[PATCH 3/9] block: provide a direct_make_request helper

[Sagi Grimberg]

> +/**
> + * direct_make_request - hand a buffer directly to its device driver for I/O
> + * @bio:  The bio describing the location in memory and on the device.
> + *
> + * This function behaves like generic_make_request(), but does not protect
> + * against recursion.  Must only be used if the called driver is known
> + * to not re-issue this bio or a split to itself.
> + */

Can you explain a bit on the comment? What happens if nvme attempts
to failover a split if the original IO didn't comply to the
virt_boundary?

Would that cause any problems?