On Wed, Feb 04 2015 at 1:41pm -0500, Mike Snitzer <snitzer@xxxxxxxxxx> wrote: > @@ -527,9 +522,10 @@ static void normal_map_bio(struct dm_target *ti, struct bio *bio) > struct log_writes_c *lc = ti->private; > > bio->bi_bdev = lc->dev->bdev; > + // FIXME: why would bi_sector ever need to be changed? > + // if you just copied dm-linear then it is misplaced since there isn't an offset > if (bio_sectors(bio)) > - bio->bi_iter.bi_sector = > - dm_target_offset(ti, bio->bi_iter.bi_sector); > + bio->bi_iter.bi_sector = dm_target_offset(ti, bio->bi_iter.bi_sector); > } In above FIXME: s/misplaced/incomplete/ FYI sharing this quick private exchange I had with Alasdair just to make sure I'm clear on what the above FIXME was trying to convey: On Wed, Feb 04 2015 at 6:28pm -0500, Mike Snitzer <snitzer@xxxxxxxxxx> wrote: > On Wed, Feb 04 2015 at 5:43pm -0500, > Alasdair G Kergon <agk@xxxxxxxxxx> wrote: > > > On Wed, Feb 04, 2015 at 01:41:09PM -0500, Mike Snitzer wrote: > > > + // FIXME: why would bi_sector ever need to be changed? > > > + // if you just copied dm-linear then it is misplaced since there isn't an offset > > > > Why shouldn't we use this target on the 2nd or later line of a > table? > > Wasn't saying it shouldn't. Just was saying that Josef's target didn't > go as far as say dm-linear with its 'start' offset. Without it then > this dm-log-writes target implicitly assumes every logical address > space, be it 2nd or later, identity maps to exact same offset on the > backing the data disk. > > My FIXME was too cryptic. I can follow-up on this point. -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
