NFSv4: Fix another nfs4_sequence corruptor

nfs4_release_lockowner needs to set the rpc_message reply to point to
the nfs4_sequence_res in order to avoid another Oopsable situation
in nfs41_assign_slot.

Fixes: fbd4bfd1 (NFS: Add nfs4_sequence calls for RELEASE_LOCKOWNER)
Cc: stable@vger.kernel.org # 3.12+
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

fs/nfs/nfs4proc.c

@@ -5828,8 +5828,7 @@ struct nfs_release_lockowner_data {
 	struct nfs4_lock_state *lsp;
 	struct nfs_server *server;
 	struct nfs_release_lockowner_args args;
-	struct nfs4_sequence_args seq_args;
-	struct nfs4_sequence_res seq_res;
+	struct nfs_release_lockowner_res res;
 	unsigned long timestamp;
 };
 
@@ -5837,7 +5836,7 @@ static void nfs4_release_lockowner_prepare(struct rpc_task *task, void *calldata
 {
 	struct nfs_release_lockowner_data *data = calldata;
 	nfs40_setup_sequence(data->server,
-				&data->seq_args, &data->seq_res, task);
+				&data->args.seq_args, &data->res.seq_res, task);
 	data->timestamp = jiffies;
 }
 
@@ -5846,7 +5845,7 @@ static void nfs4_release_lockowner_done(struct rpc_task *task, void *calldata)
 	struct nfs_release_lockowner_data *data = calldata;
 	struct nfs_server *server = data->server;
 
-	nfs40_sequence_done(task, &data->seq_res);
+	nfs40_sequence_done(task, &data->res.seq_res);
 
 	switch (task->tk_status) {
 	case 0:
@@ -5887,7 +5886,6 @@ static int nfs4_release_lockowner(struct nfs_server *server, struct nfs4_lock_st
 	data = kmalloc(sizeof(*data), GFP_NOFS);
 	if (!data)
 		return -ENOMEM;
-	nfs4_init_sequence(&data->seq_args, &data->seq_res, 0);
 	data->lsp = lsp;
 	data->server = server;
 	data->args.lock_owner.clientid = server->nfs_client->cl_clientid;
@@ -5895,6 +5893,8 @@ static int nfs4_release_lockowner(struct nfs_server *server, struct nfs4_lock_st
 	data->args.lock_owner.s_dev = server->s_dev;
 
 	msg.rpc_argp = &data->args;
+	msg.rpc_resp = &data->res;
+	nfs4_init_sequence(&data->args.seq_args, &data->res.seq_res, 0);
 	rpc_call_async(server->client, &msg, 0, &nfs4_release_lockowner_ops, data);
 	return 0;
 }

include/linux/nfs_xdr.h

@@ -467,9 +467,14 @@ struct nfs_lockt_res {
 };
 
 struct nfs_release_lockowner_args {
+	struct nfs4_sequence_args	seq_args;
 	struct nfs_lowner	lock_owner;
 };
 
+struct nfs_release_lockowner_res {
+	struct nfs4_sequence_res	seq_res;
+};
+
 struct nfs4_delegreturnargs {
 	struct nfs4_sequence_args	seq_args;
 	const struct nfs_fh *fhandle;