From: "J. Bruce Fields" <email@example.com> To: NeilBrown <firstname.lastname@example.org> Cc: Steve Dickson <SteveD@redhat.com>, Chuck Lever <email@example.com>, NFS <firstname.lastname@example.org>, Carsten Ziepke <email@example.com> Subject: Re: [PATCH - nfs-utils] Fix fallback from tcp to udp Date: Fri, 21 Feb 2014 09:59:56 -0500 [thread overview] Message-ID: <20140221145956.GE13433@fieldses.org> (raw) In-Reply-To: <firstname.lastname@example.org> On Fri, Feb 21, 2014 at 02:26:41PM +1100, NeilBrown wrote: > On Thu, 20 Feb 2014 15:37:02 -0500 "J. Bruce Fields" <email@example.com> > wrote: > > Any NFS server has to support either tcp or rpcbind. But it's OK for a > > server to support only of those two. So the only way to handle both > > cases while continuing to retry after ECONNREFUSED is to alternate > > between trying nfs4/tcp and rpcbind until you can connect to one or the > > other. > > > > If it's the rpcbind call that succeeds first then I think we want to do > > one more try of nfs4/tcp just to make sure it didn't just come up, > > before falling back to v3. > > > > The rpcbind call is done in userspace, if I understand right, so I think > > this is doable. Looking at utils/mount/ I don't understand the mount > > process well enough to understand exactly how to do it. Maybe > > everything but the final nfs_sys_mount needs to be moved out of > > nfs_do_mount_v3v2 into a new nfs_do_probe_v3v2 and nfs_autonegotiate > > should alternate between nfs_try_mount_v4 and nfs_do_probe_v3v2 as long > > as both return ECONNREFUSED, calling nfs_try_mount_v3v2 only if > > nfs_try_mount_v4 has failed after a succesful nfs_do_probe_v3v2? > > > > Except the v3v2 mount logic seems to actually modify the mount_options, > > so probably that doesn't quite work. > > I had come to much the same conclusion after reading Steve's mail: when TCP > fails we need rpcbind to be sure what to do. > I suspect it should be fairly straight forward to implement (I'm less > pessimistic than you). I'll have a go on Monday. OK, great! Yeah, the mount code looked like a maze for me but I probably spent less than an hour trying to trace through it, I'm sure it's not that bad. --b.
next prev parent reply other threads:[~2014-02-21 15:00 UTC|newest] Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top 2014-02-17 23:43 NeilBrown 2014-02-20 17:50 ` Steve Dickson 2014-02-20 20:37 ` J. Bruce Fields 2014-02-20 20:42 ` J. Bruce Fields 2014-02-21 3:26 ` NeilBrown 2014-02-21 14:59 ` J. Bruce Fields [this message] 2014-02-21 15:22 ` Chuck Lever
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=20140221145956.GE13433@fieldses.org \ --firstname.lastname@example.org \ --cc=SteveD@redhat.com \ --email@example.com \ --firstname.lastname@example.org \ --email@example.com \ --firstname.lastname@example.org \ --subject='Re: [PATCH - nfs-utils] Fix fallback from tcp to udp' \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: link
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.