Hi Bruce- Last week I updated my test server from v4.14 to v4.15-rc4, and began to observe intermittent failures in the git regression suite on NFSv4.1. I was able to reproduce these failures with NFSv4.1 on both TCP and RDMA, yet there has not been a reproduction with NFSv3 or NFSv4.0. The server hardware is a single-socket 4-core system with 32GB of RAM. The export is a tmpfs. Networking is 56Gb InfiniBand (or IPoIB). The git regression suite reports individual test failures in the SVN and CVS tests. On occasion, the client mount point freezes, requiring that the client be rebooted in order to unstick the mount. Just before Christmas, I bisected the problem to: commit 659aefb68eca28ba9aa482a9fc64de107332e256 Author: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx> Date: Fri Nov 3 08:00:13 2017 -0400 nfsd: Ensure we don't recognise lock stateids after freeing them In order to deal with lookup races, nfsd4_free_lock_stateid() needs to be able to signal to other stateful functions that the lock stateid is no longer valid. Right now, nfsd_lock() will check whether or not an existing stateid is still hashed, but only in the "new lock" path. To ensure the stateid invalidation is also recognised by the "existing lock" path, and also by a second call to nfsd4_free_lock_stateid() itself, we can change the type to NFS4_CLOSED_STID under the stp->st_mutex. Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx> Signed-off-by: J. Bruce Fields <bfields@xxxxxxxxxx> Since we're already at v4.15-rc5 I thought it would be best to break the holiday moratorium instead of waiting another week to report this. -- Chuck Lever -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html