On Mon, Oct 13, 2014 at 10:43:14AM +0700, Pavel Goran wrote: > Hello Zheng, > > Monday, October 13, 2014, 10:45:37 AM, you wrote: > > > Yes, detaching a backing device will make all dirty data to be written > > back to the backing device. But if I understand correctly it couldn't > > invalidate all data in cache device. That means that after attaching > > backing device the data in cache device is still valid. > > It would be a bug if cached data were considered valid after detaching and > re-attaching. Because while a cache device an a backing device were separated, > data could be written to a backing device, this would possibly make data in a > "disconnected" cache obsolete. Ah, Thanks for pointing it out. I got it. BTW, there is a bug when I tried to detach/attach a backing device. A patch has sent out to the mailing list. That would be great if some one can review it. Regards, - Zheng -- To unsubscribe from this list: send the line "unsubscribe linux-bcache" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html