On Tue, Dec 15, 2020 at 02:05:35PM +0000, Pavel Begunkov wrote: > > You may find clue from the following link: > > > > https://www.mail-archive.com/linux-kernel@xxxxxxxxxxxxxxx/msg2262077.html > > Thanks for the link! > > Al, you mentioned "Zero-length segments are not disallowed", do you have > a strong opinion on that? Apart from already diverged behaviour from the > block layer and getting in the way of this series, without it we'd also be > able to remove some extra ifs, e.g. in iterate_bvec() I'd prefer not to support zero-length ITER_BVEC and catching them early, as the block layer can't deal with them either. From a quick look at iter_file_splice_write it should be pretty trivial to fix there, although we'll need to audit other callers as well (even if I don't expect them to submit this degenerate case).