vfio/container: reform vfio_container_connect cleanup

Replace the proliferation of exit labels in vfio_container_connect with
conditionals for cleaning each piece of state.  No functional change.

Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Reviewed-by: Cedric Le Goater <clg@redhat.com>
Link: https://lore.kernel.org/qemu-devel/1746195760-101443-3-git-send-email-steven.sistare@oracle.com
[ clg: vfio_attach_discard_disable() -> vfio_container_attach_discard_disable() ]
Signed-off-by: Cédric Le Goater <clg@redhat.com>

hw/vfio/container.c

@@ -563,9 +563,12 @@ static bool vfio_container_connect(VFIOGroup *group, AddressSpace *as,
 {
     VFIOContainer *container;
     VFIOContainerBase *bcontainer;
-    int ret, fd;
+    int ret, fd = -1;
     VFIOAddressSpace *space;
-    VFIOIOMMUClass *vioc;
+    VFIOIOMMUClass *vioc = NULL;
+    bool new_container = false;
+    bool group_was_added = false;
+    bool discard_disabled = false;
 
     space = vfio_address_space_get(as);
 
@@ -584,35 +587,37 @@ static bool vfio_container_connect(VFIOGroup *group, AddressSpace *as,
 
     fd = qemu_open("/dev/vfio/vfio", O_RDWR, errp);
     if (fd < 0) {
-        goto put_space_exit;
+        goto fail;
     }
 
     ret = ioctl(fd, VFIO_GET_API_VERSION);
     if (ret != VFIO_API_VERSION) {
         error_setg(errp, "supported vfio version: %d, "
                    "reported version: %d", VFIO_API_VERSION, ret);
-        goto close_fd_exit;
+        goto fail;
     }
 
     container = vfio_create_container(fd, group, errp);
     if (!container) {
-        goto close_fd_exit;
+        goto fail;
     }
+    new_container = true;
     bcontainer = &container->bcontainer;
 
     if (!vfio_cpr_register_container(bcontainer, errp)) {
-        goto free_container_exit;
+        goto fail;
     }
 
     if (!vfio_container_attach_discard_disable(container, group, errp)) {
-        goto unregister_container_exit;
+        goto fail;
     }
+    discard_disabled = true;
 
     vioc = VFIO_IOMMU_GET_CLASS(bcontainer);
     assert(vioc->setup);
 
     if (!vioc->setup(bcontainer, errp)) {
-        goto enable_discards_exit;
+        goto fail;
     }
 
     vfio_group_add_kvm_device(group);
@@ -621,35 +626,36 @@ static bool vfio_container_connect(VFIOGroup *group, AddressSpace *as,
 
     group->container = container;
     QLIST_INSERT_HEAD(&container->group_list, group, container_next);
+    group_was_added = true;
 
     if (!vfio_listener_register(bcontainer, errp)) {
-        goto listener_release_exit;
+        goto fail;
     }
 
     bcontainer->initialized = true;
 
     return true;
-listener_release_exit:
-    QLIST_REMOVE(group, container_next);
-    vfio_group_del_kvm_device(group);
+
+fail:
     vfio_listener_unregister(bcontainer);
-    if (vioc->release) {
+
+    if (group_was_added) {
+        QLIST_REMOVE(group, container_next);
+        vfio_group_del_kvm_device(group);
+    }
+    if (vioc && vioc->release) {
         vioc->release(bcontainer);
     }
-
-enable_discards_exit:
-    vfio_ram_block_discard_disable(container, false);
-
-unregister_container_exit:
-    vfio_cpr_unregister_container(bcontainer);
-
-free_container_exit:
-    object_unref(container);
-
-close_fd_exit:
-    close(fd);
-
-put_space_exit:
+    if (discard_disabled) {
+        vfio_ram_block_discard_disable(container, false);
+    }
+    if (new_container) {
+        vfio_cpr_unregister_container(bcontainer);
+        object_unref(container);
+    }
+    if (fd >= 0) {
+        close(fd);
+    }
     vfio_address_space_put(space);
 
     return false;