131 lines
3.3 KiB
C
131 lines
3.3 KiB
C
/*
|
|
* Copyright (C) 2003 Sistina Software
|
|
*
|
|
* This file is released under the LGPL.
|
|
*/
|
|
|
|
#ifndef DM_DIRTY_LOG
|
|
#define DM_DIRTY_LOG
|
|
|
|
#include "dm.h"
|
|
|
|
typedef sector_t region_t;
|
|
|
|
struct dirty_log_type;
|
|
|
|
struct dirty_log {
|
|
struct dirty_log_type *type;
|
|
void *context;
|
|
};
|
|
|
|
struct dirty_log_type {
|
|
struct list_head list;
|
|
const char *name;
|
|
struct module *module;
|
|
unsigned int use_count;
|
|
|
|
int (*ctr)(struct dirty_log *log, struct dm_target *ti,
|
|
unsigned int argc, char **argv);
|
|
void (*dtr)(struct dirty_log *log);
|
|
|
|
/*
|
|
* There are times when we don't want the log to touch
|
|
* the disk.
|
|
*/
|
|
int (*suspend)(struct dirty_log *log);
|
|
int (*resume)(struct dirty_log *log);
|
|
|
|
/*
|
|
* Retrieves the smallest size of region that the log can
|
|
* deal with.
|
|
*/
|
|
uint32_t (*get_region_size)(struct dirty_log *log);
|
|
|
|
/*
|
|
* A predicate to say whether a region is clean or not.
|
|
* May block.
|
|
*/
|
|
int (*is_clean)(struct dirty_log *log, region_t region);
|
|
|
|
/*
|
|
* Returns: 0, 1, -EWOULDBLOCK, < 0
|
|
*
|
|
* A predicate function to check the area given by
|
|
* [sector, sector + len) is in sync.
|
|
*
|
|
* If -EWOULDBLOCK is returned the state of the region is
|
|
* unknown, typically this will result in a read being
|
|
* passed to a daemon to deal with, since a daemon is
|
|
* allowed to block.
|
|
*/
|
|
int (*in_sync)(struct dirty_log *log, region_t region, int can_block);
|
|
|
|
/*
|
|
* Flush the current log state (eg, to disk). This
|
|
* function may block.
|
|
*/
|
|
int (*flush)(struct dirty_log *log);
|
|
|
|
/*
|
|
* Mark an area as clean or dirty. These functions may
|
|
* block, though for performance reasons blocking should
|
|
* be extremely rare (eg, allocating another chunk of
|
|
* memory for some reason).
|
|
*/
|
|
void (*mark_region)(struct dirty_log *log, region_t region);
|
|
void (*clear_region)(struct dirty_log *log, region_t region);
|
|
|
|
/*
|
|
* Returns: <0 (error), 0 (no region), 1 (region)
|
|
*
|
|
* The mirrord will need perform recovery on regions of
|
|
* the mirror that are in the NOSYNC state. This
|
|
* function asks the log to tell the caller about the
|
|
* next region that this machine should recover.
|
|
*
|
|
* Do not confuse this function with 'in_sync()', one
|
|
* tells you if an area is synchronised, the other
|
|
* assigns recovery work.
|
|
*/
|
|
int (*get_resync_work)(struct dirty_log *log, region_t *region);
|
|
|
|
/*
|
|
* This notifies the log that the resync of an area has
|
|
* been completed. The log should then mark this region
|
|
* as CLEAN.
|
|
*/
|
|
void (*complete_resync_work)(struct dirty_log *log,
|
|
region_t region, int success);
|
|
|
|
/*
|
|
* Returns the number of regions that are in sync.
|
|
*/
|
|
region_t (*get_sync_count)(struct dirty_log *log);
|
|
|
|
/*
|
|
* Support function for mirror status requests.
|
|
*/
|
|
int (*status)(struct dirty_log *log, status_type_t status_type,
|
|
char *result, unsigned int maxlen);
|
|
};
|
|
|
|
int dm_register_dirty_log_type(struct dirty_log_type *type);
|
|
int dm_unregister_dirty_log_type(struct dirty_log_type *type);
|
|
|
|
|
|
/*
|
|
* Make sure you use these two functions, rather than calling
|
|
* type->constructor/destructor() directly.
|
|
*/
|
|
struct dirty_log *dm_create_dirty_log(const char *type_name, struct dm_target *ti,
|
|
unsigned int argc, char **argv);
|
|
void dm_destroy_dirty_log(struct dirty_log *log);
|
|
|
|
/*
|
|
* init/exit functions.
|
|
*/
|
|
int dm_dirty_log_init(void);
|
|
void dm_dirty_log_exit(void);
|
|
|
|
#endif
|