From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: linux-nfs-owner@vger.kernel.org Received: from mx1.redhat.com ([209.132.183.28]:18597 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751684Ab2FSO7R (ORCPT ); Tue, 19 Jun 2012 10:59:17 -0400 Message-ID: <4FE0937E.3010705@RedHat.com> Date: Tue, 19 Jun 2012 10:58:06 -0400 From: Steve Dickson MIME-Version: 1.0 To: Jeff Layton CC: linux-nfs@vger.kernel.org, chuck.lever@oracle.com Subject: Re: [PATCH] mount.nfs: try the next address after mount fails with ETIMEDOUT References: <1338469436-5411-1-git-send-email-jlayton@redhat.com> In-Reply-To: <1338469436-5411-1-git-send-email-jlayton@redhat.com> Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-nfs-owner@vger.kernel.org List-ID: On 05/31/2012 09:03 AM, Jeff Layton wrote: > If a NFS mount attempt fails with an ETIMEDOUT error, the mount.nfs code > doesn't currently attempt the next address in the list. For a NFSv4 mount > the initial mount() call almost always ends up going over > NFS_DEF_FG_TIMEOUT_MINUTES and the mount is never retried. > > For a v3 mount, it ends up continually retrying against the same IPv6 > address, and never tries the IPv4 address. Eventually it gives up once > it hits the NFS_DEF_FG_TIMEOUT_MINUTES timeout. > > It's possible that a server is just unreachable via IPv6 (due to a > routing misconfiguration for instance), or is dropping IPv6 frames on > the floor. In that situation, it might still be reachable via IPv4 and > trying the next address could have allowed the mount to succeed. > > Fix this by treating ETIMEDOUT in a similar fashion to ECONNREFUSED. > Have the client try the next address in the list before giving up and > returning an error. > > Our QA folks noticed this after a routing problem in one of our test > labs. I was able to reproduce it by having the server drop incoming > IPv6 frames from the client's address. > > With this patch, the mount eventually succeeds over IPv4 instead of > returning an error. > > Cc: Chuck Lever > Signed-off-by: Jeff Layton Committed... steved. > --- > utils/mount/stropts.c | 2 ++ > 1 files changed, 2 insertions(+), 0 deletions(-) > > diff --git a/utils/mount/stropts.c b/utils/mount/stropts.c > index e09aa7c..0aa9a75 100644 > --- a/utils/mount/stropts.c > +++ b/utils/mount/stropts.c > @@ -665,6 +665,7 @@ static int nfs_try_mount_v3v2(struct nfsmount_info *mi) > case ECONNREFUSED: > case EOPNOTSUPP: > case EHOSTUNREACH: > + case ETIMEDOUT: > continue; > default: > goto out; > @@ -752,6 +753,7 @@ static int nfs_try_mount_v4(struct nfsmount_info *mi) > switch (errno) { > case ECONNREFUSED: > case EHOSTUNREACH: > + case ETIMEDOUT: > continue; > default: > goto out;