1 #define _XOPEN_SOURCE 500
8 #include "kerncompat.h"
9 #include "radix-tree.h"
13 int mkfs(int fd, u64 num_blocks, u16 blocksize)
15 struct btrfs_super_block super;
16 struct btrfs_leaf empty_leaf;
17 struct btrfs_root_item root_item;
18 struct btrfs_item item;
19 struct btrfs_extent_item extent_item;
24 btrfs_set_super_blocknr(&super, 16);
25 btrfs_set_super_root(&super, 17);
26 strcpy((char *)(&super.magic), BTRFS_MAGIC);
27 btrfs_set_super_blocksize(&super, blocksize);
28 btrfs_set_super_total_blocks(&super, num_blocks);
29 btrfs_set_super_blocks_used(&super, 0);
31 block = malloc(blocksize);
32 memset(block, 0, blocksize);
33 BUG_ON(sizeof(super) > blocksize);
34 memcpy(block, &super, sizeof(super));
35 ret = pwrite(fd, block, blocksize, BTRFS_SUPER_INFO_OFFSET(blocksize));
36 BUG_ON(ret != blocksize);
38 /* create the tree of root objects */
39 memset(&empty_leaf, 0, sizeof(empty_leaf));
40 btrfs_set_header_parentid(&empty_leaf.header, BTRFS_ROOT_TREE_OBJECTID);
41 btrfs_set_header_blocknr(&empty_leaf.header, 17);
42 btrfs_set_header_nritems(&empty_leaf.header, 2);
44 /* create the items for the root tree */
45 btrfs_set_root_blocknr(&root_item, 18);
46 btrfs_set_root_refs(&root_item, 1);
47 itemoff = LEAF_DATA_SIZE - sizeof(root_item);
48 btrfs_set_item_offset(&item, itemoff);
49 btrfs_set_item_size(&item, sizeof(root_item));
50 btrfs_set_key_objectid(&item.key, BTRFS_EXTENT_TREE_OBJECTID);
51 btrfs_set_key_offset(&item.key, 0);
52 btrfs_set_key_flags(&item.key, 0);
53 memcpy(empty_leaf.items, &item, sizeof(item));
54 memcpy(empty_leaf.data + itemoff, &root_item, sizeof(root_item));
56 btrfs_set_root_blocknr(&root_item, 19);
57 itemoff = itemoff - sizeof(root_item);
58 btrfs_set_item_offset(&item, itemoff);
59 btrfs_set_key_objectid(&item.key, BTRFS_FS_TREE_OBJECTID);
60 memcpy(empty_leaf.items + 1, &item, sizeof(item));
61 memcpy(empty_leaf.data + itemoff, &root_item, sizeof(root_item));
62 ret = pwrite(fd, &empty_leaf, blocksize, 17 * blocksize);
64 /* create the items for the extent tree */
65 btrfs_set_header_parentid(&empty_leaf.header,
66 BTRFS_EXTENT_TREE_OBJECTID);
67 btrfs_set_header_blocknr(&empty_leaf.header, 18);
68 btrfs_set_header_nritems(&empty_leaf.header, 4);
70 /* item1, reserve blocks 0-16 */
71 btrfs_set_key_objectid(&item.key, 0);
72 btrfs_set_key_offset(&item.key, 17);
73 btrfs_set_key_flags(&item.key, 0);
74 itemoff = LEAF_DATA_SIZE - sizeof(struct btrfs_extent_item);
75 btrfs_set_item_offset(&item, itemoff);
76 btrfs_set_item_size(&item, sizeof(struct btrfs_extent_item));
77 btrfs_set_extent_refs(&extent_item, 1);
78 btrfs_set_extent_owner(&extent_item, 0);
79 memcpy(empty_leaf.items, &item, sizeof(item));
80 memcpy(empty_leaf.data + btrfs_item_offset(&item), &extent_item,
81 btrfs_item_size(&item));
83 /* item2, give block 17 to the root */
84 btrfs_set_key_objectid(&item.key, 17);
85 btrfs_set_key_offset(&item.key, 1);
86 itemoff = itemoff - sizeof(struct btrfs_extent_item);
87 btrfs_set_item_offset(&item, itemoff);
88 btrfs_set_extent_owner(&extent_item, BTRFS_ROOT_TREE_OBJECTID);
89 memcpy(empty_leaf.items + 1, &item, sizeof(item));
90 memcpy(empty_leaf.data + btrfs_item_offset(&item), &extent_item,
91 btrfs_item_size(&item));
93 /* item3, give block 18 to the extent root */
94 btrfs_set_key_objectid(&item.key, 18);
95 btrfs_set_key_offset(&item.key, 1);
96 itemoff = itemoff - sizeof(struct btrfs_extent_item);
97 btrfs_set_item_offset(&item, itemoff);
98 btrfs_set_extent_owner(&extent_item, BTRFS_EXTENT_TREE_OBJECTID);
99 memcpy(empty_leaf.items + 2, &item, sizeof(item));
100 memcpy(empty_leaf.data + btrfs_item_offset(&item), &extent_item,
101 btrfs_item_size(&item));
103 /* item4, give block 19 to the FS root */
104 btrfs_set_key_objectid(&item.key, 19);
105 btrfs_set_key_offset(&item.key, 1);
106 itemoff = itemoff - sizeof(struct btrfs_extent_item);
107 btrfs_set_item_offset(&item, itemoff);
108 btrfs_set_extent_owner(&extent_item, BTRFS_FS_TREE_OBJECTID);
109 memcpy(empty_leaf.items + 3, &item, sizeof(item));
110 memcpy(empty_leaf.data + btrfs_item_offset(&item), &extent_item,
111 btrfs_item_size(&item));
112 ret = pwrite(fd, &empty_leaf, blocksize, 18 * blocksize);
113 if (ret != sizeof(empty_leaf))
116 /* finally create the FS root */
117 btrfs_set_header_parentid(&empty_leaf.header, BTRFS_FS_TREE_OBJECTID);
118 btrfs_set_header_blocknr(&empty_leaf.header, 19);
119 btrfs_set_header_nritems(&empty_leaf.header, 0);
120 ret = pwrite(fd, &empty_leaf, blocksize, 19 * blocksize);
121 if (ret != sizeof(empty_leaf))
129 struct btrfs_root_info info[2];
130 struct btrfs_leaf empty_leaf;
131 struct btrfs_item item;
132 struct btrfs_extent_item extent_item;
135 /* setup the super block area */
136 memset(info, 0, sizeof(info));
137 btrfs_set_root_blocknr(info, 16);
138 btrfs_set_root_objectid(info, 1);
139 btrfs_set_root_tree_root(info, 17);
141 btrfs_set_root_blocknr(info + 1, 16);
142 btrfs_set_root_objectid(info + 1, 2);
143 btrfs_set_root_tree_root(info + 1, 18);
145 ret = pwrite(fd, info, sizeof(info),
146 BTRFS_SUPER_INFO_OFFSET(BTRFS_BLOCKSIZE));
147 if (ret != sizeof(info))
150 /* create leaves for the tree root and extent root */
151 memset(&empty_leaf, 0, sizeof(empty_leaf));
152 btrfs_set_header_parentid(&empty_leaf.header, 1);
153 btrfs_set_header_blocknr(&empty_leaf.header, 17);
154 ret = pwrite(fd, &empty_leaf, sizeof(empty_leaf), 17 * BTRFS_BLOCKSIZE);
155 if (ret != sizeof(empty_leaf))
158 btrfs_set_header_parentid(&empty_leaf.header, 2);
159 btrfs_set_header_blocknr(&empty_leaf.header, 18);
160 btrfs_set_header_nritems(&empty_leaf.header, 3);
162 /* item1, reserve blocks 0-16 */
163 btrfs_set_key_objectid(&item.key, 0);
164 btrfs_set_key_offset(&item.key, 17);
165 btrfs_set_key_flags(&item.key, 0);
166 btrfs_set_item_offset(&item, LEAF_DATA_SIZE -
167 sizeof(struct btrfs_extent_item));
168 btrfs_set_item_size(&item, sizeof(struct btrfs_extent_item));
169 btrfs_set_extent_refs(&extent_item, 1);
170 btrfs_set_extent_owner(&extent_item, 0);
171 memcpy(empty_leaf.items, &item, sizeof(item));
172 memcpy(empty_leaf.data + btrfs_item_offset(&item), &extent_item,
173 btrfs_item_size(&item));
175 /* item2, give block 17 to the root */
176 btrfs_set_key_objectid(&item.key, 17);
177 btrfs_set_key_offset(&item.key, 1);
178 btrfs_set_item_offset(&item, LEAF_DATA_SIZE -
179 sizeof(struct btrfs_extent_item) * 2);
180 btrfs_set_extent_owner(&extent_item, 1);
181 memcpy(empty_leaf.items + 1, &item, sizeof(item));
182 memcpy(empty_leaf.data + btrfs_item_offset(&item), &extent_item,
183 btrfs_item_size(&item));
185 /* item3, give block 18 for the extent root */
186 btrfs_set_key_objectid(&item.key, 18);
187 btrfs_set_key_offset(&item.key, 1);
188 btrfs_set_item_offset(&item, LEAF_DATA_SIZE -
189 sizeof(struct btrfs_extent_item) * 3);
190 btrfs_set_extent_owner(&extent_item, 2);
191 memcpy(empty_leaf.items + 2, &item, sizeof(item));
192 memcpy(empty_leaf.data + btrfs_item_offset(&item), &extent_item,
193 btrfs_item_size(&item));
194 ret = pwrite(fd, &empty_leaf, sizeof(empty_leaf), 18 * BTRFS_BLOCKSIZE);
195 if (ret != sizeof(empty_leaf))