evms.h

unxi下共享内存的使用

/* -*- linux-c -*- */
/*
 *
 *   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.h
 *
 * EVMS public kernel header file
 *
 */

#ifndef __EVMS_INCLUDED__
#define __EVMS_INCLUDED__

#include <linux/genhd.h>
#include <linux/fs.h>
#include <linux/iobuf.h>
#include <linux/kdev_t.h>
#include <linux/hdreg.h>
#include <linux/slab.h>
#include <linux/proc_fs.h>

#define FALSE                           0
#define TRUE                            1

/* tracing info */
#define EVMS_INFO_CRITICAL              0
#define EVMS_INFO_SERIOUS               1
#define EVMS_INFO_ERROR                 2
#define EVMS_INFO_WARNING               3
#define EVMS_INFO_DEFAULT               5
#define EVMS_INFO_DETAILS               6
#define EVMS_INFO_DEBUG                 7
#define EVMS_INFO_EXTRA                 8
#define EVMS_INFO_ENTRY_EXIT            9
#define EVMS_INFO_EVERYTHING            10

extern int evms_info_level;
/* information message: e.g., configuration, major event */
#define evmsTRACE(info_level,prspec) { if (evms_info_level >= info_level) printk prspec; }
#define evmsTRACE2(info_level,statement) { if (evms_info_level >= info_level) statement; }
// sample - be sure to use enclose "prspec" or "statement" with parens ()
// evmsTRACE(info_level,(KERN_INFO "evms_myfunction: name = %s\n", name));
// evmsTRACE2(info_level,(print_mem( buffer_address, buffer_length)));
                                                            
/* LOG MACROS to make evms log messages look much 
 * cleaner in the source.
 */
#define EVMS_LOG_PREFIX "evms: "
#define LOG_CRITICAL(msg, args...)	evmsTRACE(EVMS_INFO_CRITICAL,   (KERN_CRIT    EVMS_LOG_PREFIX LOG_PREFIX msg, ## args))
#define LOG_SERIOUS(msg, args...)	evmsTRACE(EVMS_INFO_SERIOUS,    (KERN_ERR     EVMS_LOG_PREFIX LOG_PREFIX msg, ## args))
#define LOG_ERROR(msg, args...)		evmsTRACE(EVMS_INFO_ERROR,      (KERN_ERR     EVMS_LOG_PREFIX LOG_PREFIX msg, ## args))
#define LOG_WARNING(msg, args...)	evmsTRACE(EVMS_INFO_WARNING,    (KERN_WARNING EVMS_LOG_PREFIX LOG_PREFIX msg, ## args))
#define LOG_DEFAULT(msg, args...)	evmsTRACE(EVMS_INFO_DEFAULT,    (KERN_INFO    EVMS_LOG_PREFIX LOG_PREFIX msg, ## args))
#define LOG_DETAILS(msg, args...)	evmsTRACE(EVMS_INFO_DETAILS,    (KERN_INFO    EVMS_LOG_PREFIX LOG_PREFIX msg, ## args))
#define LOG_DEBUG(msg, args...)		evmsTRACE(EVMS_INFO_DEBUG,      (KERN_INFO    EVMS_LOG_PREFIX LOG_PREFIX msg, ## args))
#define LOG_EXTRA(msg, args...)		evmsTRACE(EVMS_INFO_EXTRA,      (KERN_INFO    EVMS_LOG_PREFIX LOG_PREFIX msg, ## args))
#define LOG_ENTRY_EXIT(msg, args...)	evmsTRACE(EVMS_INFO_ENTRY_EXIT, (KERN_INFO    EVMS_LOG_PREFIX LOG_PREFIX msg, ## args))
#define LOG_EVERYTHING(msg, args...)	evmsTRACE(EVMS_INFO_EVERYTHING, (KERN_INFO    EVMS_LOG_PREFIX LOG_PREFIX msg, ## args))

#ifdef CONFIG_PROC_FS
#define PROCPRINT(msg, args...) (sz += sprintf(page + sz, msg, ## args))
#endif

#define EVMS_HANDLE_KEY         0x89ABCDEF

/* Plugin structure definitions */

typedef struct evms_plugin_header_s {
        u_int32_t                 id;
        evms_version_t            version;
        evms_version_t            required_common_services_version;
        struct evms_plugin_function_table_s  *function_table;
} evms_plugin_header_t;

typedef struct evms_volume_info_s {
/*  0*/ u_int64_t               volume_serial_number;
/*  8*/ u_int32_t               volume_system_id;       /* the minor is stored here */
/* 12*/ char                    volume_name[EVMS_VOLUME_NAME_SIZE+1];
/*140*/
} evms_volume_info_t;

/* flags field bit definitions in evms_common.h */
/* iflags field used internally by the kernel only */
#define EVMS_FEATURE_BOTTOM			(1<<0)
typedef struct evms_logical_node_s {
/*  0*/ evms_sector_t                    total_vsectors;
/*  8*/ evms_plugin_header_t           * plugin;
/* 12*/ void                           * instance_data;         /* ptr to private instance data */
/* 16*/ unsigned int                     flags;
/* 20*/	unsigned int			 iflags;
/* 24*/	int				 hardsector_size;
/* 28*/	int				 block_size;
/* 32*/ unsigned int	                 system_id;
/* 36*/	evms_volume_info_t	       * volume_info;
/* 40*/ evms_feature_header_t          * feature_header;
/* 44*/ struct evms_logical_node_s     * next;
/* 48*/	char 			         name[EVMS_VOLUME_NAME_SIZE+1];
/*176*/
} evms_logical_node_t;

/* this macro will retrieve the appropriate kernel node name
 * based on the node type.
 */
#define EVMS_GET_NODE_NAME(node) 				\
	((node->flags & EVMS_VOLUME_FLAG) ?			\
		node->volume_info->volume_name :		\
		node->name)

/* bit definitions of FLAGS field in logical volume struct */
/* NOTE: these bit field definitions can be found in 
 * evms_ioctl.h above the evms_volume_data_t structure
 */
typedef struct evms_logical_volume_s {
        char                           * name;                  /* devfs name if any */
        evms_logical_node_t            * node;                  /* ptr to top logical node */
	int				 flags;
        int                              quiesced;
	int                              vfs_quiesced;
        atomic_t                         requests_in_progress;
        wait_queue_head_t                wait_queue;
        devfs_handle_t                   devfs_handle;
#ifdef CONFIG_SMP
	request_queue_t		         request_queue;
#endif
} evms_logical_volume_t;

/* EVMS generic I/O structure */
typedef struct eio_s {
	evms_sector_t		rsector;
	evms_sector_t		rsize;
	struct buffer_head     *bh;
} eio_t;

/* Abstraction MACROs */
#define EVMS_IO_ERROR(eio) (buffer_IO_error(eio->bh))

/*
 * The following function table is used for all plugins.
 */
typedef struct evms_plugin_function_table_s {
        int  (* discover)(evms_logical_node_t **);
        int  (* end_discover)(evms_logical_node_t **);
        int  (* delete)  (evms_logical_node_t *);
        void (* read)    (evms_logical_node_t *, eio_t *);
        void (* write)   (evms_logical_node_t *, eio_t *);
        int  (* init_io) (evms_logical_node_t *, int, evms_sector_t, 
                          evms_sector_t, void *);
        int  (* ioctl)   (evms_logical_node_t *, struct inode *, 
                          struct file *, unsigned int, unsigned long);
	int  (* direct_ioctl)(struct inode *, struct file *,
		              unsigned int, unsigned long);
} evms_plugin_function_table_t;

/* 
 * These macros facilitate easier use of the 
 * entry points in the function table
 */
#define DISCOVER(node, list) ((node)->plugin->function_table->discover(list))
#define END_DISCOVER(node, list) ((node)->plugin->function_table->end_discover(list))
#define DELETE(node) ((node)->plugin->function_table->delete(node))
#define R_IO(node, eio)  ((node)->plugin->function_table->read(node, eio))
#define W_IO(node, eio)  ((node)->plugin->function_table->write(node, eio))
#define INIT_IO(node, rw_flag, start_sec, num_secs, buf_addr) ((node)->plugin->function_table->init_io(node, rw_flag, start_sec, num_secs, buf_addr))
#define INT_IO(node, rw_flag, start_sec, num_secs, buf_addr) ((node)->plugin->function_table->int_io(node, rw_flag, start_sec, num_secs, buf_addr))
#define IOCTL(node, inode, file, cmd, arg)    ((node)->plugin->function_table->ioctl(node, inode, file, cmd, arg))
#define DIRECT_IOCTL(reg_record, inode, file, cmd, arg)   ((reg_record)->plugin->function_table->direct_ioctl(inode, file, cmd, arg))

typedef struct evms_list_node_s {
	void 			*item;
	struct evms_list_node_s *next;
} evms_list_node_t;

/* pool management structure */
typedef struct evms_pool_mgmt_s {
	kmem_cache_t	*cachep;
	int		 member_size;
	void		*head;
	atomic_t	 waiters;
	wait_queue_head_t wait_queue;
	/* WARNING!!! pool name MUST be less than 20 chars */
	char 		*name;
} evms_pool_mgmt_t;

/*
 * Notes:  
 *	All of the following kernel thread functions belong to EVMS base.
 *	These functions were copied from md_core.c
 */
#define EVMS_THREAD_WAKEUP 0
typedef struct evms_thread_s {
	void			(*run) (void *data);
	void			*data;
	wait_queue_head_t	wqueue;
	unsigned long           flags;
	struct completion	*event;
	struct task_struct	*tsk;
	const char		*name;
} evms_thread_t;

/* EVMS (common services) exported functions prototypes */
#define EVMS_COMMON_SERVICES_MAJOR              0
#define EVMS_COMMON_SERVICES_MINOR              6
#define EVMS_COMMON_SERVICES_PATCHLEVEL         0

void evms_cs_get_version(int *, int *);
int evms_cs_check_version(evms_version_t *, evms_version_t *);
int evms_cs_register_plugin(evms_plugin_header_t *);
int evms_cs_unregister_plugin(evms_plugin_header_t *);
#ifdef EVMS_MEM_DEBUG
int evms_cs_verify_memory_integrity(int);
#endif
int evms_cs_allocate_memory(void **, int);
int evms_cs_deallocate_memory(void *);
int evms_cs_allocate_logical_node(evms_logical_node_t **);
void evms_cs_deallocate_volume_info(evms_logical_node_t *);
int evms_cs_deallocate_logical_node(evms_logical_node_t *);
int evms_cs_add_logical_node_to_list(evms_logical_node_t **, 
                                     evms_logical_node_t *);
int evms_cs_remove_logical_node_from_list(evms_logical_node_t **,
                                          evms_logical_node_t *);
int evms_cs_kernel_ioctl(evms_logical_node_t *, unsigned int, 
                         unsigned long);
int evms_cs_get_hardsect_size(evms_logical_node_t *, int *);
int evms_cs_get_blocksize_size(evms_logical_node_t *, int *);
unsigned long evms_cs_size_in_sectors(unsigned long, unsigned long);
unsigned long evms_cs_size_in_vsectors(long long);
int evms_cs_log2(long long);
u_int32_t evms_cs_calculate_crc(u_int32_t, void *, u_int32_t);
int evms_cs_register_for_end_io_notification(void *,
                                             struct buffer_head *,
                                             void *callback_function);
evms_pool_mgmt_t * evms_cs_create_pool(
	int,
	char *, 
        void (*ctor)(void*, kmem_cache_t *, unsigned long),
	void (*dtor)(void*, kmem_cache_t *, unsigned long));
#define EVMS_BLOCKABLE	TRUE
void * evms_cs_allocate_from_pool(evms_pool_mgmt_t *, int);
void   evms_cs_deallocate_to_pool(evms_pool_mgmt_t *, void *);
void   evms_cs_destroy_pool(evms_pool_mgmt_t *);
int evms_cs_add_item_to_list(evms_list_node_t **, void *);
int evms_cs_remove_item_from_list(evms_list_node_t **, void *);
int evms_cs_register_device(evms_logical_node_t *);
int evms_cs_unregister_device(evms_logical_node_t *);
int evms_cs_find_next_device(evms_logical_node_t *, 
			     evms_logical_node_t **);
void evms_cs_signal_event(int);
evms_thread_t * evms_cs_register_thread (
	void (*run) (void *), 
	void *data, 
	const char *name);
void evms_cs_unregister_thread (evms_thread_t *thread);
void evms_cs_wakeup_thread(evms_thread_t *thread);
void evms_cs_interrupt_thread (evms_thread_t *thread);
struct proc_dir_entry *evms_cs_get_evms_proc_dir(void);
int evms_cs_volume_request_in_progress(kdev_t, int, int *);


/* EVMS exported global variables */
extern evms_pool_mgmt_t *evms_bh_pool;
extern char *evms_primary_string;
extern char *evms_secondary_string;
#endif