Patchwork [09/11] cpus: Let vm_stop[_force_state]() always flush block devices

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Submitter Stefan Hajnoczi
Date July 19, 2013, 8:38 a.m.
Message ID <1374223132-29107-10-git-send-email-stefanha@redhat.com>
Download mbox | patch
Permalink /patch/260211/
State New
Headers show

Comments

Stefan Hajnoczi - July 19, 2013, 8:38 a.m.
From: Kevin Wolf <kwolf@redhat.com>

Even if the VM is already stopped, we cannot assume that all data has
already been successfully flushed to disk. The flush during the previous
vm_stop() could have failed.

Run bdrv_flush_all() unconditionally so that we get an error each time
if the block device isn't really flushed.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 cpus.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

Patch

diff --git a/cpus.c b/cpus.c
index 8062cdd..2509eb5 100644
--- a/cpus.c
+++ b/cpus.c
@@ -443,11 +443,12 @@  static int do_vm_stop(RunState state)
         pause_all_vcpus();
         runstate_set(state);
         vm_state_notify(0, state);
-        bdrv_drain_all();
-        ret = bdrv_flush_all();
         monitor_protocol_event(QEVENT_STOP, NULL);
     }
 
+    bdrv_drain_all();
+    ret = bdrv_flush_all();
+
     return ret;
 }
 
@@ -1126,7 +1127,9 @@  int vm_stop_force_state(RunState state)
         return vm_stop(state);
     } else {
         runstate_set(state);
-        return 0;
+        /* Make sure to return an error if the flush in a previous vm_stop()
+         * failed. */
+        return bdrv_flush_all();
     }
 }