From: Keir Fraser <kfraser@endor.localdomain>
Date: Mon, 4 Aug 2008 10:08:09 +0000 (+0100)
Subject: stubdom: fix read-only disks access
X-Git-Tag: xen-3.3.0-rc3~3
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=6aab00fe35201f1eaeb349b8148d2af5edb187a2;p=qemu-xen-4.0-testing.git

stubdom: fix read-only disks access

There is no need for a flush on read-only disks.  It would actually even
error out and disturb the guest.

Signed-off-by: Samuel Thibault <samuel.thibault@eu.citrix.com>
---

diff --git a/block-vbd.c b/block-vbd.c
index a3465b74..58015bdf 100644
--- a/block-vbd.c
+++ b/block-vbd.c
@@ -273,6 +273,10 @@ static BlockDriverAIOCB *vbd_aio_flush(BlockDriverState *bs,
     BDRVVbdState *s = bs->opaque;
     VbdAIOCB *acb = NULL;
 
+    if (s->info.mode == O_RDONLY) {
+        cb(opaque, 0);
+        return NULL;
+    }
     if (s->info.barrier == 1) {
         acb = vbd_aio_setup(bs, 0, NULL, 0,
                 s->info.flush == 1 ? vbd_nop_cb : cb, opaque);