evms_bbr_k.h

unxi下共享内存的使用

#ifndef __EVMS_BBR_K__
#define __EVMS_BBR_K__

/*
 *
 *   Copyright (c) International Business Machines  Corp., 2000
 *
 *   This program is free software;  you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY;  without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
 *   the GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program;  if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

/* linux/include/linux/evms/evms_bbr_k.h
 *
 * Kernel header file for Bad Block Relocation (BBR) Feature
 *
 * BBR feature is designed to remap I/O write failures to another safe location on disk.
 * Note that most disk drives have BBR built into them, this means that our software BBR
 * will be only activated when all hardware BBR replacement sectors have been used.
 */

#include <linux/config.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/smp_lock.h>
#include <linux/locks.h>
#include <linux/delay.h>
#include <linux/reboot.h>
#include <linux/completion.h>
#include <linux/vmalloc.h>
#include <asm/uaccess.h>
#include <linux/blk.h>

#include <linux/evms/evms_kernel.h>
#include <linux/evms/evms_bbr.h>

#define BBR_POOL_NAME_LENGTH	20

/* Required common services version */
#define EVMS_BBR_COMMON_SERVICES_MAJOR		0
#define EVMS_BBR_COMMON_SERVICES_MINOR		6
#define EVMS_BBR_COMMON_SERVICES_PATCHLEVEL	0


static int bbr_notify_reboot(
	struct notifier_block *this,
	unsigned long code, 
	void *x);

typedef struct bbr_runtime_remap_s {
	evms_bbr_table_entry_t		 remap;
	struct bbr_runtime_remap_s 	*left;	/** for binary tree */
	struct bbr_runtime_remap_s 	*right;	/** for binary tree */
}bbr_runtime_remap_t;


/* local instance data structure definition */

#define BBR_STOP_REMAP	(1<<0)

typedef struct bbr_instance_data_s {
	struct bbr_instance_data_s *next;	/* link all bbr_instances */
	evms_logical_node_t	*node;		/* bbr_node */
	evms_logical_node_t	*source;	/* consumed node */
	evms_bbr_table_t	*bbr_table;
	u_int64_t		lba_table1;
	u_int64_t		lba_table2;
	u_int64_t		nr_sects_bbr_table;
	u_int64_t		nr_replacement_blks;
	u_int64_t		start_replacement_sect;
	u_int32_t		blksize_in_sects;
	evms_pool_mgmt_t	*bbr_bh_pool;
	char			bh_pool_name[BBR_POOL_NAME_LENGTH+1];
	evms_pool_mgmt_t	*remap_pool;
	char			remap_pool_name[BBR_POOL_NAME_LENGTH+1];
	atomic_t		in_use_replacement_blks;
	bbr_runtime_remap_t	*remap_root;		/* for binary tree */
	spinlock_t		bbr_id_lock;    	/* lock for runtime remap table */
	u_int32_t		flag;
	evms_sector_t		total_vsectors;
} bbr_instance_data_t;

#define BBR_BH_USE_EVMS_CALLBACK (1<<0)		// Set if an EVMS callback was registered for this I/O

typedef struct bbr_bh_s {
	struct bbr_bh_s		*next;		// Used by bbr_io_list.
	bbr_instance_data_t	*BBRID;		// Object for this request.
	eio_t			eio;		// Original eio.
	atomic_t		waiters;	// Used by bbr_init_io.
	int			rw;		// READ or WRITE
	int			rc;		// Return code from bbr_io_handler.
	unsigned long		flag;
}bbr_bh_t;


/*   --- discovery support functions ---  */
static int load_feature_data(
	evms_logical_node_t *node,
	bbr_instance_data_t **ID);

static int load_meta_data(
	evms_logical_node_t *node,
	evms_sector_t LSN,
	evms_bbr_metadata_t **md,
	evms_bbr_table_t **bbr_table);

static int validate_meta_data(evms_bbr_metadata_t *md);
static int validate_bbr_table_sector(evms_bbr_table_t *p);
static u_int32_t validate_bbr_table(
	evms_bbr_metadata_t *md,
	evms_bbr_table_t *p);
static u_int32_t validate_bbr_tables(
	evms_logical_node_t *node,
	evms_bbr_metadata_t *MD1,
	evms_bbr_metadata_t *MD2,
	evms_bbr_table_t *p1,
	evms_bbr_table_t *p2);
void update_invalid_bbr_table_sector(
	evms_logical_node_t *node,
	evms_bbr_table_t *valid,
	evms_bbr_table_t *invalid,
	evms_sector_t LSN);

static u_int32_t bbr_table_to_remap_list(bbr_instance_data_t *BBRID);

static int bbr_create_pools(bbr_instance_data_t *BBRID);
static void bbr_destroy_pools(bbr_instance_data_t *BBRID);

#ifdef EVMS_BBR_DEBUG
static void print_meta_data(evms_bbr_metadata_t *md);
static void print_bbr_table_sector(evms_bbr_table_t *bbr_table);
static void print_remap_list(bbr_instance_data_t *BBRID);
#define BBR_DEBUG_PRINT_META_DATA(md) print_meta_data(md)
#define BBR_DEBUG_PRINT_TABLE_SECTOR(table) print_bbr_table_sector(table)
#define BBR_DEBUG_PRINT_REMAP_LIST(BBRID) print_remap_list(BBRID)
#else
#define BBR_DEBUG_PRINT_META_DATA(md)
#define BBR_DEBUG_PRINT_TABLE_SECTOR(table)
#define BBR_DEBUG_PRINT_REMAP_LIST(BBRID)
#endif

#define BBR_BUG(msg) LOG_SERIOUS(__FUNCTION__ msg "\n")

/* -- Mapping functions -- */
void bbr_binary_tree_insert(
	bbr_runtime_remap_t **node, 
	bbr_runtime_remap_t *newnode);
bbr_runtime_remap_t * bbr_binary_search(
	bbr_runtime_remap_t *node, 
	evms_sector_t bad_sect);
static int bbr_insert_remap_entry(
	bbr_instance_data_t *BBRID,
	evms_bbr_table_entry_t *new_bbr_entry);
static evms_bbr_table_entry_t * bbr_search_remap_entry(
	bbr_instance_data_t *BBRID,
	evms_sector_t sect);
static inline int bbr_remap(
	bbr_instance_data_t *BBRID,
	evms_sector_t *lsn);
static void bbr_free_remap(bbr_instance_data_t *BBRID);
static void bbr_free_instance_data(bbr_instance_data_t *BBRID);
static inline void bbr_list_add(bbr_instance_data_t *BBRID);
static void bbr_list_remove(bbr_instance_data_t *BBRID);
static bbr_instance_data_t *bbr_find_instance_data (char * object_name);

/*   --- runtime support functions ---  */
static bbr_bh_t * allocate_bbr_bh(
	bbr_instance_data_t *BBRID,
	int rw);
static void bbr_io_handler( void * void_data );

/* -- EVMS Plugin interface functions -- */
static int  bbr_discover(evms_logical_node_t **);
static int  bbr_delete(evms_logical_node_t *);
static void bbr_read(evms_logical_node_t *, eio_t *);
static void bbr_write(evms_logical_node_t *, eio_t *);
static int bbr_ioctl (
	evms_logical_node_t *bbr_node,
	struct inode *inode,
	struct file *file,
	unsigned int cmd,
	unsigned long arg);
static int bbr_direct_ioctl (
	struct inode *inode,
	struct file *file,
	unsigned int cmd,
	unsigned long arg);

static int bbr_init_io(
	evms_logical_node_t * bbr_node,
	int io_flag,
	evms_sector_t startLSN,
	evms_sector_t nr_sects,
	void *bufptr );

#endif