linux/include/linux/dm-region-hash.h
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   1/*
   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, struct bio *bio);
  82
  83/*
  84 * Region recovery control.
  85 */
  86
  87/* Prepare some regions for recovery by starting to quiesce them. */
  88void dm_rh_recovery_prepare(struct dm_region_hash *rh);
  89
  90/* Try fetching a quiesced region for recovery. */
  91struct dm_region *dm_rh_recovery_start(struct dm_region_hash *rh);
  92
  93/* Report recovery end on a region. */
  94void dm_rh_recovery_end(struct dm_region *reg, int error);
  95
  96/* Returns number of regions with recovery work outstanding. */
  97int dm_rh_recovery_in_flight(struct dm_region_hash *rh);
  98
  99/* Start/stop recovery. */
 100void dm_rh_start_recovery(struct dm_region_hash *rh);
 101void dm_rh_stop_recovery(struct dm_region_hash *rh);
 102
 103#endif /* DM_REGION_HASH_H */
 104
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