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1/* SPDX-License-Identifier: GPL-2.0-only */2/*3 * Copyright (C) 2010-2011 Red Hat, Inc.4 *5 * This file is released under the GPL.6 */7 8#ifndef DM_THIN_METADATA_H9#define DM_THIN_METADATA_H10 11#include "persistent-data/dm-block-manager.h"12#include "persistent-data/dm-space-map.h"13#include "persistent-data/dm-space-map-metadata.h"14 15#define THIN_METADATA_BLOCK_SIZE DM_SM_METADATA_BLOCK_SIZE16 17/*18 * The metadata device is currently limited in size.19 */20#define THIN_METADATA_MAX_SECTORS DM_SM_METADATA_MAX_SECTORS21 22/*23 * A metadata device larger than 16GB triggers a warning.24 */25#define THIN_METADATA_MAX_SECTORS_WARNING (16 * (1024 * 1024 * 1024 >> SECTOR_SHIFT))26 27/*----------------------------------------------------------------*/28 29/*30 * Thin metadata superblock flags.31 */32#define THIN_METADATA_NEEDS_CHECK_FLAG (1 << 0)33 34struct dm_pool_metadata;35struct dm_thin_device;36 37/*38 * Device identifier39 */40typedef uint64_t dm_thin_id;41 42/*43 * Reopens or creates a new, empty metadata volume.44 */45struct dm_pool_metadata *dm_pool_metadata_open(struct block_device *bdev,46 sector_t data_block_size,47 bool format_device);48 49int dm_pool_metadata_close(struct dm_pool_metadata *pmd);50 51/*52 * Compat feature flags. Any incompat flags beyond the ones53 * specified below will prevent use of the thin metadata.54 */55#define THIN_FEATURE_COMPAT_SUPP 0UL56#define THIN_FEATURE_COMPAT_RO_SUPP 0UL57#define THIN_FEATURE_INCOMPAT_SUPP 0UL58 59/*60 * Device creation/deletion.61 */62int dm_pool_create_thin(struct dm_pool_metadata *pmd, dm_thin_id dev);63 64/*65 * An internal snapshot.66 *67 * You can only snapshot a quiesced origin i.e. one that is either68 * suspended or not instanced at all.69 */70int dm_pool_create_snap(struct dm_pool_metadata *pmd, dm_thin_id dev,71 dm_thin_id origin);72 73/*74 * Deletes a virtual device from the metadata. It _is_ safe to call this75 * when that device is open. Operations on that device will just start76 * failing. You still need to call close() on the device.77 */78int dm_pool_delete_thin_device(struct dm_pool_metadata *pmd,79 dm_thin_id dev);80 81/*82 * Commits _all_ metadata changes: device creation, deletion, mapping83 * updates.84 */85int dm_pool_commit_metadata(struct dm_pool_metadata *pmd);86 87/*88 * Discards all uncommitted changes. Rereads the superblock, rolling back89 * to the last good transaction. Thin devices remain open.90 * dm_thin_aborted_changes() tells you if they had uncommitted changes.91 *92 * If this call fails it's only useful to call dm_pool_metadata_close().93 * All other methods will fail with -EINVAL.94 */95int dm_pool_abort_metadata(struct dm_pool_metadata *pmd);96 97/*98 * Set/get userspace transaction id.99 */100int dm_pool_set_metadata_transaction_id(struct dm_pool_metadata *pmd,101 uint64_t current_id,102 uint64_t new_id);103 104int dm_pool_get_metadata_transaction_id(struct dm_pool_metadata *pmd,105 uint64_t *result);106 107/*108 * Hold/get root for userspace transaction.109 *110 * The metadata snapshot is a copy of the current superblock (minus the111 * space maps). Userland can access the data structures for READ112 * operations only. A small performance hit is incurred by providing this113 * copy of the metadata to userland due to extra copy-on-write operations114 * on the metadata nodes. Release this as soon as you finish with it.115 */116int dm_pool_reserve_metadata_snap(struct dm_pool_metadata *pmd);117int dm_pool_release_metadata_snap(struct dm_pool_metadata *pmd);118 119int dm_pool_get_metadata_snap(struct dm_pool_metadata *pmd,120 dm_block_t *result);121 122/*123 * Actions on a single virtual device.124 */125 126/*127 * Opening the same device more than once will fail with -EBUSY.128 */129int dm_pool_open_thin_device(struct dm_pool_metadata *pmd, dm_thin_id dev,130 struct dm_thin_device **td);131 132int dm_pool_close_thin_device(struct dm_thin_device *td);133 134dm_thin_id dm_thin_dev_id(struct dm_thin_device *td);135 136struct dm_thin_lookup_result {137 dm_block_t block;138 bool shared:1;139};140 141/*142 * Returns:143 * -EWOULDBLOCK iff @can_issue_io is set and would issue IO144 * -ENODATA iff that mapping is not present.145 * 0 success146 */147int dm_thin_find_block(struct dm_thin_device *td, dm_block_t block,148 int can_issue_io, struct dm_thin_lookup_result *result);149 150/*151 * Retrieve the next run of contiguously mapped blocks. Useful for working152 * out where to break up IO. Returns 0 on success, < 0 on error.153 */154int dm_thin_find_mapped_range(struct dm_thin_device *td,155 dm_block_t begin, dm_block_t end,156 dm_block_t *thin_begin, dm_block_t *thin_end,157 dm_block_t *pool_begin, bool *maybe_shared);158 159/*160 * Obtain an unused block.161 */162int dm_pool_alloc_data_block(struct dm_pool_metadata *pmd, dm_block_t *result);163 164/*165 * Insert or remove block.166 */167int dm_thin_insert_block(struct dm_thin_device *td, dm_block_t block,168 dm_block_t data_block);169 170int dm_thin_remove_range(struct dm_thin_device *td,171 dm_block_t begin, dm_block_t end);172 173/*174 * Queries.175 */176bool dm_thin_changed_this_transaction(struct dm_thin_device *td);177 178bool dm_pool_changed_this_transaction(struct dm_pool_metadata *pmd);179 180bool dm_thin_aborted_changes(struct dm_thin_device *td);181 182int dm_thin_get_highest_mapped_block(struct dm_thin_device *td,183 dm_block_t *highest_mapped);184 185int dm_thin_get_mapped_count(struct dm_thin_device *td, dm_block_t *result);186 187int dm_pool_get_free_block_count(struct dm_pool_metadata *pmd,188 dm_block_t *result);189 190int dm_pool_get_free_metadata_block_count(struct dm_pool_metadata *pmd,191 dm_block_t *result);192 193int dm_pool_get_metadata_dev_size(struct dm_pool_metadata *pmd,194 dm_block_t *result);195 196int dm_pool_get_data_dev_size(struct dm_pool_metadata *pmd, dm_block_t *result);197 198int dm_pool_block_is_shared(struct dm_pool_metadata *pmd, dm_block_t b, bool *result);199 200int dm_pool_inc_data_range(struct dm_pool_metadata *pmd, dm_block_t b, dm_block_t e);201int dm_pool_dec_data_range(struct dm_pool_metadata *pmd, dm_block_t b, dm_block_t e);202 203/*204 * Returns -ENOSPC if the new size is too small and already allocated205 * blocks would be lost.206 */207int dm_pool_resize_data_dev(struct dm_pool_metadata *pmd, dm_block_t new_size);208int dm_pool_resize_metadata_dev(struct dm_pool_metadata *pmd, dm_block_t new_size);209 210/*211 * Flicks the underlying block manager into read only mode, so you know212 * that nothing is changing.213 */214void dm_pool_metadata_read_only(struct dm_pool_metadata *pmd);215void dm_pool_metadata_read_write(struct dm_pool_metadata *pmd);216 217int dm_pool_register_metadata_threshold(struct dm_pool_metadata *pmd,218 dm_block_t threshold,219 dm_sm_threshold_fn fn,220 void *context);221 222/*223 * Updates the superblock immediately.224 */225int dm_pool_metadata_set_needs_check(struct dm_pool_metadata *pmd);226bool dm_pool_metadata_needs_check(struct dm_pool_metadata *pmd);227 228/*229 * Issue any prefetches that may be useful.230 */231void dm_pool_issue_prefetches(struct dm_pool_metadata *pmd);232 233/* Pre-commit callback */234typedef int (*dm_pool_pre_commit_fn)(void *context);235 236void dm_pool_register_pre_commit_callback(struct dm_pool_metadata *pmd,237 dm_pool_pre_commit_fn fn,238 void *context);239 240/*----------------------------------------------------------------*/241 242#endif243