On Thu, Aug 23, 2012 at 10:25:47PM -0400, Martin K. Petersen wrote: > >>>>> "Tejun" == Tejun Heo <tj@xxxxxxxxxx> writes: > > Tejun> I complained about this in the last posting and in the previous > Tejun> patch. Please respond. Martin, are you okay with these > Tejun> integrity changes? > > I missed the first several iterations of all this while I was out on > vacation. I'll have to try to wrap my head around the new approach. > > However, I'm not sure I like the overall approach of the new splitting. > Instead of all this cloning, slicing and dicing of bio_vecs I'd rather > we bit the bullet and had an offset + length for the vector inside each > bio. That way we could keep the bio_vec immutable and make clones more > lightweight since their vecs would always point to the parent. This also > makes it trivial to split I/Os in the stacking drivers and removes evils > in the partial completion code path. It would also allow to sever the > ties between "size of block range operated on" vs. bi_size which we need > for copy offload, discard, etc. Agree 110% - making bio_vecs immutable and keeping the offset in the bio is something I've been talking about for ages, I'd love to see it happen. But that's going to be a much more invasive change so if I'm going to do it (and I am willing to work on it) it's just going to be a bit. This is really a stopgap solution. As far as the integrity splitting, it's similar to what the existing dm code does (main difference is dm already has the bio cloned, my bio_split() doesn't assume anything about the bio being split). Not sure how that affects ownership of the integrity data, honestly that part kind of confuses me. -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
