On Mon, 27 Apr 2009, Alasdair G Kergon wrote: > On Mon, Apr 20, 2009 at 04:01:11AM -0400, Mikulas Patocka wrote: > > Flush supoprt for dm-delay target. > > > @@ -281,6 +282,8 @@ static int delay_map(struct dm_target *t > > bio->bi_bdev = dc->dev_write->bdev; > > bio->bi_sector = dc->start_write + > > (bio->bi_sector - ti->begin); > > + if (!bio_sectors(bio)) > > + bio->bi_sector = 0; > > Why set bio->bi_sector twice on that path? > Should we instead guarantee it's 0 before calling? For non-barrier requests, it needs to be translated according to the table. For zero-barrier request, it should be 0. (well, non-zero values may work, but I'm setting it zero, all other kernel code sets it to zero too). > > > > return delay_bio(dc, dc->write_delay, bio); > > } > > Is flushing different - do we really want to delay it? > (I'd have thought not. But if so, should it be a separate option?) Depending how you want it. I'd see it as a write and delay it as a write. If dm-delay is to be used for example for debugging, it should have a capability to delay all requests, including flushes. > Alasdair > -- > agk@xxxxxxxxxx Mikulas -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
