1991d9fa0SJoe Thornber /* 2991d9fa0SJoe Thornber * Copyright (C) 2010-2011 Red Hat, Inc. 3991d9fa0SJoe Thornber * 4991d9fa0SJoe Thornber * This file is released under the GPL. 5991d9fa0SJoe Thornber */ 6991d9fa0SJoe Thornber 7991d9fa0SJoe Thornber #ifndef DM_THIN_METADATA_H 8991d9fa0SJoe Thornber #define DM_THIN_METADATA_H 9991d9fa0SJoe Thornber 10991d9fa0SJoe Thornber #include "persistent-data/dm-block-manager.h" 11991d9fa0SJoe Thornber 12991d9fa0SJoe Thornber #define THIN_METADATA_BLOCK_SIZE 4096 13991d9fa0SJoe Thornber 14c4a69ecdSMike Snitzer /* 15c4a69ecdSMike Snitzer * The metadata device is currently limited in size. 16c4a69ecdSMike Snitzer * 17c4a69ecdSMike Snitzer * We have one block of index, which can hold 255 index entries. Each 18c4a69ecdSMike Snitzer * index entry contains allocation info about 16k metadata blocks. 19c4a69ecdSMike Snitzer */ 20c4a69ecdSMike Snitzer #define THIN_METADATA_MAX_SECTORS (255 * (1 << 14) * (THIN_METADATA_BLOCK_SIZE / (1 << SECTOR_SHIFT))) 21c4a69ecdSMike Snitzer 22c4a69ecdSMike Snitzer /* 23c4a69ecdSMike Snitzer * A metadata device larger than 16GB triggers a warning. 24c4a69ecdSMike Snitzer */ 25c4a69ecdSMike Snitzer #define THIN_METADATA_MAX_SECTORS_WARNING (16 * (1024 * 1024 * 1024 >> SECTOR_SHIFT)) 26c4a69ecdSMike Snitzer 27991d9fa0SJoe Thornber /*----------------------------------------------------------------*/ 28991d9fa0SJoe Thornber 29991d9fa0SJoe Thornber struct dm_pool_metadata; 30991d9fa0SJoe Thornber struct dm_thin_device; 31991d9fa0SJoe Thornber 32991d9fa0SJoe Thornber /* 33991d9fa0SJoe Thornber * Device identifier 34991d9fa0SJoe Thornber */ 35991d9fa0SJoe Thornber typedef uint64_t dm_thin_id; 36991d9fa0SJoe Thornber 37991d9fa0SJoe Thornber /* 38991d9fa0SJoe Thornber * Reopens or creates a new, empty metadata volume. 39991d9fa0SJoe Thornber */ 40991d9fa0SJoe Thornber struct dm_pool_metadata *dm_pool_metadata_open(struct block_device *bdev, 41991d9fa0SJoe Thornber sector_t data_block_size); 42991d9fa0SJoe Thornber 43991d9fa0SJoe Thornber int dm_pool_metadata_close(struct dm_pool_metadata *pmd); 44991d9fa0SJoe Thornber 45991d9fa0SJoe Thornber /* 46991d9fa0SJoe Thornber * Compat feature flags. Any incompat flags beyond the ones 47991d9fa0SJoe Thornber * specified below will prevent use of the thin metadata. 48991d9fa0SJoe Thornber */ 49991d9fa0SJoe Thornber #define THIN_FEATURE_COMPAT_SUPP 0UL 50991d9fa0SJoe Thornber #define THIN_FEATURE_COMPAT_RO_SUPP 0UL 51991d9fa0SJoe Thornber #define THIN_FEATURE_INCOMPAT_SUPP 0UL 52991d9fa0SJoe Thornber 53991d9fa0SJoe Thornber /* 54991d9fa0SJoe Thornber * Device creation/deletion. 55991d9fa0SJoe Thornber */ 56991d9fa0SJoe Thornber int dm_pool_create_thin(struct dm_pool_metadata *pmd, dm_thin_id dev); 57991d9fa0SJoe Thornber 58991d9fa0SJoe Thornber /* 59991d9fa0SJoe Thornber * An internal snapshot. 60991d9fa0SJoe Thornber * 61991d9fa0SJoe Thornber * You can only snapshot a quiesced origin i.e. one that is either 62991d9fa0SJoe Thornber * suspended or not instanced at all. 63991d9fa0SJoe Thornber */ 64991d9fa0SJoe Thornber int dm_pool_create_snap(struct dm_pool_metadata *pmd, dm_thin_id dev, 65991d9fa0SJoe Thornber dm_thin_id origin); 66991d9fa0SJoe Thornber 67991d9fa0SJoe Thornber /* 68991d9fa0SJoe Thornber * Deletes a virtual device from the metadata. It _is_ safe to call this 69991d9fa0SJoe Thornber * when that device is open. Operations on that device will just start 70991d9fa0SJoe Thornber * failing. You still need to call close() on the device. 71991d9fa0SJoe Thornber */ 72991d9fa0SJoe Thornber int dm_pool_delete_thin_device(struct dm_pool_metadata *pmd, 73991d9fa0SJoe Thornber dm_thin_id dev); 74991d9fa0SJoe Thornber 75991d9fa0SJoe Thornber /* 76991d9fa0SJoe Thornber * Commits _all_ metadata changes: device creation, deletion, mapping 77991d9fa0SJoe Thornber * updates. 78991d9fa0SJoe Thornber */ 79991d9fa0SJoe Thornber int dm_pool_commit_metadata(struct dm_pool_metadata *pmd); 80991d9fa0SJoe Thornber 81991d9fa0SJoe Thornber /* 82991d9fa0SJoe Thornber * Set/get userspace transaction id. 83991d9fa0SJoe Thornber */ 84991d9fa0SJoe Thornber int dm_pool_set_metadata_transaction_id(struct dm_pool_metadata *pmd, 85991d9fa0SJoe Thornber uint64_t current_id, 86991d9fa0SJoe Thornber uint64_t new_id); 87991d9fa0SJoe Thornber 88991d9fa0SJoe Thornber int dm_pool_get_metadata_transaction_id(struct dm_pool_metadata *pmd, 89991d9fa0SJoe Thornber uint64_t *result); 90991d9fa0SJoe Thornber 91991d9fa0SJoe Thornber /* 92991d9fa0SJoe Thornber * Hold/get root for userspace transaction. 93cc8394d8SJoe Thornber * 94cc8394d8SJoe Thornber * The metadata snapshot is a copy of the current superblock (minus the 95cc8394d8SJoe Thornber * space maps). Userland can access the data structures for READ 96cc8394d8SJoe Thornber * operations only. A small performance hit is incurred by providing this 97cc8394d8SJoe Thornber * copy of the metadata to userland due to extra copy-on-write operations 98cc8394d8SJoe Thornber * on the metadata nodes. Release this as soon as you finish with it. 99991d9fa0SJoe Thornber */ 100cc8394d8SJoe Thornber int dm_pool_reserve_metadata_snap(struct dm_pool_metadata *pmd); 101cc8394d8SJoe Thornber int dm_pool_release_metadata_snap(struct dm_pool_metadata *pmd); 102991d9fa0SJoe Thornber 103cc8394d8SJoe Thornber int dm_pool_get_metadata_snap(struct dm_pool_metadata *pmd, 104991d9fa0SJoe Thornber dm_block_t *result); 105991d9fa0SJoe Thornber 106991d9fa0SJoe Thornber /* 107991d9fa0SJoe Thornber * Actions on a single virtual device. 108991d9fa0SJoe Thornber */ 109991d9fa0SJoe Thornber 110991d9fa0SJoe Thornber /* 111991d9fa0SJoe Thornber * Opening the same device more than once will fail with -EBUSY. 112991d9fa0SJoe Thornber */ 113991d9fa0SJoe Thornber int dm_pool_open_thin_device(struct dm_pool_metadata *pmd, dm_thin_id dev, 114991d9fa0SJoe Thornber struct dm_thin_device **td); 115991d9fa0SJoe Thornber 116991d9fa0SJoe Thornber int dm_pool_close_thin_device(struct dm_thin_device *td); 117991d9fa0SJoe Thornber 118991d9fa0SJoe Thornber dm_thin_id dm_thin_dev_id(struct dm_thin_device *td); 119991d9fa0SJoe Thornber 120991d9fa0SJoe Thornber struct dm_thin_lookup_result { 121991d9fa0SJoe Thornber dm_block_t block; 122*17b7d63fSMike Snitzer unsigned shared:1; 123991d9fa0SJoe Thornber }; 124991d9fa0SJoe Thornber 125991d9fa0SJoe Thornber /* 126991d9fa0SJoe Thornber * Returns: 127991d9fa0SJoe Thornber * -EWOULDBLOCK iff @can_block is set and would block. 128991d9fa0SJoe Thornber * -ENODATA iff that mapping is not present. 129991d9fa0SJoe Thornber * 0 success 130991d9fa0SJoe Thornber */ 131991d9fa0SJoe Thornber int dm_thin_find_block(struct dm_thin_device *td, dm_block_t block, 132991d9fa0SJoe Thornber int can_block, struct dm_thin_lookup_result *result); 133991d9fa0SJoe Thornber 134991d9fa0SJoe Thornber /* 135991d9fa0SJoe Thornber * Obtain an unused block. 136991d9fa0SJoe Thornber */ 137991d9fa0SJoe Thornber int dm_pool_alloc_data_block(struct dm_pool_metadata *pmd, dm_block_t *result); 138991d9fa0SJoe Thornber 139991d9fa0SJoe Thornber /* 140991d9fa0SJoe Thornber * Insert or remove block. 141991d9fa0SJoe Thornber */ 142991d9fa0SJoe Thornber int dm_thin_insert_block(struct dm_thin_device *td, dm_block_t block, 143991d9fa0SJoe Thornber dm_block_t data_block); 144991d9fa0SJoe Thornber 145991d9fa0SJoe Thornber int dm_thin_remove_block(struct dm_thin_device *td, dm_block_t block); 146991d9fa0SJoe Thornber 147991d9fa0SJoe Thornber /* 148991d9fa0SJoe Thornber * Queries. 149991d9fa0SJoe Thornber */ 150991d9fa0SJoe Thornber int dm_thin_get_highest_mapped_block(struct dm_thin_device *td, 151991d9fa0SJoe Thornber dm_block_t *highest_mapped); 152991d9fa0SJoe Thornber 153991d9fa0SJoe Thornber int dm_thin_get_mapped_count(struct dm_thin_device *td, dm_block_t *result); 154991d9fa0SJoe Thornber 155991d9fa0SJoe Thornber int dm_pool_get_free_block_count(struct dm_pool_metadata *pmd, 156991d9fa0SJoe Thornber dm_block_t *result); 157991d9fa0SJoe Thornber 158991d9fa0SJoe Thornber int dm_pool_get_free_metadata_block_count(struct dm_pool_metadata *pmd, 159991d9fa0SJoe Thornber dm_block_t *result); 160991d9fa0SJoe Thornber 161991d9fa0SJoe Thornber int dm_pool_get_metadata_dev_size(struct dm_pool_metadata *pmd, 162991d9fa0SJoe Thornber dm_block_t *result); 163991d9fa0SJoe Thornber 164991d9fa0SJoe Thornber int dm_pool_get_data_block_size(struct dm_pool_metadata *pmd, sector_t *result); 165991d9fa0SJoe Thornber 166991d9fa0SJoe Thornber int dm_pool_get_data_dev_size(struct dm_pool_metadata *pmd, dm_block_t *result); 167991d9fa0SJoe Thornber 168991d9fa0SJoe Thornber /* 169991d9fa0SJoe Thornber * Returns -ENOSPC if the new size is too small and already allocated 170991d9fa0SJoe Thornber * blocks would be lost. 171991d9fa0SJoe Thornber */ 172991d9fa0SJoe Thornber int dm_pool_resize_data_dev(struct dm_pool_metadata *pmd, dm_block_t new_size); 173991d9fa0SJoe Thornber 174991d9fa0SJoe Thornber /*----------------------------------------------------------------*/ 175991d9fa0SJoe Thornber 176991d9fa0SJoe Thornber #endif 177