/* SPDX-License-Identifier: GPL-2.0-only */ /* * Copyright (C) 2010-2011 Red Hat, Inc. * * This file is released under the GPL. */ #ifndef DM_THIN_METADATA_H #define DM_THIN_METADATA_H #include "persistent-data/dm-block-manager.h" #include "persistent-data/dm-space-map.h" #include "persistent-data/dm-space-map-metadata.h" #define THIN_METADATA_BLOCK_SIZE … /* * The metadata device is currently limited in size. */ #define THIN_METADATA_MAX_SECTORS … /* * A metadata device larger than 16GB triggers a warning. */ #define THIN_METADATA_MAX_SECTORS_WARNING … /*----------------------------------------------------------------*/ /* * Thin metadata superblock flags. */ #define THIN_METADATA_NEEDS_CHECK_FLAG … struct dm_pool_metadata; struct dm_thin_device; /* * Device identifier */ dm_thin_id; /* * Reopens or creates a new, empty metadata volume. */ struct dm_pool_metadata *dm_pool_metadata_open(struct block_device *bdev, sector_t data_block_size, bool format_device); int dm_pool_metadata_close(struct dm_pool_metadata *pmd); /* * Compat feature flags. Any incompat flags beyond the ones * specified below will prevent use of the thin metadata. */ #define THIN_FEATURE_COMPAT_SUPP … #define THIN_FEATURE_COMPAT_RO_SUPP … #define THIN_FEATURE_INCOMPAT_SUPP … /* * Device creation/deletion. */ int dm_pool_create_thin(struct dm_pool_metadata *pmd, dm_thin_id dev); /* * An internal snapshot. * * You can only snapshot a quiesced origin i.e. one that is either * suspended or not instanced at all. */ int dm_pool_create_snap(struct dm_pool_metadata *pmd, dm_thin_id dev, dm_thin_id origin); /* * Deletes a virtual device from the metadata. It _is_ safe to call this * when that device is open. Operations on that device will just start * failing. You still need to call close() on the device. */ int dm_pool_delete_thin_device(struct dm_pool_metadata *pmd, dm_thin_id dev); /* * Commits _all_ metadata changes: device creation, deletion, mapping * updates. */ int dm_pool_commit_metadata(struct dm_pool_metadata *pmd); /* * Discards all uncommitted changes. Rereads the superblock, rolling back * to the last good transaction. Thin devices remain open. * dm_thin_aborted_changes() tells you if they had uncommitted changes. * * If this call fails it's only useful to call dm_pool_metadata_close(). * All other methods will fail with -EINVAL. */ int dm_pool_abort_metadata(struct dm_pool_metadata *pmd); /* * Set/get userspace transaction id. */ int dm_pool_set_metadata_transaction_id(struct dm_pool_metadata *pmd, uint64_t current_id, uint64_t new_id); int dm_pool_get_metadata_transaction_id(struct dm_pool_metadata *pmd, uint64_t *result); /* * Hold/get root for userspace transaction. * * The metadata snapshot is a copy of the current superblock (minus the * space maps). Userland can access the data structures for READ * operations only. A small performance hit is incurred by providing this * copy of the metadata to userland due to extra copy-on-write operations * on the metadata nodes. Release this as soon as you finish with it. */ int dm_pool_reserve_metadata_snap(struct dm_pool_metadata *pmd); int dm_pool_release_metadata_snap(struct dm_pool_metadata *pmd); int dm_pool_get_metadata_snap(struct dm_pool_metadata *pmd, dm_block_t *result); /* * Actions on a single virtual device. */ /* * Opening the same device more than once will fail with -EBUSY. */ int dm_pool_open_thin_device(struct dm_pool_metadata *pmd, dm_thin_id dev, struct dm_thin_device **td); int dm_pool_close_thin_device(struct dm_thin_device *td); dm_thin_id dm_thin_dev_id(struct dm_thin_device *td); struct dm_thin_lookup_result { … }; /* * Returns: * -EWOULDBLOCK iff @can_issue_io is set and would issue IO * -ENODATA iff that mapping is not present. * 0 success */ int dm_thin_find_block(struct dm_thin_device *td, dm_block_t block, int can_issue_io, struct dm_thin_lookup_result *result); /* * Retrieve the next run of contiguously mapped blocks. Useful for working * out where to break up IO. Returns 0 on success, < 0 on error. */ int dm_thin_find_mapped_range(struct dm_thin_device *td, dm_block_t begin, dm_block_t end, dm_block_t *thin_begin, dm_block_t *thin_end, dm_block_t *pool_begin, bool *maybe_shared); /* * Obtain an unused block. */ int dm_pool_alloc_data_block(struct dm_pool_metadata *pmd, dm_block_t *result); /* * Insert or remove block. */ int dm_thin_insert_block(struct dm_thin_device *td, dm_block_t block, dm_block_t data_block); int dm_thin_remove_range(struct dm_thin_device *td, dm_block_t begin, dm_block_t end); /* * Queries. */ bool dm_thin_changed_this_transaction(struct dm_thin_device *td); bool dm_pool_changed_this_transaction(struct dm_pool_metadata *pmd); bool dm_thin_aborted_changes(struct dm_thin_device *td); int dm_thin_get_highest_mapped_block(struct dm_thin_device *td, dm_block_t *highest_mapped); int dm_thin_get_mapped_count(struct dm_thin_device *td, dm_block_t *result); int dm_pool_get_free_block_count(struct dm_pool_metadata *pmd, dm_block_t *result); int dm_pool_get_free_metadata_block_count(struct dm_pool_metadata *pmd, dm_block_t *result); int dm_pool_get_metadata_dev_size(struct dm_pool_metadata *pmd, dm_block_t *result); int dm_pool_get_data_dev_size(struct dm_pool_metadata *pmd, dm_block_t *result); int dm_pool_block_is_shared(struct dm_pool_metadata *pmd, dm_block_t b, bool *result); int dm_pool_inc_data_range(struct dm_pool_metadata *pmd, dm_block_t b, dm_block_t e); int dm_pool_dec_data_range(struct dm_pool_metadata *pmd, dm_block_t b, dm_block_t e); /* * Returns -ENOSPC if the new size is too small and already allocated * blocks would be lost. */ int dm_pool_resize_data_dev(struct dm_pool_metadata *pmd, dm_block_t new_size); int dm_pool_resize_metadata_dev(struct dm_pool_metadata *pmd, dm_block_t new_size); /* * Flicks the underlying block manager into read only mode, so you know * that nothing is changing. */ void dm_pool_metadata_read_only(struct dm_pool_metadata *pmd); void dm_pool_metadata_read_write(struct dm_pool_metadata *pmd); int dm_pool_register_metadata_threshold(struct dm_pool_metadata *pmd, dm_block_t threshold, dm_sm_threshold_fn fn, void *context); /* * Updates the superblock immediately. */ int dm_pool_metadata_set_needs_check(struct dm_pool_metadata *pmd); bool dm_pool_metadata_needs_check(struct dm_pool_metadata *pmd); /* * Issue any prefetches that may be useful. */ void dm_pool_issue_prefetches(struct dm_pool_metadata *pmd); /* Pre-commit callback */ dm_pool_pre_commit_fn; void dm_pool_register_pre_commit_callback(struct dm_pool_metadata *pmd, dm_pool_pre_commit_fn fn, void *context); /*----------------------------------------------------------------*/ #endif
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