nfs: run state manager in privileged mode

Signed-off-by: NAlexandros Batsakis <batsakis@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

fs/nfs/nfs4proc.c

@@ -477,7 +477,8 @@ static int nfs41_setup_sequence(struct nfs4_session *session,
 	tbl = &session->fc_slot_table;
 
 	spin_lock(&tbl->slot_tbl_lock);
-	if (test_bit(NFS4CLNT_SESSION_DRAINING, &session->clp->cl_state)) {
+	if (test_bit(NFS4CLNT_SESSION_DRAINING, &session->clp->cl_state) &&
+	    !rpc_task_has_priority(task, RPC_PRIORITY_PRIVILEGED)) {
 		/*
 		 * The state manager will wait until the slot table is empty.
 		 * Schedule the reset thread

fs/nfs/nfs4state.c

@@ -135,9 +135,9 @@ static int nfs41_setup_state_renewal(struct nfs_client *clp)
 	return status;
 }
 
-static void nfs41_end_drain_session(struct nfs_client *clp,
-		struct nfs4_session *ses)
+static void nfs4_end_drain_session(struct nfs_client *clp)
 {
+	struct nfs4_session *ses = clp->cl_session;
 	int max_slots;
 
 	if (test_and_clear_bit(NFS4CLNT_SESSION_DRAINING, &clp->cl_state)) {
@@ -156,9 +156,9 @@ static void nfs41_end_drain_session(struct nfs_client *clp,
 	}
 }
 
-static int nfs41_begin_drain_session(struct nfs_client *clp,
-		struct nfs4_session *ses)
+static int nfs4_begin_drain_session(struct nfs_client *clp)
 {
+	struct nfs4_session *ses = clp->cl_session;
 	struct nfs4_slot_table *tbl = &ses->fc_slot_table;
 
 	spin_lock(&tbl->slot_tbl_lock);
@@ -176,16 +176,12 @@ int nfs41_init_clientid(struct nfs_client *clp, struct rpc_cred *cred)
 {
 	int status;
 
-	status = nfs41_begin_drain_session(clp, clp->cl_session);
-	if (status != 0)
-		goto out;
 	status = nfs4_proc_exchange_id(clp, cred);
 	if (status != 0)
 		goto out;
 	status = nfs4_proc_create_session(clp);
 	if (status != 0)
 		goto out;
-	nfs41_end_drain_session(clp, clp->cl_session);
 	nfs41_setup_state_renewal(clp);
 	nfs_mark_client_ready(clp, NFS_CS_READY);
 out:
@@ -1271,13 +1267,8 @@ void nfs41_handle_sequence_flag_errors(struct nfs_client *clp, u32 flags)
 
 static int nfs4_reset_session(struct nfs_client *clp)
 {
-	struct nfs4_session *ses = clp->cl_session;
 	int status;
 
-	status = nfs41_begin_drain_session(clp, ses);
-	if (status != 0)
-		return status;
-
 	status = nfs4_proc_destroy_session(clp->cl_session);
 	if (status && status != -NFS4ERR_BADSESSION &&
 	    status != -NFS4ERR_DEADSESSION) {
@@ -1293,19 +1284,18 @@ static int nfs4_reset_session(struct nfs_client *clp)
 out:
 	/*
 	 * Let the state manager reestablish state
-	 * without waking other tasks yet.
 	 */
-	if (!test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state)) {
-		/* Wake up the next rpc task */
-		nfs41_end_drain_session(clp, ses);
-		if (status == 0)
-			nfs41_setup_state_renewal(clp);
-	}
+	if (!test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) &&
+	    status == 0)
+		nfs41_setup_state_renewal(clp);
+
 	return status;
 }
 
 #else /* CONFIG_NFS_V4_1 */
 static int nfs4_reset_session(struct nfs_client *clp) { return 0; }
+static int nfs4_begin_drain_session(struct nfs_client *clp) { return 0; }
+static int nfs4_end_drain_session(struct nfs_client *clp) { return 0; }
 #endif /* CONFIG_NFS_V4_1 */
 
 /* Set NFS4CLNT_LEASE_EXPIRED for all v4.0 errors and for recoverable errors
@@ -1337,6 +1327,7 @@ static void nfs4_state_manager(struct nfs_client *clp)
 	for(;;) {
 		if (test_and_clear_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state)) {
 			/* We're going to have to re-establish a clientid */
+			nfs4_begin_drain_session(clp);
 			status = nfs4_reclaim_lease(clp);
 			if (status) {
 				nfs4_set_lease_expired(clp, status);
@@ -1363,6 +1354,7 @@ static void nfs4_state_manager(struct nfs_client *clp)
 		/* Initialize or reset the session */
 		if (test_and_clear_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state)
 		   && nfs4_has_session(clp)) {
+			nfs4_begin_drain_session(clp);
 			status = nfs4_reset_session(clp);
 			if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state))
 				continue;
@@ -1396,6 +1388,7 @@ static void nfs4_state_manager(struct nfs_client *clp)
 				goto out_error;
 		}
 
+		nfs4_end_drain_session(clp);
 		if (test_and_clear_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state)) {
 			nfs_client_return_marked_delegations(clp);
 			continue;
@@ -1412,6 +1405,7 @@ static void nfs4_state_manager(struct nfs_client *clp)
 out_error:
 	printk(KERN_WARNING "Error: state manager failed on NFSv4 server %s"
 			" with error %d\n", clp->cl_hostname, -status);
+	nfs4_end_drain_session(clp);
 	nfs4_clear_state_manager_bit(clp);
 }