Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2003 Sistina Software |
Heinz Mauelshagen | 416cd17 | 2008-04-24 21:43:35 +0100 | [diff] [blame] | 3 | * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved. |
| 4 | * |
| 5 | * Device-Mapper dirty region log. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 6 | * |
| 7 | * This file is released under the LGPL. |
| 8 | */ |
| 9 | |
Heinz Mauelshagen | 416cd17 | 2008-04-24 21:43:35 +0100 | [diff] [blame] | 10 | #ifndef _LINUX_DM_DIRTY_LOG |
| 11 | #define _LINUX_DM_DIRTY_LOG |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 12 | |
Heinz Mauelshagen | 416cd17 | 2008-04-24 21:43:35 +0100 | [diff] [blame] | 13 | #ifdef __KERNEL__ |
| 14 | |
| 15 | #include <linux/types.h> |
| 16 | #include <linux/device-mapper.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 17 | |
| 18 | typedef sector_t region_t; |
| 19 | |
Heinz Mauelshagen | 416cd17 | 2008-04-24 21:43:35 +0100 | [diff] [blame] | 20 | struct dm_dirty_log_type; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 21 | |
Heinz Mauelshagen | 416cd17 | 2008-04-24 21:43:35 +0100 | [diff] [blame] | 22 | struct dm_dirty_log { |
| 23 | struct dm_dirty_log_type *type; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 24 | void *context; |
| 25 | }; |
| 26 | |
Heinz Mauelshagen | 416cd17 | 2008-04-24 21:43:35 +0100 | [diff] [blame] | 27 | struct dm_dirty_log_type { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 28 | const char *name; |
| 29 | struct module *module; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 30 | |
Heinz Mauelshagen | 416cd17 | 2008-04-24 21:43:35 +0100 | [diff] [blame] | 31 | int (*ctr)(struct dm_dirty_log *log, struct dm_target *ti, |
| 32 | unsigned argc, char **argv); |
| 33 | void (*dtr)(struct dm_dirty_log *log); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 34 | |
| 35 | /* |
| 36 | * There are times when we don't want the log to touch |
| 37 | * the disk. |
| 38 | */ |
Heinz Mauelshagen | 416cd17 | 2008-04-24 21:43:35 +0100 | [diff] [blame] | 39 | int (*presuspend)(struct dm_dirty_log *log); |
| 40 | int (*postsuspend)(struct dm_dirty_log *log); |
| 41 | int (*resume)(struct dm_dirty_log *log); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 42 | |
| 43 | /* |
| 44 | * Retrieves the smallest size of region that the log can |
| 45 | * deal with. |
| 46 | */ |
Heinz Mauelshagen | 416cd17 | 2008-04-24 21:43:35 +0100 | [diff] [blame] | 47 | uint32_t (*get_region_size)(struct dm_dirty_log *log); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 48 | |
Heinz Mauelshagen | 416cd17 | 2008-04-24 21:43:35 +0100 | [diff] [blame] | 49 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 50 | * A predicate to say whether a region is clean or not. |
| 51 | * May block. |
| 52 | */ |
Heinz Mauelshagen | 416cd17 | 2008-04-24 21:43:35 +0100 | [diff] [blame] | 53 | int (*is_clean)(struct dm_dirty_log *log, region_t region); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 54 | |
| 55 | /* |
| 56 | * Returns: 0, 1, -EWOULDBLOCK, < 0 |
| 57 | * |
| 58 | * A predicate function to check the area given by |
| 59 | * [sector, sector + len) is in sync. |
| 60 | * |
| 61 | * If -EWOULDBLOCK is returned the state of the region is |
| 62 | * unknown, typically this will result in a read being |
| 63 | * passed to a daemon to deal with, since a daemon is |
| 64 | * allowed to block. |
| 65 | */ |
Heinz Mauelshagen | 416cd17 | 2008-04-24 21:43:35 +0100 | [diff] [blame] | 66 | int (*in_sync)(struct dm_dirty_log *log, region_t region, |
| 67 | int can_block); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 68 | |
| 69 | /* |
| 70 | * Flush the current log state (eg, to disk). This |
| 71 | * function may block. |
| 72 | */ |
Heinz Mauelshagen | 416cd17 | 2008-04-24 21:43:35 +0100 | [diff] [blame] | 73 | int (*flush)(struct dm_dirty_log *log); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 74 | |
| 75 | /* |
| 76 | * Mark an area as clean or dirty. These functions may |
| 77 | * block, though for performance reasons blocking should |
| 78 | * be extremely rare (eg, allocating another chunk of |
| 79 | * memory for some reason). |
| 80 | */ |
Heinz Mauelshagen | 416cd17 | 2008-04-24 21:43:35 +0100 | [diff] [blame] | 81 | void (*mark_region)(struct dm_dirty_log *log, region_t region); |
| 82 | void (*clear_region)(struct dm_dirty_log *log, region_t region); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 83 | |
| 84 | /* |
| 85 | * Returns: <0 (error), 0 (no region), 1 (region) |
| 86 | * |
| 87 | * The mirrord will need perform recovery on regions of |
| 88 | * the mirror that are in the NOSYNC state. This |
| 89 | * function asks the log to tell the caller about the |
| 90 | * next region that this machine should recover. |
| 91 | * |
| 92 | * Do not confuse this function with 'in_sync()', one |
| 93 | * tells you if an area is synchronised, the other |
| 94 | * assigns recovery work. |
| 95 | */ |
Heinz Mauelshagen | 416cd17 | 2008-04-24 21:43:35 +0100 | [diff] [blame] | 96 | int (*get_resync_work)(struct dm_dirty_log *log, region_t *region); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 97 | |
| 98 | /* |
Jonathan E Brassow | f3ee6b2 | 2006-12-08 02:41:11 -0800 | [diff] [blame] | 99 | * This notifies the log that the resync status of a region |
| 100 | * has changed. It also clears the region from the recovering |
| 101 | * list (if present). |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 102 | */ |
Heinz Mauelshagen | 416cd17 | 2008-04-24 21:43:35 +0100 | [diff] [blame] | 103 | void (*set_region_sync)(struct dm_dirty_log *log, |
Jonathan E Brassow | f3ee6b2 | 2006-12-08 02:41:11 -0800 | [diff] [blame] | 104 | region_t region, int in_sync); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 105 | |
Heinz Mauelshagen | 416cd17 | 2008-04-24 21:43:35 +0100 | [diff] [blame] | 106 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 107 | * Returns the number of regions that are in sync. |
Heinz Mauelshagen | 416cd17 | 2008-04-24 21:43:35 +0100 | [diff] [blame] | 108 | */ |
| 109 | region_t (*get_sync_count)(struct dm_dirty_log *log); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 110 | |
| 111 | /* |
| 112 | * Support function for mirror status requests. |
| 113 | */ |
Heinz Mauelshagen | 416cd17 | 2008-04-24 21:43:35 +0100 | [diff] [blame] | 114 | int (*status)(struct dm_dirty_log *log, status_type_t status_type, |
| 115 | char *result, unsigned maxlen); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 116 | }; |
| 117 | |
Heinz Mauelshagen | 416cd17 | 2008-04-24 21:43:35 +0100 | [diff] [blame] | 118 | int dm_dirty_log_type_register(struct dm_dirty_log_type *type); |
| 119 | int dm_dirty_log_type_unregister(struct dm_dirty_log_type *type); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 120 | |
| 121 | /* |
| 122 | * Make sure you use these two functions, rather than calling |
| 123 | * type->constructor/destructor() directly. |
| 124 | */ |
Heinz Mauelshagen | 416cd17 | 2008-04-24 21:43:35 +0100 | [diff] [blame] | 125 | struct dm_dirty_log *dm_dirty_log_create(const char *type_name, |
| 126 | struct dm_target *ti, |
| 127 | unsigned argc, char **argv); |
| 128 | void dm_dirty_log_destroy(struct dm_dirty_log *log); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 129 | |
Heinz Mauelshagen | 416cd17 | 2008-04-24 21:43:35 +0100 | [diff] [blame] | 130 | #endif /* __KERNEL__ */ |
| 131 | #endif /* _LINUX_DM_DIRTY_LOG_H */ |