From a82a87f26b0a6bacb53f3c7cd200a86a026ab6df Mon Sep 17 00:00:00 2001
From: Jiri Denemark <jdenemar@redhat.com>
Date: Mon, 8 Feb 2010 16:10:02 +0100
Subject: [PATCH] Create raw storage files with O_DSYNC

When creating preallocated large raw files opening them with O_DSYNC
prevents long delays in reading because cache pages can be immediately
reused without writing them on a disk first.
---
 src/storage/storage_backend.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/storage/storage_backend.c b/src/storage/storage_backend.c
index 8d85de8a11..4c62d48477 100644
--- a/src/storage/storage_backend.c
+++ b/src/storage/storage_backend.c
@@ -300,7 +300,7 @@ virStorageBackendCreateRaw(virConnectPtr conn,
         goto cleanup;
     }
 
-    if ((fd = open(vol->target.path, O_RDWR | O_EXCL)) < 0) {
+    if ((fd = open(vol->target.path, O_RDWR | O_EXCL | O_DSYNC)) < 0) {
         virReportSystemError(errno,
                              _("cannot open new path '%s'"),
                              vol->target.path);