lxccontainer: improve do_lxcapi_create()

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>

src/lxc/conf.c

@@ -5568,15 +5568,8 @@ int userns_exec_mapped_root(const char *path, int path_fd,
 	if (pid < 0)
 		return log_error(-1, "Failed to create child process");
 
-	ret = lxc_wait_for_pid_status(pid);
-	if (ret < 0)
-		return syserror("Failed to wait on child process %d", pid);
-	if (WIFSIGNALED(ret))
-		return log_error(-1, "Child process %d terminated by signal %ld", pid, WTERMSIG(ret));
-	if (!WIFEXITED(ret))
-		return log_error(-1, "Child did not termiate correctly");
-	if (WEXITSTATUS(ret))
-		return log_error(-1, "Child terminated with error %ld", WEXITSTATUS(ret));
+	if (!wait_exited(pid))
+		return -1;
 
 	return 0;
 }

src/lxc/lxccontainer.c

@@ -1777,15 +1777,15 @@ static bool do_lxcapi_create(struct lxc_container *c, const char *t,
 	int partial_fd;
 	mode_t mask;
 	pid_t pid;
-	bool ret = false, rootfs_managed = true;
+	bool bret = false, rootfs_managed = true;
 
 	if (!c)
 		return false;
 
 	if (t) {
 		path_template = get_template_path(t);
 		if (!path_template)
-			return syserror_set(ENOENT, "Template \"%s\" not found", t);
+			return log_error(false, "Template \"%s\" not found", t);
 	}
 
 	/* If a template is passed in, and the rootfs already is defined in the
@@ -1794,15 +1794,16 @@ static bool do_lxcapi_create(struct lxc_container *c, const char *t,
 	 */
 	if (do_lxcapi_is_defined(c) && c->lxc_conf && c->lxc_conf->rootfs.path &&
 	    access(c->lxc_conf->rootfs.path, F_OK) == 0 && path_template)
-		return syserror_set(EEXIST, "Container \"%s\" already exists in \"%s\"", c->name, c->config_path);
+		return log_error(false, "Container \"%s\" already exists in \"%s\"",
+				 c->name, c->config_path);
 
 	if (!c->lxc_conf &&
 	    !do_lxcapi_load_config(c, lxc_global_config_value("lxc.default_config")))
-		return syserror_set(EINVAL, "Failed to load default configuration file %s",
-				    lxc_global_config_value("lxc.default_config"));
+		return log_error(false, "Failed to load default configuration file %s",
+				 lxc_global_config_value("lxc.default_config"));
 
 	if (!create_container_dir(c))
-		return syserror_set(EINVAL, "Failed to create container %s", c->name);
+		return log_error(false, "Failed to create container %s", c->name);
 
 	if (c->lxc_conf->rootfs.path)
 		rootfs_managed = false;
@@ -1817,13 +1818,16 @@ static bool do_lxcapi_create(struct lxc_container *c, const char *t,
 			ERROR("Failed to save initial config for \"%s\"", c->name);
 			goto out;
 		}
-		ret = true;
+
+		bret = true;
 		goto out;
 	}
 
 	/* Rootfs passed into configuration, but does not exist. */
-	if (c->lxc_conf->rootfs.path && access(c->lxc_conf->rootfs.path, F_OK) != 0)
+	if (c->lxc_conf->rootfs.path && access(c->lxc_conf->rootfs.path, F_OK) != 0) {
+		ERROR("The rootfs \"%s\" does not exist",  c->lxc_conf->rootfs.path);
 		goto out;
+	}
 
 	if (do_lxcapi_is_defined(c) && c->lxc_conf->rootfs.path && !path_template) {
 		/* Rootfs already existed, user just wanted to save the loaded
@@ -1832,14 +1836,16 @@ static bool do_lxcapi_create(struct lxc_container *c, const char *t,
 		if (!c->save_config(c, NULL))
 			ERROR("Failed to save initial config for \"%s\"", c->name);
 
-		ret = true;
+		bret = true;
 		goto out;
 	}
 
 	/* Mark that this container is being created */
 	partial_fd = create_partial(c);
-	if (partial_fd < 0)
+	if (partial_fd < 0) {
+		SYSERROR("Failed to mark container as being partially created");
 		goto out;
+	}
 
 	/* No need to get disk lock bc we have the partial lock. */
 
@@ -1881,7 +1887,7 @@ static bool do_lxcapi_create(struct lxc_container *c, const char *t,
 		_exit(EXIT_SUCCESS);
 	}
 
-	if (wait_for_pid(pid) != 0)
+	if (!wait_exited(pid))
 		goto out_unlock;
 
 	/* Reload config to get the rootfs. */
@@ -1906,14 +1912,14 @@ static bool do_lxcapi_create(struct lxc_container *c, const char *t,
 		}
 	}
 
-	ret = load_config_locked(c, c->configfile);
+	bret = load_config_locked(c, c->configfile);
 
 out_unlock:
 	umask(mask);
 	remove_partial(c, partial_fd);
 
 out:
-	if (!ret) {
+	if (!bret) {
 		bool reset_managed = c->lxc_conf->rootfs.managed;
 
 		/*
@@ -1926,7 +1932,7 @@ static bool do_lxcapi_create(struct lxc_container *c, const char *t,
 		c->lxc_conf->rootfs.managed = reset_managed;
 	}
 
-	return ret;
+	return bret;
 }
 
 static bool lxcapi_create(struct lxc_container *c, const char *t,

src/lxc/utils.c

@@ -329,6 +329,24 @@ int lxc_wait_for_pid_status(pid_t pid)
 	return status;
 }
 
+bool wait_exited(pid_t pid)
+{
+	int status;
+
+	status = lxc_wait_for_pid_status(pid);
+	if (status < 0)
+		return log_error(false, "Failed to reap on child process %d", pid);
+	if (WIFSIGNALED(status))
+		return log_error(false, "Child process %d terminated by signal %d", pid, WTERMSIG(status));
+	if (!WIFEXITED(status))
+		return log_error(false, "Child did not termiate correctly");
+	if (WEXITSTATUS(status))
+		return log_error(false, "Child terminated with error %d", WEXITSTATUS(status));
+
+	TRACE("Reaped child process %d", pid);
+	return true;
+}
+
 #ifdef HAVE_OPENSSL
 #include <openssl/evp.h>
 

src/lxc/utils.h

@@ -81,6 +81,7 @@ static inline void __auto_lxc_pclose__(struct lxc_popen_FILE **f)
 __hidden extern int wait_for_pid(pid_t pid);
 __hidden extern int lxc_wait_for_pid_status(pid_t pid);
 __hidden extern int wait_for_pidfd(int pidfd);
+__hidden extern bool wait_exited(pid_t pid);
 
 #if HAVE_OPENSSL
 __hidden extern int sha1sum_file(char *fnam, unsigned char *md_value, unsigned int *md_len);