Re: [PATCH v3] nfs(5): adding new mount option 'fasc'

[Steve Dickson <steved@redhat.com>]

Hello,

My apologies on this delay...

On 8/28/23 1:53 AM, Chengen Du wrote:
> Add an option that triggers the clearing of the file
> access cache as soon as the cache timestamp becomes
> older than the user's login time.
> 
> Signed-off-by: Chengen Du <chengen.du@canonical.com>
On a 6.7-rc0 kernel I'm getting "nfs: Unknown parameter 'fasc'"
error... was this never implemented?

steved.

> ---
>   utils/mount/nfs.man | 13 +++++++++++++
>   1 file changed, 13 insertions(+)
> 
> diff --git a/utils/mount/nfs.man b/utils/mount/nfs.man
> index 9b4bc9c9..2ac7b4ad 100644
> --- a/utils/mount/nfs.man
> +++ b/utils/mount/nfs.man
> @@ -608,6 +608,19 @@ option is not specified,
>   the default behavior depends on the kernel version,
>   but is usually equivalent to
>   .BR "xprtsec=none" .
> +.TP 1.5i
> +.BI fasc
> +Triggers the clearing of the file access cache as soon as the cache
> +timestamp becomes older than the user's login time. It is supported
> +in kernels 6.4 and later.
> +.IP
> +NFS servers often refresh their users' group membership at their
> +own cadence, which means the NFS client's file access cache can
> +become stale if the user's group membership changes on the server
> +after they've logged in on the client. To align with the principles
> +of the POSIX design, which only refreshes the user's supplementary
> +group information upon login, the mechanism uses the user's login
> +time to determine whether the file access cache needs to be refreshed.
>   .SS "Options for NFS versions 2 and 3 only"
>   Use these options, along with the options in the above subsection,
>   for NFS versions 2 and 3 only.