[lxc-devel] [PATCH 1/2] restore: Hoist handler to function level

[Tycho Andersen]

This commit is in preparation for the cgroups create work, since we will need
the handler in both the parent and the child. This commit also re-works how
errors are propagated to be less verbose.

Signed-off-by: Tycho Andersen <tycho.andersen at canonical.com>
---
 src/lxc/lxccontainer.c | 70 +++++++++++++++++++++++---------------------------
 1 file changed, 32 insertions(+), 38 deletions(-)

diff --git a/src/lxc/lxccontainer.c b/src/lxc/lxccontainer.c
index 4f90f35..7e3a6b2 100644
--- a/src/lxc/lxccontainer.c
+++ b/src/lxc/lxccontainer.c
@@ -3805,6 +3805,8 @@ static bool lxcapi_restore(struct lxc_container *c, char *directory, bool verbos
 	struct lxc_list *it;
 	struct lxc_rootfs *rootfs;
 	char pidfile[L_tmpnam];
+	struct lxc_handler *handler;
+	bool error = false;
 
 	if (!criu_ok(c))
 		return false;
@@ -3817,9 +3819,18 @@ static bool lxcapi_restore(struct lxc_container *c, char *directory, bool verbos
 	if (!tmpnam(pidfile))
 		return false;
 
+	handler = lxc_init(c->name, c->lxc_conf, c->config_path);
+	if (!handler)
+		return false;
+
+	if (!cgroup_init(handler)) {
+		ERROR("failed initing cgroups");
+		goto out_fini_handler;
+	}
+
 	pid = fork();
 	if (pid < 0)
-		return false;
+		goto out_fini_handler;
 
 	if (pid == 0) {
 		struct criu_opts os;
@@ -3858,30 +3869,22 @@ static bool lxcapi_restore(struct lxc_container *c, char *directory, bool verbos
 		exit(1);
 	} else {
 		int status;
-		struct lxc_handler *handler;
-		bool error = false;
 
 		pid_t w = waitpid(pid, &status, 0);
 
 		if (w == -1) {
 			perror("waitpid");
-			return false;
+			goto out_fini_handler;
 		}
 
-		handler = lxc_init(c->name, c->lxc_conf, c->config_path);
-		if (!handler)
-			return false;
-
 		if (WIFEXITED(status)) {
 			if (WEXITSTATUS(status)) {
-				error = true;
 				goto out_fini_handler;
 			}
 			else {
 				int netnr = 0, ret;
 				FILE *f = fopen(pidfile, "r");
 				if (!f) {
-					error = true;
 					perror("reading pidfile");
 					ERROR("couldn't read restore's init pidfile %s\n", pidfile);
 					goto out_fini_handler;
@@ -3890,71 +3893,62 @@ static bool lxcapi_restore(struct lxc_container *c, char *directory, bool verbos
 				ret = fscanf(f, "%d", (int*) &handler->pid);
 				fclose(f);
 				if (ret != 1) {
-					error = true;
 					ERROR("reading restore pid failed");
 					goto out_fini_handler;
 				}
 
-				if (!cgroup_init(handler)) {
-					error = true;
-					ERROR("failed initing cgroups");
-					goto out_fini_handler;
-				}
-
 				if (!cgroup_parse_existing_cgroups(handler)) {
-					ERROR("failed creating cgroups");
+					ERROR("failed creating groups");
 					goto out_fini_handler;
 				}
 
-				if (container_mem_lock(c)) {
-					error = true;
+				if (container_mem_lock(c))
 					goto out_fini_handler;
-				}
 
 				lxc_list_for_each(it, &c->lxc_conf->network) {
 					char eth[128], veth[128];
 					struct lxc_netdev *netdev = it->elem;
 
 					if (read_criu_file(directory, "veth", netnr, veth)) {
-						error = true;
-						goto out_unlock;
+						container_mem_unlock(c);
+						goto out_fini_handler;
 					}
+
 					if (read_criu_file(directory, "eth", netnr, eth)) {
-						error = true;
-						goto out_unlock;
+						container_mem_unlock(c);
+						goto out_fini_handler;
 					}
+
 					netdev->priv.veth_attr.pair = strdup(veth);
 					if (!netdev->priv.veth_attr.pair) {
-						error = true;
-						goto out_unlock;
+						container_mem_unlock(c);
+						goto out_fini_handler;
 					}
+
 					netnr++;
 				}
-out_unlock:
+
 				container_mem_unlock(c);
-				if (error)
-					goto out_fini_handler;
 
-				if (lxc_set_state(c->name, handler, RUNNING)) {
-					error = true;
+				if (lxc_set_state(c->name, handler, RUNNING))
 					goto out_fini_handler;
-				}
 			}
 		} else {
 			ERROR("CRIU was killed with signal %d\n", WTERMSIG(status));
-			error = true;
 			goto out_fini_handler;
 		}
 
 		if (lxc_poll(c->name, handler)) {
 			lxc_abort(c->name, handler);
-			return false;
+			goto out_fini_handler;
 		}
+	}
+
+	error = false;
 
 out_fini_handler:
-		lxc_fini(c->name, handler);
-		return !error;
-	}
+	lxc_fini(c->name, handler);
+	return !error;
 }
 
 static int lxcapi_attach_run_waitl(struct lxc_container *c, lxc_attach_options_t *options, const char *program, const char *arg, ...)
-- 
1.9.1