[linux-2.6-block.git] / drivers / md / persistent-data / dm-space-map-common.h

/*
 * Copyright (C) 2011 Red Hat, Inc.
 *
 * This file is released under the GPL.
 */

#ifndef DM_SPACE_MAP_COMMON_H
#define DM_SPACE_MAP_COMMON_H

#include "dm-btree.h"

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

/*
 * Low level disk format
 *
 * Bitmap btree
 * ------------
 *
 * Each value stored in the btree is an index_entry.  This points to a
 * block that is used as a bitmap.  Within the bitmap hold 2 bits per
 * entry, which represent UNUSED = 0, REF_COUNT = 1, REF_COUNT = 2 and
 * REF_COUNT = many.
 *
 * Refcount btree
 * --------------
 *
 * Any entry that has a ref count higher than 2 gets entered in the ref
 * count tree.  The leaf values for this tree is the 32-bit ref count.
 */

struct disk_index_entry {
	__le64 blocknr;
	__le32 nr_free;
	__le32 none_free_before;
} __packed;


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

	struct disk_index_entry index[MAX_METADATA_BITMAPS];
} __packed;

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);

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 disk_sm_root {
	__le64 nr_blocks;
	__le64 nr_allocated;
	__le64 bitmap_root;
	__le64 ref_count_root;
} __packed;

#define ENTRIES_PER_BYTE 4

struct disk_bitmap_header {
	__le32 csum;
	__le32 not_used;
	__le64 blocknr;
} __packed;

enum allocation_event {
	SM_NONE,
	SM_ALLOC,
	SM_FREE,
};

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

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);
int sm_ll_insert(struct ll_disk *ll, dm_block_t b, uint32_t ref_count, enum allocation_event *ev);
int sm_ll_inc(struct ll_disk *ll, dm_block_t b, enum allocation_event *ev);
int sm_ll_dec(struct ll_disk *ll, dm_block_t b, enum allocation_event *ev);
int sm_ll_commit(struct ll_disk *ll);

int sm_ll_new_metadata(struct ll_disk *ll, struct dm_transaction_manager *tm);
int sm_ll_open_metadata(struct ll_disk *ll, struct dm_transaction_manager *tm,
			void *root_le, size_t len);

int sm_ll_new_disk(struct ll_disk *ll, struct dm_transaction_manager *tm);
int sm_ll_open_disk(struct ll_disk *ll, struct dm_transaction_manager *tm,
		    void *root_le, size_t len);

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

#endif	/* DM_SPACE_MAP_COMMON_H */
Commit	Line	Data
3241b1d3 JT	1	/*
	2	* Copyright (C) 2011 Red Hat, Inc.
	3	*
	4	* This file is released under the GPL.
	5	*/
	6
	7	#ifndef DM_SPACE_MAP_COMMON_H
	8	#define DM_SPACE_MAP_COMMON_H
	9
	10	#include "dm-btree.h"
	11
	12	/----------------------------------------------------------------/
	13
	14	/*
	15	* Low level disk format
	16	*
	17	* Bitmap btree
	18	* ------------
	19	*
	20	* Each value stored in the btree is an index_entry. This points to a
	21	* block that is used as a bitmap. Within the bitmap hold 2 bits per
	22	* entry, which represent UNUSED = 0, REF_COUNT = 1, REF_COUNT = 2 and
	23	* REF_COUNT = many.
	24	*
	25	* Refcount btree
	26	* --------------
	27	*
	28	* Any entry that has a ref count higher than 2 gets entered in the ref
	29	* count tree. The leaf values for this tree is the 32-bit ref count.
	30	*/
	31
	32	struct disk_index_entry {
	33	__le64 blocknr;
	34	__le32 nr_free;
	35	__le32 none_free_before;
	36	} __packed;
	37
	38
	39	#define MAX_METADATA_BITMAPS 255
	40	struct disk_metadata_index {
	41	__le32 csum;
	42	__le32 padding;
	43	__le64 blocknr;
	44
	45	struct disk_index_entry index[MAX_METADATA_BITMAPS];
	46	} __packed;
	47
	48	struct ll_disk;
	49
	50	typedef int (load_ie_fn)(struct ll_disk ll, dm_block_t index, struct disk_index_entry *result);
	51	typedef int (save_ie_fn)(struct ll_disk ll, dm_block_t index, struct disk_index_entry *ie);
	52	typedef int (init_index_fn)(struct ll_disk ll);
	53	typedef int (open_index_fn)(struct ll_disk ll);
	54	typedef dm_block_t (max_index_entries_fn)(struct ll_disk ll);
	55	typedef int (commit_fn)(struct ll_disk ll);
	56
	57	struct ll_disk {
	58	struct dm_transaction_manager *tm;
	59	struct dm_btree_info bitmap_info;
	60	struct dm_btree_info ref_count_info;
	61
	62	uint32_t block_size;
	63	uint32_t entries_per_block;
	64	dm_block_t nr_blocks;
65	dm_block_t nr_allocated;
66
67	/*
68	* bitmap_root may be a btree root or a simple index.
69	*/
70	dm_block_t bitmap_root;
71
72	dm_block_t ref_count_root;
73
74	struct disk_metadata_index mi_le;
75	load_ie_fn load_ie;
76	save_ie_fn save_ie;
77	init_index_fn init_index;
78	open_index_fn open_index;
79	max_index_entries_fn max_entries;
80	commit_fn commit;
f4b90369	81	bool bitmap_index_changed:1;
3241b1d3 JT	82	};
	83
	84	struct disk_sm_root {
	85	__le64 nr_blocks;
	86	__le64 nr_allocated;
	87	__le64 bitmap_root;
	88	__le64 ref_count_root;
	89	} __packed;
	90
	91	#define ENTRIES_PER_BYTE 4
	92
	93	struct disk_bitmap_header {
	94	__le32 csum;
	95	__le32 not_used;
	96	__le64 blocknr;
	97	} __packed;
	98
	99	enum allocation_event {
	100	SM_NONE,
	101	SM_ALLOC,
	102	SM_FREE,
	103	};
	104
	105	/----------------------------------------------------------------/
	106
	107	int sm_ll_extend(struct ll_disk *ll, dm_block_t extra_blocks);
	108	int sm_ll_lookup_bitmap(struct ll_disk ll, dm_block_t b, uint32_t result);
	109	int sm_ll_lookup(struct ll_disk ll, dm_block_t b, uint32_t result);
	110	int sm_ll_find_free_block(struct ll_disk *ll, dm_block_t begin,
	111	dm_block_t end, dm_block_t *result);
	112	int sm_ll_insert(struct ll_disk ll, dm_block_t b, uint32_t ref_count, enum allocation_event ev);
	113	int sm_ll_inc(struct ll_disk ll, dm_block_t b, enum allocation_event ev);
	114	int sm_ll_dec(struct ll_disk ll, dm_block_t b, enum allocation_event ev);
	115	int sm_ll_commit(struct ll_disk *ll);
	116
	117	int sm_ll_new_metadata(struct ll_disk ll, struct dm_transaction_manager tm);
	118	int sm_ll_open_metadata(struct ll_disk ll, struct dm_transaction_manager tm,
	119	void *root_le, size_t len);
	120
	121	int sm_ll_new_disk(struct ll_disk ll, struct dm_transaction_manager tm);
	122	int sm_ll_open_disk(struct ll_disk ll, struct dm_transaction_manager tm,
	123	void *root_le, size_t len);
	124
	125	/----------------------------------------------------------------/
	126
	127	#endif /* DM_SPACE_MAP_COMMON_H */