Try to get Manjunath's e-mail address right. > On Aug 9, 2017, at 6:04 PM, Chuck Lever <chuck.lever@xxxxxxxxxx> wrote: > > If I repeatedly run the cthon04 lock test on NFSv3, at some point > the Linux NFS server reports "lockd: server not responding". The NFS > server is sending a GRANTED_MSG request via TCP, but the NFS client > lockd has restarted and changed ports. The correct recovery is for > the NFS server to rebind and reconnect to the new client port, but > the server never rebinds, and the request times out and fails. > > The underlying problem is that the RPC client on the NFS server is > attempting to reconnect in a loop, and does not return control to > the NLM layer until the request times out. There is never a chance > for the NLM layer to force a rebind until the request has failed. > > To address this, set the RPC_TASK_SOFTCONN flag when sending async > NLM requests. The request fails immediately if it cannot connect, > and the code can force a rebind and then retry the request. > > Sidebar: Using SOFTCONN could be reasonable for the NFS client side > as well. > > Sidebar: Is h_nextrebind appropriate for NLM on TCP? > > Sidebar: If XPRT_BOUND is cleared while the RPC client is > connecting, the connect can fail in xs_tcp_finish_connecting: > > 2353 if (!xprt_bound(xprt)) > 2354 goto out; > > There's no recovery in xs_tcp_setup_socket for this case, so an > error message is logged, and connection set up fails. The error > is noise. Does the RPC client try to connect again in this case? > > BugLink: https://bugzilla.linux-nfs.org/show_bug.cgi?id=311 > Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx> > --- > fs/lockd/clntproc.c | 2 +- > fs/lockd/host.c | 7 ++++++- > fs/lockd/svclock.c | 2 +- > 3 files changed, 8 insertions(+), 3 deletions(-) > > diff --git a/fs/lockd/clntproc.c b/fs/lockd/clntproc.c > index 066ac31..5806e1a 100644 > --- a/fs/lockd/clntproc.c > +++ b/fs/lockd/clntproc.c > @@ -342,7 +342,7 @@ static struct rpc_task *__nlm_async_call(struct nlm_rqst *req, u32 proc, struct > .rpc_message = msg, > .callback_ops = tk_ops, > .callback_data = req, > - .flags = RPC_TASK_ASYNC, > + .flags = RPC_TASK_ASYNC | RPC_TASK_SOFTCONN, > }; > > dprintk("lockd: call procedure %d on %s (async)\n", > diff --git a/fs/lockd/host.c b/fs/lockd/host.c > index d716c99..be0f847 100644 > --- a/fs/lockd/host.c > +++ b/fs/lockd/host.c > @@ -490,7 +490,12 @@ struct rpc_clnt * > nlm_rebind_host(struct nlm_host *host) > { > dprintk("lockd: rebind host %s\n", host->h_name); > - if (host->h_rpcclnt && time_after_eq(jiffies, host->h_nextrebind)) { > + > + if (!host->h_rpcclnt) > + return; > + > + if (time_after_eq(jiffies, host->h_nextrebind) || > + host->h_proto == IPPROTO_TCP) { > rpc_force_rebind(host->h_rpcclnt); > host->h_nextrebind = jiffies + NLM_HOST_REBIND; > } > diff --git a/fs/lockd/svclock.c b/fs/lockd/svclock.c > index 3507c80..2f64a6b 100644 > --- a/fs/lockd/svclock.c > +++ b/fs/lockd/svclock.c > @@ -830,7 +830,7 @@ static void nlmsvc_grant_callback(struct rpc_task *task, void *data) > * can be done, though. */ > if (task->tk_status < 0) { > /* RPC error: Re-insert for retransmission */ > - timeout = 10 * HZ; > + timeout = 5 * HZ; > } else { > /* Call was successful, now wait for client callback */ > timeout = 60 * HZ; > > -- > 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 -- 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
