1*4882a593Smuzhiyun /* SPDX-License-Identifier: GPL-2.0-only */ 2*4882a593Smuzhiyun /* -*- mode: c; c-basic-offset: 8; -*- 3*4882a593Smuzhiyun * vim: noexpandtab sw=8 ts=8 sts=0: 4*4882a593Smuzhiyun * 5*4882a593Smuzhiyun * blockcheck.h 6*4882a593Smuzhiyun * 7*4882a593Smuzhiyun * Checksum and ECC codes for the OCFS2 userspace library. 8*4882a593Smuzhiyun * 9*4882a593Smuzhiyun * Copyright (C) 2004, 2008 Oracle. All rights reserved. 10*4882a593Smuzhiyun */ 11*4882a593Smuzhiyun 12*4882a593Smuzhiyun #ifndef OCFS2_BLOCKCHECK_H 13*4882a593Smuzhiyun #define OCFS2_BLOCKCHECK_H 14*4882a593Smuzhiyun 15*4882a593Smuzhiyun 16*4882a593Smuzhiyun /* Count errors and error correction from blockcheck.c */ 17*4882a593Smuzhiyun struct ocfs2_blockcheck_stats { 18*4882a593Smuzhiyun spinlock_t b_lock; 19*4882a593Smuzhiyun u64 b_check_count; /* Number of blocks we've checked */ 20*4882a593Smuzhiyun u64 b_failure_count; /* Number of failed checksums */ 21*4882a593Smuzhiyun u64 b_recover_count; /* Number of blocks fixed by ecc */ 22*4882a593Smuzhiyun 23*4882a593Smuzhiyun /* 24*4882a593Smuzhiyun * debugfs entries, used if this is passed to 25*4882a593Smuzhiyun * ocfs2_blockcheck_stats_debugfs_install() 26*4882a593Smuzhiyun */ 27*4882a593Smuzhiyun struct dentry *b_debug_dir; /* Parent of the debugfs files */ 28*4882a593Smuzhiyun }; 29*4882a593Smuzhiyun 30*4882a593Smuzhiyun 31*4882a593Smuzhiyun /* High level block API */ 32*4882a593Smuzhiyun void ocfs2_compute_meta_ecc(struct super_block *sb, void *data, 33*4882a593Smuzhiyun struct ocfs2_block_check *bc); 34*4882a593Smuzhiyun int ocfs2_validate_meta_ecc(struct super_block *sb, void *data, 35*4882a593Smuzhiyun struct ocfs2_block_check *bc); 36*4882a593Smuzhiyun void ocfs2_compute_meta_ecc_bhs(struct super_block *sb, 37*4882a593Smuzhiyun struct buffer_head **bhs, int nr, 38*4882a593Smuzhiyun struct ocfs2_block_check *bc); 39*4882a593Smuzhiyun int ocfs2_validate_meta_ecc_bhs(struct super_block *sb, 40*4882a593Smuzhiyun struct buffer_head **bhs, int nr, 41*4882a593Smuzhiyun struct ocfs2_block_check *bc); 42*4882a593Smuzhiyun 43*4882a593Smuzhiyun /* Lower level API */ 44*4882a593Smuzhiyun void ocfs2_block_check_compute(void *data, size_t blocksize, 45*4882a593Smuzhiyun struct ocfs2_block_check *bc); 46*4882a593Smuzhiyun int ocfs2_block_check_validate(void *data, size_t blocksize, 47*4882a593Smuzhiyun struct ocfs2_block_check *bc, 48*4882a593Smuzhiyun struct ocfs2_blockcheck_stats *stats); 49*4882a593Smuzhiyun void ocfs2_block_check_compute_bhs(struct buffer_head **bhs, int nr, 50*4882a593Smuzhiyun struct ocfs2_block_check *bc); 51*4882a593Smuzhiyun int ocfs2_block_check_validate_bhs(struct buffer_head **bhs, int nr, 52*4882a593Smuzhiyun struct ocfs2_block_check *bc, 53*4882a593Smuzhiyun struct ocfs2_blockcheck_stats *stats); 54*4882a593Smuzhiyun 55*4882a593Smuzhiyun /* Debug Initialization */ 56*4882a593Smuzhiyun void ocfs2_blockcheck_stats_debugfs_install(struct ocfs2_blockcheck_stats *stats, 57*4882a593Smuzhiyun struct dentry *parent); 58*4882a593Smuzhiyun void ocfs2_blockcheck_stats_debugfs_remove(struct ocfs2_blockcheck_stats *stats); 59*4882a593Smuzhiyun 60*4882a593Smuzhiyun /* 61*4882a593Smuzhiyun * Hamming code functions 62*4882a593Smuzhiyun */ 63*4882a593Smuzhiyun 64*4882a593Smuzhiyun /* 65*4882a593Smuzhiyun * Encoding hamming code parity bits for a buffer. 66*4882a593Smuzhiyun * 67*4882a593Smuzhiyun * This is the low level encoder function. It can be called across 68*4882a593Smuzhiyun * multiple hunks just like the crc32 code. 'd' is the number of bits 69*4882a593Smuzhiyun * _in_this_hunk_. nr is the bit offset of this hunk. So, if you had 70*4882a593Smuzhiyun * two 512B buffers, you would do it like so: 71*4882a593Smuzhiyun * 72*4882a593Smuzhiyun * parity = ocfs2_hamming_encode(0, buf1, 512 * 8, 0); 73*4882a593Smuzhiyun * parity = ocfs2_hamming_encode(parity, buf2, 512 * 8, 512 * 8); 74*4882a593Smuzhiyun * 75*4882a593Smuzhiyun * If you just have one buffer, use ocfs2_hamming_encode_block(). 76*4882a593Smuzhiyun */ 77*4882a593Smuzhiyun u32 ocfs2_hamming_encode(u32 parity, void *data, unsigned int d, 78*4882a593Smuzhiyun unsigned int nr); 79*4882a593Smuzhiyun /* 80*4882a593Smuzhiyun * Fix a buffer with a bit error. The 'fix' is the original parity 81*4882a593Smuzhiyun * xor'd with the parity calculated now. 82*4882a593Smuzhiyun * 83*4882a593Smuzhiyun * Like ocfs2_hamming_encode(), this can handle hunks. nr is the bit 84*4882a593Smuzhiyun * offset of the current hunk. If bit to be fixed is not part of the 85*4882a593Smuzhiyun * current hunk, this does nothing. 86*4882a593Smuzhiyun * 87*4882a593Smuzhiyun * If you only have one buffer, use ocfs2_hamming_fix_block(). 88*4882a593Smuzhiyun */ 89*4882a593Smuzhiyun void ocfs2_hamming_fix(void *data, unsigned int d, unsigned int nr, 90*4882a593Smuzhiyun unsigned int fix); 91*4882a593Smuzhiyun 92*4882a593Smuzhiyun /* Convenience wrappers for a single buffer of data */ 93*4882a593Smuzhiyun extern u32 ocfs2_hamming_encode_block(void *data, unsigned int blocksize); 94*4882a593Smuzhiyun extern void ocfs2_hamming_fix_block(void *data, unsigned int blocksize, 95*4882a593Smuzhiyun unsigned int fix); 96*4882a593Smuzhiyun #endif 97