Re: [PATCH v2 0/5] md: use bio_clone_fast()

[Shaohua Li]

On Tue, Feb 14, 2017 at 11:28:58PM +0800, Ming Lei wrote:
> Hi,
> 
> This patches replaces bio_clone() with bio_fast_clone() in
> bio_clone_mddev() because:
> 
> 1) bio_clone_mddev() is used in raid normal I/O and isn't in
> resync I/O path, and all the direct access to bvec table in
> raid happens on resync I/O only except for write behind of raid1.
> Write behind is treated specially, so the replacement is safe.
> 
> 2) for write behind, bio_clone() is kept, but this patchset
> introduces bio_clone_bioset_partial() to just clone one specific 
> bvecs range instead of whole table. Then write behind is improved
> too.
> 
> V2:
> 	1) move 3rd patch into 2nd one
> 	2) kill  bio_clone_mddev() and use  bio_clone_fast() directly
> 	3) define local variable 'offset' as sector_t in raid1_write_request()
> 
> V1:
> 	1) don't introduce bio_clone_slow_mddev_partial()
> 	2) return failure if mddev->bio_set can't be created
> 	3) remove check in bio_clone_mddev() as suggested by
> 	Christoph Hellwig.
> 	4) rename bio_clone_mddev() as bio_clone_fast_mddev()

Applied, thanks!
 
> Ming Lei (5):
>   block: introduce bio_clone_bioset_partial()
>   md: fail if mddev->bio_set can't be created
>   md/raid1: use bio_clone_bioset_partial() in case of write behind
>   md: remove unnecessary check on mddev
>   md: fast clone bio in bio_clone_mddev()
> 
>  block/bio.c         | 61 +++++++++++++++++++++++++++++++++++++++++------------
>  drivers/md/faulty.c |  2 +-
>  drivers/md/md.c     | 15 ++++---------
>  drivers/md/md.h     |  2 --
>  drivers/md/raid1.c  | 28 +++++++++++++++++-------
>  drivers/md/raid10.c | 11 +++++-----
>  drivers/md/raid5.c  |  4 ++--
>  include/linux/bio.h | 11 ++++++++--
>  8 files changed, 89 insertions(+), 45 deletions(-)
> 
> -- 
> 2.7.4
>