Re: [PATCH 0/6] Fix up NFS client mount option regressions

[Trond Myklebust <trondmy@kernel.org>]

On Thu, 2026-01-29 at 15:06 +0800, Li Lingfeng wrote:
> Hi Trond,
> 
> 在 2025/11/29 12:06, Trond Myklebust 写道:
> > From: Trond Myklebust <trond.myklebust@hammerspace.com>
> > 
> > The recent changes to suppress the 'ro' and 'rw' mount options when
> > mounting the same NFS filesystem with different settings are
> > causing
> > confusion with users, and are an unnecessary restriction. They
> > represent
> > a functionality regression.
> > 
> > The following patch set reverts the regressions, before applying a
> > different set of fixes to address the original problem, which was
> > one of
> > the NFSv4 mount automounter code failing to propagate the correct
> > mount
> > options.
> > 
> > Trond Myklebust (6):
> >    Revert "nfs: ignore SB_RDONLY when remounting nfs"
> >    Revert "nfs: clear SB_RDONLY before getting superblock"
> >    Revert "nfs: ignore SB_RDONLY when mounting nfs"
> >    NFS: Automounted filesystem should inherit ro,noexec,nodev,sync
> > flags
> >    NFS: Fix inheritance of the block sizes when automounting
> >    NFS: Fix up the automount fs_context to use the correct cred
> > 
> >   fs/nfs/client.c           | 21 +++++++++++++++++----
> >   fs/nfs/internal.h         |  3 +--
> >   fs/nfs/namespace.c        | 16 +++++++++++++++-
> >   fs/nfs/nfs4client.c       | 18 ++++++++++++++----
> >   fs/nfs/super.c            | 33 +++------------------------------
> >   include/linux/nfs_fs_sb.h |  5 +++++
> >   6 files changed, 55 insertions(+), 41 deletions(-)
> After this series of patches was merged, I found that the issue
> described
> in link [1] has appeared again.
> 
> [root@nfs-client1 ~]# mount /dev/sda /mnt2
> [root@nfs-client1 ~]# echo "/mnt2 *(rw,no_root_squash,fsid=0)"
> >/etc/exports
> [root@nfs-client1 ~]# systemctl restart nfs-server
> [root@nfs-client1 ~]# mount -t nfs -o ro,vers=4 127.0.0.1:/ /mnt/sdaa
> [root@nfs-client1 ~]# mount -t nfs -o rw,vers=4 127.0.0.1:/ /mnt/sdaa
> [root@nfs-client1 ~]# mount -t nfs -o ro,vers=4 127.0.0.1:/ /mnt/sdaa
> [root@nfs-client1 ~]# mount -t nfs -o rw,vers=4 127.0.0.1:/ /mnt/sdaa
> [root@nfs-client1 ~]# mount | grep nfs4
> 127.0.0.1:/ on /mnt/sdaa type nfs4 
> (ro,relatime,vers=4.2,rsize=1048576,wsize=1048576,namlen=255,hard,fat
> al_neterrors=none,proto=tcp,timeo=600,retrans=2,sec=sys,clientaddr=12
> 7.0.0.1,local_lock=none,addr=127.0.0.1)
> 127.0.0.1:/ on /mnt/sdaa type nfs4 
> (rw,relatime,vers=4.2,rsize=1048576,wsize=1048576,namlen=255,hard,fat
> al_neterrors=none,proto=tcp,timeo=600,retrans=2,sec=sys,clientaddr=12
> 7.0.0.1,local_lock=none,addr=127.0.0.1)
> 127.0.0.1:/ on /mnt/sdaa type nfs4 
> (ro,relatime,vers=4.2,rsize=1048576,wsize=1048576,namlen=255,hard,fat
> al_neterrors=none,proto=tcp,timeo=600,retrans=2,sec=sys,clientaddr=12
> 7.0.0.1,local_lock=none,addr=127.0.0.1)
> 127.0.0.1:/ on /mnt/sdaa type nfs4 
> (rw,relatime,vers=4.2,rsize=1048576,wsize=1048576,namlen=255,hard,fat
> al_neterrors=none,proto=tcp,timeo=600,retrans=2,sec=sys,clientaddr=12
> 7.0.0.1,local_lock=none,addr=127.0.0.1)
> [root@nfs-client1 ~]# uname -a
> Linux nfs-client1 6.19.0-rc7+ #178 SMP PREEMPT_DYNAMIC Thu Jan 29 
> 14:06:54 CST 2026 x86_64 x86_64 x86_64 GNU/Linux
> [root@nfs-client1 ~]#
> 
> [1] 
> https://lore.kernel.org/all/20241114045303.1656426-1-lilingfeng3@huawei.com/
> 
> Thanks,
> Lingfeng.

What does the output of "cat /proc/fs/nfsfs/volumes" show? Does it show
more than 2 devices associated with that fsid?
 
-- 
Trond Myklebust
Linux NFS client maintainer, Hammerspace
trondmy@kernel.org, trond.myklebust@hammerspace.com