From 5ad21740e4fbb4a10c1395396d058b85cd6c9dab Mon Sep 17 00:00:00 2001
From: Dylan Reid <dgreid@chromium.org>
Date: Thu, 12 Jul 2018 18:05:34 -0700
Subject: [PATCH] devices: block: sync after setting refcount

Make sure that the refcount update is commited to disk before we start
to write data to the cluster.

Change-Id: Ibdf5dde7a75c3582f87df46af1095c7dc0007d98
Signed-off-by: Dylan Reid <dgreid@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/1136019
Reviewed-by: Stephen Barber <smbarber@chromium.org>
---
 qcow/src/qcow.rs | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/qcow/src/qcow.rs b/qcow/src/qcow.rs
index 2052545dfb..d4cb6affb7 100644
--- a/qcow/src/qcow.rs
+++ b/qcow/src/qcow.rs
@@ -411,6 +411,8 @@ impl QcowFile {
         self.file.sync_data()?;
         // The cluster refcount starts at one indicating it is used but doesn't need COW.
         self.set_cluster_refcount(new_addr, 1)?;
+        // Ensure that the refcount is updated before starting to use the cluster.
+        self.file.sync_data()?;
         Ok(new_addr)
     }