1 #define _XOPEN_SOURCE 500
12 #include <uuid/uuid.h>
13 #include "kerncompat.h"
14 #include "radix-tree.h"
17 #include "transaction.h"
20 #define BLKGETSIZE64 0
21 static inline int ioctl(int fd
, int define
, u64
*size
) { return 0; }
24 static int __make_root_dir(struct btrfs_trans_handle
*trans
,
25 struct btrfs_root
*root
, u64 objectid
)
29 struct btrfs_key inode_map
;
30 struct btrfs_inode_item inode_item
;
35 inode_map
.objectid
= objectid
;
37 btrfs_set_key_type(&inode_map
, BTRFS_INODE_ITEM_KEY
);
40 memset(&inode_item
, 0, sizeof(inode_item
));
41 btrfs_set_inode_generation(&inode_item
, root
->fs_info
->generation
);
42 btrfs_set_inode_size(&inode_item
, 6);
43 btrfs_set_inode_nlink(&inode_item
, 1);
44 btrfs_set_inode_nblocks(&inode_item
, 1);
45 btrfs_set_inode_mode(&inode_item
, S_IFDIR
| 0555);
47 if (root
->fs_info
->tree_root
== root
)
48 btrfs_set_super_root_dir(root
->fs_info
->disk_super
, objectid
);
50 ret
= btrfs_insert_inode(trans
, root
, objectid
, &inode_item
);
53 ret
= btrfs_insert_dir_item(trans
, root
, buf
, 1, objectid
,
57 ret
= btrfs_insert_dir_item(trans
, root
, buf
, 2, objectid
,
61 btrfs_set_root_dirid(&root
->root_item
, objectid
);
67 static int make_root_dir(int fd
) {
68 struct btrfs_root
*root
;
69 struct btrfs_super_block super
;
70 struct btrfs_trans_handle
*trans
;
72 struct btrfs_key location
;
74 root
= open_ctree_fd(fd
, &super
);
77 fprintf(stderr
, "ctree init failed\n");
80 trans
= btrfs_start_transaction(root
, 1);
81 ret
= __make_root_dir(trans
, root
->fs_info
->tree_root
,
82 BTRFS_ROOT_TREE_DIR_OBJECTID
);
85 ret
= __make_root_dir(trans
, root
, BTRFS_FIRST_FREE_OBJECTID
);
88 memcpy(&location
, &root
->fs_info
->fs_root
->root_key
, sizeof(location
));
89 location
.offset
= (u64
)-1;
90 ret
= btrfs_insert_dir_item(trans
, root
->fs_info
->tree_root
,
91 "default", strlen("default"),
92 btrfs_super_root_dir(root
->fs_info
->disk_super
),
96 btrfs_commit_transaction(trans
, root
, root
->fs_info
->disk_super
);
97 ret
= close_ctree(root
, &super
);
102 int mkfs(int fd
, char *pathname
, u64 num_blocks
, u32 blocksize
)
104 struct btrfs_super_block super
;
105 struct btrfs_leaf
*empty_leaf
;
106 struct btrfs_root_item root_item
;
107 struct btrfs_item item
;
108 struct btrfs_extent_item extent_item
;
109 struct btrfs_inode_item
*inode_item
;
110 struct btrfs_device_item dev_item
;
114 u32 start_block
= BTRFS_SUPER_INFO_OFFSET
/ blocksize
;
117 btrfs_set_super_generation(&super
, 1);
118 btrfs_set_super_blocknr(&super
, start_block
);
119 btrfs_set_super_root(&super
, start_block
+ 1);
120 strcpy((char *)(&super
.magic
), BTRFS_MAGIC
);
121 btrfs_set_super_blocksize(&super
, blocksize
);
122 btrfs_set_super_total_blocks(&super
, num_blocks
);
123 btrfs_set_super_blocks_used(&super
, start_block
+ 5);
124 btrfs_set_super_device_block_start(&super
, 0);
125 btrfs_set_super_device_num_blocks(&super
, num_blocks
);
126 btrfs_set_super_device_root(&super
, start_block
+ 2);
127 btrfs_set_super_device_id(&super
, 1);
128 btrfs_set_super_last_device_id(&super
, 1);
129 uuid_generate(super
.fsid
);
131 block
= malloc(blocksize
);
132 memset(block
, 0, blocksize
);
133 BUG_ON(sizeof(super
) > blocksize
);
134 memcpy(block
, &super
, sizeof(super
));
135 ret
= pwrite(fd
, block
, blocksize
, BTRFS_SUPER_INFO_OFFSET
);
136 BUG_ON(ret
!= blocksize
);
138 /* create the tree of root objects */
139 empty_leaf
= malloc(blocksize
);
140 memset(empty_leaf
, 0, blocksize
);
141 btrfs_set_header_blocknr(&empty_leaf
->header
, start_block
+ 1);
142 btrfs_set_header_nritems(&empty_leaf
->header
, 2);
143 btrfs_set_header_generation(&empty_leaf
->header
, 0);
144 memcpy(empty_leaf
->header
.fsid
, super
.fsid
,
145 sizeof(empty_leaf
->header
.fsid
));
147 /* create the items for the root tree */
148 inode_item
= &root_item
.inode
;
149 memset(inode_item
, 0, sizeof(*inode_item
));
150 btrfs_set_inode_generation(inode_item
, 1);
151 btrfs_set_inode_size(inode_item
, 3);
152 btrfs_set_inode_nlink(inode_item
, 1);
153 btrfs_set_inode_nblocks(inode_item
, 1);
154 btrfs_set_inode_mode(inode_item
, S_IFDIR
| 0755);
156 btrfs_set_root_dirid(&root_item
, 0);
157 btrfs_set_root_refs(&root_item
, 1);
158 btrfs_set_disk_key_offset(&item
.key
, 0);
159 btrfs_set_disk_key_flags(&item
.key
, 0);
160 btrfs_set_item_size(&item
, sizeof(root_item
));
161 btrfs_set_disk_key_type(&item
.key
, BTRFS_ROOT_ITEM_KEY
);
163 itemoff
= __BTRFS_LEAF_DATA_SIZE(blocksize
) - sizeof(root_item
);
164 btrfs_set_root_blocknr(&root_item
, start_block
+ 3);
165 btrfs_set_item_offset(&item
, itemoff
);
166 btrfs_set_disk_key_objectid(&item
.key
, BTRFS_EXTENT_TREE_OBJECTID
);
167 memcpy(empty_leaf
->items
, &item
, sizeof(item
));
168 memcpy(btrfs_leaf_data(empty_leaf
) + itemoff
,
169 &root_item
, sizeof(root_item
));
171 btrfs_set_root_blocknr(&root_item
, start_block
+ 4);
172 itemoff
= itemoff
- sizeof(root_item
);
173 btrfs_set_item_offset(&item
, itemoff
);
174 btrfs_set_disk_key_objectid(&item
.key
, BTRFS_FS_TREE_OBJECTID
);
175 memcpy(empty_leaf
->items
+ 1, &item
, sizeof(item
));
176 memcpy(btrfs_leaf_data(empty_leaf
) + itemoff
,
177 &root_item
, sizeof(root_item
));
178 ret
= pwrite(fd
, empty_leaf
, blocksize
, (start_block
+ 1) * blocksize
);
180 /* create the item for the dev tree */
181 btrfs_set_header_blocknr(&empty_leaf
->header
, start_block
+ 2);
182 btrfs_set_header_nritems(&empty_leaf
->header
, 1);
183 btrfs_set_disk_key_objectid(&item
.key
, 0);
184 btrfs_set_disk_key_offset(&item
.key
, num_blocks
);
185 btrfs_set_disk_key_flags(&item
.key
, 0);
186 btrfs_set_disk_key_type(&item
.key
, BTRFS_DEV_ITEM_KEY
);
188 item_size
= sizeof(struct btrfs_device_item
) + strlen(pathname
);
189 itemoff
= __BTRFS_LEAF_DATA_SIZE(blocksize
) - item_size
;
190 btrfs_set_item_offset(&item
, itemoff
);
191 btrfs_set_item_size(&item
, item_size
);
192 btrfs_set_device_pathlen(&dev_item
, strlen(pathname
));
193 btrfs_set_device_id(&dev_item
, 1);
194 memcpy(empty_leaf
->items
, &item
, sizeof(item
));
195 memcpy(btrfs_leaf_data(empty_leaf
) + itemoff
, &dev_item
,
197 memcpy(btrfs_leaf_data(empty_leaf
) + itemoff
+ sizeof(dev_item
),
198 pathname
, strlen(pathname
));
199 ret
= pwrite(fd
, empty_leaf
, blocksize
, (start_block
+ 2) * blocksize
);
200 if (ret
!= blocksize
)
203 /* create the items for the extent tree */
204 btrfs_set_header_blocknr(&empty_leaf
->header
, start_block
+ 3);
205 btrfs_set_header_nritems(&empty_leaf
->header
, 5);
207 /* item1, reserve blocks 0-16 */
208 btrfs_set_disk_key_objectid(&item
.key
, 0);
209 btrfs_set_disk_key_offset(&item
.key
, start_block
+ 1);
210 btrfs_set_disk_key_flags(&item
.key
, 0);
211 btrfs_set_disk_key_type(&item
.key
, BTRFS_EXTENT_ITEM_KEY
);
212 itemoff
= __BTRFS_LEAF_DATA_SIZE(blocksize
) -
213 sizeof(struct btrfs_extent_item
);
214 btrfs_set_item_offset(&item
, itemoff
);
215 btrfs_set_item_size(&item
, sizeof(struct btrfs_extent_item
));
216 btrfs_set_extent_refs(&extent_item
, 1);
217 memcpy(empty_leaf
->items
, &item
, sizeof(item
));
218 memcpy(btrfs_leaf_data(empty_leaf
) + btrfs_item_offset(&item
),
219 &extent_item
, btrfs_item_size(&item
));
221 /* item2, give block 17 to the root */
222 btrfs_set_disk_key_objectid(&item
.key
, start_block
+ 1);
223 btrfs_set_disk_key_offset(&item
.key
, 1);
224 itemoff
= itemoff
- sizeof(struct btrfs_extent_item
);
225 btrfs_set_item_offset(&item
, itemoff
);
226 memcpy(empty_leaf
->items
+ 1, &item
, sizeof(item
));
227 memcpy(btrfs_leaf_data(empty_leaf
) + btrfs_item_offset(&item
),
228 &extent_item
, btrfs_item_size(&item
));
230 /* item3, give block 18 to the dev root */
231 btrfs_set_disk_key_objectid(&item
.key
, start_block
+ 2);
232 btrfs_set_disk_key_offset(&item
.key
, 1);
233 itemoff
= itemoff
- sizeof(struct btrfs_extent_item
);
234 btrfs_set_item_offset(&item
, itemoff
);
235 memcpy(empty_leaf
->items
+ 2, &item
, sizeof(item
));
236 memcpy(btrfs_leaf_data(empty_leaf
) + btrfs_item_offset(&item
),
237 &extent_item
, btrfs_item_size(&item
));
239 /* item4, give block 19 to the extent root */
240 btrfs_set_disk_key_objectid(&item
.key
, start_block
+ 3);
241 btrfs_set_disk_key_offset(&item
.key
, 1);
242 itemoff
= itemoff
- sizeof(struct btrfs_extent_item
);
243 btrfs_set_item_offset(&item
, itemoff
);
244 memcpy(empty_leaf
->items
+ 3, &item
, sizeof(item
));
245 memcpy(btrfs_leaf_data(empty_leaf
) + btrfs_item_offset(&item
),
246 &extent_item
, btrfs_item_size(&item
));
248 /* item5, give block 20 to the FS root */
249 btrfs_set_disk_key_objectid(&item
.key
, start_block
+ 4);
250 btrfs_set_disk_key_offset(&item
.key
, 1);
251 itemoff
= itemoff
- sizeof(struct btrfs_extent_item
);
252 btrfs_set_item_offset(&item
, itemoff
);
253 memcpy(empty_leaf
->items
+ 4, &item
, sizeof(item
));
254 memcpy(btrfs_leaf_data(empty_leaf
) + btrfs_item_offset(&item
),
255 &extent_item
, btrfs_item_size(&item
));
256 ret
= pwrite(fd
, empty_leaf
, blocksize
, (start_block
+ 3) * blocksize
);
257 if (ret
!= blocksize
)
260 /* finally create the FS root */
261 btrfs_set_header_blocknr(&empty_leaf
->header
, start_block
+ 4);
262 btrfs_set_header_nritems(&empty_leaf
->header
, 0);
263 ret
= pwrite(fd
, empty_leaf
, blocksize
, (start_block
+ 4) * blocksize
);
264 if (ret
!= blocksize
)
269 u64
device_size(int fd
, struct stat
*st
)
272 if (S_ISREG(st
->st_mode
)) {
275 if (!S_ISBLK(st
->st_mode
)) {
278 if (ioctl(fd
, BLKGETSIZE64
, &size
) >= 0) {
283 int main(int ac
, char **av
)
291 char *buf
= malloc(4096);
299 block_count
= atoi(av
[2]);
301 fprintf(stderr
, "error finding block count\n");
306 fprintf(stderr
, "usage: mkfs.btrfs file [block count]\n");
309 fd
= open(file
, O_RDWR
);
311 fprintf(stderr
, "unable to open %s\n", file
);
314 ret
= fstat(fd
, &st
);
316 fprintf(stderr
, "unable to stat %s\n", file
);
319 if (block_count
== 0) {
320 block_count
= device_size(fd
, &st
);
321 if (block_count
== 0) {
322 fprintf(stderr
, "unable to find %s size\n", file
);
327 if (block_count
< 256) {
328 fprintf(stderr
, "device %s is too small\n", file
);
331 memset(buf
, 0, 4096);
332 for(i
= 0; i
< 64; i
++) {
333 ret
= write(fd
, buf
, 4096);
335 fprintf(stderr
, "unable to zero fill device\n");
339 realpath_name
= realpath(file
, NULL
);
340 ret
= mkfs(fd
, realpath_name
, block_count
, 4096);
342 fprintf(stderr
, "error during mkfs %d\n", ret
);
345 ret
= make_root_dir(fd
);
347 fprintf(stderr
, "failed to setup the root directory\n");
350 printf("fs created on %s blocksize %d blocks %Lu\n",
351 file
, 4096, block_count
);