On Fri, Jan 17, 2020 at 02:56:05PM +0000, Trond Myklebust wrote: > It sounds to me like we rather need a meta-topic about "How do we get > simple things done in the Linux fs community?" > > It shouldn't take a ticket to Palm Springs to perform something simple > like adding a new flag to a syscall. Sure - adding a new flag is trivial. Coming up with sane semantics for it, OTOH, can be rather non-trivial and in this case it is, unfortunately. "something like link(2), only it tolerates the existing target and atomically replaces it" does _not_ specify the semantics. Try to sit down for a few minutes and come up with the cases when behaviour is undefined by the above; it won't take longer than that. We can do it by asking the proponent to come up with full description to be included into the proposal, then have at it on fsdevel/linux-abi (as well as security lists). Doable, but not a small amount of PITA for original poster and dealing with questions/objections/etc. is certain to grow a large thread with many branches (and lots of bikeshedding thrown in) _and_ would include tons of roundtrips, so the latency (especially early on, while the proposal is still raw) will be a factor. It's not the question of how to implement it; it's what should it _do_. And "we'll tweak the behaviour in corner cases later on" is good in a lot of situations, but not for userland ABI. I'd been guilty of such fuckups several times and they are not cheap to fix afterwards ;-/
