--- linux-2.6.18-267.0.0.0.1.el5.i686/fs/nfs/read.c.orig	2011-06-27 10:05:18.000000000 +0800
+++ linux-2.6.18-267.0.0.0.1.el5.i686/fs/nfs/read.c	2011-06-27 12:27:47.000000000 +0800
@@ -83,7 +83,8 @@ void nfs_readdata_release(void *data)
 {
 	struct nfs_read_data *rdata = data;
 
-	put_nfs_open_context(rdata->args.context);
+	if (rdata->args.context)
+		put_nfs_open_context(rdata->args.context);
 	nfs_readdata_free(rdata);
 }
 
--- linux-2.6.18-267.0.0.0.1.el5.i686/fs/nfs/write.c.orig	2011-06-27 10:05:25.000000000 +0800
+++ linux-2.6.18-267.0.0.0.1.el5.i686/fs/nfs/write.c	2011-06-27 12:28:08.000000000 +0800
@@ -151,7 +151,8 @@ void nfs_writedata_release(void *data)
 {
 	struct nfs_write_data *wdata = data;
 
-	put_nfs_open_context(wdata->args.context);
+	if (wdata->args.context)
+		put_nfs_open_context(wdata->args.context);
 	nfs_writedata_free(wdata);
 }