1 /* SPDX-License-Identifier: GPL-2.0-only */ 2 /* -*- mode: c; c-basic-offset: 8; -*- 3 * vim: noexpandtab sw=8 ts=8 sts=0: 4 * 5 * blockcheck.h 6 * 7 * Checksum and ECC codes for the OCFS2 userspace library. 8 * 9 * Copyright (C) 2004, 2008 Oracle. All rights reserved. 10 */ 11 12 #ifndef OCFS2_BLOCKCHECK_H 13 #define OCFS2_BLOCKCHECK_H 14 15 16 /* Count errors and error correction from blockcheck.c */ 17 struct ocfs2_blockcheck_stats { 18 spinlock_t b_lock; 19 u64 b_check_count; /* Number of blocks we've checked */ 20 u64 b_failure_count; /* Number of failed checksums */ 21 u64 b_recover_count; /* Number of blocks fixed by ecc */ 22 23 /* 24 * debugfs entries, used if this is passed to 25 * ocfs2_blockcheck_stats_debugfs_install() 26 */ 27 struct dentry *b_debug_dir; /* Parent of the debugfs files */ 28 }; 29 30 31 /* High level block API */ 32 void ocfs2_compute_meta_ecc(struct super_block *sb, void *data, 33 struct ocfs2_block_check *bc); 34 int ocfs2_validate_meta_ecc(struct super_block *sb, void *data, 35 struct ocfs2_block_check *bc); 36 void ocfs2_compute_meta_ecc_bhs(struct super_block *sb, 37 struct buffer_head **bhs, int nr, 38 struct ocfs2_block_check *bc); 39 int ocfs2_validate_meta_ecc_bhs(struct super_block *sb, 40 struct buffer_head **bhs, int nr, 41 struct ocfs2_block_check *bc); 42 43 /* Lower level API */ 44 void ocfs2_block_check_compute(void *data, size_t blocksize, 45 struct ocfs2_block_check *bc); 46 int ocfs2_block_check_validate(void *data, size_t blocksize, 47 struct ocfs2_block_check *bc, 48 struct ocfs2_blockcheck_stats *stats); 49 void ocfs2_block_check_compute_bhs(struct buffer_head **bhs, int nr, 50 struct ocfs2_block_check *bc); 51 int ocfs2_block_check_validate_bhs(struct buffer_head **bhs, int nr, 52 struct ocfs2_block_check *bc, 53 struct ocfs2_blockcheck_stats *stats); 54 55 /* Debug Initialization */ 56 void ocfs2_blockcheck_stats_debugfs_install(struct ocfs2_blockcheck_stats *stats, 57 struct dentry *parent); 58 void ocfs2_blockcheck_stats_debugfs_remove(struct ocfs2_blockcheck_stats *stats); 59 60 /* 61 * Hamming code functions 62 */ 63 64 /* 65 * Encoding hamming code parity bits for a buffer. 66 * 67 * This is the low level encoder function. It can be called across 68 * multiple hunks just like the crc32 code. 'd' is the number of bits 69 * _in_this_hunk_. nr is the bit offset of this hunk. So, if you had 70 * two 512B buffers, you would do it like so: 71 * 72 * parity = ocfs2_hamming_encode(0, buf1, 512 * 8, 0); 73 * parity = ocfs2_hamming_encode(parity, buf2, 512 * 8, 512 * 8); 74 * 75 * If you just have one buffer, use ocfs2_hamming_encode_block(). 76 */ 77 u32 ocfs2_hamming_encode(u32 parity, void *data, unsigned int d, 78 unsigned int nr); 79 /* 80 * Fix a buffer with a bit error. The 'fix' is the original parity 81 * xor'd with the parity calculated now. 82 * 83 * Like ocfs2_hamming_encode(), this can handle hunks. nr is the bit 84 * offset of the current hunk. If bit to be fixed is not part of the 85 * current hunk, this does nothing. 86 * 87 * If you only have one buffer, use ocfs2_hamming_fix_block(). 88 */ 89 void ocfs2_hamming_fix(void *data, unsigned int d, unsigned int nr, 90 unsigned int fix); 91 92 /* Convenience wrappers for a single buffer of data */ 93 extern u32 ocfs2_hamming_encode_block(void *data, unsigned int blocksize); 94 extern void ocfs2_hamming_fix_block(void *data, unsigned int blocksize, 95 unsigned int fix); 96 #endif 97