On Tue, 14 Feb 2023, Trond Myklebust wrote: > On Tue, 2023-02-14 at 09:57 +1100, NeilBrown wrote: > > > > Linux-NFS responds to NFS4ERR_OLD_STATEID by simply retrying the > > request, hoping to make use of an updated stateid that might have > > arrived from the server. This is usually successful. > > > > However if the client and server get out-of-sync for some reason and > > if > > there is no new stateid to try, this can result in an indefinite loop > > which looks a bit like a DoS attack. > > > > This can particularly happen when a server replies with success to an > > OPEN request, but fails a subsequent GETATTR. This has been observed > > with Netapp and Hitachi servers when a concurrent unlink from a > > different client removes the file between the OPEN and the GETATTR. > > The > > GETATTR returns NFS4ERR_STALE. > > Then they are both badly broken servers, and people should complain to > NetApp and Hitachi. We're still not fixing their server bugs in the > Linux client. It's not about fixing a server bug. It is defensive programming. We shouldn't let a buggy server cause a melt-down. > > NACK... Oh well, I tried. Thanks, NeilBrown > -- > Trond Myklebust > Linux NFS client maintainer, Hammerspace > trond.myklebust@xxxxxxxxxxxxxxx > > >
