Re: [libvirt] [PATCH 16/17] nwfilter: Remove recursive locking for nwfilter instantiation

The current algorithm required usage of recursive locks because there was no other mechanism available to ensure that the object wasn't deleted whilst the instantiation was taking place. Now that we have object references, lets use those to ensure the object isn't deleted whilst we're working through the instantiation thus removing the need for recursive locks. Signed-off-by: John Ferlan <jferlan(a)redhat.com&gt; --- src/conf/virnwfilterobj.c | 13 +++++++++-- src/nwfilter/nwfilter_gentech_driver.c | 40 +++++++++++++++++++--------------- 2 files changed, 34 insertions(+), 19 deletions(-) diff --git a/src/conf/virnwfilterobj.c b/src/conf/virnwfilterobj.c index 84ef7d1..ea1323d 100644 --- a/src/conf/virnwfilterobj.c +++ b/src/conf/virnwfilterobj.c @@ -303,13 +303,22 @@ virNWFilterObjListFindByName(virNWFilterObjListPtr nwfilters, } +/** + * To avoid the need to have recursive locks as a result of how the + * virNWFilterInstantiateFilter processing works, this API will not + * lock the returned object, instead just increase the refcnt of the + * object to the caller to allow the caller to handle. + */ virNWFilterObjPtr virNWFilterObjListFindInstantiateFilter(virNWFilterObjListPtr nwfilters, const char *filtername) { virNWFilterObjPtr obj; - if (!(obj = virNWFilterObjListFindByName(nwfilters, filtername))) { + virObjectLock(nwfilters); + obj = virNWFilterObjListFindByNameLocked(nwfilters, filtername); + virObjectUnlock(nwfilters); + if (!obj) { virReportError(VIR_ERR_INTERNAL_ERROR, _("referenced filter '%s' is missing"), filtername); return NULL; @@ -318,7 +327,7 @@ virNWFilterObjListFindInstantiateFilter(virNWFilterObjListPtr nwfilters, if (virNWFilterObjWantRemoved(obj)) { virReportError(VIR_ERR_NO_NWFILTER, _("Filter '%s' is in use."), filtername); - virNWFilterObjEndAPI(&obj); + virNWFilterObjUnref(obj); return NULL; }