From a765e20eeb423d0fa6a02ffab51141e53bbd93cb Mon Sep 17 00:00:00 2001 From: Alasdair G Kergon Date: Thu, 24 Apr 2008 22:02:01 +0100 Subject: dm: move include files Publish the dm-io, dm-log and dm-kcopyd headers in include/linux. Signed-off-by: Alasdair G Kergon --- include/linux/dm-dirty-log.h | 131 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 131 insertions(+) create mode 100644 include/linux/dm-dirty-log.h (limited to 'include/linux/dm-dirty-log.h') diff --git a/include/linux/dm-dirty-log.h b/include/linux/dm-dirty-log.h new file mode 100644 index 00000000000..600c5fb2daa --- /dev/null +++ b/include/linux/dm-dirty-log.h @@ -0,0 +1,131 @@ +/* + * 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 +#include + +typedef sector_t region_t; + +struct dm_dirty_log_type; + +struct dm_dirty_log { + struct dm_dirty_log_type *type; + void *context; +}; + +struct dm_dirty_log_type { + const char *name; + struct module *module; + + 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); +}; + +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, + unsigned argc, char **argv); +void dm_dirty_log_destroy(struct dm_dirty_log *log); + +#endif /* __KERNEL__ */ +#endif /* _LINUX_DM_DIRTY_LOG_H */ -- cgit v1.2.3-70-g09d2