[LTP] [PATCH 2/2] nfsstat01: Check that RPC stats don't leak between net namespaces

[Petr Vorel]

> When the NFS server and client run on the same host in different net
> namespaces, check that RPC calls from the client namespace don't
> change RPC statistics in the root namespace.

> Signed-off-by: Martin Doucha <mdoucha@suse.cz>
> ---

> I've initially tried to test both NFS and RPC client stats but it appears
> that NFS client stats are still shared across all namespaces. Only RPC
> client stats are separate for each net namespace. The kernel patchset[1]
> which introduced per-NS stats confirms that only RPC stats have been changed.

> If NFS client stats should be separate for each namespace as well, let
> me know and I'll return the second set of NS checks in patch v2.

> Tested on kernel v5.14 with Neil's backports.

> [1] https://lore.kernel.org/linux-nfs/cover.1708026931.git.josef@toxicpanda.com/

>  testcases/network/nfs/nfsstat01/nfsstat01.sh | 18 ++++++++++++++++--
>  1 file changed, 16 insertions(+), 2 deletions(-)

> diff --git a/testcases/network/nfs/nfsstat01/nfsstat01.sh b/testcases/network/nfs/nfsstat01/nfsstat01.sh
> index 8d7202cf3..3379c4d46 100755
> --- a/testcases/network/nfs/nfsstat01/nfsstat01.sh
> +++ b/testcases/network/nfs/nfsstat01/nfsstat01.sh
> @@ -22,6 +22,7 @@ get_calls()
>  	local name=$1
>  	local field=$2
>  	local nfs_f=$3
> +	local netns=${4:-rhost}
>  	local type="lhost"
>  	local calls opt

> @@ -30,7 +31,8 @@ get_calls()

>  	if tst_net_use_netns; then
>  		# In netns setup, rhost is the client
> -		[ "$nfs_f" = "nfs" ] && [ $NS_STAT_RHOST -ne 0 ] && type="rhost"
> +		[ "$nfs_f" = "nfs" ] && [ $NS_STAT_RHOST -ne 0 ] && \
> +			type="$netns"
>  	else
>  		[ "$nfs_f" != "nfs" ] && type="rhost"
>  	fi
> @@ -64,13 +66,14 @@ get_calls()
>  do_test()
>  {
>  	local client_calls server_calls new_server_calls new_client_calls
> -	local client_field server_field
> +	local client_field server_field root_calls new_root_calls
>  	local client_v=$VERSION server_v=$VERSION

>  	tst_res TINFO "checking RPC calls for server/client"

>  	server_calls="$(get_calls rpc 2 nfsd)"
>  	client_calls="$(get_calls rpc 2 nfs)"
> +	root_calls="$(get_calls rpc 2 nfs lhost)"

>  	tst_res TINFO "calls $server_calls/$client_calls"

> @@ -79,6 +82,7 @@ do_test()

>  	new_server_calls="$(get_calls rpc 2 nfsd)"
>  	new_client_calls="$(get_calls rpc 2 nfs)"
> +	new_root_calls="$(get_calls rpc 2 nfs lhost)"
>  	tst_res TINFO "new calls $new_server_calls/$new_client_calls"

>  	if [ "$new_server_calls" -le "$server_calls" ]; then
> @@ -93,6 +97,16 @@ do_test()
>  		tst_res TPASS "client RPC calls increased"
>  	fi

> +	if [ $NS_STAT_RHOST -ne 0 ]; then
> +		tst_res TINFO "Root NS client RPC calls: $root_calls => $new_root_calls"
> +
> +		if [ $root_calls -ne $new_root_calls ]; then
> +			tst_res TFAIL "RPC stats leaked between net namespaces"
> +		else
> +			tst_res TPASS "RPC stats stay within net namespaces"
> +		fi

Maybe also add TCONF message? (can be added before merge)

    else
		tst_res TCONF "Not testing leak between root NS and net NS due old kernel"

Reviewed-by: Petr Vorel <pvorel@suse.cz>
Tested-by: Petr Vorel <pvorel@suse.cz>

Thanks for this test!

Kind regards,
Petr

> +	fi
> +
>  	tst_res TINFO "checking NFS calls for server/client"
>  	case $VERSION in
>  	2) client_field=13 server_field=13