Jens, Christoph & everyone-- Hi-- I believe I have a general idea what's going on. On Thu, Nov 16, 2017 at 3:02 PM, Michael Lyle <mlyle@xxxxxxxx> wrote: > On 11/16/2017 12:31 PM, Jens Axboe wrote: > > I'd suggest just doing a bisect between 4.13 and 4.14, sounds like the > > issue is trivially reproducible. > Took me awhile to get a repro but I have one now. Will start bisecting > tonight. It looks like the regression came from commit is 74d46992e0d9dee7f1f376de0d56d31614c8a17a (3/3 repros with it, 0/3 repros without it and hacked to build). I don't have time to analyze this tonight as I have a couple other things to do, but will look at fully analyzing it tomorrow morning. I think the probable cause is this: we construct bios based on previously completed bios in a few places, but blk_partition_remap sets the partno to 0 and adjusts the disk offset. It seems like a lot of potential uses of bio_copy_dev could be dangerous for this reason. Mike
