Hi, This is the caching part of raid5-cache. The journal part was released with kernel 4.4. The caching part uses same disk format of raid456 journal, and provides acceleration to writes. Write operations are committed (bio_endio) once the data is secured in journal. Reconstruct and RMW are postponed to reclaim path, which is (hopefully) not on the critical path. The patch are splitted in 3 major changes: read path (chunk_aligned_read), write part (the main changes), and a naive reclaim. I have tested read and write patches (0001-0004), including data-verify in degraded modes. The reclaim patch still needs some work. I haven't finished the recovery part of the raid5-cache. But as the patch set grows, I would like feedback about current changes. Thanks, Song Song Liu (5): add bio_split_mddev move stripe cache define and functions to raid5.h r5cache: look up stripe cache for chunk_aligned_read r5cache: write part of r5cache r5cache: naive reclaim approach drivers/md/md.c | 14 +- drivers/md/md.h | 2 + drivers/md/raid5-cache.c | 711 +++++++++++++++++++++++++++++++++++++++++++++-- drivers/md/raid5.c | 264 ++++++++++++------ drivers/md/raid5.h | 101 ++++++- 5 files changed, 990 insertions(+), 102 deletions(-) -- 2.8.0.rc2 -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
