On Wed, Jul 04, 2018 at 13:09:01 +0200, Michal Privoznik wrote:
https://bugzilla.redhat.com/show_bug.cgi?id=1598084
When creating a snapshot with --quiesce an async job is grabbed
and just before executing guest fs-freeze command an agent job is
grabbed. This is achieved by calling
qemuDomainObjBeginJobInternal(job = QEMU_JOB_NONE,
agentJob = QEMU_AGENT_JOB_MODIFY);
Since there already is an async job set on the domain (by the
same thread) qemuDomainNestedJobAllowed(priv, job) is consulted
if @job is allowed by job mask. But this function returns false
(meaning sync @job is not allowed) which leads to a deadlock.
Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com>
---
src/qemu/qemu_domain.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c
index a60bca29ca..1b8fb71ba8 100644
--- a/src/qemu/qemu_domain.c
+++ b/src/qemu/qemu_domain.c
@@ -6414,7 +6414,9 @@ qemuDomainObjReleaseAsyncJob(virDomainObjPtr obj)
static bool
qemuDomainNestedJobAllowed(qemuDomainObjPrivatePtr priv, qemuDomainJob job)
{
- return !priv->job.asyncJob || (priv->job.mask & JOB_MASK(job)) != 0;
+ return !priv->job.asyncJob ||
+ job == QEMU_JOB_NONE ||
+ (priv->job.mask & JOB_MASK(job)) != 0;
I think the following alignment would be a bit better:
return !priv->job.asyncJob ||
job == QEMU_JOB_NONE ||
(priv->job.mask & JOB_MASK(job)) != 0;
And I would probably put the job == QEMU_JOB_NONE check first, but it
doesn't make any functional difference.
Reviewed-by: Jiri Denemark <jdenemar(a)redhat.com>