xen/qemu-xen-upstream-qdisk-cache-unsafe.patch

https://bugzilla.novell.com/show_bug.cgi?id=879425
---
 tools/qemu-xen-dir-remote/hw/block/xen_disk.c |   15 +++++++++++++++
 1 file changed, 15 insertions(+)

Index: xen-4.5.0-testing/tools/qemu-xen-dir-remote/hw/block/xen_disk.c
===================================================================
--- xen-4.5.0-testing.orig/tools/qemu-xen-dir-remote/hw/block/xen_disk.c
+++ xen-4.5.0-testing/tools/qemu-xen-dir-remote/hw/block/xen_disk.c
@@ -120,6 +120,7 @@ struct XenBlkDev {
     int                 requests_inflight;
     int                 requests_finished;
 
+    gboolean            cache_unsafe;
     /* Persistent grants extension */
     gboolean            feature_discard;
     gboolean            feature_persistent;
@@ -780,6 +781,16 @@ static void blk_parse_discard(struct Xen
     }
 }
 
+static void blk_parse_cache_unsafe(struct XenBlkDev *blkdev)
+{
+    int enable;
+
+    blkdev->cache_unsafe = false;
+
+    if (xenstore_read_be_int(&blkdev->xendev, "suse-diskcache-disable-flush", &enable) == 0)
+	    blkdev->cache_unsafe = !!enable;
+}
+
 static int blk_init(struct XenDevice *xendev)
 {
     struct XenBlkDev *blkdev = container_of(xendev, struct XenBlkDev, xendev);
@@ -848,6 +859,7 @@ static int blk_init(struct XenDevice *xe
     xenstore_write_be_int(&blkdev->xendev, "info", info);
 
     blk_parse_discard(blkdev);
+    blk_parse_cache_unsafe(blkdev);
 
     g_free(directiosafe);
     return 0;
@@ -888,6 +900,9 @@ static int blk_connect(struct XenDevice
         qflags |= BDRV_O_UNMAP;
     }
 
+    if (blkdev->cache_unsafe)
+        qflags |= BDRV_O_NO_FLUSH;
+
     /* init qemu block driver */
     index = (blkdev->xendev.dev - 202 * 256) / 16;
     blkdev->dinfo = drive_get(IF_XEN, 0, index);