[libvirt] [PATCH v2 18/24] virNetworkObjFindBy*: Return an reference to found object
Peter Krempa
pkrempa at redhat.com
Fri Mar 6 12:40:41 UTC 2015
On Fri, Mar 06, 2015 at 11:12:21 +0100, Michal Privoznik wrote:
> On 06.03.2015 10:23, Peter Krempa wrote:
> > On Thu, Mar 05, 2015 at 12:05:19 +0100, Michal Privoznik wrote:
> >> This patch turns both virNetworkObjFindByUUID() and
> >> virNetworkObjFindByName() to return an referenced object so that
> >> even if caller unlocks it, it's for sure that object won't
> >> disappear meanwhile. Especially if the object (in general) is
> >> locked and unlocked during the caller run.
> >> Moreover, this commit is nicely small, since the object unrefing
> >> can be done in virNetworkObjEndAPI().
> >>
> >> Signed-off-by: Michal Privoznik <mprivozn at redhat.com>
> >> ---
> >> src/conf/network_conf.c | 7 +++++--
> >> src/network/bridge_driver.c | 18 +++++-------------
> >> src/test/test_driver.c | 10 ++++------
> >> 3 files changed, 14 insertions(+), 21 deletions(-)
> >>
> >> diff --git a/src/conf/network_conf.c b/src/conf/network_conf.c
> >> index 7af303e..3d318ce 100644
> >> --- a/src/conf/network_conf.c
> >> +++ b/src/conf/network_conf.c
> >> @@ -137,6 +137,7 @@ virNetworkObjEndAPI(virNetworkObjPtr *net)
> >> return;
> >>
> >> virObjectUnlock(*net);
> >> + virObjectUnref(*net);
> >> *net = NULL;
> >> }
> >>
> >> @@ -164,6 +165,7 @@ virNetworkObjFindByUUIDLocked(virNetworkObjListPtr nets,
> >> virObjectLock(nets->objs[i]);
> >> if (!memcmp(nets->objs[i]->def->uuid, uuid, VIR_UUID_BUFLEN)) {
> >> ret = nets->objs[i];
> >> + virObjectRef(ret);
> >> break;
> >> }
> >> virObjectUnlock(nets->objs[i]);
> >> @@ -194,6 +196,7 @@ virNetworkObjFindByNameLocked(virNetworkObjListPtr nets,
> >> virObjectLock(nets->objs[i]);
> >> if (STREQ(nets->objs[i]->def->name, name)) {
> >> ret = nets->objs[i];
> >> + virObjectRef(ret);
> >> break;
> >> }
> >> virObjectUnlock(nets->objs[i]);
> >> @@ -491,13 +494,13 @@ virNetworkAssignDef(virNetworkObjListPtr nets,
> >>
> >> network->def = def;
> >> network->persistent = !live;
> >> + virObjectRef(network);
> >> virObjectUnlock(nets);
> >> return network;
> >>
> >> error:
> >> virObjectUnlock(nets);
> >> - virObjectUnlock(network);
> >> - virObjectUnref(network);
> >> + virNetworkObjEndAPI(&network);
> >> return NULL;
> >>
> >> }
> >> diff --git a/src/network/bridge_driver.c b/src/network/bridge_driver.c
> >> index 8501603..d3f3f4a 100644
> >> --- a/src/network/bridge_driver.c
> >> +++ b/src/network/bridge_driver.c
> >> @@ -2939,7 +2939,6 @@ static virNetworkPtr networkCreateXML(virConnectPtr conn, const char *xml)
> >> if (networkStartNetwork(network) < 0) {
> >> virNetworkRemoveInactive(driver->networks,
> >> network);
> >> - network = NULL;
> >> goto cleanup;
> >> }
> >>
> >> @@ -2988,7 +2987,6 @@ static virNetworkPtr networkDefineXML(virConnectPtr conn, const char *xml)
> >> if (virNetworkSaveConfig(driver->networkConfigDir, def) < 0) {
> >> if (!virNetworkObjIsActive(network)) {
> >> virNetworkRemoveInactive(driver->networks, network);
> >
> > As virNetworkRemoveInactive() now doesn't free the object due to the
> > existing reference, but unlocks it ...
> >
> >> - network = NULL;
> >
> > ... and you don't invalidate the pointer, you'd touch the unlocked
> > object in virNetworkObjEndAPI() and try to unlock it once more.
> >
> >> goto cleanup;
> >> }
> >> /* if network was active already, just undo new persistent
> >
> > NACK, virNetworkRemoveInactive needs to be fixed first.
>
> Correct. Nice catch! Would I make you reconsider NACK if I squash this
> into this commit?
>
> diff --git a/src/conf/network_conf.c b/src/conf/network_conf.c
> index 3d318ce..20a257b 100644
> --- a/src/conf/network_conf.c
> +++ b/src/conf/network_conf.c
> @@ -668,17 +668,18 @@ void virNetworkRemoveInactive(virNetworkObjListPtr
> nets,
> {
> size_t i;
>
> + /* It's not needed to reference the @net as we are called
> + * from an API which surely already has at least one
> + * reference to the object. */
> virObjectUnlock(net);
> virObjectLock(nets);
> + virObjectLock(net);
> for (i = 0; i < nets->count; i++) {
> - virObjectLock(nets->objs[i]);
> if (nets->objs[i] == net) {
> VIR_DELETE_ELEMENT(nets->objs, i, nets->count);
> - virObjectUnlock(net);
> virObjectUnref(net);
> break;
> }
> - virObjectUnlock(nets->objs[i]);
> }
> virObjectUnlock(nets);
> }
Fair enough. ACK with the above fixup.
Peter
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