1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * QNX6 file system, Linux implementation. |
4 | * |
5 | * Version : 1.0.0 |
6 | * |
7 | * History : |
8 | * |
9 | * 01-02-2012 by Kai Bankett (chaosman@ontika.net) : first release. |
10 | * |
11 | */ |
12 | |
13 | #include <linux/buffer_head.h> |
14 | #include <linux/slab.h> |
15 | #include <linux/crc32.h> |
16 | #include "qnx6.h" |
17 | |
18 | static void qnx6_mmi_copy_sb(struct qnx6_super_block *qsb, |
19 | struct qnx6_mmi_super_block *sb) |
20 | { |
21 | qsb->sb_magic = sb->sb_magic; |
22 | qsb->sb_checksum = sb->sb_checksum; |
23 | qsb->sb_serial = sb->sb_serial; |
24 | qsb->sb_blocksize = sb->sb_blocksize; |
25 | qsb->sb_num_inodes = sb->sb_num_inodes; |
26 | qsb->sb_free_inodes = sb->sb_free_inodes; |
27 | qsb->sb_num_blocks = sb->sb_num_blocks; |
28 | qsb->sb_free_blocks = sb->sb_free_blocks; |
29 | |
30 | /* the rest of the superblock is the same */ |
31 | memcpy(&qsb->Inode, &sb->Inode, sizeof(sb->Inode)); |
32 | memcpy(&qsb->Bitmap, &sb->Bitmap, sizeof(sb->Bitmap)); |
33 | memcpy(&qsb->Longfile, &sb->Longfile, sizeof(sb->Longfile)); |
34 | } |
35 | |
36 | struct qnx6_super_block *qnx6_mmi_fill_super(struct super_block *s, int silent) |
37 | { |
38 | struct buffer_head *bh1, *bh2 = NULL; |
39 | struct qnx6_mmi_super_block *sb1, *sb2; |
40 | struct qnx6_super_block *qsb = NULL; |
41 | struct qnx6_sb_info *sbi; |
42 | __u64 offset; |
43 | |
44 | /* Check the superblock signatures |
45 | start with the first superblock */ |
46 | bh1 = sb_bread(sb: s, block: 0); |
47 | if (!bh1) { |
48 | pr_err("Unable to read first mmi superblock\n" ); |
49 | return NULL; |
50 | } |
51 | sb1 = (struct qnx6_mmi_super_block *)bh1->b_data; |
52 | sbi = QNX6_SB(sb: s); |
53 | if (fs32_to_cpu(sbi, n: sb1->sb_magic) != QNX6_SUPER_MAGIC) { |
54 | if (!silent) { |
55 | pr_err("wrong signature (magic) in superblock #1.\n" ); |
56 | goto out; |
57 | } |
58 | } |
59 | |
60 | /* checksum check - start at byte 8 and end at byte 512 */ |
61 | if (fs32_to_cpu(sbi, n: sb1->sb_checksum) != |
62 | crc32_be(crc: 0, p: (char *)(bh1->b_data + 8), len: 504)) { |
63 | pr_err("superblock #1 checksum error\n" ); |
64 | goto out; |
65 | } |
66 | |
67 | /* calculate second superblock blocknumber */ |
68 | offset = fs32_to_cpu(sbi, n: sb1->sb_num_blocks) + QNX6_SUPERBLOCK_AREA / |
69 | fs32_to_cpu(sbi, n: sb1->sb_blocksize); |
70 | |
71 | /* set new blocksize */ |
72 | if (!sb_set_blocksize(s, fs32_to_cpu(sbi, n: sb1->sb_blocksize))) { |
73 | pr_err("unable to set blocksize\n" ); |
74 | goto out; |
75 | } |
76 | /* blocksize invalidates bh - pull it back in */ |
77 | brelse(bh: bh1); |
78 | bh1 = sb_bread(sb: s, block: 0); |
79 | if (!bh1) |
80 | goto out; |
81 | sb1 = (struct qnx6_mmi_super_block *)bh1->b_data; |
82 | |
83 | /* read second superblock */ |
84 | bh2 = sb_bread(sb: s, block: offset); |
85 | if (!bh2) { |
86 | pr_err("unable to read the second superblock\n" ); |
87 | goto out; |
88 | } |
89 | sb2 = (struct qnx6_mmi_super_block *)bh2->b_data; |
90 | if (fs32_to_cpu(sbi, n: sb2->sb_magic) != QNX6_SUPER_MAGIC) { |
91 | if (!silent) |
92 | pr_err("wrong signature (magic) in superblock #2.\n" ); |
93 | goto out; |
94 | } |
95 | |
96 | /* checksum check - start at byte 8 and end at byte 512 */ |
97 | if (fs32_to_cpu(sbi, n: sb2->sb_checksum) |
98 | != crc32_be(crc: 0, p: (char *)(bh2->b_data + 8), len: 504)) { |
99 | pr_err("superblock #1 checksum error\n" ); |
100 | goto out; |
101 | } |
102 | |
103 | qsb = kmalloc(size: sizeof(*qsb), GFP_KERNEL); |
104 | if (!qsb) { |
105 | pr_err("unable to allocate memory.\n" ); |
106 | goto out; |
107 | } |
108 | |
109 | if (fs64_to_cpu(sbi, n: sb1->sb_serial) > |
110 | fs64_to_cpu(sbi, n: sb2->sb_serial)) { |
111 | /* superblock #1 active */ |
112 | qnx6_mmi_copy_sb(qsb, sb: sb1); |
113 | #ifdef CONFIG_QNX6FS_DEBUG |
114 | qnx6_superblock_debug(qsb, s); |
115 | #endif |
116 | memcpy(bh1->b_data, qsb, sizeof(struct qnx6_super_block)); |
117 | |
118 | sbi->sb_buf = bh1; |
119 | sbi->sb = (struct qnx6_super_block *)bh1->b_data; |
120 | brelse(bh: bh2); |
121 | pr_info("superblock #1 active\n" ); |
122 | } else { |
123 | /* superblock #2 active */ |
124 | qnx6_mmi_copy_sb(qsb, sb: sb2); |
125 | #ifdef CONFIG_QNX6FS_DEBUG |
126 | qnx6_superblock_debug(qsb, s); |
127 | #endif |
128 | memcpy(bh2->b_data, qsb, sizeof(struct qnx6_super_block)); |
129 | |
130 | sbi->sb_buf = bh2; |
131 | sbi->sb = (struct qnx6_super_block *)bh2->b_data; |
132 | brelse(bh: bh1); |
133 | pr_info("superblock #2 active\n" ); |
134 | } |
135 | kfree(objp: qsb); |
136 | |
137 | /* offset for mmi_fs is just SUPERBLOCK_AREA bytes */ |
138 | sbi->s_blks_off = QNX6_SUPERBLOCK_AREA / s->s_blocksize; |
139 | |
140 | /* success */ |
141 | return sbi->sb; |
142 | |
143 | out: |
144 | if (bh1 != NULL) |
145 | brelse(bh: bh1); |
146 | if (bh2 != NULL) |
147 | brelse(bh: bh2); |
148 | return NULL; |
149 | } |
150 | |