[CRIU] [PATCH 01/13] crtools: close all desriptors only for the root task

[Andrey Vagin]

For all other tasks only unsed service descriptors will be closed.

This change allows to have file descriptors, which may be used for
restoring namespaces. All non-server descriptors must be closed before
restoring files.

Signed-off-by: Andrey Vagin <avagin at openvz.org>
---
 cr-restore.c        | 19 ++++++++++---------
 include/servicefd.h |  1 +
 util.c              | 12 ++++++++++++
 3 files changed, 23 insertions(+), 9 deletions(-)

diff --git a/cr-restore.c b/cr-restore.c
index ab8fa77..0e6c731 100644
--- a/cr-restore.c
+++ b/cr-restore.c
@@ -1214,15 +1214,19 @@ static int restore_task_with_children(void *_arg)
 				current->pid.real, current->pid.virt);
 	}
 
-	if ( !(ca->clone_flags & CLONE_FILES))
-		close_safe(&ca->fd);
-
 	if (current->state != TASK_HELPER) {
 		ret = clone_service_fd(current->rst->service_fd_id);
 		if (ret)
 			exit(1);
 	}
 
+	if ( !(ca->clone_flags & CLONE_FILES)) {
+		close_safe(&ca->fd);
+
+		if (current->parent && current->parent->rst->fdt)
+			close_old_servie_fd(current->parent->rst->fdt->nr);
+	}
+
 	pid = getpid();
 	if (current->pid.virt != pid) {
 		pr_err("Pid %d do not match expected %d\n", pid, current->pid.virt);
@@ -1238,6 +1242,9 @@ static int restore_task_with_children(void *_arg)
 		if (restore_finish_stage(CR_STATE_RESTORE_NS) < 0)
 			exit(1);
 
+		if (close_old_fds(current))
+			exit(1);
+
 		if (collect_mount_info(getpid()))
 			exit(1);
 
@@ -1272,12 +1279,6 @@ static int restore_task_with_children(void *_arg)
 	if (prepare_mappings(pid))
 		exit(1);
 
-	if (!(ca->clone_flags & CLONE_FILES)) {
-		ret = close_old_fds(current);
-		if (ret)
-			exit(1);
-	}
-
 	if (create_children_and_session())
 		exit(1);
 
diff --git a/include/servicefd.h b/include/servicefd.h
index 2a2542c..f855fe8 100644
--- a/include/servicefd.h
+++ b/include/servicefd.h
@@ -25,6 +25,7 @@ extern int get_service_fd(enum sfd_type type);
 extern int reserve_service_fd(enum sfd_type type);
 extern int install_service_fd(enum sfd_type type, int fd);
 extern int close_service_fd(enum sfd_type type);
+extern void close_old_servie_fd(int nr);
 extern bool is_service_fd(int fd, enum sfd_type type);
 extern bool is_any_service_fd(int fd);
 
diff --git a/util.c b/util.c
index 4304a91..c5681c9 100644
--- a/util.c
+++ b/util.c
@@ -341,6 +341,18 @@ int close_service_fd(enum sfd_type type)
 	return 0;
 }
 
+/* Close all unused service descriptors on a depth of nr. */
+void close_old_servie_fd(int nr)
+{
+	int level, i;
+	BUG_ON(service_fd_id != 0);
+	for (level = 1; level < nr; level++) {
+		for (i = SERVICE_FD_MIN + 1; i < SERVICE_FD_MAX; i++) {
+			close(__get_service_fd(i, level));
+		}
+	}
+}
+
 int clone_service_fd(int id)
 {
 	int ret = -1, i;
-- 
1.8.5.3