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* Copyright (C) 2003 Sistina Software Limited.
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* Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved.
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* Device-Mapper dirty region hash interface.
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* This file is released under the GPL.
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#ifndef DM_REGION_HASH_H
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#define DM_REGION_HASH_H
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#include <linux/dm-dirty-log.h>
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/*-----------------------------------------------------------------
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*----------------------------------------------------------------*/
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struct dm_region_hash;
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* States a region can have.
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enum dm_rh_region_states {
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DM_RH_CLEAN = 0x01, /* No writes in flight. */
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DM_RH_DIRTY = 0x02, /* Writes in flight. */
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DM_RH_NOSYNC = 0x04, /* Out of sync. */
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DM_RH_RECOVERING = 0x08, /* Under resynchronization. */
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* Region hash create/destroy.
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struct dm_region_hash *dm_region_hash_create(
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void *context, void (*dispatch_bios)(void *context,
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struct bio_list *bios),
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void (*wakeup_workers)(void *context),
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void (*wakeup_all_recovery_waiters)(void *context),
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sector_t target_begin, unsigned max_recovery,
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struct dm_dirty_log *log, uint32_t region_size,
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void dm_region_hash_destroy(struct dm_region_hash *rh);
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struct dm_dirty_log *dm_rh_dirty_log(struct dm_region_hash *rh);
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* Conversion functions.
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region_t dm_rh_bio_to_region(struct dm_region_hash *rh, struct bio *bio);
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sector_t dm_rh_region_to_sector(struct dm_region_hash *rh, region_t region);
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region_t dm_rh_sector_to_region(struct dm_region_hash *rh, sector_t sector);
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void *dm_rh_region_context(struct dm_region *reg);
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* Get region size and key (ie. number of the region).
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sector_t dm_rh_get_region_size(struct dm_region_hash *rh);
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region_t dm_rh_get_region_key(struct dm_region *reg);
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* Get/set/update region state (and dirty log).
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int dm_rh_get_state(struct dm_region_hash *rh, region_t region, int may_block);
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void dm_rh_set_state(struct dm_region_hash *rh, region_t region,
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enum dm_rh_region_states state, int may_block);
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/* Non-zero errors_handled leaves the state of the region NOSYNC */
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void dm_rh_update_states(struct dm_region_hash *rh, int errors_handled);
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/* Flush the region hash and dirty log. */
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int dm_rh_flush(struct dm_region_hash *rh);
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/* Inc/dec pending count on regions. */
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void dm_rh_inc(struct dm_region_hash *rh, region_t region);
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void dm_rh_inc_pending(struct dm_region_hash *rh, struct bio_list *bios);
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void dm_rh_dec(struct dm_region_hash *rh, region_t region);
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/* Delay bios on regions. */
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void dm_rh_delay(struct dm_region_hash *rh, struct bio *bio);
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void dm_rh_delay_by_region(struct dm_region_hash *rh, struct bio *bio,
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void dm_rh_mark_nosync(struct dm_region_hash *rh,
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struct bio *bio, unsigned done, int error);
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* Region recovery control.
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/* Prepare some regions for recovery by starting to quiesce them. */
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void dm_rh_recovery_prepare(struct dm_region_hash *rh);
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/* Try fetching a quiesced region for recovery. */
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struct dm_region *dm_rh_recovery_start(struct dm_region_hash *rh);
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/* Report recovery end on a region. */
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void dm_rh_recovery_end(struct dm_region *reg, int error);
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/* Returns number of regions with recovery work outstanding. */
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int dm_rh_recovery_in_flight(struct dm_region_hash *rh);
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/* Start/stop recovery. */
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void dm_rh_start_recovery(struct dm_region_hash *rh);
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void dm_rh_stop_recovery(struct dm_region_hash *rh);
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#endif /* DM_REGION_HASH_H */