>>>>> "Mike" == Mike Snitzer <snitzer@xxxxxxxxxx> writes: Mike, Mike> Seems I took the time to add a comment whose FIXME doesn't ring Mike> many bells now! But ignoring that, the comment before the FIXME Mike> is making a veiled reference to userspace having consumed Mike> alignment_offset. I read and understood the comment. But even then explicitly zeroing out those two values didn't make sense (because if user space did in fact do the right thing they'd always be zero). I know that the DM utilities take care of business. And that DM devices are special because they are always set up by user space and not a kernel discovery process. But since the code *is* in place to validate things I'm not so keen on you clearing fields that have been calculated and have a meaning. For me it masked a case where the DM utilities did the wrong thing (because they were old). With the Enterprise Linux hat on it is easy for us to specify that you must use this version of the kernel and the device mapper utilities. But reality is that lots of people are running upstream kernels on distributions with older userland. And some distributions get things wrong, ship broken bits, etc. It's great that new DM utils will transparently adjust the starting offset. That's the way it's supposed to work. No arguments there. My main concern is making sure that we never get into a case where we run with misaligned components without indicating that there is a problem. Ever! Regardless of which DM utils might be in place. We have the power to get that right. All the pieces are in place. I'd simply like us to stop making assumptions about user space always doing the right thing. -- Martin K. Petersen Oracle Linux Engineering -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
