On Wed, Jul 22, 2015 at 07:57:12AM -0400, Martin K. Petersen wrote: > This fixes a data corruption bug when using discard on top of MD linear, > raid0 and raid10 personalities. > > Commit 20d0189b1012 "block: Introduce new bio_split()" permits sharing > the bio_vec between the two resulting bios. That is fine for read/write > requests where the bio_vec is immutable. For discards, however, we need > to be able to attach a payload and update the bio_vec so the page can > get mapped to a scatterlist entry. Therefore the bio_vec can not be > shared when splitting discards and we must do a full clone. Eww. The magic discard payload comes bac to bite us again. I wish someone smarter than me could come up with a scheme to avoid this issue. Looks good, Reviewed-by: Christoph Hellwig <hch@xxxxxx> -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html