Btw, I really start to wonder if the request level is the right place to do this on-stack plugging. Wouldn't it be better to just plug bios in the on-stack queue? That way we could also stop doing the special case merging when adding to the plug list, and leave all the merging / I/O schedule logic in the __make_request path. Probably not .39 material, but worth a prototype? Also what this dicussion brought up is that the block layer data structures are highly confusing. Using a small subset of the request_queue also for make_request based driver just doesn't make sense. It seems like we should try to migrate the required state to struct gendisk, and submit I/O through a block_device_ops.submit method, leaving the request_queue as an internal abstraction for the request based drivers. -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
