1 /* 2 * Copyright (C) 2010-2011 Red Hat, Inc. 3 * 4 * This file is released under the GPL. 5 */ 6 7 #ifndef DM_THIN_METADATA_H 8 #define DM_THIN_METADATA_H 9 10 #include "persistent-data/dm-block-manager.h" 11 12 #define THIN_METADATA_BLOCK_SIZE 4096 13 14 /*----------------------------------------------------------------*/ 15 16 struct dm_pool_metadata; 17 struct dm_thin_device; 18 19 /* 20 * Device identifier 21 */ 22 typedef uint64_t dm_thin_id; 23 24 /* 25 * Reopens or creates a new, empty metadata volume. 26 */ 27 struct dm_pool_metadata *dm_pool_metadata_open(struct block_device *bdev, 28 sector_t data_block_size); 29 30 int dm_pool_metadata_close(struct dm_pool_metadata *pmd); 31 32 /* 33 * Compat feature flags. Any incompat flags beyond the ones 34 * specified below will prevent use of the thin metadata. 35 */ 36 #define THIN_FEATURE_COMPAT_SUPP 0UL 37 #define THIN_FEATURE_COMPAT_RO_SUPP 0UL 38 #define THIN_FEATURE_INCOMPAT_SUPP 0UL 39 40 /* 41 * Device creation/deletion. 42 */ 43 int dm_pool_create_thin(struct dm_pool_metadata *pmd, dm_thin_id dev); 44 45 /* 46 * An internal snapshot. 47 * 48 * You can only snapshot a quiesced origin i.e. one that is either 49 * suspended or not instanced at all. 50 */ 51 int dm_pool_create_snap(struct dm_pool_metadata *pmd, dm_thin_id dev, 52 dm_thin_id origin); 53 54 /* 55 * Deletes a virtual device from the metadata. It _is_ safe to call this 56 * when that device is open. Operations on that device will just start 57 * failing. You still need to call close() on the device. 58 */ 59 int dm_pool_delete_thin_device(struct dm_pool_metadata *pmd, 60 dm_thin_id dev); 61 62 /* 63 * Commits _all_ metadata changes: device creation, deletion, mapping 64 * updates. 65 */ 66 int dm_pool_commit_metadata(struct dm_pool_metadata *pmd); 67 68 /* 69 * Set/get userspace transaction id. 70 */ 71 int dm_pool_set_metadata_transaction_id(struct dm_pool_metadata *pmd, 72 uint64_t current_id, 73 uint64_t new_id); 74 75 int dm_pool_get_metadata_transaction_id(struct dm_pool_metadata *pmd, 76 uint64_t *result); 77 78 /* 79 * Hold/get root for userspace transaction. 80 */ 81 int dm_pool_hold_metadata_root(struct dm_pool_metadata *pmd); 82 83 int dm_pool_get_held_metadata_root(struct dm_pool_metadata *pmd, 84 dm_block_t *result); 85 86 /* 87 * Actions on a single virtual device. 88 */ 89 90 /* 91 * Opening the same device more than once will fail with -EBUSY. 92 */ 93 int dm_pool_open_thin_device(struct dm_pool_metadata *pmd, dm_thin_id dev, 94 struct dm_thin_device **td); 95 96 int dm_pool_close_thin_device(struct dm_thin_device *td); 97 98 dm_thin_id dm_thin_dev_id(struct dm_thin_device *td); 99 100 struct dm_thin_lookup_result { 101 dm_block_t block; 102 int shared; 103 }; 104 105 /* 106 * Returns: 107 * -EWOULDBLOCK iff @can_block is set and would block. 108 * -ENODATA iff that mapping is not present. 109 * 0 success 110 */ 111 int dm_thin_find_block(struct dm_thin_device *td, dm_block_t block, 112 int can_block, struct dm_thin_lookup_result *result); 113 114 /* 115 * Obtain an unused block. 116 */ 117 int dm_pool_alloc_data_block(struct dm_pool_metadata *pmd, dm_block_t *result); 118 119 /* 120 * Insert or remove block. 121 */ 122 int dm_thin_insert_block(struct dm_thin_device *td, dm_block_t block, 123 dm_block_t data_block); 124 125 int dm_thin_remove_block(struct dm_thin_device *td, dm_block_t block); 126 127 /* 128 * Queries. 129 */ 130 int dm_thin_get_highest_mapped_block(struct dm_thin_device *td, 131 dm_block_t *highest_mapped); 132 133 int dm_thin_get_mapped_count(struct dm_thin_device *td, dm_block_t *result); 134 135 int dm_pool_get_free_block_count(struct dm_pool_metadata *pmd, 136 dm_block_t *result); 137 138 int dm_pool_get_free_metadata_block_count(struct dm_pool_metadata *pmd, 139 dm_block_t *result); 140 141 int dm_pool_get_metadata_dev_size(struct dm_pool_metadata *pmd, 142 dm_block_t *result); 143 144 int dm_pool_get_data_block_size(struct dm_pool_metadata *pmd, sector_t *result); 145 146 int dm_pool_get_data_dev_size(struct dm_pool_metadata *pmd, dm_block_t *result); 147 148 /* 149 * Returns -ENOSPC if the new size is too small and already allocated 150 * blocks would be lost. 151 */ 152 int dm_pool_resize_data_dev(struct dm_pool_metadata *pmd, dm_block_t new_size); 153 154 /*----------------------------------------------------------------*/ 155 156 #endif 157