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 */ 107