> On May 17, 2019, at 5:06 PM, Dave Wysochanski <dwysocha@xxxxxxxxxx> wrote:
>
> On the NFS client there is no low-impact way to determine the nfs4
> lease time or whether the lease is expired, so add these to mountstats
> with times displayed in seconds.
>
> If the lease is not expired, display lease_expired=0. Otherwise,
> display lease_expired=seconds_since_expired, similar to 'age:' line
> in mountstats.
>
> Signed-off-by: Dave Wysochanski <dwysocha@xxxxxxxxxx>
> ---
> fs/nfs/super.c | 11 +++++++++++
> 1 file changed, 11 insertions(+)
>
> diff --git a/fs/nfs/super.c b/fs/nfs/super.c
> index c27ac96..6e52f0c 100644
> --- a/fs/nfs/super.c
> +++ b/fs/nfs/super.c
> @@ -730,6 +730,16 @@ int nfs_show_options(struct seq_file *m, struct dentry *root)
> EXPORT_SYMBOL_GPL(nfs_show_options);
>
> #if IS_ENABLED(CONFIG_NFS_V4)
> +static void show_lease(struct seq_file *m, struct nfs_server *server)
> +{
> + struct nfs_client *clp = server->nfs_client;
> + unsigned long expire;
> +
> + seq_printf(m, ",lease_time=%ld", clp->cl_lease_time / HZ);
> + expire = clp->cl_last_renewal + clp->cl_lease_time;
> + seq_printf(m, ",lease_expired=%ld",
> + time_after(expire, jiffies) ? 0 : (jiffies - expire) / HZ);
> +}
> #ifdef CONFIG_NFS_V4_1
> static void show_sessions(struct seq_file *m, struct nfs_server *server)
> {
> @@ -838,6 +848,7 @@ int nfs_show_stats(struct seq_file *m, struct dentry *root)
> seq_printf(m, ",acl=0x%x", nfss->acl_bitmask);
> show_sessions(m, nfss);
> show_pnfs(m, nfss);
> + show_lease(m, nfss);
> }
> #endif
>
> --
> 1.8.3.1
>
I didn't look closely at the patch content, but IMO this is a good
observability enhancement.
--
Chuck Lever
