nova coverage create lots empty folders even with coverage extension disabled

[zhu zhu]

with nova coverage extenstion disabled as a default behavior, we noticed that a lot of empty folders is created under /tmp folder. And also with each time the nova service reboot, it will create new directory with name like nova_coverage_*. WIth time go by, there will be nubmer of the empty folders accumulated.
 It is expected that no folder will be created when user is not triggering nova coverage-start.

[zhu@oc6577483446 tmp]$ ls|grep -i nova-coverage
nova-coverage_29dgT1
nova-coverage_2JGlhm
nova-coverage_3Ej4gX
nova-coverage_4AKucJ
nova-coverage_5NHeSp
nova-coverage_5Xs2PX
nova-coverage_6aX6ZQ
nova-coverage_6hYJH9
nova-coverage_9LP_qK
nova-coverage_9xV_Kx
nova-coverage_AbREq9
nova-coverage_bm1Txh
nova-coverage_BPEEIV
nova-coverage_BYQqqs
nova-coverage_bzBCBK
nova-coverage_d6ECdf
nova-coverage_DDfA7V
nova-coverage_DFJ2mw
nova-coverage_doofU8
nova-coverage_EALSBX
nova-coverage_FoFvNk
nova-coverage_FPkb3e
nova-coverage_fTs83X
nova-coverage_h8dCkH
nova-coverage_icQkDp
nova-coverage__ieixY
nova-coverage_iraOfI
nova-coverage_ixtqEK
nova-coverage_j0nh4y
nova-coverage_JbVKk8
nova-coverage_M86NW4
nova-coverage_MHZQg2
nova-coverage_NDRbNw
nova-coverage_NEjCOM
nova-coverage_nEN3v3
nova-coverage_NPr_2z
nova-coverage_oIln31
nova-coverage__pNnUH
nova-coverage_q6hIL0
nova-coverage_qG7rwo
nova-coverage_Qw74oZ
nova-coverage_rlMcZa
nova-coverage_Rrs1gU
nova-coverage_s49_WJ
nova-coverage_sMwMSa
nova-coverage_tO1vXH
nova-coverage_TS0RBa
nova-coverage_U0bvDh
nova-coverage_UUGtv2
nova-coverage_V97Zt8
nova-coverage_vD_5cr
nova-coverage_vJv1uF
nova-coverage_wHw9NI
nova-coverage_Y5QJf4
nova-coverage_yDd_ml
nova-coverage_YiUEgY
nova-coverage_yQqYOD
nova-coverage_YwVSJl

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/27046

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/27049

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/27049
Committed: http://github.com/openstack/nova/commit/b6e072a84a31eca1f7d7c44117327c5042e153c2
Submitter: Jenkins
Branch: master

commit b6e072a84a31eca1f7d7c44117327c5042e153c2
Author: Yang Yu <email address hidden>
Date: Wed Apr 17 18:11:02 2013 +0800

    nova coverage creates lots of empty folders

    With nova coverage extension disabled as a default behaviour,
    nova will create lots of empty folders under /tmp folder. And also
    with each time the nova service reboot, it will create a new
    directory with name like nova_coverage_*. There will be number of
    the empty folders accumulated.

    Patch-Set 3: Rebase for merging code
    Fixes: bug 1169005

    Change-Id: I26d1037eb66d781ac6ef6b600cca04a709bff3f7

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/grizzly
Review: https://review.openstack.org/28180

[zhu zhu (zhuzhubj)]

I will be out of the office starting 04/28/2013 and will not return until
05/06/2013.

I will on vacation from 4/29 to 5/3 and will return to office on 5/6. I
will check note periodically during the vacation.

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/28180
Committed: http://github.com/openstack/nova/commit/5094e837b513c785021a56d0f4b7af269440f66e
Submitter: Jenkins
Branch: stable/grizzly

commit 5094e837b513c785021a56d0f4b7af269440f66e
Author: Yang Yu <email address hidden>
Date: Wed Apr 17 18:11:02 2013 +0800

    nova coverage creates lots of empty folders

    With nova coverage extension disabled as a default behaviour,
    nova will create lots of empty folders under /tmp folder. And also
    with each time the nova service reboot, it will create a new
    directory with name like nova_coverage_*. There will be number of
    the empty folders accumulated.

    Patch-Set 3: Rebase for merging code
    Fixes: bug 1169005

    Conflicts:
     nova/api/openstack/compute/contrib/coverage_ext.py

    Change-Id: I26d1037eb66d781ac6ef6b600cca04a709bff3f7
    (cherry picked from commit b6e072a84a31eca1f7d7c44117327c5042e153c2)