[PATCH RFC 3/5] block: validate bio bounds in the queue entered context

[Chris S]

Got you. Please let me know if you need any help.

Best,
Chao

On Mon, Aug 10, 2026 at 5:23 PM Keith Busch <kbusch at kernel.org> wrote:
>
> On Mon, Aug 10, 2026 at 05:12:45PM -0400, Chris S wrote:
> > Keith, I checked this patch against the nvme_setup_rw() WARN I reported
> > (the second link in your cover letter).  __bio_split_to_limits() is
> > called from blk_mq_submit_bio() after bio_queue_enter(), on both the
> > cached-request path and the newly-allocated-request path, so the bounds
> > check is now serialized against the freeze window in
> > nvme_update_ns_info_block().  With the capacity forced to 0, the bio is
> > failed here and can no longer reach nvme_queue_rq(), which is exactly
> > the race I hit.  Thanks for picking it up, and sorry for the slow reply.
> >
> > I'll drop my own "nvme: don't WARN on I/O to a namespace revalidated to
> > unusable metadata" patch in favour of this.
>
> I'll need to revisit this approach as it is dependent on something in
> the stack calling the split to limits functions, as well as the upper
> layers error handling for a catching the end-of-device condition later
> than before.