On Mon, Nov 25, 2019 at 6:46 PM J . Bruce Fields <bfields@xxxxxxxxxxxx> wrote: > > On Sun, Nov 24, 2019 at 09:31:45PM +0200, Amir Goldstein wrote: > > Push clamping timestamps down the call stack into notify_change(), so > > in-kernel callers like nfsd and overlayfs will get similar timestamp > > set behavior as utimes. > > So, nfsd has always bypassed timestamp_truncate() and we've never > noticed till now? What are the symptoms? (Do timestamps go backwards > after cache eviction on filesystems with large time granularity?) Clamping seems to be new behavior since v5.4-rc1. Before that clamping was done implicitly when hitting the disk IIUC, so it was observed mostly after cache eviction. > > Looks like generic/402 has never run in my tests: > > generic/402 [not run] no kernel support for y2038 sysfs switch > The test in its current form is quite recent as well or at the _require has changed recently. See acb2ba78 - overlay: support timestamp range check You'd probably need something similar for nfs (?) Thanks, Amir.