Jens & everyone-- thanks for the speedy review and handling. I've updated my test cases to ensure that volumes from old releases work, even when I "don't think" there's been a disk format change. Bart-- On 11/17/2017 08:50 AM, Bart Van Assche wrote: > Have you considered to use bio_copy_dev() instead of open-coding it? One could... Right now almost all the uses of bio_copy_dev are in bcache and they need to change for other reasons. (e.g. macro uses parameter more than once, function is passed in as parameter). There's a whole lot of places to change if it's desired to make bio_copy_dev universally used to copy device information. > Additionally, there is more code that copies these fields, e.g. the code in > bio_clone_bioset(). Shouldn't that code be modified such that it also copies > bi_partno? Yes, when I was grepping around there were other things that looked possibly unsafe. I don't have test environments for all of these other subsystems. I wanted to get the minimal fix for this in, though, because people are actively losing data to the problem it triggers with bcache. Mike