if (!page)
                return NULL;
 
-       wait_on_page_writeback(page);
        if (!page_has_buffers(page))
                create_empty_buffers(page, root->fs_info->sb->s_blocksize, 0);
        head = page_buffers(page);
        fs_info->btree_inode->i_mapping->a_ops = &btree_aops;
        mapping_set_gfp_mask(fs_info->btree_inode->i_mapping, GFP_NOFS);
        fs_info->hash_tfm = crypto_alloc_hash("sha256", 0, CRYPTO_ALG_ASYNC);
-       if (!fs_info->hash_tfm) {
+       spin_lock_init(&fs_info->hash_lock);
+
+       if (!fs_info->hash_tfm || IS_ERR(fs_info->hash_tfm)) {
                printk("failed to allocate sha256 hash\n");
                return NULL;
        }
-       spin_lock_init(&fs_info->hash_lock);
 
        mutex_init(&fs_info->trans_mutex);
        mutex_init(&fs_info->fs_mutex);
        btrfs_block_release(root, root->commit_root);
        btrfs_block_release(root, root->fs_info->sb_buffer);
        crypto_free_hash(root->fs_info->hash_tfm);
+       truncate_inode_pages(root->fs_info->btree_inode->i_mapping, 0);
        iput(root->fs_info->btree_inode);
        kfree(root->fs_info->extent_root);
        kfree(root->fs_info->inode_root);