On Fri, Sep 03 2010 at 6:29am -0400, Tejun Heo <tj@xxxxxxxxxx> wrote: > This patch converts bio-based dm to support REQ_FLUSH/FUA instead of > now deprecated REQ_HARDBARRIER. > > * -EOPNOTSUPP handling logic dropped. > > * Preflush is handled as before but postflush is dropped and replaced > with passing down REQ_FUA to member request_queues. This replaces > one array wide cache flush w/ member specific FUA writes. > > * __split_and_process_bio() now calls __clone_and_map_flush() directly > for flushes and guarantees all FLUSH bio's going to targets are zero > ` length. > > * It's now guaranteed that all FLUSH bio's which are passed onto dm > targets are zero length. bio_empty_barrier() tests are replaced > with REQ_FLUSH tests. > > * Empty WRITE_BARRIERs are replaced with WRITE_FLUSHes. > > * Dropped unlikely() around REQ_FLUSH tests. Flushes are not unlikely > enough to be marked with unlikely(). > > * Block layer now filters out REQ_FLUSH/FUA bio's if the request_queue > doesn't support cache flushing. Advertise REQ_FLUSH | REQ_FUA > capability. > > * Request based dm isn't converted yet. dm_init_request_based_queue() > resets flush support to 0 for now. To avoid disturbing request > based dm code, dm->flush_error is added for bio based dm while > requested based dm continues to use dm->barrier_error. > > Lightly tested linear, stripe, raid1, snap and crypt targets. Please > proceed with caution as I'm not familiar with the code base. Reviewed-by: Mike Snitzer <snitzer@xxxxxxxxxx> Mikulas and/or Alasdair won't be able to review this until next week. -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
