On Wed, 30 Dec 2015 18:18:26 +0100 David Sterba <dsterba@xxxxxxx> wrote: > That's just the comment copied, the changelog does not explain why > it's ok to do just the run_xor there. It does not seem trivial to me. > Please describe that the end result after the code change is expected. In the RAID 6 case after a failure, we discover that the failure affected the entire P stripe, without any bad data occurring. Hence, we xor the previously stored parity data to return the data that was lost in the P stripe failure. The xor-red data is from the parity blocks. Hence, we are left with recovered data belonging to the P stripe. If there is an error during the completion of the xor (provided by the patch ), we got to the cleanup function. Hope that is satisfactory. -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
