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Heinz Mauelshagen1f965b12008-10-21 17:45:06 +01001/*
2 * Copyright (C) 2003 Sistina Software Limited.
3 * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved.
4 *
5 * Device-Mapper dirty region hash interface.
6 *
7 * This file is released under the GPL.
8 */
9
10#ifndef DM_REGION_HASH_H
11#define DM_REGION_HASH_H
12
13#include <linux/dm-dirty-log.h>
14
15/*-----------------------------------------------------------------
16 * Region hash
17 *----------------------------------------------------------------*/
18struct dm_region_hash;
19struct dm_region;
20
21/*
22 * States a region can have.
23 */
24enum dm_rh_region_states {
25 DM_RH_CLEAN = 0x01, /* No writes in flight. */
26 DM_RH_DIRTY = 0x02, /* Writes in flight. */
27 DM_RH_NOSYNC = 0x04, /* Out of sync. */
28 DM_RH_RECOVERING = 0x08, /* Under resynchronization. */
29};
30
31/*
32 * Region hash create/destroy.
33 */
34struct bio_list;
35struct dm_region_hash *dm_region_hash_create(
36 void *context, void (*dispatch_bios)(void *context,
37 struct bio_list *bios),
38 void (*wakeup_workers)(void *context),
39 void (*wakeup_all_recovery_waiters)(void *context),
40 sector_t target_begin, unsigned max_recovery,
41 struct dm_dirty_log *log, uint32_t region_size,
42 region_t nr_regions);
43void dm_region_hash_destroy(struct dm_region_hash *rh);
44
45struct dm_dirty_log *dm_rh_dirty_log(struct dm_region_hash *rh);
46
47/*
48 * Conversion functions.
49 */
50region_t dm_rh_bio_to_region(struct dm_region_hash *rh, struct bio *bio);
51sector_t dm_rh_region_to_sector(struct dm_region_hash *rh, region_t region);
52void *dm_rh_region_context(struct dm_region *reg);
53
54/*
55 * Get region size and key (ie. number of the region).
56 */
57sector_t dm_rh_get_region_size(struct dm_region_hash *rh);
58region_t dm_rh_get_region_key(struct dm_region *reg);
59
60/*
61 * Get/set/update region state (and dirty log).
62 *
63 */
64int dm_rh_get_state(struct dm_region_hash *rh, region_t region, int may_block);
65void dm_rh_set_state(struct dm_region_hash *rh, region_t region,
66 enum dm_rh_region_states state, int may_block);
67
68/* Non-zero errors_handled leaves the state of the region NOSYNC */
69void dm_rh_update_states(struct dm_region_hash *rh, int errors_handled);
70
71/* Flush the region hash and dirty log. */
72int dm_rh_flush(struct dm_region_hash *rh);
73
74/* Inc/dec pending count on regions. */
75void dm_rh_inc_pending(struct dm_region_hash *rh, struct bio_list *bios);
76void dm_rh_dec(struct dm_region_hash *rh, region_t region);
77
78/* Delay bios on regions. */
79void dm_rh_delay(struct dm_region_hash *rh, struct bio *bio);
80
81void dm_rh_mark_nosync(struct dm_region_hash *rh,
82 struct bio *bio, unsigned done, int error);
83
84/*
85 * Region recovery control.
86 */
87
88/* Prepare some regions for recovery by starting to quiesce them. */
89void dm_rh_recovery_prepare(struct dm_region_hash *rh);
90
91/* Try fetching a quiesced region for recovery. */
92struct dm_region *dm_rh_recovery_start(struct dm_region_hash *rh);
93
94/* Report recovery end on a region. */
95void dm_rh_recovery_end(struct dm_region *reg, int error);
96
97/* Returns number of regions with recovery work outstanding. */
98int dm_rh_recovery_in_flight(struct dm_region_hash *rh);
99
100/* Start/stop recovery. */
101void dm_rh_start_recovery(struct dm_region_hash *rh);
102void dm_rh_stop_recovery(struct dm_region_hash *rh);
103
104#endif /* DM_REGION_HASH_H */