From: Keir Fraser <keir.fraser@citrix.com>
Date: Mon, 4 Aug 2008 10:07:17 +0000 (+0100)
Subject: stubdom: fix read-only disks access
X-Git-Tag: archive/raspbian/4.8.0-1+rpi1~1^2~14165^2~40
X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=c5c5a831765f5b18e36543bab1614d7d63b0bbee;p=xen.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/tools/ioemu/block-vbd.c b/tools/ioemu/block-vbd.c
index a3465b748a..58015bdf00 100644
--- a/tools/ioemu/block-vbd.c
+++ b/tools/ioemu/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);