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. Thanks, Ming Ming Lei (4): block: introduce bio_clone_bioset_partial() md: introduce bio_clone_slow_mddev_partial() md/raid1: use bio_clone_slow_mddev_partial in case of write behind md: fast clone bio in bio_clone_mddev() block/bio.c | 61 +++++++++++++++++++++++++++++++++++++++++------------ drivers/md/md.c | 24 +++++++++++++++++++-- drivers/md/md.h | 3 +++ drivers/md/raid1.c | 21 +++++++++++++----- include/linux/bio.h | 11 ++++++++-- 5 files changed, 98 insertions(+), 22 deletions(-) -- 2.7.4
