OVS internal ports with veth create infinite port add loop

Issue

OVS internal ports with veth create infinite port add loop

Version-Release number of OVS for the test:
openvswitch-2.5.0-14.git20160727.el7fdp.x86_64

How to reproduce this issue (note: TYPE=OVSIntPort and the veth part):

[root@overcloud-compute-0 network-scripts]# cat ifcfg-eth3
NAME=eth3
ONBOOT=yes
NETBOOT=yes
BOOTPROTO=static
DEVICE=eth3
DEVICETYPE=ovs
TYPE=OVSPort
OVS_OPTIONS="vlan_mode=native-untagged tag=1"
OVS_BRIDGE=br-eth3
MTU=9000
[root@overcloud-compute-0 network-scripts]# cat ifcfg-br-eth3
DEVICE=br-eth3
ONBOOT=yes
DEVICETYPE=ovs
TYPE=OVSBridge
HOTPLUG=no
USERCTL=no
[root@overcloud-compute-0 network-scripts]# cat ifcfg-mgmt0-lldp
DEVICE=eth3_ll1
ONBOOT=yes
DEVICETYPE=ovs
TYPE=OVSIntPort
OVS_BRIDGE=br-eth3
HOTPLUG=no
USERCTL=no
BOOTPROTO=static
MTU=9000
OVS_EXTRA="set bridge br-eth3 other-config:forward-bpdu=true"

Run manually

ip link add name eth3_ll1 type veth peer name eth3_ll2

Run

ifup br-eth3
ifup eth3
ifup mgmt0-lldp
ip link set dev eth3_ll2 up

The moment eth3_ll2 comes up, the following happens - this happens as
soon as one brings up the opposite end of the veth port:

[root@overcloud-compute-0 ~]# tail -f /var/log/openvswitch/ovs-vswitchd.log &
[1] 929479
[root@overcloud-compute-0 ~]#
2017-05-15T19:00:16.021Z|17950|bridge|INFO|bridge br-eth3: added
interface eth3_ll1 on port 17374
2017-05-15T19:00:16.027Z|17951|bridge|INFO|bridge br-eth3: added
interface eth3_ll1 on port 17375
2017-05-15T19:00:16.034Z|17952|bridge|INFO|bridge br-eth3: added
interface eth3_ll1 on port 17376
2017-05-15T19:00:16.042Z|17953|bridge|INFO|bridge br-eth3: added
interface eth3_ll1 on port 17377
2017-05-15T19:00:16.052Z|17954|bridge|INFO|bridge br-eth3: added
interface eth3_ll1 on port 17378
2017-05-15T19:00:16.060Z|17955|bridge|INFO|bridge br-eth3: added
interface eth3_ll1 on port 17379
2017-05-15T19:00:16.068Z|17956|bridge|INFO|bridge br-eth3: added
interface eth3_ll1 on port 17380
2017-05-15T19:00:16.074Z|17957|bridge|INFO|bridge br-eth3: added
interface eth3_ll1 on port 17381
2017-05-15T19:00:16.083Z|17958|bridge|INFO|bridge br-eth3: added
interface eth3_ll1 on port 17382
2017-05-15T19:00:16.092Z|17959|bridge|INFO|bridge br-eth3: added
interface eth3_ll1 on port 17383

[root@overcloud-compute-0 ~]#
(reverse-i-search)`id': journalctl | egrep 'eth3|mgmt0' | grep br^Cge
[root@overcloud-compute-0 ~]# ^C
[root@overcloud-compute-0 ~]# ifup mgmt0-lldp
2017-05-15T19:00:40.662Z|17960|dpif|WARN|Dropped 32 log messages in
last 25 seconds (most recently, 25 seconds ago) due to excessive rate
2017-05-15T19:00:40.662Z|17961|dpif|WARN|system@ovs-system: failed to
add eth3_ll1 as port: File exists
ovs-vsctl: Error detected while setting up 'eth3_ll1'.  See
ovs-vswitchd log for details.
2017-05-15T19:00:40.922Z|17962|dpif|WARN|system@ovs-system: failed to
add eth3_ll1 as port: File exists
[root@overcloud-compute-0 ~]#
[root@overcloud-compute-0 ~]#
[root@overcloud-compute-0 ~]#
[root@overcloud-compute-0 ~]# ip link ls | grep ll
28: eth3_ll2@eth3_ll1: <BROADCAST,MULTICAST> mtu 1500 qdisc noqueue
state DOWN mode DEFAULT qlen 1000
29: eth3_ll1@eth3_ll2: <NO-CARRIER,BROADCAST,MULTICAST,UP,M-DOWN> mtu
9000 qdisc noqueue state LOWERLAYERDOWN mode DEFAULT qlen 1000
[root@overcloud-compute-0 ~]# ip link set dev eth3_ll2 up
[root@overcloud-compute-0 ~]#
2017-05-15T19:00:56.849Z|17963|dpif|WARN|system@ovs-system: failed to
add eth3_ll1 as port: File exists
2017-05-15T19:00:56.851Z|17964|bridge|INFO|bridge br-eth3: added
interface eth3_ll1 on port 17384
2017-05-15T19:00:56.854Z|17965|dpif|WARN|system@ovs-system: failed to
add eth3_ll1 as port: File exists
2017-05-15T19:00:56.856Z|17966|bridge|INFO|bridge br-eth3: added
interface eth3_ll1 on port 17385
2017-05-15T19:00:56.859Z|17967|dpif|WARN|system@ovs-system: failed to
add eth3_ll1 as port: File exists
2017-05-15T19:00:56.861Z|17968|bridge|INFO|bridge br-eth3: added
interface eth3_ll1 on port 17386
2017-05-15T19:00:56.864Z|17969|dpif|WARN|system@ovs-system: failed to
add eth3_ll1 as port: File exists
2017-05-15T19:00:56.866Z|17970|bridge|INFO|bridge br-eth3: added
interface eth3_ll1 on port 17387
2017-05-15T19:00:56.869Z|17971|dpif|WARN|system@ovs-system: failed to
add eth3_ll1 as port: File exists
2017-05-15T19:00:56.873Z|17972|bridge|INFO|bridge br-eth3: added
interface eth3_ll1 on port 17388
2017-05-15T19:00:56.877Z|17973|dpif|WARN|system@ovs-system: failed to
add eth3_ll1 as port: File exists
2017-05-15T19:00:56.880Z|17974|bridge|INFO|bridge br-eth3: added
interface eth3_ll1 on port 17389

Note that the issue does not occur when one switches the port to a
non-internal port type TYPE=OVSPort

[root@overcloud-compute-0 ~]# cat
/etc/sysconfig/network-scripts/ifcfg-mgmt0-lldp
DEVICE=eth3_ll1
ONBOOT=yes
DEVICETYPE=ovs
TYPE=OVSPort
OVS_BRIDGE=br-eth3
HOTPLUG=no
USERCTL=no
BOOTPROTO=static
MTU=9000
OVS_EXTRA="set bridge br-eth3 other-config:forward-bpdu=true"

[root@overcloud-compute-0 ~]# ovs-vsctl show | grep br-eth3 -A7
    Bridge "br-eth3"
        Port "eth3"
            tag: 1
            Interface "eth3"
        Port "eth3_ll1"
            Interface "eth3_ll1"
        Port "br-eth3"
            Interface "br-eth3"
                type: internal
    Bridge br-ex
        Controller "tcp:127.0.0.1:6633"
            is_connected: true
        fail_mode: secure
        Port "vlan902"
            tag: 902

[root@overcloud-compute-0 ~]# ifup br-eth3
ifu2017-05-15T19:03:49.036Z|30270|bridge|INFO|bridge br-eth3: added
interface br-eth3 on port 65534
2017-05-15T19:03:49.036Z|30271|bridge|INFO|bridge br-eth3: using
datapath ID 0000c2b7b41b0947
2017-05-15T19:03:49.036Z|30272|connmgr|INFO|br-eth3: added service
controller "punix:/var/run/openvswitch/br-eth3.mgmt"
p br-eth[root@overcloud-compute-0 ~]# ifup eth3

2017-05-15T19:03:54.990Z|30273|bridge|INFO|bridge br-eth3: added
interface eth3 on port 1
[root@overcloud-compute-0 ~]#
[root@overcloud-compute-0 ~]#
[root@overcloud-compute-0 ~]#
[root@overcloud-compute-0 ~]# ifup mgmt0-lldp
2017-05-15T19:04:02.071Z|30274|bridge|INFO|bridge br-eth3: added
interface eth3_ll1 on port 2
[root@overcloud-compute-0 ~]#
[root@overcloud-compute-0 ~]#
[root@overcloud-compute-0 ~]# ip link ls | grep ll
28: eth3_ll2@eth3_ll1: <BROADCAST,MULTICAST> mtu 1500 qdisc noqueue
state DOWN mode DEFAULT qlen 1000
29: eth3_ll1@eth3_ll2: <NO-CARRIER,BROADCAST,MULTICAST,UP,M-DOWN> mtu
9000 qdisc noqueue master ovs-system state LOWERLAYERDOWN mode DEFAULT
qlen 1000
[root@overcloud-compute-0 ~]# ip link set dev eth3_ll2 up
[root@overcloud-compute-0 ~]# ip link ls | grep ll
28: eth3_ll2@eth3_ll1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500
qdisc noqueue state UP mode DEFAULT qlen 1000
29: eth3_ll1@eth3_ll2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 9000
qdisc noqueue master ovs-system state UP mode DEFAULT qlen 1000

About the difference between OVSPort and OVSIntPort

        OVSPort)
                ifup_ovs_bridge
                ${OTHERSCRIPT} ${CONFIG} ${2}
                # The port might be already in the database but not yet
                # in the datapath.  So, remove the stale interface first.
                ovs-vsctl -t ${TIMEOUT} \
                        -- --if-exists del-port "$OVS_BRIDGE" "$DEVICE" \
                        -- add-port "$OVS_BRIDGE" "$DEVICE"
$OVS_OPTIONS ${OVS_EXTRA+-- $OVS_EXTRA}
                OVSINTF=${DEVICE} /sbin/ifup "$OVS_BRIDGE"
                ;;
        OVSIntPort)
                ifup_ovs_bridge
                ovs-vsctl -t ${TIMEOUT} \
                        -- --if-exists del-port "$OVS_BRIDGE" "$DEVICE" \
                        -- add-port "$OVS_BRIDGE" "$DEVICE" $OVS_OPTIONS \
                        -- set Interface "$DEVICE" type=internal
${OVS_EXTRA+-- $OVS_EXTRA}
                if [ -n "${OVSDHCPINTERFACES}" ]; then
                        for _iface in ${OVSDHCPINTERFACES}; do
                                /sbin/ifup ${_iface}
                        done
                fi
                BOOTPROTO="${OVSBOOTPROTO}" ${OTHERSCRIPT} ${CONFIG} ${2}
                ;;