| Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 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 | }; |
| 82 | |
| 83 | struct disk_sm_root { |
| 84 | __le64 nr_blocks; |
| 85 | __le64 nr_allocated; |
| 86 | __le64 bitmap_root; |
| 87 | __le64 ref_count_root; |
| 88 | } __packed; |
| 89 | |
| 90 | #define ENTRIES_PER_BYTE 4 |
| 91 | |
| 92 | struct disk_bitmap_header { |
| 93 | __le32 csum; |
| 94 | __le32 not_used; |
| 95 | __le64 blocknr; |
| 96 | } __packed; |
| 97 | |
| 98 | enum allocation_event { |
| 99 | SM_NONE, |
| 100 | SM_ALLOC, |
| 101 | SM_FREE, |
| 102 | }; |
| 103 | |
| 104 | /*----------------------------------------------------------------*/ |
| 105 | |
| 106 | int sm_ll_extend(struct ll_disk *ll, dm_block_t extra_blocks); |
| 107 | int sm_ll_lookup_bitmap(struct ll_disk *ll, dm_block_t b, uint32_t *result); |
| 108 | int sm_ll_lookup(struct ll_disk *ll, dm_block_t b, uint32_t *result); |
| 109 | int sm_ll_find_free_block(struct ll_disk *ll, dm_block_t begin, |
| 110 | dm_block_t end, dm_block_t *result); |
| 111 | int sm_ll_insert(struct ll_disk *ll, dm_block_t b, uint32_t ref_count, enum allocation_event *ev); |
| 112 | int sm_ll_inc(struct ll_disk *ll, dm_block_t b, enum allocation_event *ev); |
| 113 | int sm_ll_dec(struct ll_disk *ll, dm_block_t b, enum allocation_event *ev); |
| 114 | int sm_ll_commit(struct ll_disk *ll); |
| 115 | |
| 116 | int sm_ll_new_metadata(struct ll_disk *ll, struct dm_transaction_manager *tm); |
| 117 | int sm_ll_open_metadata(struct ll_disk *ll, struct dm_transaction_manager *tm, |
| 118 | void *root_le, size_t len); |
| 119 | |
| 120 | int sm_ll_new_disk(struct ll_disk *ll, struct dm_transaction_manager *tm); |
| 121 | int sm_ll_open_disk(struct ll_disk *ll, struct dm_transaction_manager *tm, |
| 122 | void *root_le, size_t len); |
| 123 | |
| 124 | /*----------------------------------------------------------------*/ |
| 125 | |
| 126 | #endif /* DM_SPACE_MAP_COMMON_H */ |