From: Peter Krempa <pkrempa@redhat.com>
Date: Mon, 1 Oct 2012 15:58:29 +0000 (+0200)
Subject: qemu: Use proper agent entering function when freezing filesystems
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=e0316b5ebd85ca7c20db9a3fe8f6062b4b5e051d;p=people%2Fliuw%2Flibxenctrl-split%2Flibvirt.git

qemu: Use proper agent entering function when freezing filesystems

When doing snapshots, the filesystem freeze function used the agent
entering function that expects the qemud_driver unlocked. This might
cause a deadlock of the qemu driver if the agent does not respond.

The only call path of this function has the qemud_driver locked, so this
patch changes the entering functions to those expecting the driver
locked.
---

diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index b0a0bb539..50f44ce70 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -10375,6 +10375,7 @@ qemuDomainSnapshotIsAllowed(virDomainObjPtr vm)
     return true;
 }
 
+/* this function expects the driver lock to be held by the caller */
 static int
 qemuDomainSnapshotFSFreeze(struct qemud_driver *driver,
                            virDomainObjPtr vm) {
@@ -10393,9 +10394,9 @@ qemuDomainSnapshotFSFreeze(struct qemud_driver *driver,
         return -1;
     }
 
-    qemuDomainObjEnterAgent(driver, vm);
+    qemuDomainObjEnterAgentWithDriver(driver, vm);
     freezed = qemuAgentFSFreeze(priv->agent);
-    qemuDomainObjExitAgent(driver, vm);
+    qemuDomainObjExitAgentWithDriver(driver, vm);
 
     return freezed;
 }