Hi Josef and Jens,
this series tries to deal with the fallout of the recent lock scope
reduction as pointed out by Tetsuo and szybot and inspired by /
reused from the catchall patch by Tetsuo. One big change is that
I finally decided to kill off the ->destroy_complete scheme entirely
because I'm pretty sure it is not needed with the various fixes and
we can just return an error for the tiny race condition where it
matters. Xiubo, can you double check this with your nbd-runner
setup? nbd-runner itself seems pretty generic and not directly
reproduce anything here.
Note that the syzbot reproduer still fails eventually, but in
devtmpfsd in a way that does not look related to the loop code
at all.