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; 81 bool bitmap_index_changed:1; 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 */ 128