Hi Santosh,
On Tue, 2018-12-11 at 15:28 +0530, Santosh kumar pradhan wrote:
> From: Santosh Kumar Pradhan <santoshkumar.pradhan@xxxxxxx>
>
> Multipathing: In case of NFSv3, rpc_clnt_test_and_add_xprt() adds
> the xprt to xprt switch (i.e. xps) if rpc_call_null_helper() returns
> success. But in case of NFSv4.1, it needs to do EXCHANGEID to verify
> the path along with check for session trunking.
>
> Add the xprt once nfs4_test_session_trunk() returns success.
> Also release refcount hold by rpc_clnt_setup_test_and_add_xprt().
>
> Signed-off-by: Santosh Kumar Pradhan <santoshkumar.pradhan@xxxxxxx>
> Tested-by: Suresh Jayaraman <suresh.jayaraman@xxxxxxx>
> ---
> net/sunrpc/clnt.c | 10 +++++++---
> 1 file changed, 7 insertions(+), 3 deletions(-)
>
> diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
> index d839c33ae7d9..053f594cc144 100644
> --- a/net/sunrpc/clnt.c
> +++ b/net/sunrpc/clnt.c
> @@ -2654,10 +2654,14 @@ int rpc_clnt_setup_test_and_add_xprt(struct
> rpc_clnt *clnt,
> goto out_err;
>
> /* rpc_xprt_switch and rpc_xprt are deferrenced by
> add_xprt_test() */
> - xtest->add_xprt_test(clnt, xprt, xtest->data);
> + status = xtest->add_xprt_test(clnt, xprt, xtest->data);
> + if (status != 0)
> + goto out_err;
>
> - /* so that rpc_clnt_add_xprt does not call
> rpc_xprt_switch_add_xprt */
> - return 1;
> + xprt_put(xprt);
> + xprt_switch_put(xps);
> + /* so that rpc_clnt_add_xprt calls rpc_xprt_switch_add_xprt */
> + return 0;
> out_err:
> xprt_put(xprt);
> xprt_switch_put(xps);
I'd really prefer to have callbacks that don't return values here so
that they can be made asynchronous at some point in the future. For
that reason, I'd prefer a fix in the NFS code, not the RPC code.
Can you therefore please change struct rpc_add_xprt_test to something
like the following:
struct rpc_add_xprt_test {
void (*add_xprt_test)(struct rpc_clnt *,
struct rpc_xprt *,
void *calldata);
void *data;
};
and then simply have nfs4_test_session_trunk() call
rpc_clnt_xprt_switch_add_xprt() if the call to
nfs4_detect_session_trunking() is successful?
Thanks!
Trond
--
Trond Myklebust
Linux NFS client maintainer, Hammerspace
trond.myklebust@xxxxxxxxxxxxxxx
