Introduce bitmap_index_changed to track whether or not the index changed then only commit a space map if it did. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
		
			
				
	
	
		
			127 lines
		
	
	
	
		
			3.4 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			127 lines
		
	
	
	
		
			3.4 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 * Copyright (C) 2011 Red Hat, Inc.
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 *
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 * This file is released under the GPL.
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 */
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#ifndef DM_SPACE_MAP_COMMON_H
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#define DM_SPACE_MAP_COMMON_H
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#include "dm-btree.h"
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/*----------------------------------------------------------------*/
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/*
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 * Low level disk format
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 *
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 * Bitmap btree
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 * ------------
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 *
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 * Each value stored in the btree is an index_entry.  This points to a
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 * block that is used as a bitmap.  Within the bitmap hold 2 bits per
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 * entry, which represent UNUSED = 0, REF_COUNT = 1, REF_COUNT = 2 and
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 * REF_COUNT = many.
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 *
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 * Refcount btree
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 * --------------
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 *
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 * Any entry that has a ref count higher than 2 gets entered in the ref
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 * count tree.  The leaf values for this tree is the 32-bit ref count.
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 */
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struct disk_index_entry {
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	__le64 blocknr;
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	__le32 nr_free;
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	__le32 none_free_before;
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} __packed;
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#define MAX_METADATA_BITMAPS 255
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struct disk_metadata_index {
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	__le32 csum;
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	__le32 padding;
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	__le64 blocknr;
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	struct disk_index_entry index[MAX_METADATA_BITMAPS];
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} __packed;
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struct ll_disk;
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typedef int (*load_ie_fn)(struct ll_disk *ll, dm_block_t index, struct disk_index_entry *result);
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typedef int (*save_ie_fn)(struct ll_disk *ll, dm_block_t index, struct disk_index_entry *ie);
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typedef int (*init_index_fn)(struct ll_disk *ll);
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typedef int (*open_index_fn)(struct ll_disk *ll);
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typedef dm_block_t (*max_index_entries_fn)(struct ll_disk *ll);
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typedef int (*commit_fn)(struct ll_disk *ll);
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struct ll_disk {
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	struct dm_transaction_manager *tm;
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	struct dm_btree_info bitmap_info;
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	struct dm_btree_info ref_count_info;
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	uint32_t block_size;
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	uint32_t entries_per_block;
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	dm_block_t nr_blocks;
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	dm_block_t nr_allocated;
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	/*
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	 * bitmap_root may be a btree root or a simple index.
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	 */
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	dm_block_t bitmap_root;
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	dm_block_t ref_count_root;
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	struct disk_metadata_index mi_le;
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	load_ie_fn load_ie;
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	save_ie_fn save_ie;
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	init_index_fn init_index;
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	open_index_fn open_index;
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	max_index_entries_fn max_entries;
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	commit_fn commit;
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	bool bitmap_index_changed:1;
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};
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struct disk_sm_root {
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	__le64 nr_blocks;
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	__le64 nr_allocated;
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	__le64 bitmap_root;
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	__le64 ref_count_root;
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} __packed;
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#define ENTRIES_PER_BYTE 4
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struct disk_bitmap_header {
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	__le32 csum;
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	__le32 not_used;
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	__le64 blocknr;
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} __packed;
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enum allocation_event {
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	SM_NONE,
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	SM_ALLOC,
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	SM_FREE,
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};
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/*----------------------------------------------------------------*/
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int sm_ll_extend(struct ll_disk *ll, dm_block_t extra_blocks);
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int sm_ll_lookup_bitmap(struct ll_disk *ll, dm_block_t b, uint32_t *result);
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int sm_ll_lookup(struct ll_disk *ll, dm_block_t b, uint32_t *result);
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int sm_ll_find_free_block(struct ll_disk *ll, dm_block_t begin,
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			  dm_block_t end, dm_block_t *result);
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int sm_ll_insert(struct ll_disk *ll, dm_block_t b, uint32_t ref_count, enum allocation_event *ev);
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int sm_ll_inc(struct ll_disk *ll, dm_block_t b, enum allocation_event *ev);
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int sm_ll_dec(struct ll_disk *ll, dm_block_t b, enum allocation_event *ev);
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int sm_ll_commit(struct ll_disk *ll);
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int sm_ll_new_metadata(struct ll_disk *ll, struct dm_transaction_manager *tm);
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int sm_ll_open_metadata(struct ll_disk *ll, struct dm_transaction_manager *tm,
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			void *root_le, size_t len);
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int sm_ll_new_disk(struct ll_disk *ll, struct dm_transaction_manager *tm);
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int sm_ll_open_disk(struct ll_disk *ll, struct dm_transaction_manager *tm,
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		    void *root_le, size_t len);
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/*----------------------------------------------------------------*/
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#endif	/* DM_SPACE_MAP_COMMON_H */
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