1da177e4c3
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
94 lines
2.3 KiB
C
94 lines
2.3 KiB
C
/*
|
|
* Copyright (C) 2003 Sistina Software.
|
|
* Copyright (C) 2004 Red Hat, Inc. All rights reserved.
|
|
*
|
|
* Module Author: Heinz Mauelshagen
|
|
*
|
|
* This file is released under the GPL.
|
|
*
|
|
* Path-Selector registration.
|
|
*/
|
|
|
|
#ifndef DM_PATH_SELECTOR_H
|
|
#define DM_PATH_SELECTOR_H
|
|
|
|
#include <linux/device-mapper.h>
|
|
|
|
#include "dm-mpath.h"
|
|
|
|
/*
|
|
* We provide an abstraction for the code that chooses which path
|
|
* to send some io down.
|
|
*/
|
|
struct path_selector_type;
|
|
struct path_selector {
|
|
struct path_selector_type *type;
|
|
void *context;
|
|
};
|
|
|
|
/* Information about a path selector type */
|
|
struct path_selector_type {
|
|
char *name;
|
|
struct module *module;
|
|
|
|
unsigned int table_args;
|
|
unsigned int info_args;
|
|
|
|
/*
|
|
* Constructs a path selector object, takes custom arguments
|
|
*/
|
|
int (*create) (struct path_selector *ps, unsigned argc, char **argv);
|
|
void (*destroy) (struct path_selector *ps);
|
|
|
|
/*
|
|
* Add an opaque path object, along with some selector specific
|
|
* path args (eg, path priority).
|
|
*/
|
|
int (*add_path) (struct path_selector *ps, struct path *path,
|
|
int argc, char **argv, char **error);
|
|
|
|
/*
|
|
* Chooses a path for this io, if no paths are available then
|
|
* NULL will be returned.
|
|
*
|
|
* repeat_count is the number of times to use the path before
|
|
* calling the function again. 0 means don't call it again unless
|
|
* the path fails.
|
|
*/
|
|
struct path *(*select_path) (struct path_selector *ps,
|
|
unsigned *repeat_count);
|
|
|
|
/*
|
|
* Notify the selector that a path has failed.
|
|
*/
|
|
void (*fail_path) (struct path_selector *ps, struct path *p);
|
|
|
|
/*
|
|
* Ask selector to reinstate a path.
|
|
*/
|
|
int (*reinstate_path) (struct path_selector *ps, struct path *p);
|
|
|
|
/*
|
|
* Table content based on parameters added in ps_add_path_fn
|
|
* or path selector status
|
|
*/
|
|
int (*status) (struct path_selector *ps, struct path *path,
|
|
status_type_t type, char *result, unsigned int maxlen);
|
|
|
|
int (*end_io) (struct path_selector *ps, struct path *path);
|
|
};
|
|
|
|
/* Register a path selector */
|
|
int dm_register_path_selector(struct path_selector_type *type);
|
|
|
|
/* Unregister a path selector */
|
|
int dm_unregister_path_selector(struct path_selector_type *type);
|
|
|
|
/* Returns a registered path selector type */
|
|
struct path_selector_type *dm_get_path_selector(const char *name);
|
|
|
|
/* Releases a path selector */
|
|
void dm_put_path_selector(struct path_selector_type *pst);
|
|
|
|
#endif
|