JFFS2文件系统的异常打印信息记录

在嵌入式产品中，使用JFFS2文件系统时，会遇到很多奇怪的打印：

JFFS2 notice: (154) check_node_data: wrong data CRC in data node at 0x036fef18: read 0x68bda766, calculated 0x1cd2b7dd.

打印这个说明文件系统中的文件节点读取有异常，可能导致该打印的行为：

or similar message about CRC failures. If you have ever done unclean reboots - this is harmless. This just means that the unclean reboot happened (1) during data write or write buffer sync or (2) while GC was working or (3) while the write-buffer contained some data and was not yet synced before the unclean reboot happened. In them first and the third cases, you just lose the very last data you have written, in the second case you lose nothing. The wrong nodes will eventually be recycled by Garbage Collector and the messages will go (but they may live quite long).

But this also may mean that data on your flash was corrupted for sum reasons. Unfortunately JFFS2 cannot distinguish between node corruptions cause by unclean reboots and by real media corruptions. But the latter case is very rare.

还有打印这个：

Empty flash at 0xXXXXXXXX ends at 0xXXXXXXXX

这个官方说打印这个没关系，不影响使用：

This message is generated if a block of data is partially written. It is generally not a sign of any problem

更多的MTD方面的参考：http://www.linux-mtd.infradead.org/faq/jffs2.html