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

From: Shaohua Li
Date: Wed Feb 15 2017 - 14:20:11 EST


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
>