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. 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() Ming Lei (5): block: introduce bio_clone_bioset_partial() md/raid1: use bio_clone_bioset_partial() in case of write behind md: fail if mddev->bio_set can't be created 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 | 14 ++++++------ drivers/md/md.h | 4 ++-- drivers/md/raid1.c | 26 ++++++++++++++++------- drivers/md/raid10.c | 11 +++++----- drivers/md/raid5.c | 4 ++-- include/linux/bio.h | 11 ++++++++-- 8 files changed, 92 insertions(+), 41 deletions(-) -- 2.7.4 Thanks, Ming
