Re: [libvirt] [PATCH] libxl: unref objects in error paths

On 24.02.2016 23:55, Jim Fehlig wrote: > libxlMakeNic opens a virConnect object and takes a reference on a > virNetwork object, but doesn't drop the references on all error > paths. Rework the function to follow the standard libvirt pattern > of using a local 'ret' variable to hold the function return value, > performing all cleanup and returning 'ret' at a 'cleanup' label. > > Signed-off-by: Jim Fehlig <jfehlig(a)suse.com&gt; > --- > > I noticed these leaks while trying to rework the code to use a > common virConnect object. That task has turned into quite an > effort [1], but in the meantime the leaks in the current code > should be plugged. > > [1] https://www.redhat.com/archives/libvir-list/2016-February/msg01188.html > > src/libxl/libxl_conf.c | 57 ++++++++++++++++++++++++-------------------------- > 1 file changed, 27 insertions(+), 30 deletions(-) > > diff --git a/src/libxl/libxl_conf.c b/src/libxl/libxl_conf.c > index b20df29..763f4c5 100644 > --- a/src/libxl/libxl_conf.c > +++ b/src/libxl/libxl_conf.c > @@ -1286,7 +1286,11 @@ libxlMakeNic(virDomainDefPtr def, > { > bool ioemu_nic = def->os.type == VIR_DOMAIN_OSTYPE_HVM; > virDomainNetType actual_type = virDomainNetGetActualType(l_nic); > + char *brname = NULL; > + virNetworkPtr network = NULL; > + virConnectPtr conn = NULL; > virNetDevBandwidthPtr actual_bw; > + int ret = -1; > > /* TODO: Where is mtu stored? > * > @@ -1312,64 +1316,50 @@ libxlMakeNic(virDomainDefPtr def, > > if (l_nic->model) { > if (VIR_STRDUP(x_nic->model, l_nic->model) < 0) > - return -1; > + goto cleanup; > if (STREQ(l_nic->model, "netfront")) > x_nic->nictype = LIBXL_NIC_TYPE_VIF; > } > > if (VIR_STRDUP(x_nic->ifname, l_nic->ifname) < 0) > - return -1; > + goto cleanup; > > switch (actual_type) { > case VIR_DOMAIN_NET_TYPE_BRIDGE: > if (VIR_STRDUP(x_nic->bridge, > virDomainNetGetActualBridgeName(l_nic)) < 0) > - return -1; > + goto cleanup; > /* fallthrough */ > case VIR_DOMAIN_NET_TYPE_ETHERNET: > if (VIR_STRDUP(x_nic->script, l_nic->script) < 0) > - return -1; > + goto cleanup; > if (l_nic->nips > 0) { > x_nic->ip = virSocketAddrFormat(&l_nic->ips[0]->address); > if (!x_nic->ip) > - return -1; > + goto cleanup; > } > break; > case VIR_DOMAIN_NET_TYPE_NETWORK: > { > - bool fail = false; > - char *brname = NULL; > - virNetworkPtr network; > - virConnectPtr conn; > - > if (!(conn = virConnectOpen("xen:///system"))) > - return -1; > + goto cleanup; > > if (!(network = > virNetworkLookupByName(conn, l_nic->data.network.name))) { > - virObjectUnref(conn); > - return -1; > + goto cleanup; > } > > if (l_nic->nips > 0) { > x_nic->ip = virSocketAddrFormat(&l_nic->ips[0]->address); > if (!x_nic->ip) > - return -1; > + goto cleanup; > } > > - if ((brname = virNetworkGetBridgeName(network))) { > - if (VIR_STRDUP(x_nic->bridge, brname) < 0) > - fail = true; > - } else { > - fail = true; > - } > - > - VIR_FREE(brname); > + if (!(brname = virNetworkGetBridgeName(network))) > + goto cleanup; > > - virObjectUnref(network); > - virObjectUnref(conn); > - if (fail) > - return -1; > + if (VIR_STRDUP(x_nic->bridge, brname) < 0) > + goto cleanup; How about switching pointers instead of yet another strdup?

x_nic->bridge = brname; brname = NULL; And as Joao already pointed out, the indentation of 'goto' is a bit off. Otherwise looking good. ACK and safe for the freeze.