** Description changed: - If you attempt to mount a share from a server that is dual stack (i.e. - has both an A and a AAAA record in DNS) and NFSv3-only, mount.nfs goes - into an infinite loop of retrying an NFS-v4 mount: + [Impact] + When all the following exist + - mounting a server using hostname. + - the hostname resolves to both an ipv4 and ipv6 address + - the nfs server only supports nfsv4 + Then. + * The nfs client will not fall back fo nfsv4, and will be unable to mount + the share. + * The following errors are printed in the logs. + " + mount: no type was given - I'll assume nfs because of the colon + mount.nfs: timeout set for Tue Nov 11 14:25:34 2014 + mount.nfs: trying text-based options 'vers=4,addr=x.x.x.x,clientaddr=x.x.x.x' + mount.nfs: mount(2): Protocol not supported + mount.nfs: trying text-based options 'vers=4,addr=xxxx:xxxx::xxxx,clientaddr=xxxx:xxxx::xxxx' + mount.nfs: mount(2): No route to host + mount.nfs: trying text-based options 'vers=4,addr=x.x.x.x,clientaddr=x.x.x.x' + mount.nfs: mount(2): Protocol not supported + mount.nfs: trying text-based options 'vers=4,addr=xxxx:xxxx::xxxx,clientaddr=xxxx:xxxx::xxxx' + mount.nfs: mount(2): No route to host + " + + [Test Case] + + * Restrict to nfsv3 on Server by setting RPCNFSDOPTS="--no-nfs-version 4" in /etc/default/nfs-kernel-server + * Enable dns resolution for both ipv4 and ipv6 of the server. + * Export a directory from the server (export -a) + * Attempt to mount the nfs share from client + + + [Regression Potential] + * Upstream backport that still exists upstream. + + [Other Info] + * Fix already exists in 2.6+ which means >trusty already have the fix. + + + __________________________________________________________________________ + If you attempt to mount a share from a server that is dual stack (i.e. has both an A and a AAAA record in DNS) and NFSv3-only, mount.nfs goes into an infinite loop of retrying an NFS-v4 mount: mount nfs-v3-server:/path /mnt -v mount: no type was given - I'll assume nfs because of the colon mount.nfs: timeout set for Tue Nov 11 14:25:34 2014 mount.nfs: trying text-based options 'vers=4,addr=x.x.x.x,clientaddr=x.x.x.x' mount.nfs: mount(2): Protocol not supported mount.nfs: trying text-based options 'vers=4,addr=xxxx:xxxx::xxxx,clientaddr=xxxx:xxxx::xxxx' mount.nfs: mount(2): No route to host mount.nfs: trying text-based options 'vers=4,addr=x.x.x.x,clientaddr=x.x.x.x' mount.nfs: mount(2): Protocol not supported mount.nfs: trying text-based options 'vers=4,addr=xxxx:xxxx::xxxx,clientaddr=xxxx:xxxx::xxxx' mount.nfs: mount(2): No route to host If we "hide" the AAAA record by setting an override in /etc/hosts, then mount.nfs correctly retries with NFSv3: mount -t nfs nfs-v3-server:/path /mnt -v mount.nfs: timeout set for Tue Nov 11 15:01:35 2014 mount.nfs: trying text-based options 'vers=4,addr=x.x.x.x,clientaddr=x.x.x.x' mount.nfs: mount(2): Protocol not supported mount.nfs: trying text-based options 'addr=x.x.x.x' mount.nfs: prog 100003, trying vers=3, prot=6 mount.nfs: trying x.x.x.x prog 100003 vers 3 prot TCP port 2049 mount.nfs: prog 100005, trying vers=3, prot=17 mount.nfs: trying x.x.x.x prog 100005 vers 3 prot UDP port 635 nfs-v3-server:/path on /mnt type nfs (rw) ProblemType: Bug DistroRelease: Ubuntu 12.04 Package: nfs-common 1:1.2.5-3ubuntu3.1 ProcVersionSignature: Ubuntu 3.2.0-70.105-generic 3.2.63 Uname: Linux 3.2.0-70-generic x86_64 ApportVersion: 2.0.1-0ubuntu17.8 Architecture: amd64 Date: Tue Nov 11 15:56:25 2014 InstallationMedia: Ubuntu-Server 10.04.2 LTS "Lucid Lynx" - Release amd64 (20110211.1) MarkForUpload: True ProcEnviron: SHELL=/usr/bin/ksh TERM=xterm PATH=(custom, no user) LANG=en_US SourcePackage: nfs-utils UpgradeStatus: Upgraded to precise on 2013-10-07 (400 days ago)
-- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1391662 Title: mount.nfs does not downgrade NFS version when connecting to dual-stack NFS server To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/nfs-utils/+bug/1391662/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs