forked from luck/tmp_suning_uos_patched
73be192b17
It would be nice to know how often we get checksum failures. Even better, how many of them we can fix with the single bit ecc. So, we add a statistics structure. The structure can be installed into debugfs wherever the user wants. For ocfs2, we'll put it in the superblock-specific debugfs directory and pass it down from our higher-level functions. The stats are only registered with debugfs when the filesystem supports metadata ecc. Signed-off-by: Joel Becker <joel.becker@oracle.com>
108 lines
3.8 KiB
C
108 lines
3.8 KiB
C
/* -*- mode: c; c-basic-offset: 8; -*-
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* vim: noexpandtab sw=8 ts=8 sts=0:
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*
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* blockcheck.h
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*
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* Checksum and ECC codes for the OCFS2 userspace library.
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*
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* Copyright (C) 2004, 2008 Oracle. All rights reserved.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public
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* License, version 2, as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*/
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#ifndef OCFS2_BLOCKCHECK_H
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#define OCFS2_BLOCKCHECK_H
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/* Count errors and error correction from blockcheck.c */
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struct ocfs2_blockcheck_stats {
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spinlock_t b_lock;
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u64 b_check_count; /* Number of blocks we've checked */
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u64 b_failure_count; /* Number of failed checksums */
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u64 b_recover_count; /* Number of blocks fixed by ecc */
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/*
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* debugfs entries, used if this is passed to
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* ocfs2_blockcheck_stats_debugfs_install()
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*/
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struct dentry *b_debug_dir; /* Parent of the debugfs files */
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struct dentry *b_debug_check; /* Exposes b_check_count */
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struct dentry *b_debug_failure; /* Exposes b_failure_count */
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struct dentry *b_debug_recover; /* Exposes b_recover_count */
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};
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/* High level block API */
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void ocfs2_compute_meta_ecc(struct super_block *sb, void *data,
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struct ocfs2_block_check *bc);
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int ocfs2_validate_meta_ecc(struct super_block *sb, void *data,
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struct ocfs2_block_check *bc);
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void ocfs2_compute_meta_ecc_bhs(struct super_block *sb,
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struct buffer_head **bhs, int nr,
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struct ocfs2_block_check *bc);
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int ocfs2_validate_meta_ecc_bhs(struct super_block *sb,
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struct buffer_head **bhs, int nr,
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struct ocfs2_block_check *bc);
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/* Lower level API */
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void ocfs2_block_check_compute(void *data, size_t blocksize,
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struct ocfs2_block_check *bc);
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int ocfs2_block_check_validate(void *data, size_t blocksize,
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struct ocfs2_block_check *bc,
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struct ocfs2_blockcheck_stats *stats);
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void ocfs2_block_check_compute_bhs(struct buffer_head **bhs, int nr,
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struct ocfs2_block_check *bc);
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int ocfs2_block_check_validate_bhs(struct buffer_head **bhs, int nr,
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struct ocfs2_block_check *bc,
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struct ocfs2_blockcheck_stats *stats);
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/* Debug Initialization */
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int ocfs2_blockcheck_stats_debugfs_install(struct ocfs2_blockcheck_stats *stats,
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struct dentry *parent);
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void ocfs2_blockcheck_stats_debugfs_remove(struct ocfs2_blockcheck_stats *stats);
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/*
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* Hamming code functions
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*/
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/*
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* Encoding hamming code parity bits for a buffer.
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*
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* This is the low level encoder function. It can be called across
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* multiple hunks just like the crc32 code. 'd' is the number of bits
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* _in_this_hunk_. nr is the bit offset of this hunk. So, if you had
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* two 512B buffers, you would do it like so:
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*
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* parity = ocfs2_hamming_encode(0, buf1, 512 * 8, 0);
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* parity = ocfs2_hamming_encode(parity, buf2, 512 * 8, 512 * 8);
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*
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* If you just have one buffer, use ocfs2_hamming_encode_block().
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*/
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u32 ocfs2_hamming_encode(u32 parity, void *data, unsigned int d,
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unsigned int nr);
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/*
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* Fix a buffer with a bit error. The 'fix' is the original parity
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* xor'd with the parity calculated now.
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*
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* Like ocfs2_hamming_encode(), this can handle hunks. nr is the bit
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* offset of the current hunk. If bit to be fixed is not part of the
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* current hunk, this does nothing.
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*
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* If you only have one buffer, use ocfs2_hamming_fix_block().
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*/
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void ocfs2_hamming_fix(void *data, unsigned int d, unsigned int nr,
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unsigned int fix);
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/* Convenience wrappers for a single buffer of data */
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extern u32 ocfs2_hamming_encode_block(void *data, unsigned int blocksize);
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extern void ocfs2_hamming_fix_block(void *data, unsigned int blocksize,
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unsigned int fix);
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#endif
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