[libvirt] [PATCH v2] util: don't fail if no PortData is found while getting migrateData
---
V1 here:
https://www.redhat.com/archives/libvir-list/2015-February/msg00388.html
V2:
Add "--if-exists" option to ovs-vsctl cmd, making ovs-vsctl not raise error
if there's no portData
available. Suggested by Martin.
We Tested the patch, it works.
---
Introduced by f6a2f97e
Problem description:
After multiple times of migrating a domain, which has an ovs interface with no portData
set,
with non-shared disk, nbd ports got overflowed.
The steps to reproduce the problem:
1 define and start a domain with its network configured as:
<interface type='bridge'>
<source bridge='br0'/>
<virtualport type='openvswitch'>
</virtualport>
<model type='virtio'/>
<driver name='vhost' queues='4'/>
</interface>
2 do not set the network's portData.
3 migrate(ToURI2) it with flag 91(1011011), which means:
VIR_MIGRATE_LIVE
VIR_MIGRATE_PEER2PEER
VIR_MIGRATE_PERSIST_DEST
VIR_MIGRATE_UNDEFINE_SOURCE
VIR_MIGRATE_NON_SHARED_DISK
4 migrate success, but we got an error log in libvirtd.log:
error : virCommandWait:2423 : internal error: Child process (ovs-vsctl --timeout=5 get
Interface
vnet1 external_ids:PortData) unexpected exit status 1: ovs-vsctl: no key
"PortData" in Interface
record "vnet1" column external_ids
5 migrate it back, migrate it , migrate it back, .......
6 nbd port got overflowed.
The reasons for the problem is :
1 virNetDevOpenvswitchGetMigrateData() takes it as wrong if no portData is available for
the ovs
interface of a domain. (We think it's not appropriate, as portData is just OPTIONAL)
2 in func qemuMigrationBakeCookie(), it fails in qemuMigrationCookieAddNetwork(), and
returns with -1.
qemuMigrationCookieAddNBD() is not called thereafter, and mig->nbd is still NULL.
3 However, qemuMigrationRun() just *WARN* if qemuMigrationBakeCookie() fails, migration
still successes.
cookie is NULL, it's not baked on the src side.
4 On the destination side, it would alloc a port first and then free the nbd port in
COOKIE.
But the cookie is NULL due to qemuMigrationCookieAddNetwork() failure at src side. thus
the nbd port
is not freed.
In this patch, we add "--if-exists" option to make ovs-vsctl not raise error if
there's no portData available.
Further more, because portData may be NULL in the cookie at the dest side, check it before
setting portData.
Signed-off-by: Zhou Yimin <zhouyimin(a)huawei.com>
Signed-off-by: Zhang Bo <oscar.zhangbo(a)huawei.com>
---
src/util/virnetdevopenvswitch.c | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/src/util/virnetdevopenvswitch.c b/src/util/virnetdevopenvswitch.c
index e5c87bb..722d0dd 100644
--- a/src/util/virnetdevopenvswitch.c
+++ b/src/util/virnetdevopenvswitch.c
@@ -30,9 +30,12 @@
#include "virerror.h"
#include "virmacaddr.h"
#include "virstring.h"
+#include "virlog.h"
#define VIR_FROM_THIS VIR_FROM_NONE
+VIR_LOG_INIT("util.netdevopenvswitch");
+
/**
* virNetDevOpenvswitchAddPort:
* @brname: the bridge name
@@ -206,7 +209,7 @@ int virNetDevOpenvswitchGetMigrateData(char **migrate, const char
*ifname)
virCommandPtr cmd = NULL;
int ret = -1;
- cmd = virCommandNewArgList(OVSVSCTL, "--timeout=5", "get",
"Interface",
+ cmd = virCommandNewArgList(OVSVSCTL, "--timeout=5",
"--if-exists", "get", "Interface",
ifname, "external_ids:PortData", NULL);
virCommandSetOutputBuffer(cmd, migrate);
@@ -241,6 +244,12 @@ int virNetDevOpenvswitchSetMigrateData(char *migrate, const char
*ifname)
virCommandPtr cmd = NULL;
int ret = -1;
+ if (!migrate) {
+ VIR_DEBUG("No port data for interface %s", ifname);
+ return 0;
+ }
+
cmd = virCommandNewArgList(OVSVSCTL, "--timeout=5", "set",
"Interface", ifname, NULL);
virCommandAddArgFormat(cmd, "external_ids:PortData=%s", migrate);
--
1.7.12.4