Ext3日志文件系统孤节点处理方法分析与改进

Analysis and Improvement of Isolated Node Processing Method in Ext3 Journal File System

深入分析了Ext3日志文件系统的日志块设备(Journal Block Device,JBD)结构,针对其在孤节点的判断和处理方法的不足,提出了一种改进的孤节点处理方法。通过查找索引节点结构中i_state域的标识状态来判断欲删除文件是否上锁,从而控制进程对文件的删除操作。该方法可以阻止删除正在被其它进程使用的文件,避免由此产生孤节点,进而改进日志服务,保证文件系统的一致性,提高系统的可靠性。

Based on the analysis of JBD （journal block device） structure and deficiency of handling isolated node, an efficient method of checking out the state of the i_state, which is included in the structure of the inode, was proposed. Through this method, the delete operation is controlled, the possibility of isolated node is diminished and the journal file server is improved. The consistency of file systems can be ensured and the performance of the system is also brought up.