Return-Path: Received: from mx2.netapp.com ([216.240.18.37]:63061 "EHLO mx2.netapp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932259Ab1DLRl1 (ORCPT ); Tue, 12 Apr 2011 13:41:27 -0400 Message-ID: <4DA48EB0.40600@netapp.com> Date: Tue, 12 Apr 2011 13:41:04 -0400 From: Bryan Schumaker To: Jiri Slaby CC: "Myklebust, Trond" , linux-kernel@vger.kernel.org, akpm@linux-foundation.org, mm-commits@vger.kernel.org, ML netdev , linux-nfs@vger.kernel.org, Jiri Slaby Subject: [PATCH] NFS: Fix infinite loop in gss_create_upcall() References: <201103312224.p2VMOA5g000983@imap1.linux-foundation.org> <4D96E4C5.2080302@suse.cz> <1302122693.16786.0.camel@lade.trondhjem.org> <4D9D5CC9.2040002@suse.cz> <4DA36722.2020402@suse.cz> <4DA36758.4070203@suse.cz> <4DA36DB6.8060108@suse.cz> In-Reply-To: <4DA36DB6.8060108@suse.cz> Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-nfs-owner@vger.kernel.org List-ID: MIME-Version: 1.0 On 04/11/2011 05:08 PM, Jiri Slaby wrote: > > Sorry for an extra message. I've just found out that there appears > messages in dmesg: > [ 58.656048] RPC: AUTH_GSS upcall timed out. > [ 58.656050] Please check user daemon is running. > [ 88.656065] RPC: AUTH_GSS upcall timed out. > [ 88.656068] Please check user daemon is running. > [ 118.656077] RPC: AUTH_GSS upcall timed out. > [ 118.656080] Please check user daemon is running. > [ 148.656049] RPC: AUTH_GSS upcall timed out. > [ 148.656052] Please check user daemon is running. > [ 178.656046] RPC: AUTH_GSS upcall timed out. > [ 178.656049] Please check user daemon is running. > > > I instrumented the code and it's stuck with trying RPC_AUTH_GSS_KRB5. > > I don't use GSS at all. > > regards, Does this patch help? - Bryan There can be an infinite loop if gss_create_upcall() is called without the userspace program running. To prevent this, we return -EACCES if we notice that pipe_version hasn't changed (indicating that the pipe has not been opened). Signed-off-by: Bryan Schumaker -- diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index 9bf41ea..8a03ee0 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -2224,8 +2224,9 @@ static int nfs4_proc_get_root(struct nfs_server *server, struct nfs_fh *fhandle, for (i = 0; i < len; i++) { status = nfs4_lookup_root_sec(server, fhandle, info, flav_array[i]); - if (status != -EPERM) - break; + if (status == -EPERM || status == -EACCES) + continue; + break; } if (status == 0) status = nfs4_server_capabilities(server, fhandle); diff --git a/net/sunrpc/auth_gss/auth_gss.c b/net/sunrpc/auth_gss/auth_gss.c index f3914d0..339ba64 100644 --- a/net/sunrpc/auth_gss/auth_gss.c +++ b/net/sunrpc/auth_gss/auth_gss.c @@ -520,7 +520,7 @@ gss_refresh_upcall(struct rpc_task *task) warn_gssd(); task->tk_timeout = 15*HZ; rpc_sleep_on(&pipe_version_rpc_waitqueue, task, NULL); - return 0; + return -EAGAIN; } if (IS_ERR(gss_msg)) { err = PTR_ERR(gss_msg); @@ -563,10 +563,12 @@ retry: if (PTR_ERR(gss_msg) == -EAGAIN) { err = wait_event_interruptible_timeout(pipe_version_waitqueue, pipe_version >= 0, 15*HZ); + if (pipe_version < 0) { + warn_gssd(); + err = -EACCES; + } if (err) goto out; - if (pipe_version < 0) - warn_gssd(); goto retry; } if (IS_ERR(gss_msg)) {