nfs: fix the fetch of FATTR4_OPEN_ARGUMENTS

The client doesn't properly request FATTR4_OPEN_ARGUMENTS in the initial
SERVER_CAPS getattr. Add FATTR4_WORD2_OPEN_ARGUMENTS to the initial
request.

Fixes: 707f13b (NFSv4: Add support for the FATTR4_OPEN_ARGUMENTS attribute)
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

Author: jtlayton

fs/nfs/nfs4proc.c

@@ -3931,7 +3931,8 @@ static int _nfs4_server_capabilities(struct nfs_server *server, struct nfs_fh *f
 		     FATTR4_WORD0_CASE_INSENSITIVE |
 		     FATTR4_WORD0_CASE_PRESERVING;
 	if (minorversion)
-		bitmask[2] = FATTR4_WORD2_SUPPATTR_EXCLCREAT;
+		bitmask[2] = FATTR4_WORD2_SUPPATTR_EXCLCREAT |
+			     FATTR4_WORD2_OPEN_ARGUMENTS;
 
 	status = nfs4_call_sync(server->client, server, &msg, &args.seq_args, &res.seq_res, 0);
 	if (status == 0) {