diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index 30513029c00c..1667e3984418 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -351,15 +351,13 @@ int nfs_writepages(struct address_space *mapping, struct writeback_control *wbc)
 /*
  * Insert a write request into an inode
  */
-static int nfs_inode_add_request(struct inode *inode, struct nfs_page *req)
+static void nfs_inode_add_request(struct inode *inode, struct nfs_page *req)
 {
 	struct nfs_inode *nfsi = NFS_I(inode);
 	int error;
 
 	error = radix_tree_insert(&nfsi->nfs_page_tree, req->wb_index, req);
-	BUG_ON(error == -EEXIST);
-	if (error)
-		return error;
+	BUG_ON(error);
 	if (!nfsi->npages) {
 		igrab(inode);
 		if (nfs_have_delegation(inode, FMODE_WRITE))
@@ -369,8 +367,8 @@ static int nfs_inode_add_request(struct inode *inode, struct nfs_page *req)
 	set_page_private(req->wb_page, (unsigned long)req);
 	nfsi->npages++;
 	kref_get(&req->wb_kref);
-	radix_tree_tag_set(&nfsi->nfs_page_tree, req->wb_index, NFS_PAGE_TAG_LOCKED);
-	return 0;
+	radix_tree_tag_set(&nfsi->nfs_page_tree, req->wb_index,
+				NFS_PAGE_TAG_LOCKED);
 }
 
 /*
@@ -582,6 +580,13 @@ static struct nfs_page * nfs_update_request(struct nfs_open_context* ctx,
 		/* Loop over all inode entries and see if we find
 		 * A request for the page we wish to update
 		 */
+		if (new) {
+			if (radix_tree_preload(GFP_NOFS)) {
+				nfs_release_request(new);
+				return ERR_PTR(-ENOMEM);
+			}
+		}
+
 		spin_lock(&inode->i_lock);
 		req = nfs_page_find_request_locked(page);
 		if (req) {
@@ -592,28 +597,27 @@ static struct nfs_page * nfs_update_request(struct nfs_open_context* ctx,
 				error = nfs_wait_on_request(req);
 				nfs_release_request(req);
 				if (error < 0) {
-					if (new)
+					if (new) {
+						radix_tree_preload_end();
 						nfs_release_request(new);
+					}
 					return ERR_PTR(error);
 				}
 				continue;
 			}
 			spin_unlock(&inode->i_lock);
-			if (new)
+			if (new) {
+				radix_tree_preload_end();
 				nfs_release_request(new);
+			}
 			break;
 		}
 
 		if (new) {
-			int error;
 			nfs_lock_request_dontget(new);
-			error = nfs_inode_add_request(inode, new);
-			if (error) {
-				spin_unlock(&inode->i_lock);
-				nfs_unlock_request(new);
-				return ERR_PTR(error);
-			}
+			nfs_inode_add_request(inode, new);
 			spin_unlock(&inode->i_lock);
+			radix_tree_preload_end();
 			req = new;
 			goto zero_page;
 		}
diff --git a/include/linux/sunrpc/clnt.h b/include/linux/sunrpc/clnt.h
index 129a86e25d29..6fff7f82ef12 100644
--- a/include/linux/sunrpc/clnt.h
+++ b/include/linux/sunrpc/clnt.h
@@ -127,11 +127,12 @@ int		rpcb_getport_sync(struct sockaddr_in *, u32, u32, int);
 void		rpcb_getport_async(struct rpc_task *);
 
 void		rpc_call_start(struct rpc_task *);
-int		rpc_call_async(struct rpc_clnt *clnt, struct rpc_message *msg,
-			       int flags, const struct rpc_call_ops *tk_ops,
+int		rpc_call_async(struct rpc_clnt *clnt,
+			       const struct rpc_message *msg, int flags,
+			       const struct rpc_call_ops *tk_ops,
 			       void *calldata);
-int		rpc_call_sync(struct rpc_clnt *clnt, struct rpc_message *msg,
-			      int flags);
+int		rpc_call_sync(struct rpc_clnt *clnt,
+			      const struct rpc_message *msg, int flags);
 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred,
 			       int flags);
 void		rpc_restart_call(struct rpc_task *);
diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index 0e209af39797..ea14314331b0 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -548,7 +548,7 @@ EXPORT_SYMBOL_GPL(rpc_run_task);
  * @msg: RPC call parameters
  * @flags: RPC call flags
  */
-int rpc_call_sync(struct rpc_clnt *clnt, struct rpc_message *msg, int flags)
+int rpc_call_sync(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags)
 {
 	struct rpc_task	*task;
 	struct rpc_task_setup task_setup_data = {
@@ -579,7 +579,7 @@ EXPORT_SYMBOL_GPL(rpc_call_sync);
  * @data: user call data
  */
 int
-rpc_call_async(struct rpc_clnt *clnt, struct rpc_message *msg, int flags,
+rpc_call_async(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags,
 	       const struct rpc_call_ops *tk_ops, void *data)
 {
 	struct rpc_task	*task;