[Bug 2059197] Please test proposed package

Thu Apr 18 20:00:20 UTC 2024

Hello Jeff, or anyone else affected,

Accepted nfs-utils into focal-proposed. The package will build now and
be available at https://launchpad.net/ubuntu/+source/nfs-
utils/1:1.3.4-2.5ubuntu3.7 in a few hours, and then in the -proposed
repository.

Please help us by testing this new package.  See
https://wiki.ubuntu.com/Testing/EnableProposed for documentation on how
to enable and use -proposed.  Your feedback will aid us getting this
update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug,
mentioning the version of the package you tested, what testing has been
performed on the package and change the tag from verification-needed-
focal to verification-done-focal. If it does not fix the bug for you,
please add a comment stating that, and change the tag to verification-
failed-focal. In either case, without details of your testing we will
not be able to proceed.

Further information regarding the verification process can be found at
https://wiki.ubuntu.com/QATeam/PerformingSRUVerification .  Thank you in
advance for helping!

N.B. The updated package will be released to -updates after the bug(s)
fixed by this package have been verified and the package has been in
-proposed for a minimum of 7 days.

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https://bugs.launchpad.net/bugs/2059197

Title:
  mount.nfs: Fix minor version parsing when '-t nfs4' and '-o vers=4.x'
  are used together

Status in nfs-utils package in Ubuntu:
  Fix Released
Status in nfs-utils source package in Focal:
  Fix Committed

Bug description:
  [Impact]

  When specifying both '-t nfs4' and '-o vers=4.x' on the mount command
  line, mount.nfs ignores any specific version set with '-o vers=4.x' or
  '-o vers=4,minorversion=x', and simply attempts version negotiation,
  which due to my recent changes in bug 2049262, would land on the
  highest supported nfs version, likely 4.2.

  Users who specify what version they want should get the version they
  ask for, and thus, this is a regression introduced in
  1:1.3.4-2.5ubuntu3.6.

  A workaround is to drop '-t nfs4' and to use mount.nfs directly
  instead, i.e.:

  $ sudo mount.nfs -o vers=4.1 -vvv jammy-nfs-server:/ /mnt

  [Testcase]

  Create two VMs, one jammy and one focal.

  The jammy VM will be the server.

  Server VM:
  $ sudo hostnamectl set-hostname jammy-nfs-server
  $ sudo apt update && sudo apt upgrade -y
  $ sudo apt install nfs-kernel-server
  $ sudo mkdir /export
  $ sudo mkdir /export/users
  $ sudo mkdir /home/users
  $ sudo vi /etc/fstab # add the following line:
  /home/users /export/users none bind 0 0
  $ sudo mount -a
  $ sudo vi /etc/exports # add the following lines:
  /export 192.168.122.0/24(rw,fsid=0,no_subtree_check,sync)
  /export/users 192.168.122.0/24(rw,nohide,insecure,no_subtree_check,sync)
  $ sudo systemctl restart nfs-server.service

  Focal VM:
  $ sudo hostnamectl set-hostname focal-nfs-client
  $ sudo apt update && sudo apt upgrade -y
  $ sudo apt install nfs-common

  And then try mounting with both '-t nfs4' and '-o vers=4.1':

  $ sudo mount -t nfs4 -o vers=4.1 -vvv jammy-nfs-server:/ /mnt
  mount.nfs4: timeout set for Wed Apr  3 00:51:23 2024
  mount.nfs4: trying text-based options 'vers=4.2,addr=192.168.122.217,clientaddr=192.168.122.9'

  and then try with both '-t nfs4' and '-o vers=4,minorversion=1':

  $ sudo mount -t nfs4 -o vers=4,minorversion=1 -vvv jammy-nfs-server:/ /mnt
  mount.nfs4: timeout set for Wed Apr  3 02:19:03 2024
  mount.nfs4: trying text-based options 'minorversion=1,vers=4.2,addr=192.168.122.217,clientaddr=192.168.122.9'

  In each of those mounts, it incorrectly uses protocol version 4.2,
  instead of requested 4.1.

  If you install the test packages in the following ppa:

  https://launchpad.net/~mruffell/+archive/ubuntu/lp2059197-test

  then vers should always be 4.1, instead of 4.2.

  [Where problems can occur]

  It is quite clear now that changing version negotiation and parsing is
  quite problematic, after the number of regressions the previous
  1:1.3.4-2.5ubuntu3.6 caused the community, and the sheer number of
  commits upstream took to resolve lingering issues.

  We need to be careful, to make sure we don't introduce any further
  regressions.

  This time, we are only changing how mount.nfs parses and processes
  command line arguments for version specification, and not changing
  version negotiation itself. This could impact NFS clients, when they
  go to mount NFS filesystems.

  If a regression were to occur, then users might have to manually mount
  their NFS filesystems or look into autofs. There should be no breaking
  changes to any behaviour when mounting NFS filesystems.

  There are no changes to nfs server.

  [Other Info]

  This was fixed multiple times, across the following three commits:

  commit 1e3ca7fe199531a372bb8e1c1033d8973097be50
  Author: NeilBrown <neilb at suse.com>
  Date:   Wed Jul 26 13:47:42 2017 -0400
  Subject: mount: move handling of "-t nfs4" into nfs_nfs_version()
  Link: https://git.linux-nfs.org/?p=steved/nfs-utils.git;a=commitdiff;h=1e3ca7fe199531a372bb8e1c1033d8973097be50

  commit 050153ef6a86ff5ab06ef65be36336824a323779
  Author: NeilBrown <neilb at suse.com>
  Date:   Wed Jul 26 13:51:51 2017 -0400
  Subject: mount: Fix problems with parsing minorversion=
  Link: https://git.linux-nfs.org/?p=steved/nfs-utils.git;a=commitdiff;h=050153ef6a86ff5ab06ef65be36336824a323779

  commit 71b807e1a69940beb31fdeb481c2e54509e8bd32
  Author: Steve Dickson <steved at redhat.com>
  Date:   Thu Mar 1 13:52:47 2018 -0500
  Subject: mount.nfs: minorversion setting is being ignored with the -t flag
  Link: https://git.linux-nfs.org/?p=steved/nfs-utils.git;a=commitdiff;h=71b807e1a69940beb31fdeb481c2e54509e8bd32

  commit 5f32083c759b468f5b0cb9302e4fe2848d37cc5b
  From: Steve Dickson <steved at redhat.com>
  Date: Tue, 10 Apr 2018 10:25:40 -0400
  Subject: mount.nfs: Fix auto protocol negotiation
  Link: https://git.linux-nfs.org/?p=steved/nfs-utils.git;a=commitdiff;h=5f32083c759b468f5b0cb9302e4fe2848d37cc5b

  Jammy has all of these, and does not need any fixes.

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