| #define _XOPEN_SOURCE 500 |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <sys/types.h> |
| #include <sys/stat.h> |
| #include <fcntl.h> |
| #include <unistd.h> |
| #include "kerncompat.h" |
| #include "radix-tree.h" |
| #include "ctree.h" |
| #include "disk-io.h" |
| |
| int mkfs(int fd, u64 num_blocks, u32 blocksize) |
| { |
| struct btrfs_super_block super; |
| struct btrfs_leaf *empty_leaf; |
| struct btrfs_root_item root_item; |
| struct btrfs_item item; |
| struct btrfs_extent_item extent_item; |
| char *block; |
| int ret; |
| u32 itemoff; |
| u32 start_block = BTRFS_SUPER_INFO_OFFSET / blocksize; |
| |
| btrfs_set_super_blocknr(&super, start_block); |
| btrfs_set_super_root(&super, start_block + 1); |
| strcpy((char *)(&super.magic), BTRFS_MAGIC); |
| btrfs_set_super_blocksize(&super, blocksize); |
| btrfs_set_super_total_blocks(&super, num_blocks); |
| btrfs_set_super_blocks_used(&super, 0); |
| |
| block = malloc(blocksize); |
| memset(block, 0, blocksize); |
| BUG_ON(sizeof(super) > blocksize); |
| memcpy(block, &super, sizeof(super)); |
| ret = pwrite(fd, block, blocksize, BTRFS_SUPER_INFO_OFFSET); |
| BUG_ON(ret != blocksize); |
| |
| /* create the tree of root objects */ |
| empty_leaf = malloc(blocksize); |
| memset(empty_leaf, 0, blocksize); |
| btrfs_set_header_parentid(&empty_leaf->header, |
| BTRFS_ROOT_TREE_OBJECTID); |
| btrfs_set_header_blocknr(&empty_leaf->header, start_block + 1); |
| btrfs_set_header_nritems(&empty_leaf->header, 2); |
| |
| /* create the items for the root tree */ |
| btrfs_set_root_blocknr(&root_item, start_block + 2); |
| btrfs_set_root_refs(&root_item, 1); |
| itemoff = __BTRFS_LEAF_DATA_SIZE(blocksize) - sizeof(root_item); |
| btrfs_set_item_offset(&item, itemoff); |
| btrfs_set_item_size(&item, sizeof(root_item)); |
| btrfs_set_key_objectid(&item.key, BTRFS_EXTENT_TREE_OBJECTID); |
| btrfs_set_key_offset(&item.key, 0); |
| btrfs_set_key_flags(&item.key, 0); |
| memcpy(empty_leaf->items, &item, sizeof(item)); |
| memcpy(btrfs_leaf_data(empty_leaf) + itemoff, |
| &root_item, sizeof(root_item)); |
| |
| btrfs_set_root_blocknr(&root_item, start_block + 3); |
| itemoff = itemoff - sizeof(root_item); |
| btrfs_set_item_offset(&item, itemoff); |
| btrfs_set_key_objectid(&item.key, BTRFS_FS_TREE_OBJECTID); |
| memcpy(empty_leaf->items + 1, &item, sizeof(item)); |
| memcpy(btrfs_leaf_data(empty_leaf) + itemoff, |
| &root_item, sizeof(root_item)); |
| ret = pwrite(fd, empty_leaf, blocksize, (start_block + 1) * blocksize); |
| |
| /* create the items for the extent tree */ |
| btrfs_set_header_parentid(&empty_leaf->header, |
| BTRFS_EXTENT_TREE_OBJECTID); |
| btrfs_set_header_blocknr(&empty_leaf->header, start_block + 2); |
| btrfs_set_header_nritems(&empty_leaf->header, 4); |
| |
| /* item1, reserve blocks 0-16 */ |
| btrfs_set_key_objectid(&item.key, 0); |
| btrfs_set_key_offset(&item.key, start_block + 1); |
| btrfs_set_key_flags(&item.key, 0); |
| itemoff = __BTRFS_LEAF_DATA_SIZE(blocksize) - |
| sizeof(struct btrfs_extent_item); |
| btrfs_set_item_offset(&item, itemoff); |
| btrfs_set_item_size(&item, sizeof(struct btrfs_extent_item)); |
| btrfs_set_extent_refs(&extent_item, 1); |
| btrfs_set_extent_owner(&extent_item, 0); |
| memcpy(empty_leaf->items, &item, sizeof(item)); |
| memcpy(btrfs_leaf_data(empty_leaf) + btrfs_item_offset(&item), |
| &extent_item, btrfs_item_size(&item)); |
| |
| /* item2, give block 17 to the root */ |
| btrfs_set_key_objectid(&item.key, start_block + 1); |
| btrfs_set_key_offset(&item.key, 1); |
| itemoff = itemoff - sizeof(struct btrfs_extent_item); |
| btrfs_set_item_offset(&item, itemoff); |
| btrfs_set_extent_owner(&extent_item, BTRFS_ROOT_TREE_OBJECTID); |
| memcpy(empty_leaf->items + 1, &item, sizeof(item)); |
| memcpy(btrfs_leaf_data(empty_leaf) + btrfs_item_offset(&item), |
| &extent_item, btrfs_item_size(&item)); |
| |
| /* item3, give block 18 to the extent root */ |
| btrfs_set_key_objectid(&item.key, start_block + 2); |
| btrfs_set_key_offset(&item.key, 1); |
| itemoff = itemoff - sizeof(struct btrfs_extent_item); |
| btrfs_set_item_offset(&item, itemoff); |
| btrfs_set_extent_owner(&extent_item, BTRFS_EXTENT_TREE_OBJECTID); |
| memcpy(empty_leaf->items + 2, &item, sizeof(item)); |
| memcpy(btrfs_leaf_data(empty_leaf) + btrfs_item_offset(&item), |
| &extent_item, btrfs_item_size(&item)); |
| |
| /* item4, give block 19 to the FS root */ |
| btrfs_set_key_objectid(&item.key, start_block + 3); |
| btrfs_set_key_offset(&item.key, 1); |
| itemoff = itemoff - sizeof(struct btrfs_extent_item); |
| btrfs_set_item_offset(&item, itemoff); |
| btrfs_set_extent_owner(&extent_item, BTRFS_FS_TREE_OBJECTID); |
| memcpy(empty_leaf->items + 3, &item, sizeof(item)); |
| memcpy(btrfs_leaf_data(empty_leaf) + btrfs_item_offset(&item), |
| &extent_item, btrfs_item_size(&item)); |
| ret = pwrite(fd, empty_leaf, blocksize, (start_block + 2) * blocksize); |
| if (ret != blocksize) |
| return -1; |
| |
| /* finally create the FS root */ |
| btrfs_set_header_parentid(&empty_leaf->header, BTRFS_FS_TREE_OBJECTID); |
| btrfs_set_header_blocknr(&empty_leaf->header, start_block + 3); |
| btrfs_set_header_nritems(&empty_leaf->header, 0); |
| ret = pwrite(fd, empty_leaf, blocksize, (start_block + 3) * blocksize); |
| if (ret != blocksize) |
| return -1; |
| return 0; |
| } |