On Thu, Dec 01, 2022 at 10:15:53AM +0800, Yu Kuai wrote: > Hi, > > 在 2022/12/01 4:32, Tejun Heo 写道: > > On Wed, Nov 30, 2022 at 09:21:49PM +0800, Li Nan wrote: > > > From: Yu Kuai <yukuai3@xxxxxxxxxx> > > > > > > 1) There are one place that return value of match_u64() is not checked. > > > 2) If match_u64() failed, return value is set to -EINVAL despite that > > > there are other possible errnos. > > > > Ditto. Does this matter? > > > > It's not a big deal, but I think at least return value of match_u64() > should be checked, we don't want to continue with invalid input, right? Yeah, sure. > By the way, match_u64() can return -ERANGE, which can provide more > specific error messge to user. I'm really not convinced going over 64bit range would be all that difficult to spot whether the error code is -EINVAL or -ERANGE. There isn't anything wrong with returning -ERANGE but the fact that that particular function returns an error code doesn't necessarily mean that it *must* be forwarded. Imagine that we used sscanf(buf, "%llu", &value) to parse the number instead. We'd only know whether the parsing would have succeeded or not and would probably return -EINVAL on failure and the behavior would be just fine. This does not matter *at all*. So, idk, I'm not necessarily against it but changing -EINVAL to -ERANGE is pure churn. Nothing material is being improved by that change. Thanks. -- tejun