Linux 内核文件系统与设备操作流程分析

Linux 内核文件系统与设备操作流程分析(26)     inode = NULL;
    if (bh) {
        unsigned long ino = le32_to_cpu(de->inode);
        brelse (bh);

                //
                // 如果对应的超级块(super block)无效则直接返回错误
                //
        if (!ext3_valid_inum(dir->i_sb, ino)) {
            ext3_error(dir->i_sb, "ext3_lookup",
                   "bad inode number: %lu", ino);
            inode = NULL;
        } else

                        //
                        // 有效则调用 iget() 函数得到正确的 struct inode
                        // 其实也就是根据超级块(super block)的函数集获取
                        //                
            inode = iget(dir->i_sb, ino);

        if (!inode)