linux/drivers/md/dm-hw-handler.h

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/*
* Copyright (C) 2004 Red Hat, Inc. All rights reserved.
*
* This file is released under the GPL.
*
* Multipath hardware handler registration.
*/
#ifndef DM_HW_HANDLER_H
#define DM_HW_HANDLER_H
#include <linux/device-mapper.h>
#include "dm-mpath.h"
struct hw_handler_type;
struct hw_handler {
struct hw_handler_type *type;
void *context;
};
/*
* Constructs a hardware handler object, takes custom arguments
*/
/* Information about a hardware handler type */
struct hw_handler_type {
char *name;
struct module *module;
int (*create) (struct hw_handler *handler, unsigned int argc,
char **argv);
void (*destroy) (struct hw_handler *hwh);
void (*pg_init) (struct hw_handler *hwh, unsigned bypassed,
struct dm_path *path);
unsigned (*error) (struct hw_handler *hwh, struct bio *bio);
int (*status) (struct hw_handler *hwh, status_type_t type,
char *result, unsigned int maxlen);
};
/* Register a hardware handler */
int dm_register_hw_handler(struct hw_handler_type *type);
/* Unregister a hardware handler */
int dm_unregister_hw_handler(struct hw_handler_type *type);
/* Returns a registered hardware handler type */
struct hw_handler_type *dm_get_hw_handler(const char *name);
/* Releases a hardware handler */
void dm_put_hw_handler(struct hw_handler_type *hwht);
/* Default err function */
unsigned dm_scsi_err_handler(struct hw_handler *hwh, struct bio *bio);
/* Error flags for err and dm_pg_init_complete */
#define MP_FAIL_PATH 1
#define MP_BYPASS_PG 2
#define MP_ERROR_IO 4 /* Don't retry this I/O */
#endif