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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 */
15struct 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 */
30void ocfs2_compute_meta_ecc(struct super_block *sb, void *data,
31 struct ocfs2_block_check *bc);
32int ocfs2_validate_meta_ecc(struct super_block *sb, void *data,
33 struct ocfs2_block_check *bc);
34void ocfs2_compute_meta_ecc_bhs(struct super_block *sb,
35 struct buffer_head **bhs, int nr,
36 struct ocfs2_block_check *bc);
37int 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 */
42void ocfs2_block_check_compute(void *data, size_t blocksize,
43 struct ocfs2_block_check *bc);
44int ocfs2_block_check_validate(void *data, size_t blocksize,
45 struct ocfs2_block_check *bc,
46 struct ocfs2_blockcheck_stats *stats);
47void ocfs2_block_check_compute_bhs(struct buffer_head **bhs, int nr,
48 struct ocfs2_block_check *bc);
49int 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 */
54void ocfs2_blockcheck_stats_debugfs_install(struct ocfs2_blockcheck_stats *stats,
55 struct dentry *parent);
56void 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 */
75u32 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 */
87void 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 */
91extern u32 ocfs2_hamming_encode_block(void *data, unsigned int blocksize);
92extern void ocfs2_hamming_fix_block(void *data, unsigned int blocksize,
93 unsigned int fix);
94#endif