2024-03-22 10:36:43

by Chen Hanxiao

Subject: [nfs-utils PATCH] mount: reject "namlen=" option for a NFSv4 mount

namlen is not a valid option for NFSv4.
Currently, we could pass a namlen=xxx in a NFSv4 mount,
the mount command succeed and namlen is ignored silently

# mount -o vers=4,namlen=100 192.168.122.19:/nfsroot /mnt/ -vvv
mount.nfs: timeout set for Fri Mar 22 14:22:18 2024
mount.nfs: trying text-based options 'namlen=100,vers=4.2,
addr=192.168.122.19,clientaddr=192.168.122.15'

This patch reject "namlen=" option in a NFSv4 mount.

Signed-off-by: Chen Hanxiao <[email protected]>
---
utils/mount/stropts.c | 9 +++++++++
1 file changed, 9 insertions(+)

diff --git a/utils/mount/stropts.c b/utils/mount/stropts.c
index dbdd11e7..028ff6a6 100644
--- a/utils/mount/stropts.c
+++ b/utils/mount/stropts.c
@@ -780,6 +780,15 @@ static int nfs_do_mount_v4(struct nfsmount_info *mi,
goto out_fail;
}

+ if (po_contains(options, "namlen")) {
+ if (verbose) {
+ printf(_("%s: Unsupported nfs4 mount option(s) passed '%s'\n"),
+ progname, *mi->extra_opts);
+ }
+ errno = EINVAL;
+ goto out_fail;
+ }
+
if (mi->version.v_mode != V_SPECIFIC) {
char *fmt;
switch (mi->version.minor) {
--
2.39.1

2024-04-02 16:21:47

by Steve Dickson

Subject: Re: [nfs-utils PATCH] mount: reject "namlen=" option for a NFSv4 mount

Hello,

On 3/22/24 6:36 AM, Chen Hanxiao wrote:
> namlen is not a valid option for NFSv4.
> Currently, we could pass a namlen=xxx in a NFSv4 mount,
> the mount command succeed and namlen is ignored silently
I'm not sure it makes senses to fail a mount for
a parameter that is ignored. Maybe throw a warning
that the par is being ignored...

What problem did this patch solve for you?

steved.

>
> # mount -o vers=4,namlen=100 192.168.122.19:/nfsroot /mnt/ -vvv
> mount.nfs: timeout set for Fri Mar 22 14:22:18 2024
> mount.nfs: trying text-based options 'namlen=100,vers=4.2,
> addr=192.168.122.19,clientaddr=192.168.122.15'
>
> This patch reject "namlen=" option in a NFSv4 mount.
>
> Signed-off-by: Chen Hanxiao <[email protected]>
> ---
> utils/mount/stropts.c | 9 +++++++++
> 1 file changed, 9 insertions(+)
>
> diff --git a/utils/mount/stropts.c b/utils/mount/stropts.c
> index dbdd11e7..028ff6a6 100644
> --- a/utils/mount/stropts.c
> +++ b/utils/mount/stropts.c
> @@ -780,6 +780,15 @@ static int nfs_do_mount_v4(struct nfsmount_info *mi,
> goto out_fail;
> }
>
> + if (po_contains(options, "namlen")) {
> + if (verbose) {
> + printf(_("%s: Unsupported nfs4 mount option(s) passed '%s'\n"),
> + progname, *mi->extra_opts);
> + }
> + errno = EINVAL;
> + goto out_fail;
> + }
> +
> if (mi->version.v_mode != V_SPECIFIC) {
> char *fmt;
> switch (mi->version.minor) {

2024-04-03 03:15:11

by Chen Hanxiao

Subject: Re: [nfs-utils PATCH] mount: reject "namlen=" option for a NFSv4 mount

> -----邮件原件-----
> 发件人: Steve Dickson <[email protected]>
> 发送时间: 2024年4月3日 0:21
> 收件人: Chen, Hanxiao <[email protected]>
> 抄送: [email protected]
> 主题: Re: [nfs-utils PATCH] mount: reject "namlen=" option for a NFSv4 mount
>
> Hello,
>
> On 3/22/24 6:36 AM, Chen Hanxiao wrote:
> > namlen is not a valid option for NFSv4
> > Currently, we could pass a namlen=xxx in a NFSv4 mount,
> > the mount command succeed and namlen is ignored silently
> I'm not sure it makes senses to fail a mount for
> a parameter that is ignored. Maybe throw a warning
> that the par is being ignored...
>
> What problem did this patch solve for you?
>

When I do mount tests with namelen, I'm confused about the results the test:
Parameter namlen= was ignored silently without sloppy option.

When digging into kernel source, I found that we don't need namlen for NFSv4 at all.
So, I think we'd better give user some feed back.

Throw a warning is much better than failing a mount.

Thanks for your advice.

Regards,
- Chen