Re: [PATCH 4/4] md: fast clone bio in bio_clone_mddev()

[Christoph Hellwig]

On Sun, Feb 05, 2017 at 02:22:13PM +0800, Ming Lei wrote:
> Firstly bio_clone_mddev() is used in raid normal I/O and isn't
> in resync I/O path.
> 
> Secondly all the direct access to bvec table in raid happens on
> resync I/O except for write behind of raid1, in which we still
> use bio_clone() for allocating new bvec table.
> 
> So this patch replaces bio_clone() with bio_clone_fast()
> in bio_clone_mddev().

Having the _fast in the name would be really useful for the
reader.  And as far as I can tell in the callers mddev is never
NULL and neither is ->bio_set, so replacing bio_clone_mddev with
raw calls to bio_clone_fast would be my preference.