c4a69ecdb4
The thin metadata format can only make use of a device that is <= THIN_METADATA_MAX_SECTORS (currently 15.9375 GB). Therefore, there is no practical benefit to using a larger device. However, it may be that other factors impose a certain granularity for the space that is allocated to a device (E.g. lvm2 can impose a coarse granularity through the use of large, >= 1 GB, physical extents). Rather than reject a larger metadata device, during thin-pool device construction, switch to allowing it but issue a warning if a device larger than THIN_METADATA_MAX_SECTORS_WARNING (16 GB) is provided. Any space over 15.9375 GB will not be used. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
169 lines
4.4 KiB
C
169 lines
4.4 KiB
C
/*
|
|
* 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"
|
|
|
|
#define THIN_METADATA_BLOCK_SIZE 4096
|
|
|
|
/*
|
|
* The metadata device is currently limited in size.
|
|
*
|
|
* We have one block of index, which can hold 255 index entries. Each
|
|
* index entry contains allocation info about 16k metadata blocks.
|
|
*/
|
|
#define THIN_METADATA_MAX_SECTORS (255 * (1 << 14) * (THIN_METADATA_BLOCK_SIZE / (1 << SECTOR_SHIFT)))
|
|
|
|
/*
|
|
* A metadata device larger than 16GB triggers a warning.
|
|
*/
|
|
#define THIN_METADATA_MAX_SECTORS_WARNING (16 * (1024 * 1024 * 1024 >> SECTOR_SHIFT))
|
|
|
|
/*----------------------------------------------------------------*/
|
|
|
|
struct dm_pool_metadata;
|
|
struct dm_thin_device;
|
|
|
|
/*
|
|
* Device identifier
|
|
*/
|
|
typedef uint64_t 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);
|
|
|
|
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 0UL
|
|
#define THIN_FEATURE_COMPAT_RO_SUPP 0UL
|
|
#define THIN_FEATURE_INCOMPAT_SUPP 0UL
|
|
|
|
/*
|
|
* 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);
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
int dm_pool_hold_metadata_root(struct dm_pool_metadata *pmd);
|
|
|
|
int dm_pool_get_held_metadata_root(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 {
|
|
dm_block_t block;
|
|
int shared;
|
|
};
|
|
|
|
/*
|
|
* Returns:
|
|
* -EWOULDBLOCK iff @can_block is set and would block.
|
|
* -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_block, struct dm_thin_lookup_result *result);
|
|
|
|
/*
|
|
* 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_block(struct dm_thin_device *td, dm_block_t block);
|
|
|
|
/*
|
|
* Queries.
|
|
*/
|
|
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_block_size(struct dm_pool_metadata *pmd, sector_t *result);
|
|
|
|
int dm_pool_get_data_dev_size(struct dm_pool_metadata *pmd, dm_block_t *result);
|
|
|
|
/*
|
|
* 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);
|
|
|
|
/*----------------------------------------------------------------*/
|
|
|
|
#endif
|