On Fri, Oct 23, 2020 at 12:31:05PM +0200, Hannes Reinecke wrote: > My thoughts went more into the direction of hooking into ->submit_bio, > seeing that it's a NULL pointer for most (all?) block drivers. > > But sure, I'll check how the interposer approach would turn out. submit_bio is owned by the underlying device, and for a good reason stored in a const struct..