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include/linux/dm-region-hash.h 3.11 KB
81f7e3824   Eric Lee   Initial Release, ...
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  /*
   * Copyright (C) 2003 Sistina Software Limited.
   * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved.
   *
   * Device-Mapper dirty region hash interface.
   *
   * This file is released under the GPL.
   */
  
  #ifndef DM_REGION_HASH_H
  #define DM_REGION_HASH_H
  
  #include <linux/dm-dirty-log.h>
  
  /*-----------------------------------------------------------------
   * Region hash
   *----------------------------------------------------------------*/
  struct dm_region_hash;
  struct dm_region;
  
  /*
   * States a region can have.
   */
  enum dm_rh_region_states {
  	DM_RH_CLEAN	 = 0x01,	/* No writes in flight. */
  	DM_RH_DIRTY	 = 0x02,	/* Writes in flight. */
  	DM_RH_NOSYNC	 = 0x04,	/* Out of sync. */
  	DM_RH_RECOVERING = 0x08,	/* Under resynchronization. */
  };
  
  /*
   * Region hash create/destroy.
   */
  struct bio_list;
  struct dm_region_hash *dm_region_hash_create(
  		void *context, void (*dispatch_bios)(void *context,
  						     struct bio_list *bios),
  		void (*wakeup_workers)(void *context),
  		void (*wakeup_all_recovery_waiters)(void *context),
  		sector_t target_begin, unsigned max_recovery,
  		struct dm_dirty_log *log, uint32_t region_size,
  		region_t nr_regions);
  void dm_region_hash_destroy(struct dm_region_hash *rh);
  
  struct dm_dirty_log *dm_rh_dirty_log(struct dm_region_hash *rh);
  
  /*
   * Conversion functions.
   */
  region_t dm_rh_bio_to_region(struct dm_region_hash *rh, struct bio *bio);
  sector_t dm_rh_region_to_sector(struct dm_region_hash *rh, region_t region);
  void *dm_rh_region_context(struct dm_region *reg);
  
  /*
   * Get region size and key (ie. number of the region).
   */
  sector_t dm_rh_get_region_size(struct dm_region_hash *rh);
  region_t dm_rh_get_region_key(struct dm_region *reg);
  
  /*
   * Get/set/update region state (and dirty log).
   *
   */
  int dm_rh_get_state(struct dm_region_hash *rh, region_t region, int may_block);
  void dm_rh_set_state(struct dm_region_hash *rh, region_t region,
  		     enum dm_rh_region_states state, int may_block);
  
  /* Non-zero errors_handled leaves the state of the region NOSYNC */
  void dm_rh_update_states(struct dm_region_hash *rh, int errors_handled);
  
  /* Flush the region hash and dirty log. */
  int dm_rh_flush(struct dm_region_hash *rh);
  
  /* Inc/dec pending count on regions. */
  void dm_rh_inc_pending(struct dm_region_hash *rh, struct bio_list *bios);
  void dm_rh_dec(struct dm_region_hash *rh, region_t region);
  
  /* Delay bios on regions. */
  void dm_rh_delay(struct dm_region_hash *rh, struct bio *bio);
  
  void dm_rh_mark_nosync(struct dm_region_hash *rh, struct bio *bio);
  
  /*
   * Region recovery control.
   */
  
  /* Prepare some regions for recovery by starting to quiesce them. */
  void dm_rh_recovery_prepare(struct dm_region_hash *rh);
  
  /* Try fetching a quiesced region for recovery. */
  struct dm_region *dm_rh_recovery_start(struct dm_region_hash *rh);
  
  /* Report recovery end on a region. */
  void dm_rh_recovery_end(struct dm_region *reg, int error);
  
  /* Returns number of regions with recovery work outstanding. */
  int dm_rh_recovery_in_flight(struct dm_region_hash *rh);
  
  /* Start/stop recovery. */
  void dm_rh_start_recovery(struct dm_region_hash *rh);
  void dm_rh_stop_recovery(struct dm_region_hash *rh);
  
  #endif /* DM_REGION_HASH_H */