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 struct dentry *b_debug_check; /* Exposes b_check_count */ 29 struct dentry *b_debug_failure; /* Exposes b_failure_count */ 30 struct dentry *b_debug_recover; /* Exposes b_recover_count */ 31 }; 32 33 34 /* High level block API */ 35 void ocfs2_compute_meta_ecc(struct super_block *sb, void *data, 36 struct ocfs2_block_check *bc); 37 int ocfs2_validate_meta_ecc(struct super_block *sb, void *data, 38 struct ocfs2_block_check *bc); 39 void ocfs2_compute_meta_ecc_bhs(struct super_block *sb, 40 struct buffer_head **bhs, int nr, 41 struct ocfs2_block_check *bc); 42 int ocfs2_validate_meta_ecc_bhs(struct super_block *sb, 43 struct buffer_head **bhs, int nr, 44 struct ocfs2_block_check *bc); 45 46 /* Lower level API */ 47 void ocfs2_block_check_compute(void *data, size_t blocksize, 48 struct ocfs2_block_check *bc); 49 int ocfs2_block_check_validate(void *data, size_t blocksize, 50 struct ocfs2_block_check *bc, 51 struct ocfs2_blockcheck_stats *stats); 52 void ocfs2_block_check_compute_bhs(struct buffer_head **bhs, int nr, 53 struct ocfs2_block_check *bc); 54 int ocfs2_block_check_validate_bhs(struct buffer_head **bhs, int nr, 55 struct ocfs2_block_check *bc, 56 struct ocfs2_blockcheck_stats *stats); 57 58 /* Debug Initialization */ 59 int ocfs2_blockcheck_stats_debugfs_install(struct ocfs2_blockcheck_stats *stats, 60 struct dentry *parent); 61 void ocfs2_blockcheck_stats_debugfs_remove(struct ocfs2_blockcheck_stats *stats); 62 63 /* 64 * Hamming code functions 65 */ 66 67 /* 68 * Encoding hamming code parity bits for a buffer. 69 * 70 * This is the low level encoder function. It can be called across 71 * multiple hunks just like the crc32 code. 'd' is the number of bits 72 * _in_this_hunk_. nr is the bit offset of this hunk. So, if you had 73 * two 512B buffers, you would do it like so: 74 * 75 * parity = ocfs2_hamming_encode(0, buf1, 512 * 8, 0); 76 * parity = ocfs2_hamming_encode(parity, buf2, 512 * 8, 512 * 8); 77 * 78 * If you just have one buffer, use ocfs2_hamming_encode_block(). 79 */ 80 u32 ocfs2_hamming_encode(u32 parity, void *data, unsigned int d, 81 unsigned int nr); 82 /* 83 * Fix a buffer with a bit error. The 'fix' is the original parity 84 * xor'd with the parity calculated now. 85 * 86 * Like ocfs2_hamming_encode(), this can handle hunks. nr is the bit 87 * offset of the current hunk. If bit to be fixed is not part of the 88 * current hunk, this does nothing. 89 * 90 * If you only have one buffer, use ocfs2_hamming_fix_block(). 91 */ 92 void ocfs2_hamming_fix(void *data, unsigned int d, unsigned int nr, 93 unsigned int fix); 94 95 /* Convenience wrappers for a single buffer of data */ 96 extern u32 ocfs2_hamming_encode_block(void *data, unsigned int blocksize); 97 extern void ocfs2_hamming_fix_block(void *data, unsigned int blocksize, 98 unsigned int fix); 99 #endif 100