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

[Li Lingfeng <lilingfeng3@huawei.com>]

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,fatal_neterrors=none,proto=tcp,timeo=600,retrans=2,sec=sys,clientaddr=127.0.0.1,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,fatal_neterrors=none,proto=tcp,timeo=600,retrans=2,sec=sys,clientaddr=127.0.0.1,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,fatal_neterrors=none,proto=tcp,timeo=600,retrans=2,sec=sys,clientaddr=127.0.0.1,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,fatal_neterrors=none,proto=tcp,timeo=600,retrans=2,sec=sys,clientaddr=127.0.0.1,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.