remove checkpoint / restart code

The checkpoint / restart code is too experimental regarding
the current implementation in the kernel.
As there are several implementation and we don't know which
one will be merged upstream, I remove the code and add a few
parameters to checkpoint.

The checkpoint/restart function will be plugins in order to choose
the CR solutions. This approach will allow to switch from one
implementation to another without breaking anything.

Signed-off-by: Daniel Lezcano <dlezcano@fr.ibm.com>

src/lxc/arguments.h

@@ -45,7 +45,8 @@ struct lxc_arguments {
 	const char *rcfile;
 
 	/* for lxc-checkpoint */
-	int stop;
+	int kill;
+	int pause;
 
 	/* for lxc-console */
 	int ttynum;

src/lxc/checkpoint.c

@@ -44,42 +44,7 @@
 
 lxc_log_define(lxc_checkpoint, lxc);
 
-#define MAXPIDLEN 20
+int lxc_checkpoint(const char *name, const char *statefile, unsigned long flags)
-
-int lxc_checkpoint(const char *name, const char *statefile,
-		unsigned long flags)
 {
-	char init[MAXPATHLEN];
+	return 0;
-	char val[MAXPIDLEN];
-	int fd, ret = -1;
-	size_t pid;
-
-	if (lxc_check_lock(name) < 0) {
-		return -1;
-	}
-
-	snprintf(init, MAXPATHLEN, LXCPATH "/%s/init", name);
-	fd = open(init, O_RDONLY);
-	if (fd < 0) {
-		SYSERROR("failed to open init file for %s", name);
-		goto out_close;
-	}
-
-	if (read(fd, val, sizeof(val)) < 0) {
-		SYSERROR("failed to read %s", init);
-		goto out_close;
-	}
-
-	pid = atoi(val);
-
-	if (lxc_plugin_checkpoint(pid, statefile, flags) < 0) {
-		SYSERROR("failed to checkpoint %zd", pid);
-		goto out_close;
-	}
-
-	ret = 0;
-
-out_close:
-	close(fd);
-	return ret;
 }

src/lxc/lxc_checkpoint.c

@@ -40,13 +40,15 @@ static int my_checker(const struct lxc_arguments* args)
 static int my_parser(struct lxc_arguments* args, int c, char* arg)
 {
 	switch (c) {
-	case 's': args->stop = 1; break;
+	case 'k': args->kill = 1; break;
+	case 'p': args->pause = 1; break;
 	}
 	return 0;
 }
 
 static const struct option my_longopts[] = {
-	{"stop", no_argument, 0, 's'},
+	{"kill", no_argument, 0, 'k'},
+	{"pause", no_argument, 0, 'p'},
 	LXC_COMMON_OPTIONS
 };
 
@@ -59,7 +61,9 @@ lxc-checkpoint checkpoints in STATEFILE file the NAME container\n\
 \n\
 Options :\n\
   -n, --name=NAME      NAME for name of the container\n\
-  -s, --stop           stop the container after checkpoint\n",
+  -k, --kill           stop the container after checkpoint\n\
+  -p, --pause          don't unfreeze the container after the checkpoint\n",
+
 	.options  = my_longopts,
 	.parser   = my_parser,
 	.checker  = my_checker,
@@ -71,29 +75,18 @@ int main(int argc, char *argv[])
 {
 	int ret = -1;
 
-	if (lxc_arguments_parse(&my_args, argc, argv))
+	ret = lxc_arguments_parse(&my_args, argc, argv);
+	if (ret)
 		return ret;
 
-	if (lxc_log_init(my_args.log_file, my_args.log_priority,
+	ret = lxc_log_init(my_args.log_file, my_args.log_priority,
-			 my_args.progname, my_args.quiet))
+			   my_args.progname, my_args.quiet);
+	if (ret)
 		return ret;
 
-	if (lxc_freeze(my_args.name))
+	ret = lxc_checkpoint(my_args.name, my_args.argv[0], 0);
+	if (ret)
 		return ret;
 
-	if (lxc_checkpoint(my_args.name, my_args.argv[0], 0))
-		goto out;
-
-	if (my_args.stop) {
-		if (lxc_stop(my_args.name))
-			goto out;
-	}
-
-	ret = 0;
-
-out:
-	if (lxc_unfreeze(my_args.name))
-		return -1;
-
 	return ret;
 }

src/lxc/restart.c

@@ -50,200 +50,5 @@ LXC_TTY_HANDLER(SIGQUIT);
 int lxc_restart(const char *name, const char *statefile,
 		unsigned long flags)
 {
-	struct lxc_tty_info tty_info = { 0 };
+	return 0;
-	char *init = NULL, *val = NULL;
-	char tty[MAXPATHLEN];
-	int fd, lock, sv[2], sync = 0, err = -1;
-	pid_t pid;
-	int clone_flags;
-
-	lock = lxc_get_lock(name);
-	if (lock < 0)
-		return lock;
-
-	/* Begin the set the state to STARTING*/
-	if (lxc_setstate(name, STARTING)) {
-		ERROR("failed to set state %s",
-			      lxc_state2str(STARTING));
-		goto out;
-	}
-
-	if (ttyname_r(0, tty, sizeof(tty))) {
-		tty[0] = '\0';
-		WARN("failed to get tty name");
-	}
-
-	/* Synchro socketpair */
-	if (socketpair(AF_LOCAL, SOCK_STREAM, 0, sv)) {
-		SYSERROR("failed to create communication socketpair");
-		goto out;
-	}
-
-	/* Avoid signals from terminal */
-	LXC_TTY_ADD_HANDLER(SIGINT);
-	LXC_TTY_ADD_HANDLER(SIGQUIT);
-
-	clone_flags = CLONE_NEWPID|CLONE_NEWIPC|CLONE_NEWNS;
-	if (conf_has_utsname(name))
-		clone_flags |= CLONE_NEWUTS;
-	if (conf_has_network(name))
-		clone_flags |= CLONE_NEWNET;
-
-	/* Create a process in a new set of namespaces */
-	pid = fork_ns(clone_flags);
-	if (pid < 0) {
-		SYSERROR("failed to fork into a new namespace");
-		goto err_fork_ns;
-	}
-
-	if (!pid) {
-
-		close(sv[1]);
-
-		/* Be sure we don't inherit this after the exec */
-		fcntl(sv[0], F_SETFD, FD_CLOEXEC);
-		
-		/* Tell our father he can begin to configure the container */
-		if (write(sv[0], &sync, sizeof(sync)) < 0) {
-			SYSERROR("failed to write socket");
-			return 1;
-		}
-
-		/* Wait for the father to finish the configuration */
-		if (read(sv[0], &sync, sizeof(sync)) < 0) {
-			SYSERROR("failed to read socket");
-			return 1;
-		}
-
-		/* Setup the container, ip, names, utsname, ... */
-		if (lxc_setup(name, tty, &tty_info)) {
-			ERROR("failed to setup the container");
-			if (write(sv[0], &sync, sizeof(sync)) < 0)
-				SYSERROR("failed to write the socket");
-			return -1;
-		}
-
-		lxc_plugin_restart(getpid(), statefile, flags);
-		SYSERROR("failed to restart");
-  
-		/* If the exec fails, tell that to our father */
-		if (write(sv[0], &sync, sizeof(sync)) < 0)
-			SYSERROR("failed to write the socket");
-		
-		exit(1);
-	}
-
-	close(sv[0]);
-	
-	/* Wait for the child to be ready */
-	if (read(sv[1], &sync, sizeof(sync)) < 0) {
-		SYSERROR("failed to read the socket");
-		goto err_pipe_read;
-	}
-
-	/* Create the network configuration */
-	if (clone_flags & CLONE_NEWNET && conf_create_network(name, pid)) {
-		ERROR("failed to create the configured network");
-		goto err_create_network;
-	}
-
-	/* Tell the child to continue its initialization */
-	if (write(sv[1], &sync, sizeof(sync)) < 0) {
-		SYSERROR("failed to write the socket");
-		goto err_pipe_write;
-	}
-
-	/* Wait for the child to exec or returning an error */
-	err = read(sv[1], &sync, sizeof(sync));
-	if (err < 0) {
-		ERROR("failed to read the socket");
-		goto err_pipe_read2;
-	}
-
-	if (err > 0) {
-		ERROR("something went wrong with %d", pid);
-		/* TODO : check status etc ... */
-		waitpid(pid, NULL, 0);
-		goto err_child_failed;
-	}
-
-	if (!asprintf(&val, "%d\n", pid)) {
-		SYSERROR("failed to allocate memory");
-		goto err_child_failed;
-	}
-	if (!asprintf(&init, LXCPATH "/%s/init", name)) {
-		SYSERROR("failed to allocate memory");
-		goto err_child_failed;
-	}
-	fd = open(init, O_WRONLY|O_CREAT|O_TRUNC, S_IRUSR|S_IWUSR);
-	if (fd < 0) {
-		SYSERROR("failed to open '%s'", init);
-		goto err_write;
-	}
-	
-	if (write(fd, val, strlen(val)) < 0) {
-		SYSERROR("failed to write the init pid");
-		goto err_write;
-	}
-
-	close(fd);
-
-	if (lxc_link_nsgroup(name, pid))
-		WARN("cgroupfs not found: cgroup disabled");
-
-	if (lxc_setstate(name, RUNNING)) {
-		ERROR("failed to set state to %s",
-			      lxc_state2str(RUNNING));
-		goto err_state_failed;
-	}
-
-wait_again:
-	if (waitpid(pid, NULL, 0) < 0) {
-		if (errno == EINTR) 
-			goto wait_again;
-		SYSERROR("failed to wait the pid %d", pid);
-		goto err_waitpid_failed;
-	}
-
-	if (lxc_setstate(name, STOPPING))
-		ERROR("failed to set state %s", lxc_state2str(STOPPING));
-
-	if (clone_flags & CLONE_NEWNET && conf_destroy_network(name))
-		ERROR("failed to destroy the network");
-
-	err = 0;
-out:
-	if (lxc_setstate(name, STOPPED))
-		ERROR("failed to set state %s", lxc_state2str(STOPPED));
-
-	lxc_unlink_nsgroup(name);
-	unlink(init);
-	free(init);
-	free(val);
-	lxc_put_lock(lock);
-
-	return err;
-
-err_write:
-	close(fd);
-
-err_state_failed:
-err_child_failed:
-err_pipe_read2:
-err_pipe_write:
-	if (clone_flags & CLONE_NEWNET)
-		conf_destroy_network(name);
-err_create_network:
-err_pipe_read:
-err_waitpid_failed:
-	if (lxc_setstate(name, ABORTING))
-		ERROR("failed to set state %s", lxc_state2str(STOPPED));
-
-	kill(pid, SIGKILL);
-err_fork_ns:
-	LXC_TTY_DEL_HANDLER(SIGQUIT);
-	LXC_TTY_DEL_HANDLER(SIGINT);
-	close(sv[0]);
-	close(sv[1]);
-	goto out;
 }