include/linux/dm-region-hash.h

   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 */