Index: uspace/lib/libc/generic/vfs.c
===================================================================
--- uspace/lib/libc/generic/vfs.c	(revision d1ce5503ef6e518b9ec663afa1e582b29e05a5c5)
+++ uspace/lib/libc/generic/vfs.c	(revision 07e01e6a3438b23b858b7b7c85714f1f17331052)
@@ -176,5 +176,6 @@
 	}
 	req = async_send_1(vfs_phone, VFS_READ, fildes, &answer);
-	if (ipc_data_read_start(vfs_phone, (void *)buf, nbyte) != EOK) {
+	rc = ipc_data_read_start(vfs_phone, (void *)buf, nbyte);
+	if (rc != EOK) {
 		async_wait_for(req, NULL);
 		async_serialize_end();
@@ -209,5 +210,6 @@
 	}
 	req = async_send_1(vfs_phone, VFS_WRITE, fildes, &answer);
-	if (ipc_data_write_start(vfs_phone, (void *)buf, nbyte) != EOK) {
+	rc = ipc_data_write_start(vfs_phone, (void *)buf, nbyte);
+	if (rc != EOK) {
 		async_wait_for(req, NULL);
 		async_serialize_end();