diff options
Diffstat (limited to 'mkfs.c')
| -rw-r--r-- | mkfs.c | 128 |
1 files changed, 122 insertions, 6 deletions
@@ -10,6 +10,120 @@ #include "ctree.h" #include "disk-io.h" +int mkfs(int fd, u64 num_blocks, u16 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; + u16 itemoff; + + btrfs_set_super_blocknr(&super, 16); + btrfs_set_super_root(&super, 17); + 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(blocksize)); + BUG_ON(ret != blocksize); + + /* create the tree of root objects */ + memset(&empty_leaf, 0, sizeof(empty_leaf)); + btrfs_set_header_parentid(&empty_leaf.header, BTRFS_ROOT_TREE_OBJECTID); + btrfs_set_header_blocknr(&empty_leaf.header, 17); + btrfs_set_header_nritems(&empty_leaf.header, 2); + + /* create the items for the root tree */ + btrfs_set_root_blocknr(&root_item, 18); + btrfs_set_root_refs(&root_item, 1); + itemoff = LEAF_DATA_SIZE - 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(empty_leaf.data + itemoff, &root_item, sizeof(root_item)); + + btrfs_set_root_blocknr(&root_item, 19); + 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(empty_leaf.data + itemoff, &root_item, sizeof(root_item)); + ret = pwrite(fd, &empty_leaf, blocksize, 17 * 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, 18); + 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, 17); + btrfs_set_key_flags(&item.key, 0); + itemoff = LEAF_DATA_SIZE - 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(empty_leaf.data + btrfs_item_offset(&item), &extent_item, + btrfs_item_size(&item)); + + /* item2, give block 17 to the root */ + btrfs_set_key_objectid(&item.key, 17); + 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(empty_leaf.data + btrfs_item_offset(&item), &extent_item, + btrfs_item_size(&item)); + + /* item3, give block 18 to the extent root */ + btrfs_set_key_objectid(&item.key, 18); + 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(empty_leaf.data + btrfs_item_offset(&item), &extent_item, + btrfs_item_size(&item)); + + /* item4, give block 19 to the FS root */ + btrfs_set_key_objectid(&item.key, 19); + 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(empty_leaf.data + btrfs_item_offset(&item), &extent_item, + btrfs_item_size(&item)); + ret = pwrite(fd, &empty_leaf, blocksize, 18 * blocksize); + if (ret != sizeof(empty_leaf)) + 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, 19); + btrfs_set_header_nritems(&empty_leaf.header, 0); + ret = pwrite(fd, &empty_leaf, blocksize, 19 * blocksize); + if (ret != sizeof(empty_leaf)) + return -1; + return 0; +} + +#if 0 int mkfs(int fd) { struct btrfs_root_info info[2]; @@ -20,13 +134,14 @@ int mkfs(int fd) /* setup the super block area */ memset(info, 0, sizeof(info)); - info[0].blocknr = 16; - info[0].objectid = 1; - info[0].tree_root = 17; + btrfs_set_root_blocknr(info, 16); + btrfs_set_root_objectid(info, 1); + btrfs_set_root_tree_root(info, 17); + + btrfs_set_root_blocknr(info + 1, 16); + btrfs_set_root_objectid(info + 1, 2); + btrfs_set_root_tree_root(info + 1, 18); - info[1].blocknr = 16; - info[1].objectid = 2; - info[1].tree_root = 18; ret = pwrite(fd, info, sizeof(info), BTRFS_SUPER_INFO_OFFSET(BTRFS_BLOCKSIZE)); if (ret != sizeof(info)) @@ -81,3 +196,4 @@ int mkfs(int fd) return -1; return 0; } +#endif |