criu: set RLIMIT_NOFILE to maximum only on restore

Reviewed-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>

criu/cr-restore.c

@@ -2339,10 +2339,42 @@ int prepare_dummy_task_state(struct pstree_item *pi)
 	return 0;
 }
 
+static void rlimit_unlimit_nofile_self(void)
+{
+	struct rlimit new;
+
+	new.rlim_cur = kdat.sysctl_nr_open;
+	new.rlim_max = kdat.sysctl_nr_open;
+
+	if (prlimit(getpid(), RLIMIT_NOFILE, &new, NULL)) {
+		pr_perror("rlimir: Can't setup RLIMIT_NOFILE for self");
+		return;
+	} else
+		pr_debug("rlimit: RLIMIT_NOFILE unlimited for self\n");
+	service_fd_rlim_cur = kdat.sysctl_nr_open;
+}
+
 int cr_restore_tasks(void)
 {
 	int ret = -1;
 
+	/*
+	 * Service fd engine implies that file descriptors
+	 * used won't be borrowed by the rest of the code
+	 * and default 1024 limit is not enough for high
+	 * loaded test/containers. Thus use kdat engine
+	 * to fetch current system level limit for numbers
+	 * of files allowed to open up and lift up own
+	 * limits.
+	 *
+	 * Note we have to do it before the service fd
+	 * get inited and we dont exit with errors here
+	 * because in worst scenario where clash of fd
+	 * happen we simply exit with explicit error
+	 * during real action stage.
+	 */
+	rlimit_unlimit_nofile_self();
+
 	if (cr_plugin_init(CR_PLUGIN_STAGE__RESTORE))
 		return -1;
 

criu/crtools.c

@@ -52,40 +52,8 @@
 #include "setproctitle.h"
 #include "sysctl.h"
 
-static void rlimit_unlimit_nofile_self(void)
-{
-	struct rlimit new;
-
-	new.rlim_cur = kdat.sysctl_nr_open;
-	new.rlim_max = kdat.sysctl_nr_open;
-
-	if (prlimit(getpid(), RLIMIT_NOFILE, &new, NULL)) {
-		pr_perror("rlimir: Can't setup RLIMIT_NOFILE for self");
-		return;
-	} else
-		pr_debug("rlimit: RLIMIT_NOFILE unlimited for self\n");
-}
-
 static int early_init(void)
 {
-	/*
-	 * Service fd engine implies that file descritprs
-	 * used won't be borrowed by the rest of the code
-	 * and default 1024 limit is not enough for high
-	 * loaded test/containers. Thus use kdat engine
-	 * to fetch current system level limit for numbers
-	 * of files allowed to open up and lift up own
-	 * limits.
-	 *
-	 * Note we have to do it before the service fd
-	 * get inited and we don't exit with errors here
-	 * because in worst scenario where clash of fd
-	 * happen we simply exit with explicit error
-	 * during real action stage.
-	 */
-	if (!kerndat_files_stat(true))
-		rlimit_unlimit_nofile_self();
-
 	if (init_service_fd())
 		return 1;
 

criu/files.c

@@ -44,6 +44,7 @@
 #include "autofs.h"
 #include "parasite.h"
 #include "parasite-syscall.h"
+#include "kerndat.h"
 
 #include "protobuf.h"
 #include "util.h"
@@ -898,7 +899,7 @@ int prepare_fd_pid(struct pstree_item *item)
 		if (ret <= 0)
 			break;
 
-		if (e->fd >= service_fd_min_fd(item)) {
+		if (e->fd >= kdat.sysctl_nr_open) {
 			ret = -1;
 			pr_err("Too big FD number to restore %d\n", e->fd);
 			break;