147 lines · c
1/* SPDX-License-Identifier: GPL-2.0-only */2/*3 * Copyright (C) 2011 Red Hat, Inc.4 *5 * This file is released under the GPL.6 */7 8#ifndef DM_SPACE_MAP_COMMON_H9#define DM_SPACE_MAP_COMMON_H10 11#include "dm-btree.h"12 13/*----------------------------------------------------------------*/14 15/*16 * Low level disk format17 *18 * Bitmap btree19 * ------------20 *21 * Each value stored in the btree is an index_entry. This points to a22 * block that is used as a bitmap. Within the bitmap hold 2 bits per23 * entry, which represent UNUSED = 0, REF_COUNT = 1, REF_COUNT = 2 and24 * REF_COUNT = many.25 *26 * Refcount btree27 * --------------28 *29 * Any entry that has a ref count higher than 2 gets entered in the ref30 * count tree. The leaf values for this tree is the 32-bit ref count.31 */32 33struct disk_index_entry {34 __le64 blocknr;35 __le32 nr_free;36 __le32 none_free_before;37} __packed __aligned(8);38 39 40#define MAX_METADATA_BITMAPS 25541struct disk_metadata_index {42 __le32 csum;43 __le32 padding;44 __le64 blocknr;45 46 struct disk_index_entry index[MAX_METADATA_BITMAPS];47} __packed __aligned(8);48 49struct ll_disk;50 51typedef int (*load_ie_fn)(struct ll_disk *ll, dm_block_t index, struct disk_index_entry *result);52typedef int (*save_ie_fn)(struct ll_disk *ll, dm_block_t index, struct disk_index_entry *ie);53typedef int (*init_index_fn)(struct ll_disk *ll);54typedef int (*open_index_fn)(struct ll_disk *ll);55typedef dm_block_t (*max_index_entries_fn)(struct ll_disk *ll);56typedef int (*commit_fn)(struct ll_disk *ll);57 58/*59 * A lot of time can be wasted reading and writing the same60 * index entry. So we cache a few entries.61 */62#define IE_CACHE_SIZE 6463#define IE_CACHE_MASK (IE_CACHE_SIZE - 1)64 65struct ie_cache {66 bool valid;67 bool dirty;68 dm_block_t index;69 struct disk_index_entry ie;70};71 72struct ll_disk {73 struct dm_transaction_manager *tm;74 struct dm_btree_info bitmap_info;75 struct dm_btree_info ref_count_info;76 77 uint32_t block_size;78 uint32_t entries_per_block;79 dm_block_t nr_blocks;80 dm_block_t nr_allocated;81 82 /*83 * bitmap_root may be a btree root or a simple index.84 */85 dm_block_t bitmap_root;86 87 dm_block_t ref_count_root;88 89 struct disk_metadata_index mi_le;90 load_ie_fn load_ie;91 save_ie_fn save_ie;92 init_index_fn init_index;93 open_index_fn open_index;94 max_index_entries_fn max_entries;95 commit_fn commit;96 bool bitmap_index_changed:1;97 98 struct ie_cache ie_cache[IE_CACHE_SIZE];99};100 101struct disk_sm_root {102 __le64 nr_blocks;103 __le64 nr_allocated;104 __le64 bitmap_root;105 __le64 ref_count_root;106} __packed __aligned(8);107 108#define ENTRIES_PER_BYTE 4109 110struct disk_bitmap_header {111 __le32 csum;112 __le32 not_used;113 __le64 blocknr;114} __packed __aligned(8);115 116/*----------------------------------------------------------------*/117 118int sm_ll_extend(struct ll_disk *ll, dm_block_t extra_blocks);119int sm_ll_lookup_bitmap(struct ll_disk *ll, dm_block_t b, uint32_t *result);120int sm_ll_lookup(struct ll_disk *ll, dm_block_t b, uint32_t *result);121int sm_ll_find_free_block(struct ll_disk *ll, dm_block_t begin,122 dm_block_t end, dm_block_t *result);123int sm_ll_find_common_free_block(struct ll_disk *old_ll, struct ll_disk *new_ll,124 dm_block_t begin, dm_block_t end, dm_block_t *result);125 126/*127 * The next three functions return (via nr_allocations) the net number of128 * allocations that were made. This number may be negative if there were129 * more frees than allocs.130 */131int sm_ll_insert(struct ll_disk *ll, dm_block_t b, uint32_t ref_count, int32_t *nr_allocations);132int sm_ll_inc(struct ll_disk *ll, dm_block_t b, dm_block_t e, int32_t *nr_allocations);133int sm_ll_dec(struct ll_disk *ll, dm_block_t b, dm_block_t e, int32_t *nr_allocations);134int sm_ll_commit(struct ll_disk *ll);135 136int sm_ll_new_metadata(struct ll_disk *ll, struct dm_transaction_manager *tm);137int sm_ll_open_metadata(struct ll_disk *ll, struct dm_transaction_manager *tm,138 void *root_le, size_t len);139 140int sm_ll_new_disk(struct ll_disk *ll, struct dm_transaction_manager *tm);141int sm_ll_open_disk(struct ll_disk *ll, struct dm_transaction_manager *tm,142 void *root_le, size_t len);143 144/*----------------------------------------------------------------*/145 146#endif /* DM_SPACE_MAP_COMMON_H */147