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

[Chuck Lever]

On Fri, Aug 30, 2024 at 04:13:40PM +0200, Martin Doucha wrote:
> 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.

I believe that is correct, Josef changed only RPC counters. Which
counters did you expect also would be containerized, exactly?
Perhaps this issue should be raised on linux-nfs@vger, it could be
considered to be another information leak.


> 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
> +	fi
> +
>  	tst_res TINFO "checking NFS calls for server/client"
>  	case $VERSION in
>  	2) client_field=13 server_field=13
> -- 
> 2.46.0
> 

-- 
Chuck Lever