[libvirt] [PATCH V2 2/4] libxl: acquire job in migration finish phase
Moving data reception of the perform phase of migration to a
thread introduces a race with the finish phase, where checking
if the domain is active races with the thread finishing the
perform phase. The race is easily solved by acquiring a job in
the finish phase, which must wait for the perform phase job to
complete.
While wrapping the finish phase in a job, noticed the virDomainObj
was being unlocked in a callee - libxlDomainMigrationFinish. Move
the unlocking to libxlDomainMigrateFinish3Params, where the lock
is acquired.
Signed-off-by: Jim Fehlig <jfehlig(a)suse.com>
---
V2:
- Unlock virDomainObj in libxlDomainMigrateFinish3Params instead of callee
src/libxl/libxl_driver.c | 20 +++++++++++++++++---
src/libxl/libxl_migration.c | 1 -
2 files changed, 17 insertions(+), 4 deletions(-)
diff --git a/src/libxl/libxl_driver.c b/src/libxl/libxl_driver.c
index d2c077c..651d4eb 100644
--- a/src/libxl/libxl_driver.c
+++ b/src/libxl/libxl_driver.c
@@ -4654,6 +4654,7 @@ libxlDomainMigrateFinish3Params(virConnectPtr dconn,
libxlDriverPrivatePtr driver = dconn->privateData;
virDomainObjPtr vm = NULL;
const char *dname = NULL;
+ virDomainPtr ret = NULL;
#ifdef LIBXL_HAVE_NO_SUSPEND_RESUME
virReportUnsupportedError();
@@ -4684,16 +4685,29 @@ libxlDomainMigrateFinish3Params(virConnectPtr dconn,
return NULL;
}
+ if (libxlDomainObjBeginJob(driver, vm, LIBXL_JOB_MODIFY) < 0) {
+ virObjectUnlock(vm);
+ return NULL;
+ }
+
if (!virDomainObjIsActive(vm)) {
/* Migration failed if domain is inactive */
virReportError(VIR_ERR_OPERATION_FAILED,
"%s", _("Migration failed. Domain is not running
"
"on destination host"));
- virObjectUnlock(vm);
- return NULL;
+ goto endjob;
}
- return libxlDomainMigrationFinish(dconn, vm, flags, cancelled);
+ ret = libxlDomainMigrationFinish(dconn, vm, flags, cancelled);
+
+ endjob:
+ if (!libxlDomainObjEndJob(driver, vm))
+ vm = NULL;
+
+ if (vm)
+ virObjectUnlock(vm);
+
+ return ret;
}
static int
diff --git a/src/libxl/libxl_migration.c b/src/libxl/libxl_migration.c
index c728fa2..fa80a0c 100644
--- a/src/libxl/libxl_migration.c
+++ b/src/libxl/libxl_migration.c
@@ -573,7 +573,6 @@ libxlDomainMigrationFinish(virConnectPtr dconn,
cleanup:
if (event)
libxlDomainEventQueue(driver, event);
- virObjectUnlock(vm);
virObjectUnref(cfg);
return dom;
}
--
1.8.4.5