int btrfs_make_root_dir(struct btrfs_trans_handle *trans, struct btrfs_root *root, u64 objectid) { int ret; struct btrfs_inode_item inode_item; memset(&inode_item, 0, sizeof(inode_item)); btrfs_set_stack_inode_generation(&inode_item, trans->transid); btrfs_set_stack_inode_size(&inode_item, 0); btrfs_set_stack_inode_nlink(&inode_item, 1); btrfs_set_stack_inode_nbytes(&inode_item, root->leafsize); btrfs_set_stack_inode_mode(&inode_item, S_IFDIR | 0555); if (root->fs_info->tree_root == root) btrfs_set_super_root_dir(&root->fs_info->super_copy, objectid); ret = btrfs_insert_inode(trans, root, objectid, &inode_item); if (ret) goto error; ret = btrfs_insert_inode_ref(trans, root, "..", 2, objectid, objectid, 0); if (ret) goto error; btrfs_set_root_dirid(&root->root_item, objectid); ret = 0; error: return ret; }
static noinline int create_subvol(struct btrfs_root *root, struct dentry *dentry, char *name, int namelen) { struct btrfs_trans_handle *trans; struct btrfs_key key; struct btrfs_root_item root_item; struct btrfs_inode_item *inode_item; struct extent_buffer *leaf; struct btrfs_root *new_root; struct inode *dir = dentry->d_parent->d_inode; int ret; int err; u64 objectid; u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID; u64 index = 0; ret = btrfs_find_free_objectid(NULL, root->fs_info->tree_root, 0, &objectid); if (ret) return ret; /* * 1 - inode item * 2 - refs * 1 - root item * 2 - dir items */ trans = btrfs_start_transaction(root, 6); if (IS_ERR(trans)) return PTR_ERR(trans); leaf = btrfs_alloc_free_block(trans, root, root->leafsize, 0, objectid, NULL, 0, 0, 0); if (IS_ERR(leaf)) { ret = PTR_ERR(leaf); goto fail; } memset_extent_buffer(leaf, 0, 0, sizeof(struct btrfs_header)); btrfs_set_header_bytenr(leaf, leaf->start); btrfs_set_header_generation(leaf, trans->transid); btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV); btrfs_set_header_owner(leaf, objectid); write_extent_buffer(leaf, root->fs_info->fsid, (unsigned long)btrfs_header_fsid(leaf), BTRFS_FSID_SIZE); write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid, (unsigned long)btrfs_header_chunk_tree_uuid(leaf), BTRFS_UUID_SIZE); btrfs_mark_buffer_dirty(leaf); inode_item = &root_item.inode; memset(inode_item, 0, sizeof(*inode_item)); inode_item->generation = cpu_to_le64(1); inode_item->size = cpu_to_le64(3); inode_item->nlink = cpu_to_le32(1); inode_item->nbytes = cpu_to_le64(root->leafsize); inode_item->mode = cpu_to_le32(S_IFDIR | 0755); root_item.flags = 0; root_item.byte_limit = 0; inode_item->flags = cpu_to_le64(BTRFS_INODE_ROOT_ITEM_INIT); btrfs_set_root_bytenr(&root_item, leaf->start); btrfs_set_root_generation(&root_item, trans->transid); btrfs_set_root_level(&root_item, 0); btrfs_set_root_refs(&root_item, 1); btrfs_set_root_used(&root_item, leaf->len); btrfs_set_root_last_snapshot(&root_item, 0); memset(&root_item.drop_progress, 0, sizeof(root_item.drop_progress)); root_item.drop_level = 0; btrfs_tree_unlock(leaf); free_extent_buffer(leaf); leaf = NULL; btrfs_set_root_dirid(&root_item, new_dirid); key.objectid = objectid; key.offset = 0; btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY); ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key, &root_item); if (ret) goto fail; key.offset = (u64)-1; new_root = btrfs_read_fs_root_no_name(root->fs_info, &key); BUG_ON(IS_ERR(new_root)); btrfs_record_root_in_trans(trans, new_root); ret = btrfs_create_subvol_root(trans, new_root, new_dirid, BTRFS_I(dir)->block_group); /* * insert the directory item */ ret = btrfs_set_inode_index(dir, &index); BUG_ON(ret); ret = btrfs_insert_dir_item(trans, root, name, namelen, dir->i_ino, &key, BTRFS_FT_DIR, index); if (ret) goto fail; btrfs_i_size_write(dir, dir->i_size + namelen * 2); ret = btrfs_update_inode(trans, root, dir); BUG_ON(ret); ret = btrfs_add_root_ref(trans, root->fs_info->tree_root, objectid, root->root_key.objectid, dir->i_ino, index, name, namelen); BUG_ON(ret); d_instantiate(dentry, btrfs_lookup_dentry(dir, dentry)); fail: err = btrfs_commit_transaction(trans, root); if (err && !ret) ret = err; return ret; }