[CRIU] [PATCH] restore: handle errors of restore_wait_other_tasks

[Andrei Vagin]

From: Andrei Vagin <avagin at virtuozzo.com>

In a error case, task_entries->nr_in_progress is set to -1
and we have to handle this case.

Signed-off-by: Andrei Vagin <avagin at virtuozzo.com>
---
 criu/cr-restore.c | 38 ++++++++++++++++++++++----------------
 1 file changed, 22 insertions(+), 16 deletions(-)

diff --git a/criu/cr-restore.c b/criu/cr-restore.c
index 298fb69..ed02474 100644
--- a/criu/cr-restore.c
+++ b/criu/cr-restore.c
@@ -164,12 +164,12 @@ static inline int stage_current_participants(int next_stage)
 	return -1;
 }
 
-static int restore_wait_inprogress_tasks()
+static int __restore_wait_inprogress_tasks(int participants)
 {
 	int ret;
 	futex_t *np = &task_entries->nr_in_progress;
 
-	futex_wait_while_gt(np, 0);
+	futex_wait_while_gt(np, participants);
 	ret = (int)futex_get(np);
 	if (ret < 0) {
 		set_cr_errno(get_task_cr_err());
@@ -179,6 +179,22 @@ static int restore_wait_inprogress_tasks()
 	return 0;
 }
 
+static int restore_wait_inprogress_tasks()
+{
+	return __restore_wait_inprogress_tasks(0);
+}
+
+/* Wait all tasks except the current one */
+static int restore_wait_other_tasks()
+{
+	int participants, stage;
+
+	stage = futex_get(&task_entries->start);
+	participants = stage_current_participants(stage);
+
+	return __restore_wait_inprogress_tasks(participants);
+}
+
 static inline void __restore_switch_stage_nw(int next_stage)
 {
 	futex_set(&task_entries->nr_in_progress,
@@ -200,18 +216,6 @@ static int restore_switch_stage(int next_stage)
 	return restore_wait_inprogress_tasks();
 }
 
-/* Wait all tasks except the current one */
-static void restore_wait_other_tasks()
-{
-	int participants, stage;
-
-	stage = futex_get(&task_entries->start);
-	participants = stage_current_participants(stage);
-
-	futex_wait_while_gt(&task_entries->nr_in_progress,
-				participants);
-}
-
 static int restore_finish_ns_stage(int from, int to)
 {
 	if (root_ns_mask)
@@ -1826,7 +1830,8 @@ static int restore_task_with_children(void *_arg)
 		 *
 		 * It means that all tasks entered into their namespaces.
 		 */
-		restore_wait_other_tasks();
+		if (restore_wait_other_tasks())
+			goto err;
 		fini_restore_mntns();
 		__restore_switch_stage(CR_STATE_RESTORE);
 	} else {
@@ -3333,7 +3338,8 @@ static int sigreturn_restore(pid_t pid, struct task_restore_args *task_args, uns
 
 	if (current->parent == NULL) {
 		/* Wait when all tasks restored all files */
-		restore_wait_other_tasks();
+		if (restore_wait_other_tasks())
+			goto err;
 	}
 
 	/*
-- 
2.9.4