On Fri, Mar 15, 2024 at 08:52:46AM +0100, Andreas Hindborg wrote: > Miguel Ojeda <miguel.ojeda.sandonis@xxxxxxxxx> writes: > > > On Thu, Mar 14, 2024 at 8:23 PM Andreas Hindborg <nmi@xxxxxxxxxxxx> wrote: > >> > >> The way the current code compiles, <kernel::block::mq::Request as > >> kernel::types::AlwaysRefCounted>::dec_ref` is inlined into the `rnull` > >> module. A relocation for `rust_helper_blk_mq_free_request_internal` > >> appears in `rnull_mod.ko`. I didn't test it yet, but if > >> `__blk_mq_free_request` (or the helper) is not exported, I don't think > >> this would be possible? > > > > Yeah, something needs to be exported since there is a generic > > involved, but even if you want to go the route of exporting only a > > different symbol, you would still want to put it in the C header so > > that you don't get the C missing declaration warning and so that we > > don't have to write the declaration manually in the helper. > > That is what I did: > > @@ -703,6 +703,7 @@ int blk_mq_alloc_sq_tag_set(struct blk_mq_tag_set *set, > unsigned int set_flags); > void blk_mq_free_tag_set(struct blk_mq_tag_set *set); > > +void __blk_mq_free_request(struct request *rq); > void blk_mq_free_request(struct request *rq); > int blk_rq_poll(struct request *rq, struct io_comp_batch *iob, > unsigned int poll_flags); Can you explain in detail why one block layer internal helper is called into rnull driver directly? It never happens in C driver code. Thanks, Ming
