opts: add --manage-cgroups option

criu managed cgroups is now an opt-in thing, so by default criu does not manage
(i.e. dump or restore) cgroups. This allows users to use the previous behavior.

Signed-off-by: Tycho Andersen <tycho.andersen@canonical.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

cgroup.c

@@ -10,6 +10,7 @@
 #include "list.h"
 #include "xmalloc.h"
 #include "cgroup.h"
+#include "cr_options.h"
 #include "pstree.h"
 #include "proc_parse.h"
 #include "util.h"
@@ -583,7 +584,7 @@ int dump_task_cgroup(struct pstree_item *item, u32 *cg_id)
 		 * The on-stack ctls is moved into cs inside
 		 * the get_cg_set routine.
 		 */
-		if (cs != criu_cgset && collect_cgroups(&cs->ctls))
+		if (cs != criu_cgset && opts.manage_cgroups && collect_cgroups(&cs->ctls))
 			return -1;
 	}
 
@@ -1148,7 +1149,8 @@ static int prepare_cgroup_sfd(CgroupEntry *ce)
 			goto err;
 		}
 
-		if (prepare_cgroup_dirs(paux, off + name_off, ctrl->dirs, ctrl->n_dirs))
+		if (opts.manage_cgroups &&
+		    prepare_cgroup_dirs(paux, off + name_off, ctrl->dirs, ctrl->n_dirs))
 			goto err;
 
 	}

cr-service.c

@@ -304,6 +304,9 @@ static int setup_opts_from_req(int sk, CriuOpts *req)
 	if (req->has_cpu_cap)
 		opts.cpu_cap = req->cpu_cap;
 
+	if (req->has_manage_cgroups)
+		opts.manage_cgroups = req->manage_cgroups;
+
 	return 0;
 }
 

crtools.c

@@ -49,6 +49,7 @@ void init_opts(void)
 	INIT_LIST_HEAD(&opts.ext_mounts);
 
 	opts.cpu_cap = CPU_CAP_ALL;
+	opts.manage_cgroups = false;
 }
 
 static int parse_ns_string(const char *ptr)
@@ -167,6 +168,7 @@ int main(int argc, char *argv[])
 		{ "force-irmap", no_argument, 0, 58},
 		{ "ext-mount-map", required_argument, 0, 'M'},
 		{ "exec-cmd", no_argument, 0, 59},
+		{ "manage-cgroups", no_argument, 0, 60},
 		{ },
 	};
 
@@ -353,6 +355,9 @@ int main(int argc, char *argv[])
 		case 59:
 			has_exec_cmd = true;
 			break;
+		case 60:
+			opts.manage_cgroups = true;
+			break;
 		case 'M':
 			{
 				char *aux;
@@ -541,6 +546,7 @@ usage:
 "  --force-irmap         force resolving names for inotify/fsnotify watches\n"
 "  -M|--ext-mount-map KEY:VALUE\n"
 "                        add external mount mapping\n"
+"  --manage-cgroups      dump or restore cgroups the process is in\n"
 "\n"
 "* Logging:\n"
 "  -o|--log-file FILE    log file name\n"

include/cr_options.h

@@ -51,6 +51,7 @@ struct cr_options {
 	unsigned int		cpu_cap;
 	bool			force_irmap;
 	char			**exec_cmd;
+	bool			manage_cgroups;
 };
 
 extern struct cr_options opts;

lib/criu.c

@@ -152,6 +152,12 @@ void criu_set_root(char *root)
 	opts->root = strdup(root);
 }
 
+void criu_set_manage_cgroups(bool manage)
+{
+	opts->has_manage_cgroups = true;
+	opts->manage_cgroups = manage;
+}
+
 void criu_set_log_file(char *log_file)
 {
 	opts->log_file = strdup(log_file);

lib/criu.h

@@ -47,6 +47,7 @@ void criu_set_log_level(int log_level);
 void criu_set_log_file(char *log_file);
 void criu_set_cpu_cap(unsigned int cap);
 void criu_set_root(char *root);
+void criu_set_manage_cgroups(bool manage);
 int criu_set_exec_cmd(int argc, char *argv[]);
 int criu_add_ext_mount(char *key, char *val);
 int criu_add_veth_pair(char *in, char *out);

protobuf/rpc.proto

@@ -45,6 +45,7 @@ message criu_opts {
 	repeated string			exec_cmd	= 22;
 
 	repeated ext_mount_map		ext_mnt		= 23;
+	optional bool			manage_cgroups	= 24;
 }
 
 message criu_dump_resp {

test/zdtm/live/static/cgroup00.opts

@@ -0,0 +1 @@
+--manage-cgroups

test/zdtm/live/static/cgroup01.opts

@@ -0,0 +1 @@
+--manage-cgroups