"John Garry" <john.g.garry@xxxxxxxxxx> writes: > On 15/02/2025 10:58, Andreas Hindborg wrote: >> When cloning a bio, the `bio.bi_vcnt` field is not cloned. This is a >> problem if users want to perform bounds checks on the `bio.bi_io_vec` >> field. > > Is this fixing a potential problem? Or fixing a real issue? It is fixing a problem I ran into in rnull, the rust null block implementation. When running with debug assertions enabled, a bound check on `bi_io_vec` fails for split bio, because `bio_vcnt` becomes zero in the cloned bio. I can work around this by not using a slice type to represent `bi_io_vec` in rust, not a big deal. But I am genuinely curious if there is a reason for not setting `bi_vcnt` during a clone. As far as I can tell, it should be safe to set. `bi_vcnt` being zero does not seem to have any effect other than to puzzle developers debugging the code. Maybe I missed something? Best regards, Andreas Hindborg
