Two more NFS client bugfixes for 4.13

Stable fix:
 - Fix EXCHANGE_ID corrupt verifier issue
 
 Other fix:
 - Fix double frees in nfs4_test_session_trunk()
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Merge tag 'nfs-for-4.13-4' of git://git.linux-nfs.org/projects/anna/linux-nfs

Pull NFS client fixes from Anna Schumaker:
 "Two fixes from Trond this time, now that he's back from his vacation.
  The first is a stable fix for the EXCHANGE_ID issue on the mailing
  list, and the other fixes a double-free situation that he found at the
  same time.

  Stable fix:
   - Fix EXCHANGE_ID corrupt verifier issue

  Other fix:
   - Fix double frees in nfs4_test_session_trunk()"

* tag 'nfs-for-4.13-4' of git://git.linux-nfs.org/projects/anna/linux-nfs:
  NFSv4: Fix double frees in nfs4_test_session_trunk()
  NFSv4: Fix EXCHANGE_ID corrupt verifier issue

fs/nfs/nfs4client.c

@@ -660,9 +660,6 @@ int nfs4_detect_session_trunking(struct nfs_client *clp,
 	if (!nfs4_check_server_scope(clp->cl_serverscope, res->server_scope))
 		goto out_err;
 
-	/* Session trunking passed, add the xprt */
-	rpc_clnt_xprt_switch_add_xprt(clp->cl_rpcclient, xprt);
-
 	pr_info("NFS:  %s: Session trunking succeeded for %s\n",
 		clp->cl_hostname,
 		xprt->address_strings[RPC_DISPLAY_ADDR]);

fs/nfs/nfs4proc.c

@@ -7461,7 +7461,7 @@ static void nfs4_exchange_id_done(struct rpc_task *task, void *data)
 			cdata->res.server_scope = NULL;
 		}
 		/* Save the EXCHANGE_ID verifier session trunk tests */
-		memcpy(clp->cl_confirm.data, cdata->args.verifier->data,
+		memcpy(clp->cl_confirm.data, cdata->args.verifier.data,
 		       sizeof(clp->cl_confirm.data));
 	}
 out:
@@ -7474,10 +7474,6 @@ static void nfs4_exchange_id_release(void *data)
 	struct nfs41_exchange_id_data *cdata =
 					(struct nfs41_exchange_id_data *)data;
 
-	if (cdata->xprt) {
-		xprt_put(cdata->xprt);
-		rpc_clnt_xprt_switch_put(cdata->args.client->cl_rpcclient);
-	}
 	nfs_put_client(cdata->args.client);
 	kfree(cdata->res.impl_id);
 	kfree(cdata->res.server_scope);
@@ -7498,7 +7494,6 @@ static const struct rpc_call_ops nfs4_exchange_id_call_ops = {
 static int _nfs4_proc_exchange_id(struct nfs_client *clp, struct rpc_cred *cred,
 			u32 sp4_how, struct rpc_xprt *xprt)
 {
-	nfs4_verifier verifier;
 	struct rpc_message msg = {
 		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_EXCHANGE_ID],
 		.rpc_cred = cred,
@@ -7507,7 +7502,7 @@ static int _nfs4_proc_exchange_id(struct nfs_client *clp, struct rpc_cred *cred,
 		.rpc_client = clp->cl_rpcclient,
 		.callback_ops = &nfs4_exchange_id_call_ops,
 		.rpc_message = &msg,
-		.flags = RPC_TASK_ASYNC | RPC_TASK_TIMEOUT,
+		.flags = RPC_TASK_TIMEOUT,
 	};
 	struct nfs41_exchange_id_data *calldata;
 	struct rpc_task *task;
@@ -7522,8 +7517,7 @@ static int _nfs4_proc_exchange_id(struct nfs_client *clp, struct rpc_cred *cred,
 		return -ENOMEM;
 	}
 
-	if (!xprt)
-		nfs4_init_boot_verifier(clp, &verifier);
+	nfs4_init_boot_verifier(clp, &calldata->args.verifier);
 
 	status = nfs4_init_uniform_client_string(clp);
 	if (status)
@@ -7562,11 +7556,9 @@ static int _nfs4_proc_exchange_id(struct nfs_client *clp, struct rpc_cred *cred,
 	if (xprt) {
 		calldata->xprt = xprt;
 		task_setup_data.rpc_xprt = xprt;
-		task_setup_data.flags =
-				RPC_TASK_SOFT|RPC_TASK_SOFTCONN|RPC_TASK_ASYNC;
-		calldata->args.verifier = &clp->cl_confirm;
-	} else {
-		calldata->args.verifier = &verifier;
+		task_setup_data.flags |= RPC_TASK_SOFTCONN;
+		memcpy(calldata->args.verifier.data, clp->cl_confirm.data,
+				sizeof(calldata->args.verifier.data));
 	}
 	calldata->args.client = clp;
 #ifdef CONFIG_NFS_V4_1_MIGRATION
@@ -7585,12 +7577,7 @@ static int _nfs4_proc_exchange_id(struct nfs_client *clp, struct rpc_cred *cred,
 	if (IS_ERR(task))
 		return PTR_ERR(task);
 
-	if (!xprt) {
-		status = rpc_wait_for_completion_task(task);
-		if (!status)
-			status = calldata->rpc_status;
-	} else	/* session trunking test */
-		status = calldata->rpc_status;
+	status = calldata->rpc_status;
 
 	rpc_put_task(task);
 out:

fs/nfs/nfs4xdr.c

@@ -1785,7 +1785,7 @@ static void encode_exchange_id(struct xdr_stream *xdr,
 	int len = 0;
 
 	encode_op_hdr(xdr, OP_EXCHANGE_ID, decode_exchange_id_maxsz, hdr);
-	encode_nfs4_verifier(xdr, args->verifier);
+	encode_nfs4_verifier(xdr, &args->verifier);
 
 	encode_string(xdr, strlen(args->client->cl_owner_id),
 			args->client->cl_owner_id);

include/linux/nfs_xdr.h

@@ -1235,7 +1235,7 @@ struct nfs41_state_protection {
 
 struct nfs41_exchange_id_args {
 	struct nfs_client		*client;
-	nfs4_verifier			*verifier;
+	nfs4_verifier			verifier;
 	u32				flags;
 	struct nfs41_state_protection	state_protect;
 };