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Message-ID: <ac34a186-68d2-41c6-b350-2f0d425eb156@redhat.com>
Date: Tue, 2 Apr 2024 12:20:39 -0400
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Subject: Re: [nfs-utils PATCH] mount: reject "namlen=" option for a NFSv4
 mount
To: Chen Hanxiao <chenhx.fnst@fujitsu.com>
Cc: linux-nfs@vger.kernel.org
References: <20240322103618.1270-1-chenhx.fnst@fujitsu.com>
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From: Steve Dickson <steved@redhat.com>
In-Reply-To: <20240322103618.1270-1-chenhx.fnst@fujitsu.com>
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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 <chenhx.fnst@fujitsu.com>
> ---
>   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) {