[dm-devel] [PATCH 0/2] block layer filter and block device snapshot module

[hch at infradead.org]

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..