mirror of https://github.com/Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
146 lines
3.9 KiB
146 lines
3.9 KiB
/* |
|
* Copyright (C) 2003 Sistina Software |
|
* Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved. |
|
* |
|
* Device-Mapper dirty region log. |
|
* |
|
* This file is released under the LGPL. |
|
*/ |
|
|
|
#ifndef _LINUX_DM_DIRTY_LOG |
|
#define _LINUX_DM_DIRTY_LOG |
|
|
|
#ifdef __KERNEL__ |
|
|
|
#include <linux/types.h> |
|
#include <linux/device-mapper.h> |
|
|
|
typedef sector_t region_t; |
|
|
|
struct dm_dirty_log_type; |
|
|
|
struct dm_dirty_log { |
|
struct dm_dirty_log_type *type; |
|
int (*flush_callback_fn)(struct dm_target *ti); |
|
void *context; |
|
}; |
|
|
|
struct dm_dirty_log_type { |
|
const char *name; |
|
struct module *module; |
|
|
|
/* For internal device-mapper use */ |
|
struct list_head list; |
|
|
|
int (*ctr)(struct dm_dirty_log *log, struct dm_target *ti, |
|
unsigned argc, char **argv); |
|
void (*dtr)(struct dm_dirty_log *log); |
|
|
|
/* |
|
* There are times when we don't want the log to touch |
|
* the disk. |
|
*/ |
|
int (*presuspend)(struct dm_dirty_log *log); |
|
int (*postsuspend)(struct dm_dirty_log *log); |
|
int (*resume)(struct dm_dirty_log *log); |
|
|
|
/* |
|
* Retrieves the smallest size of region that the log can |
|
* deal with. |
|
*/ |
|
uint32_t (*get_region_size)(struct dm_dirty_log *log); |
|
|
|
/* |
|
* A predicate to say whether a region is clean or not. |
|
* May block. |
|
*/ |
|
int (*is_clean)(struct dm_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 dm_dirty_log *log, region_t region, |
|
int can_block); |
|
|
|
/* |
|
* Flush the current log state (eg, to disk). This |
|
* function may block. |
|
*/ |
|
int (*flush)(struct dm_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 dm_dirty_log *log, region_t region); |
|
void (*clear_region)(struct dm_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 dm_dirty_log *log, region_t *region); |
|
|
|
/* |
|
* This notifies the log that the resync status of a region |
|
* has changed. It also clears the region from the recovering |
|
* list (if present). |
|
*/ |
|
void (*set_region_sync)(struct dm_dirty_log *log, |
|
region_t region, int in_sync); |
|
|
|
/* |
|
* Returns the number of regions that are in sync. |
|
*/ |
|
region_t (*get_sync_count)(struct dm_dirty_log *log); |
|
|
|
/* |
|
* Support function for mirror status requests. |
|
*/ |
|
int (*status)(struct dm_dirty_log *log, status_type_t status_type, |
|
char *result, unsigned maxlen); |
|
|
|
/* |
|
* is_remote_recovering is necessary for cluster mirroring. It provides |
|
* a way to detect recovery on another node, so we aren't writing |
|
* concurrently. This function is likely to block (when a cluster log |
|
* is used). |
|
* |
|
* Returns: 0, 1 |
|
*/ |
|
int (*is_remote_recovering)(struct dm_dirty_log *log, region_t region); |
|
}; |
|
|
|
int dm_dirty_log_type_register(struct dm_dirty_log_type *type); |
|
int dm_dirty_log_type_unregister(struct dm_dirty_log_type *type); |
|
|
|
/* |
|
* Make sure you use these two functions, rather than calling |
|
* type->constructor/destructor() directly. |
|
*/ |
|
struct dm_dirty_log *dm_dirty_log_create(const char *type_name, |
|
struct dm_target *ti, |
|
int (*flush_callback_fn)(struct dm_target *ti), |
|
unsigned argc, char **argv); |
|
void dm_dirty_log_destroy(struct dm_dirty_log *log); |
|
|
|
#endif /* __KERNEL__ */ |
|
#endif /* _LINUX_DM_DIRTY_LOG_H */
|
|
|