drivers/md/persistent-data/dm-space-map-common.h

Source file repositories/reference/linux-study-clean/drivers/md/persistent-data/dm-space-map-common.h

File Facts

System
Linux kernel
Corpus path
drivers/md/persistent-data/dm-space-map-common.h
Extension
.h
Size
4149 bytes
Lines
147
Domain
Driver Families
Bucket
drivers/md
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

struct disk_index_entry {
	__le64 blocknr;
	__le32 nr_free;
	__le32 none_free_before;
} __packed __aligned(8);


#define MAX_METADATA_BITMAPS 255
struct disk_metadata_index {
	__le32 csum;
	__le32 padding;
	__le64 blocknr;

	struct disk_index_entry index[MAX_METADATA_BITMAPS];
} __packed __aligned(8);

struct ll_disk;

typedef int (*load_ie_fn)(struct ll_disk *ll, dm_block_t index, struct disk_index_entry *result);
typedef int (*save_ie_fn)(struct ll_disk *ll, dm_block_t index, struct disk_index_entry *ie);
typedef int (*init_index_fn)(struct ll_disk *ll);
typedef int (*open_index_fn)(struct ll_disk *ll);
typedef dm_block_t (*max_index_entries_fn)(struct ll_disk *ll);
typedef int (*commit_fn)(struct ll_disk *ll);

/*
 * A lot of time can be wasted reading and writing the same
 * index entry.  So we cache a few entries.
 */
#define IE_CACHE_SIZE 64
#define IE_CACHE_MASK (IE_CACHE_SIZE - 1)

struct ie_cache {
	bool valid;
	bool dirty;
	dm_block_t index;
	struct disk_index_entry ie;
};

struct ll_disk {
	struct dm_transaction_manager *tm;
	struct dm_btree_info bitmap_info;
	struct dm_btree_info ref_count_info;

	uint32_t block_size;
	uint32_t entries_per_block;
	dm_block_t nr_blocks;
	dm_block_t nr_allocated;

	/*
	 * bitmap_root may be a btree root or a simple index.
	 */
	dm_block_t bitmap_root;

	dm_block_t ref_count_root;

	struct disk_metadata_index mi_le;
	load_ie_fn load_ie;
	save_ie_fn save_ie;
	init_index_fn init_index;
	open_index_fn open_index;
	max_index_entries_fn max_entries;
	commit_fn commit;
	bool bitmap_index_changed:1;

	struct ie_cache ie_cache[IE_CACHE_SIZE];
};

struct disk_sm_root {
	__le64 nr_blocks;
	__le64 nr_allocated;
	__le64 bitmap_root;
	__le64 ref_count_root;
} __packed __aligned(8);

#define ENTRIES_PER_BYTE 4

struct disk_bitmap_header {
	__le32 csum;
	__le32 not_used;
	__le64 blocknr;
} __packed __aligned(8);

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

int sm_ll_extend(struct ll_disk *ll, dm_block_t extra_blocks);
int sm_ll_lookup_bitmap(struct ll_disk *ll, dm_block_t b, uint32_t *result);
int sm_ll_lookup(struct ll_disk *ll, dm_block_t b, uint32_t *result);
int sm_ll_find_free_block(struct ll_disk *ll, dm_block_t begin,
			  dm_block_t end, dm_block_t *result);

Annotation

Implementation Notes