CasperSecurity
/*
* 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 */