diff -urNp linux-1380/fs/nfs/inode.c linux-1391/fs/nfs/inode.c
--- linux-1380/fs/nfs/inode.c	
+++ linux-1391/fs/nfs/inode.c	
@@ -418,10 +418,16 @@ nfs_read_super(struct super_block *sb, v
         }
 
 	/* Work out a lot of parameters */
-	if (data->rsize == 0)
+	if (data->rsize == 0) {
 		server->rsize = nfs_block_size(fsinfo.rtpref, NULL);
-	if (data->wsize == 0)
+		if (server->rsize > NFS_DEF_FILE_IO_BUFFER_SIZE)
+			server->rsize = NFS_DEF_FILE_IO_BUFFER_SIZE;
+	}
+	if (data->wsize == 0) {
 		server->wsize = nfs_block_size(fsinfo.wtpref, NULL);
+		if (server->wsize > NFS_DEF_FILE_IO_BUFFER_SIZE)
+			server->wsize = NFS_DEF_FILE_IO_BUFFER_SIZE;
+	}
 	/* NFSv3: we don't have bsize, but rather rtmult and wtmult... */
 	if (!fsinfo.bsize)
 		fsinfo.bsize = (fsinfo.rtmult>fsinfo.wtmult) ? fsinfo.rtmult : fsinfo.wtmult;