On Mon, Aug 30 2010 at 11:45am -0400, Tejun Heo <tj@xxxxxxxxxx> wrote: > This patch converts request-based dm to support the new REQ_FLUSH/FUA. > > The original request-based flush implementation depended on > request_queue blocking other requests while a barrier sequence is in > progress, which is no longer true for the new REQ_FLUSH/FUA. > > In general, request-based dm doesn't have infrastructure for cloning > one source request to multiple targets, but the original flush > implementation had a special mostly independent path which can issue > flushes to multiple targets and sequence them. However, the > capability isn't currently in use and adds a lot of complexity. > Moreoever, it's unlikely to be useful in its current form as it > doesn't make sense to be able to send out flushes to multiple targets > when write requests can't be. > > This patch rips out special flush code path and deals handles > REQ_FLUSH/FUA requests the same way as other requests. The only > special treatment is that REQ_FLUSH requests use the block address 0 > when finding target, which is enough for now. > > * added BUG_ON(!dm_target_is_valid(ti)) in dm_request_fn() as > suggested by Mike Snitzer > > Signed-off-by: Tejun Heo <tj@xxxxxxxxxx> Looks good. Acked-by: Mike Snitzer <snitzer@xxxxxxxxxx> Junichi and/or Kiyoshi, Could you please review this patch and add your Acked-by if it is OK? (Alasdair will want to see NEC's Ack to accept this patch). Thanks, Mike -- 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
