[CRIU] [PATCH] restore: define root_as_sibling before using it

[Pavel Emelyanov]

On 09/10/2014 02:18 PM, Pavel Emelyanov wrote:

> How about adding the 2nd option called --restore-child and make their
> meaning look like this:

I mean like this:

---

diff --git a/cr-restore.c b/cr-restore.c
index 7e00bb3..4d5ccd5 100644
--- a/cr-restore.c
+++ b/cr-restore.c
@@ -963,8 +963,7 @@ static void maybe_clone_parent(struct pstree_item *item,
 	 * off of 3.11, this condition can be simplified to just test the
 	 * options and not have the pdeath_sig test.
 	 */
-	if (opts.swrk_restore ||
-	    (opts.restore_detach && ca->core->thread_core->pdeath_sig)) {
+	if (opts.restore_sibling) {
 		/*
 		 * This means we're called from lib's criu_restore_child().
 		 * In that case create the root task as the child one to+
@@ -985,6 +984,10 @@ static void maybe_clone_parent(struct pstree_item *item,
 		if (item->rst->clone_flags & CLONE_NEWPID)
 			pr_warn("Set CLONE_PARENT | CLONE_NEWPID but it might cause restore problem,"
 				"because not all kernels support such clone flags combinations!\n");
+	} else if (opts.restore_detach) {
+		if (ca->core->thread_core->pdeath_sig)
+			pr_warn("Root task has pdeath_sig configured, so it will receive one _right_"
+				"after restore on CRIU exit\n");
 	}
 }
 
diff --git a/cr-service.c b/cr-service.c
index 43840d6..97df433 100644
--- a/cr-service.c
+++ b/cr-service.c
@@ -259,6 +259,14 @@ static int setup_opts_from_req(int sk, CriuOpts *req)
 	if (req->root)
 		opts.root = req->root;
 
+	if (req->has_rst_sibling) {
+		pr_err("rst_sibling is not allowed in standalone service\n");
+		if (!opts.swrk_restore)
+			return -1;
+
+		opts.restore_sibling = req->rst_sibling;
+	}
+
 	if (req->has_tcp_established)
 		opts.tcp_established_ok = req->tcp_established;
 
diff --git a/crtools.c b/crtools.c
index 1c31392..3e2299f 100644
--- a/crtools.c
+++ b/crtools.c
@@ -133,13 +133,14 @@ int main(int argc, char *argv[], char *envp[])
 	int log_level = LOG_UNSET;
 	char *imgs_dir = ".";
 	char *work_dir = NULL;
-	static const char short_opts[] = "dsRf:F:t:p:hcD:o:n:v::xVr:jlW:L:M:";
+	static const char short_opts[] = "dSsRf:F:t:p:hcD:o:n:v::xVr:jlW:L:M:";
 	static struct option long_opts[] = {
 		{ "tree", required_argument, 0, 't' },
 		{ "pid", required_argument, 0, 'p' },
 		{ "leave-stopped", no_argument, 0, 's' },
 		{ "leave-running", no_argument, 0, 'R' },
 		{ "restore-detached", no_argument, 0, 'd' },
+		{ "restore-sibling", no_argument, 0, 'S' },
 		{ "daemon", no_argument, 0, 'd' },
 		{ "contents", no_argument, 0, 'c' },
 		{ "file", required_argument, 0, 'f' },
@@ -247,6 +248,9 @@ int main(int argc, char *argv[], char *envp[])
 		case 'd':
 			opts.restore_detach = true;
 			break;
+		case 'S':
+			opts.restore_sibling = true;
+			break;
 		case 'D':
 			imgs_dir = optarg;
 			break;
@@ -404,6 +408,11 @@ int main(int argc, char *argv[], char *envp[])
 		}
 	}
 
+	if (!opts.restore_detach && opts.restore_sibling) {
+		pr_msg("--restore-sibling only makes sense with --restore-detach\n");
+		return 1;
+	}
+
 	if (work_dir == NULL)
 		work_dir = imgs_dir;
 
@@ -540,6 +549,7 @@ usage:
 "* Generic:\n"
 "  -t|--tree PID         checkpoint a process tree identified by PID\n"
 "  -d|--restore-detached detach after restore\n"
+"  -S|--restore-sibling  restore root task as sibling\n"
 "  -s|--leave-stopped    leave tasks in stopped state after checkpoint\n"
 "  -R|--leave-running    leave tasks in running state after checkpoint\n"
 "  -D|--images-dir DIR   directory for image files\n"
diff --git a/include/cr_options.h b/include/cr_options.h
index e00d075..5a7edd9 100644
--- a/include/cr_options.h
+++ b/include/cr_options.h
@@ -24,6 +24,7 @@ struct cr_options {
 	bool			check_ms_kernel;
 	bool			show_pages_content;
 	bool			restore_detach;
+	bool			restore_sibling;
 	bool			ext_unix_sk;
 	bool			shell_job;
 	bool			handle_file_locks;
diff --git a/lib/criu.c b/lib/criu.c
index c83c4d8..ad419ba 100644
--- a/lib/criu.c
+++ b/lib/criu.c
@@ -666,6 +666,9 @@ int criu_restore_child(void)
 	req.type	= CRIU_REQ_TYPE__RESTORE;
 	req.opts	= opts;
 
+	req.opts->has_rst_sibling = true;
+	req.opts->rst_sibling = true;
+
 	ret = send_req_and_recv_resp_sk(sks[0], &req, &resp);
 
 	close(sks[0]);
diff --git a/protobuf/rpc.proto b/protobuf/rpc.proto
index 8ace89c..4617e7b 100644
--- a/protobuf/rpc.proto
+++ b/protobuf/rpc.proto
@@ -53,6 +53,8 @@ message criu_opts {
 	repeated ext_mount_map		ext_mnt		= 23;
 	optional bool			manage_cgroups	= 24;
 	repeated cgroup_root		cg_root		= 25;
+
+	optional bool			rst_sibling	= 26; /* swrk only */
 }
 
 message criu_dump_resp {