OVS lib deferred apply cannot handle concurrency

[Édouard Thuleau]

OVS lib propose a deferred apply methods to save system calls to 'ovs-ofctl' binaries ('ovs-ofctl' can apply flow from file or stdin if file is '-').

This method use a dict for 'add', mod' or 'del' flow actions that contain a concatenated string flows. This dict is purge after all flows are applied at the end of 'deferred_apply_off' method.
If another call is made on that dict during the 'deferred_apply_off', some flows could be deleted a the end when they have not been applied.

I can see that on ML2 plugin with l2-pop mechanism driver. If I delete more than one port at a time, some flooding flow rules could be not deleted on the br-tun bridge.

[Yves-Gwenael Bourhis (yves-gwenael-bourhis)]

Fix proposed to branch: master
Review: https://review.openstack.org/63917

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/havana
Review: https://review.openstack.org/84966

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/63917
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=501213686886baccd3280e10b8856a25d3517519
Submitter: Jenkins
Branch: master

commit 501213686886baccd3280e10b8856a25d3517519
Author: Édouard Thuleau <email address hidden>
Date: Mon Mar 3 18:08:33 2014 +0100

    OVS lib defer apply doesn't handle concurrency

    The OVS lib deferred apply methods use a dict to save flows to add,
    modify or delete when deffered apply is switched off.
    If another thread adds, modifies or deletes flows on that dict during
    another process called deffered_apply_off, its flows could be ignored.

    This fix stash reference flows list and point the flows list to a new
    cleared flows list. Then, it applies flows from the stashed flows list.

    Closes-bug: #1263866
    Change-Id: Ia3c6ce181e1599d1474da7eb944feff7d84f1d73

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/icehouse
Review: https://review.openstack.org/94250

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/havana
Review: https://review.openstack.org/94253

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/94250
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=efa4f2895f739ba191cfdd8dbe35e37fbead06c4
Submitter: Jenkins
Branch: stable/icehouse

commit efa4f2895f739ba191cfdd8dbe35e37fbead06c4
Author: Édouard Thuleau <email address hidden>
Date: Mon Mar 3 18:08:33 2014 +0100

    OVS lib defer apply doesn't handle concurrency

    The OVS lib deferred apply methods use a dict to save flows to add,
    modify or delete when deffered apply is switched off.
    If another thread adds, modifies or deletes flows on that dict during
    another process called deffered_apply_off, its flows could be ignored.

    This fix stash reference flows list and point the flows list to a new
    cleared flows list. Then, it applies flows from the stashed flows list.

    Closes-bug: #1263866
    Change-Id: Ia3c6ce181e1599d1474da7eb944feff7d84f1d73
    (cherry picked from commit 501213686886baccd3280e10b8856a25d3517519)

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/94253
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=ff973b6d754846694569f4d402cf38034a9a1e0f
Submitter: Jenkins
Branch: stable/havana

commit ff973b6d754846694569f4d402cf38034a9a1e0f
Author: Édouard Thuleau <email address hidden>
Date: Mon Mar 3 18:08:33 2014 +0100

    OVS lib defer apply doesn't handle concurrency

    The OVS lib deferred apply methods use a dict to save flows to add,
    modify or delete when deffered apply is switched off.
    If another thread adds, modifies or deletes flows on that dict during
    another process called deffered_apply_off, its flows could be ignored.

    This fix stash reference flows list and point the flows list to a new
    cleared flows list. Then, it applies flows from the stashed flows list.

    Closes-bug: #1263866
    (cherry picked from commit 501213686886baccd3280e10b8856a25d3517519)

    Conflicts:
     neutron/tests/unit/agent/linux/test_ovs_lib.py

    Change-Id: I3b22c7ec055934d7f30067924c7a7fd71b2f6081

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/77578
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=990d596ec09242733f8bc3669b70136ca6741d6e
Submitter: Jenkins
Branch: master

commit 990d596ec09242733f8bc3669b70136ca6741d6e
Author: cedric.brandily <email address hidden>
Date: Fri May 16 16:18:45 2014 -0400

    OVS flows apply concurrently using a deferred OVSBridge

    This change is an improvement of the commit
    501213686886baccd3280e10b8856a25d3517519 and provides a cleaner
    implementation. Previously flows were applied on
    OVSBridge.defer_apply_off which could be called by an other
    greenthread: it was impossible to ensure that all flows are applied
    in a unique OVSBridge.defer_apply_off call. This change ensures that
    all flows defined using a DeferredOVSBridge are applied on
    DeferredOVSBridge.apply_flows or DeferredOVSBridge.__exit__ if not
    exception is raised.

    Author: Cedric Brandily <email address hidden>
    Co-Authored-By: Edouard Thuleau <email address hidden>

    Related-bug: #1263866
    Change-Id: I1f260629ef95b98ee80e2ff946c3606da8fe7608