Initialize the clone-info's index to the original bio's index. Required to properly handle stacking DM devices. --- linux-2.5.53a/drivers/md/dm.c Mon Dec 23 23:21:04 2002 +++ linux-2.5.53b/drivers/md/dm.c Fri Dec 27 14:50:29 2002 @@ -475,7 +482,7 @@ ci.io->md = md; ci.sector = bio->bi_sector; ci.sector_count = bio_sectors(bio); - ci.idx = 0; + ci.idx = bio->bi_idx; atomic_inc(&md->pending); while (ci.sector_count)