This patch seemed like a good idea to me; I just checked linux-next, and looks like nothing like this is planned to be merged. Just thought I would send a prod-o-gram to see what the current thinking was around adding something like this. Thanks, - Ted On Tue, Nov 30, 2010 at 05:41:24PM +0100, Christoph Hellwig wrote: > FYI, here's an updated version of my patch to not run pure flushes > that also works on SCSI/ATA and not just virtio. I suspect the patch > alone might not be enough, but together with a variant of Neil's > suggestion might do the trick, with my patch taking care of the > highend-devices and Neil's scheme of taking care of stupid SATA disks. > > > Index: linux-2.6/block/blk-flush.c > =================================================================== > --- linux-2.6.orig/block/blk-flush.c 2010-11-30 17:27:33.108254088 +0100 > +++ linux-2.6/block/blk-flush.c 2010-11-30 17:27:38.790004333 +0100 > @@ -143,6 +143,17 @@ struct request *blk_do_flush(struct requ > unsigned skip = 0; > > /* > + * Just issue pure flushes directly. > + */ > + if (!blk_rq_sectors(rq)) { > + if (!do_preflush) { > + __blk_end_request_all(rq, 0); > + return NULL; > + } > + return rq; > + } > + > + /* > * Special case. If there's data but flush is not necessary, > * the request can be issued directly. > * > Index: linux-2.6/drivers/scsi/scsi_lib.c > =================================================================== > --- linux-2.6.orig/drivers/scsi/scsi_lib.c 2010-11-30 17:27:33.120254298 +0100 > +++ linux-2.6/drivers/scsi/scsi_lib.c 2010-11-30 17:27:38.791003634 +0100 > @@ -1060,7 +1060,7 @@ int scsi_setup_blk_pc_cmnd(struct scsi_d > * that does not transfer data, in which case they may optionally > * submit a request without an attached bio. > */ > - if (req->bio) { > + if (req->bio && !(req->cmd_flags & REQ_FLUSH)) { > int ret; > > BUG_ON(!req->nr_phys_segments); -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html