Re: [libvirt] [PATCH 4/5] libvirtd: Alter refcnt processing for server program objects
On Tue, Nov 07, 2017 at 09:39:55PM -0500, John Ferlan wrote:
Instead of holding onto the reference for each program added to
a NetServer, let's Unref the program reference as soon as the
attempt is made to add to the @srv->programs list. This then
allows the virNetServerDispose to handle the final Unref of
the object for actual deletion and cleans up the cleanup: path.
Signed-off-by: John Ferlan <jferlan(a)redhat.com>
---
daemon/libvirtd.c | 24 ++++++++++++++++--------
1 file changed, 16 insertions(+), 8 deletions(-)
diff --git a/daemon/libvirtd.c b/daemon/libvirtd.c
index 5c47e49d48..87c5b22710 100644
--- a/daemon/libvirtd.c
+++ b/daemon/libvirtd.c
@@ -1352,7 +1352,10 @@ int main(int argc, char **argv) {
ret = VIR_DAEMON_ERR_INIT;
goto cleanup;
}
- if (virNetServerAddProgram(srv, remoteProgram) < 0) {
+
+ rc = virNetServerAddProgram(srv, remoteProgram);
+ virObjectUnref(remoteProgram);
Again, why can't we drop the ref from the AddProgram, if we as the @srv mutex
owners got rescheduled and someone unreff'd @program before we inserted it to
the array (while holding mutex), we'd fail to ref a dangling pointer
consequently, so I don't see any added protection here and I think ^these hunks
are unnecessary, once we agree to drop virObjectRef from virNet<Foo>Add<Bar>
during the init phase.
+ if (rc < 0) {
ret = VIR_DAEMON_ERR_INIT;
goto cleanup;
}
@@ -1364,7 +1367,10 @@ int main(int argc, char **argv) {
ret = VIR_DAEMON_ERR_INIT;
goto cleanup;
}
- if (virNetServerAddProgram(srv, lxcProgram) < 0) {
+
+ rc = virNetServerAddProgram(srv, lxcProgram);
+ virObjectUnref(lxcProgram);
+ if (rc < 0) {
ret = VIR_DAEMON_ERR_INIT;
goto cleanup;
}
@@ -1376,7 +1382,10 @@ int main(int argc, char **argv) {
ret = VIR_DAEMON_ERR_INIT;
goto cleanup;
}
- if (virNetServerAddProgram(srv, qemuProgram) < 0) {
+
+ rc = virNetServerAddProgram(srv, qemuProgram);
+ virObjectUnref(qemuProgram);
+ if (rc < 0) {
ret = VIR_DAEMON_ERR_INIT;
goto cleanup;
}
@@ -1414,7 +1423,10 @@ int main(int argc, char **argv) {
ret = VIR_DAEMON_ERR_INIT;
goto cleanup;
}
- if (virNetServerAddProgram(srvAdm, adminProgram) < 0) {
+
+ rc = virNetServerAddProgram(srvAdm, adminProgram);
+ virObjectUnref(adminProgram);
+ if (rc < 0) {
ret = VIR_DAEMON_ERR_INIT;
goto cleanup;
}
@@ -1513,10 +1525,6 @@ int main(int argc, char **argv) {
cleanup:
virNetlinkEventServiceStopAll();
- virObjectUnref(remoteProgram);
- virObjectUnref(lxcProgram);
- virObjectUnref(qemuProgram);
- virObjectUnref(adminProgram);
This hunk would stay either way.
Erik