1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3 * Copyright (C) 2003 Sistina Software Limited.
4 * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved.
5 *
6 * Device-Mapper dirty region hash interface.
7 *
8 * This file is released under the GPL.
9 */
10
11 #ifndef DM_REGION_HASH_H
12 #define DM_REGION_HASH_H
13
14 #include <linux/dm-dirty-log.h>
15
16 /*
17 *----------------------------------------------------------------
18 * Region hash
19 *----------------------------------------------------------------
20 */
21 struct dm_region_hash;
22 struct dm_region;
23
24 /*
25 * States a region can have.
26 */
27 enum dm_rh_region_states {
28 DM_RH_CLEAN = 0x01, /* No writes in flight. */
29 DM_RH_DIRTY = 0x02, /* Writes in flight. */
30 DM_RH_NOSYNC = 0x04, /* Out of sync. */
31 DM_RH_RECOVERING = 0x08, /* Under resynchronization. */
32 };
33
34 /*
35 * Region hash create/destroy.
36 */
37 struct bio_list;
38 struct dm_region_hash *dm_region_hash_create(
39 void *context, void (*dispatch_bios)(void *context,
40 struct bio_list *bios),
41 void (*wakeup_workers)(void *context),
42 void (*wakeup_all_recovery_waiters)(void *context),
43 sector_t target_begin, unsigned int max_recovery,
44 struct dm_dirty_log *log, uint32_t region_size,
45 region_t nr_regions);
46 void dm_region_hash_destroy(struct dm_region_hash *rh);
47
48 struct dm_dirty_log *dm_rh_dirty_log(struct dm_region_hash *rh);
49
50 /*
51 * Conversion functions.
52 */
53 region_t dm_rh_bio_to_region(struct dm_region_hash *rh, struct bio *bio);
54 sector_t dm_rh_region_to_sector(struct dm_region_hash *rh, region_t region);
55 void *dm_rh_region_context(struct dm_region *reg);
56
57 /*
58 * Get region size and key (ie. number of the region).
59 */
60 sector_t dm_rh_get_region_size(struct dm_region_hash *rh);
61 region_t dm_rh_get_region_key(struct dm_region *reg);
62
63 /*
64 * Get/set/update region state (and dirty log).
65 *
66 */
67 int dm_rh_get_state(struct dm_region_hash *rh, region_t region, int may_block);
68 void dm_rh_set_state(struct dm_region_hash *rh, region_t region,
69 enum dm_rh_region_states state, int may_block);
70
71 /* Non-zero errors_handled leaves the state of the region NOSYNC */
72 void dm_rh_update_states(struct dm_region_hash *rh, int errors_handled);
73
74 /* Flush the region hash and dirty log. */
75 int dm_rh_flush(struct dm_region_hash *rh);
76
77 /* Inc/dec pending count on regions. */
78 void dm_rh_inc_pending(struct dm_region_hash *rh, struct bio_list *bios);
79 void dm_rh_dec(struct dm_region_hash *rh, region_t region);
80
81 /* Delay bios on regions. */
82 void dm_rh_delay(struct dm_region_hash *rh, struct bio *bio);
83
84 void dm_rh_mark_nosync(struct dm_region_hash *rh, struct bio *bio);
85
86 /*
87 * Region recovery control.
88 */
89
90 /* Prepare some regions for recovery by starting to quiesce them. */
91 void dm_rh_recovery_prepare(struct dm_region_hash *rh);
92
93 /* Try fetching a quiesced region for recovery. */
94 struct dm_region *dm_rh_recovery_start(struct dm_region_hash *rh);
95
96 /* Report recovery end on a region. */
97 void dm_rh_recovery_end(struct dm_region *reg, int error);
98
99 /* Returns number of regions with recovery work outstanding. */
100 int dm_rh_recovery_in_flight(struct dm_region_hash *rh);
101
102 /* Start/stop recovery. */
103 void dm_rh_start_recovery(struct dm_region_hash *rh);
104 void dm_rh_stop_recovery(struct dm_region_hash *rh);
105
106 #endif /* DM_REGION_HASH_H */
107
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