On Mon, 2021-12-13 at 19:42 +0000, Chuck Lever III wrote: > Hi Rick- > > > On Dec 9, 2021, at 6:15 PM, Rick Macklem <rmacklem@xxxxxxxxxxx> > > wrote: > > > > Hi, > > > > When testing against the knfsd in a Linux 5.15.1 kernel, I received > > a > > write reply with FILE_SYNC and a writeverf of all 0 bytes. > > (Previous write verifiers were not all 0 bytes.) > > > > The server seemed to be functioning normally and had not rebooted. > > > > Is this intended behaviour? > > > > Normally I would not expect the writeverf in a Write operation > > reply > > to change unless the server had rebooted, but I can see there might > > be circumstances where the knfsd server wants all non-FILE_SYNC > > writes to be redone by the client and would choose to change the > > writeverf. > > However, changing it to all 0 bytes seems particularly odd? > > I don't immediately see a code path for WRITE or COMMIT that would > set the verifier to zeroes. When Linux NFSD resets its write > verifier, > it sets it to the current time. > > Do you have a reproducer you can share? > Rick is using FILE_SYNC, whereas nfsd_vfs_write() only actually sets the boot verifier if the write is unstable or DATA_SYNC. -- Trond Myklebust Linux NFS client maintainer, Hammerspace trond.myklebust@xxxxxxxxxxxxxxx
