[linux-2.6-block.git] / fs / ocfs2 / blockcheck.h

/* SPDX-License-Identifier: GPL-2.0-only */
/* -*- mode: c; c-basic-offset: 8; -*-
 * vim: noexpandtab sw=8 ts=8 sts=0:
 *
 * blockcheck.h
 *
 * Checksum and ECC codes for the OCFS2 userspace library.
 *
 * Copyright (C) 2004, 2008 Oracle.  All rights reserved.
 */

#ifndef OCFS2_BLOCKCHECK_H
#define OCFS2_BLOCKCHECK_H


/* Count errors and error correction from blockcheck.c */
struct ocfs2_blockcheck_stats {
	spinlock_t b_lock;
	u64 b_check_count;	/* Number of blocks we've checked */
	u64 b_failure_count;	/* Number of failed checksums */
	u64 b_recover_count;	/* Number of blocks fixed by ecc */

	/*
	 * debugfs entries, used if this is passed to
	 * ocfs2_blockcheck_stats_debugfs_install()
	 */
	struct dentry *b_debug_dir;	/* Parent of the debugfs  files */
};


/* High level block API */
void ocfs2_compute_meta_ecc(struct super_block *sb, void *data,
			    struct ocfs2_block_check *bc);
int ocfs2_validate_meta_ecc(struct super_block *sb, void *data,
			    struct ocfs2_block_check *bc);
void ocfs2_compute_meta_ecc_bhs(struct super_block *sb,
				struct buffer_head **bhs, int nr,
				struct ocfs2_block_check *bc);
int ocfs2_validate_meta_ecc_bhs(struct super_block *sb,
				struct buffer_head **bhs, int nr,
				struct ocfs2_block_check *bc);

/* Lower level API */
void ocfs2_block_check_compute(void *data, size_t blocksize,
			       struct ocfs2_block_check *bc);
int ocfs2_block_check_validate(void *data, size_t blocksize,
			       struct ocfs2_block_check *bc,
			       struct ocfs2_blockcheck_stats *stats);
void ocfs2_block_check_compute_bhs(struct buffer_head **bhs, int nr,
				   struct ocfs2_block_check *bc);
int ocfs2_block_check_validate_bhs(struct buffer_head **bhs, int nr,
				   struct ocfs2_block_check *bc,
				   struct ocfs2_blockcheck_stats *stats);

/* Debug Initialization */
void ocfs2_blockcheck_stats_debugfs_install(struct ocfs2_blockcheck_stats *stats,
					    struct dentry *parent);
void ocfs2_blockcheck_stats_debugfs_remove(struct ocfs2_blockcheck_stats *stats);

/*
 * Hamming code functions
 */

/*
 * Encoding hamming code parity bits for a buffer.
 *
 * This is the low level encoder function.  It can be called across
 * multiple hunks just like the crc32 code.  'd' is the number of bits
 * _in_this_hunk_.  nr is the bit offset of this hunk.  So, if you had
 * two 512B buffers, you would do it like so:
 *
 * parity = ocfs2_hamming_encode(0, buf1, 512 * 8, 0);
 * parity = ocfs2_hamming_encode(parity, buf2, 512 * 8, 512 * 8);
 *
 * If you just have one buffer, use ocfs2_hamming_encode_block().
 */
u32 ocfs2_hamming_encode(u32 parity, void *data, unsigned int d,
			 unsigned int nr);
/*
 * Fix a buffer with a bit error.  The 'fix' is the original parity
 * xor'd with the parity calculated now.
 *
 * Like ocfs2_hamming_encode(), this can handle hunks.  nr is the bit
 * offset of the current hunk.  If bit to be fixed is not part of the
 * current hunk, this does nothing.
 *
 * If you only have one buffer, use ocfs2_hamming_fix_block().
 */
void ocfs2_hamming_fix(void *data, unsigned int d, unsigned int nr,
		       unsigned int fix);

/* Convenience wrappers for a single buffer of data */
extern u32 ocfs2_hamming_encode_block(void *data, unsigned int blocksize);
extern void ocfs2_hamming_fix_block(void *data, unsigned int blocksize,
				    unsigned int fix);
#endif
Commit	Line	Data
1802d0be	1	/* SPDX-License-Identifier: GPL-2.0-only */
70ad1ba7 JB	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.
70ad1ba7 JB	10	*/
	11
	12	#ifndef OCFS2_BLOCKCHECK_H
	13	#define OCFS2_BLOCKCHECK_H
	14
	15
73be192b JB	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 */
73be192b JB	28	};
	29
	30
70ad1ba7 JB	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,
73be192b JB	47	struct ocfs2_block_check *bc,
73be192b JB	48	struct ocfs2_blockcheck_stats *stats);
70ad1ba7 JB	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,
73be192b JB	52	struct ocfs2_block_check *bc,
	53	struct ocfs2_blockcheck_stats *stats);
	54
	55	/* Debug Initialization */
e581595e GKH	56	void ocfs2_blockcheck_stats_debugfs_install(struct ocfs2_blockcheck_stats *stats,
e581595e GKH	57	struct dentry *parent);
73be192b	58	void ocfs2_blockcheck_stats_debugfs_remove(struct ocfs2_blockcheck_stats *stats);
70ad1ba7 JB	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