cpu(sbi, sb1->sb_serial) >
109 fs64_to_cpu(sbi, sb2->sb_serial)) {
110 /* superblock #1 active */
111 qnx6_mmi_copy_sb(qsb, sb1);
112#ifdef CONFIG_QNX6FS_DEBUG
113 qnx6_superblock_debug(qsb, s);
114#endif
115 memcpy(bh1->b_data, qsb, sizeof(struct qnx6_super_block));
116
117 sbi->sb_buf = bh1;
118 sbi->sb = (struct qnx6_super_block *)bh1->b_data;
119 brelse(bh2);
Fabian Fredericke6c32612014-08-08 14:23:05 -0700120 pr_info("superblock #1 active\n");
Kai Bankett5d026c72012-02-17 05:59:20 +0100121 } else {
122 /* superblock #2 active */
123 qnx6_mmi_copy_sb(qsb, sb2);
124#ifdef CONFIG_QNX6FS_DEBUG
125 qnx6_superblock_debug(qsb, s);
126#endif
127 memcpy(bh2->b_data, qsb, sizeof(struct qnx6_super_block));
128
129 sbi->sb_buf = bh2;
130 sbi->sb = (struct qnx6_super_block *)bh2->b_data;
131 brelse(bh1);
Fabian Fredericke6c32612014-08-08 14:23:05 -0700132 pr_info("superblock #2 active\n");
Kai Bankett5d026c72012-02-17 05:59:20 +0100133 }
134 kfree(qsb);
135
136 /* offset for mmi_fs is just SUPERBLOCK_AREA bytes */
137 sbi->s_blks_off = QNX6_SUPERBLOCK_AREA / s->s_blocksize;
138
139 /* success */
140 return sbi->sb;
141
142out:
143 if (bh1 != NULL)
144 brelse(bh1);
145 if (bh2 != NULL)
146 brelse(bh2);
147 return NULL;
148}