linux-imx

/*

 * Copyright (C) 2012 Red Hat, Inc.

 *

 * This file is released under the GPL.

 */

​

#ifndef DM_CACHE_METADATA_H

#define DM_CACHE_METADATA_H

​

#include "dm-cache-block-types.h"

#include "dm-cache-policy-internal.h"

#include "persistent-data/dm-space-map-metadata.h"

​

/*----------------------------------------------------------------*/

​

#define DM_CACHE_METADATA_BLOCK_SIZE DM_SM_METADATA_BLOCK_SIZE

​

/* FIXME: remove this restriction */

/*

 * The metadata device is currently limited in size.

 */

#define DM_CACHE_METADATA_MAX_SECTORS DM_SM_METADATA_MAX_SECTORS

​

/*

 * A metadata device larger than 16GB triggers a warning.

 */

#define DM_CACHE_METADATA_MAX_SECTORS_WARNING (16 * (1024 * 1024 * 1024 >> SECTOR_SHIFT))

​

/*----------------------------------------------------------------*/

​

/*

 * Ext[234]-style compat feature flags.

 *

 * A new feature which old metadata will still be compatible with should

 * define a DM_CACHE_FEATURE_COMPAT_* flag (rarely useful).

 *

 * A new feature that is not compatible with old code should define a

 * DM_CACHE_FEATURE_INCOMPAT_* flag and guard the relevant code with

 * that flag.

 *

 * A new feature that is not compatible with old code accessing the

 * metadata RDWR should define a DM_CACHE_FEATURE_RO_COMPAT_* flag and

 * guard the relevant code with that flag.

 *

 * As these various flags are defined they should be added to the

 * following masks.

 */

​

#define DM_CACHE_FEATURE_COMPAT_SUPP      0UL

#define DM_CACHE_FEATURE_COMPAT_RO_SUPP   0UL

#define DM_CACHE_FEATURE_INCOMPAT_SUPP    0UL

​

struct dm_cache_metadata;

​

/*

 * Reopens or creates a new, empty metadata volume.  Returns an ERR_PTR on

 * failure.  If reopening then features must match.

 */

struct dm_cache_metadata *dm_cache_metadata_open(struct block_device *bdev,

                         sector_t data_block_size,

                         bool may_format_device,

                         size_t policy_hint_size,

                         unsigned metadata_version);

​

void dm_cache_metadata_close(struct dm_cache_metadata *cmd);

​

/*

 * The metadata needs to know how many cache blocks there are.  We don't

 * care about the origin, assuming the core target is giving us valid

 * origin blocks to map to.

 */

int dm_cache_resize(struct dm_cache_metadata *cmd, dm_cblock_t new_cache_size);

int dm_cache_size(struct dm_cache_metadata *cmd, dm_cblock_t *result);

​

int dm_cache_discard_bitset_resize(struct dm_cache_metadata *cmd,

                   sector_t discard_block_size,

                   dm_dblock_t new_nr_entries);

​

typedef int (*load_discard_fn)(void *context, sector_t discard_block_size,

                   dm_dblock_t dblock, bool discarded);

int dm_cache_load_discards(struct dm_cache_metadata *cmd,

               load_discard_fn fn, void *context);

​

int dm_cache_set_discard(struct dm_cache_metadata *cmd, dm_dblock_t dblock, bool discard);

​

int dm_cache_remove_mapping(struct dm_cache_metadata *cmd, dm_cblock_t cblock);

int dm_cache_insert_mapping(struct dm_cache_metadata *cmd, dm_cblock_t cblock, dm_oblock_t oblock);

int dm_cache_changed_this_transaction(struct dm_cache_metadata *cmd);

​

typedef int (*load_mapping_fn)(void *context, dm_oblock_t oblock,

                   dm_cblock_t cblock, bool dirty,

                   uint32_t hint, bool hint_valid);