On Tue, Dec 14, 2021 at 12:50:53AM +0000, suy.fnst@xxxxxxxxxxx wrote: > Thanks for your quick reply! > > >>Without looking at this case in detail: > > >>Delegations are granted at the server's discretion, so this certainly > >>isn't a bug. > > Got it. > > >>It might be suboptimal behavior. If there's evidence that this causes > >>significant regressions on some important workload, then we'd want to > >>look into fixing it. > > If I understand the case correctly, the most common workload it influences like: > > One nfs client opens a file with flag O_WRONLY/O_RDWR, close it. > Then some nfs clients open the file with O_RDONLY right now then it will prevent > server to give any delegation to other clients. It may cause many unnecessary > requests from clients because lack of delegations. Right. For the moment, this is something I'd accept patches for, but I'm not actively working on. I think it's been suggested that we could even turn off the file cache completely in the v4 case, since in that case we don't have to re-open on every IO. --b.
