1 | /* SPDX-License-Identifier: GPL-2.0-only */ |
2 | /* |
3 | * blockcheck.h |
4 | * |
5 | * Checksum and ECC codes for the OCFS2 userspace library. |
6 | * |
7 | * Copyright (C) 2004, 2008 Oracle. All rights reserved. |
8 | */ |
9 | |
10 | #ifndef OCFS2_BLOCKCHECK_H |
11 | #define OCFS2_BLOCKCHECK_H |
12 | |
13 | |
14 | /* Count errors and error correction from blockcheck.c */ |
15 | struct ocfs2_blockcheck_stats { |
16 | spinlock_t b_lock; |
17 | u64 b_check_count; /* Number of blocks we've checked */ |
18 | u64 b_failure_count; /* Number of failed checksums */ |
19 | u64 b_recover_count; /* Number of blocks fixed by ecc */ |
20 | |
21 | /* |
22 | * debugfs entries, used if this is passed to |
23 | * ocfs2_blockcheck_stats_debugfs_install() |
24 | */ |
25 | struct dentry *b_debug_dir; /* Parent of the debugfs files */ |
26 | }; |
27 | |
28 | |
29 | /* High level block API */ |
30 | void ocfs2_compute_meta_ecc(struct super_block *sb, void *data, |
31 | struct ocfs2_block_check *bc); |
32 | int ocfs2_validate_meta_ecc(struct super_block *sb, void *data, |
33 | struct ocfs2_block_check *bc); |
34 | void ocfs2_compute_meta_ecc_bhs(struct super_block *sb, |
35 | struct buffer_head **bhs, int nr, |
36 | struct ocfs2_block_check *bc); |
37 | int ocfs2_validate_meta_ecc_bhs(struct super_block *sb, |
38 | struct buffer_head **bhs, int nr, |
39 | struct ocfs2_block_check *bc); |
40 | |
41 | /* Lower level API */ |
42 | void ocfs2_block_check_compute(void *data, size_t blocksize, |
43 | struct ocfs2_block_check *bc); |
44 | int ocfs2_block_check_validate(void *data, size_t blocksize, |
45 | struct ocfs2_block_check *bc, |
46 | struct ocfs2_blockcheck_stats *stats); |
47 | void ocfs2_block_check_compute_bhs(struct buffer_head **bhs, int nr, |
48 | struct ocfs2_block_check *bc); |
49 | int ocfs2_block_check_validate_bhs(struct buffer_head **bhs, int nr, |
50 | struct ocfs2_block_check *bc, |
51 | struct ocfs2_blockcheck_stats *stats); |
52 | |
53 | /* Debug Initialization */ |
54 | void ocfs2_blockcheck_stats_debugfs_install(struct ocfs2_blockcheck_stats *stats, |
55 | struct dentry *parent); |
56 | void ocfs2_blockcheck_stats_debugfs_remove(struct ocfs2_blockcheck_stats *stats); |
57 | |
58 | /* |
59 | * Hamming code functions |
60 | */ |
61 | |
62 | /* |
63 | * Encoding hamming code parity bits for a buffer. |
64 | * |
65 | * This is the low level encoder function. It can be called across |
66 | * multiple hunks just like the crc32 code. 'd' is the number of bits |
67 | * _in_this_hunk_. nr is the bit offset of this hunk. So, if you had |
68 | * two 512B buffers, you would do it like so: |
69 | * |
70 | * parity = ocfs2_hamming_encode(0, buf1, 512 * 8, 0); |
71 | * parity = ocfs2_hamming_encode(parity, buf2, 512 * 8, 512 * 8); |
72 | * |
73 | * If you just have one buffer, use ocfs2_hamming_encode_block(). |
74 | */ |
75 | u32 ocfs2_hamming_encode(u32 parity, void *data, unsigned int d, |
76 | unsigned int nr); |
77 | /* |
78 | * Fix a buffer with a bit error. The 'fix' is the original parity |
79 | * xor'd with the parity calculated now. |
80 | * |
81 | * Like ocfs2_hamming_encode(), this can handle hunks. nr is the bit |
82 | * offset of the current hunk. If bit to be fixed is not part of the |
83 | * current hunk, this does nothing. |
84 | * |
85 | * If you only have one buffer, use ocfs2_hamming_fix_block(). |
86 | */ |
87 | void ocfs2_hamming_fix(void *data, unsigned int d, unsigned int nr, |
88 | unsigned int fix); |
89 | |
90 | /* Convenience wrappers for a single buffer of data */ |
91 | extern u32 ocfs2_hamming_encode_block(void *data, unsigned int blocksize); |
92 | extern void ocfs2_hamming_fix_block(void *data, unsigned int blocksize, |
93 | unsigned int fix); |
94 | #endif |
95 | |