NFS: send state management on a single connection.

With NFSv4.1, different network connections need to be explicitly
bound to a session.  During session startup, this is not possible
so only a single connection must be used for session startup.

So add a task flag to disable the default round-robin choice of
connections (when nconnect > 1) and force the use of a single
connection.
Then use that flag on all requests for session management - for
consistence, include NFSv4.0 management (SETCLIENTID) and session
destruction

Reported-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 26626ea..d115d99 100644 (file)
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -5992,7 +5992,7 @@ int nfs4_proc_setclientid(struct nfs_client *clp, u32 program,
                .rpc_message = &msg,
                .callback_ops = &nfs4_setclientid_ops,
                .callback_data = &setclientid,
-               .flags = RPC_TASK_TIMEOUT,
+               .flags = RPC_TASK_TIMEOUT | RPC_TASK_NO_ROUND_ROBIN,
        };
        int status;
 
@@ -6058,7 +6058,8 @@ int nfs4_proc_setclientid_confirm(struct nfs_client *clp,
        dprintk("NFS call  setclientid_confirm auth=%s, (client ID %llx)\n",
                clp->cl_rpcclient->cl_auth->au_ops->au_name,
                clp->cl_clientid);
-       status = rpc_call_sync(clp->cl_rpcclient, &msg, RPC_TASK_TIMEOUT);
+       status = rpc_call_sync(clp->cl_rpcclient, &msg,
+                              RPC_TASK_TIMEOUT | RPC_TASK_NO_ROUND_ROBIN);
        trace_nfs4_setclientid_confirm(clp, status);
        dprintk("NFS reply setclientid_confirm: %d\n", status);
        return status;
@@ -7639,7 +7640,7 @@ static int _nfs4_proc_secinfo(struct inode *dir, const struct qstr *name, struct
                NFS_SP4_MACH_CRED_SECINFO, &clnt, &msg);
 
        status = nfs4_call_sync(clnt, NFS_SERVER(dir), &msg, &args.seq_args,
-                               &res.seq_res, 0);
+                               &res.seq_res, RPC_TASK_NO_ROUND_ROBIN);
        dprintk("NFS reply  secinfo: %d\n", status);
 
        put_cred(cred);
@@ -7977,7 +7978,7 @@ nfs4_run_exchange_id(struct nfs_client *clp, const struct cred *cred,
                .rpc_client = clp->cl_rpcclient,
                .callback_ops = &nfs4_exchange_id_call_ops,
                .rpc_message = &msg,
-               .flags = RPC_TASK_TIMEOUT,
+               .flags = RPC_TASK_TIMEOUT | RPC_TASK_NO_ROUND_ROBIN,
        };
        struct nfs41_exchange_id_data *calldata;
        int status;
@@ -8202,7 +8203,8 @@ static int _nfs4_proc_destroy_clientid(struct nfs_client *clp,
        };
        int status;
 
-       status = rpc_call_sync(clp->cl_rpcclient, &msg, RPC_TASK_TIMEOUT);
+       status = rpc_call_sync(clp->cl_rpcclient, &msg,
+                              RPC_TASK_TIMEOUT | RPC_TASK_NO_ROUND_ROBIN);
        trace_nfs4_destroy_clientid(clp, status);
        if (status)
                dprintk("NFS: Got error %d from the server %s on "
@@ -8481,7 +8483,8 @@ static int _nfs4_proc_create_session(struct nfs_client *clp,
        nfs4_init_channel_attrs(&args, clp->cl_rpcclient);
        args.flags = (SESSION4_PERSIST | SESSION4_BACK_CHAN);
 
-       status = rpc_call_sync(session->clp->cl_rpcclient, &msg, RPC_TASK_TIMEOUT);
+       status = rpc_call_sync(session->clp->cl_rpcclient, &msg,
+                              RPC_TASK_TIMEOUT | RPC_TASK_NO_ROUND_ROBIN);
        trace_nfs4_create_session(clp, status);
 
        switch (status) {
@@ -8557,7 +8560,8 @@ int nfs4_proc_destroy_session(struct nfs4_session *session,
        if (!test_and_clear_bit(NFS4_SESSION_ESTABLISHED, &session->session_state))
                return 0;
 
-       status = rpc_call_sync(session->clp->cl_rpcclient, &msg, RPC_TASK_TIMEOUT);
+       status = rpc_call_sync(session->clp->cl_rpcclient, &msg,
+                              RPC_TASK_TIMEOUT | RPC_TASK_NO_ROUND_ROBIN);
        trace_nfs4_destroy_session(session->clp, status);
 
        if (status)
@@ -8811,7 +8815,7 @@ static int nfs41_proc_reclaim_complete(struct nfs_client *clp,
                .rpc_client = clp->cl_rpcclient,
                .rpc_message = &msg,
                .callback_ops = &nfs4_reclaim_complete_call_ops,
-               .flags = RPC_TASK_ASYNC,
+               .flags = RPC_TASK_ASYNC | RPC_TASK_NO_ROUND_ROBIN,
        };
        int status = -ENOMEM;
 
@@ -9330,7 +9334,7 @@ _nfs41_proc_secinfo_no_name(struct nfs_server *server, struct nfs_fh *fhandle,
 
        dprintk("--> %s\n", __func__);
        status = nfs4_call_sync(clnt, server, &msg, &args.seq_args,
-                               &res.seq_res, 0);
+                               &res.seq_res, RPC_TASK_NO_ROUND_ROBIN);
        dprintk("<-- %s status=%d\n", __func__, status);
 
        put_cred(cred);

diff --git a/include/linux/sunrpc/sched.h b/include/linux/sunrpc/sched.h
index d0e4518..11424bd 100644 (file)
--- a/include/linux/sunrpc/sched.h
+++ b/include/linux/sunrpc/sched.h
@@ -126,6 +126,7 @@ struct rpc_task_setup {
 #define RPC_CALL_MAJORSEEN     0x0020          /* major timeout seen */
 #define RPC_TASK_ROOTCREDS     0x0040          /* force root creds */
 #define RPC_TASK_DYNAMIC       0x0080          /* task was kmalloc'ed */
+#define        RPC_TASK_NO_ROUND_ROBIN 0x0100          /* send requests on "main" xprt */
 #define RPC_TASK_SOFT          0x0200          /* Use soft timeouts */
 #define RPC_TASK_SOFTCONN      0x0400          /* Fail if can't connect */
 #define RPC_TASK_SENT          0x0800          /* message was sent */

diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index b6aca8c..d599fab 100644 (file)
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -995,6 +995,24 @@ rpc_task_get_xprt(struct rpc_clnt *clnt)
        return xprt;
 }
 
+static struct rpc_xprt *
+rpc_task_get_first_xprt(struct rpc_clnt *clnt)
+{
+       struct rpc_xprt_switch *xps;
+       struct rpc_xprt *xprt;
+
+       rcu_read_lock();
+       xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
+       if (xprt) {
+               atomic_long_inc(&xprt->queuelen);
+               xps = rcu_dereference(clnt->cl_xpi.xpi_xpswitch);
+               atomic_long_inc(&xps->xps_queuelen);
+       }
+       rcu_read_unlock();
+
+       return xprt;
+}
+
 static void
 rpc_task_release_xprt(struct rpc_clnt *clnt, struct rpc_xprt *xprt)
 {
@@ -1042,7 +1060,11 @@ void rpc_task_release_client(struct rpc_task *task)
 static
 void rpc_task_set_transport(struct rpc_task *task, struct rpc_clnt *clnt)
 {
-       if (!task->tk_xprt)
+       if (task->tk_xprt)
+               return;
+       if (task->tk_flags & RPC_TASK_NO_ROUND_ROBIN)
+               task->tk_xprt = rpc_task_get_first_xprt(clnt);
+       else
                task->tk_xprt = rpc_task_get_xprt(clnt);
 }