From c81248e53bd43a2132ce0b0a5aee4951c8618b6f Mon Sep 17 00:00:00 2001
From: Jan Chaloupka <jchaloup@redhat.com>
Date: Thu, 7 Aug 2014 07:17:23 +0200
Subject: [PATCH] retry to set control file

---
 src/api.c | 35 +++++++++++++++++++++++++++++++++++
 1 file changed, 35 insertions(+)

diff --git a/src/api.c b/src/api.c
index ae8396e..03c8068 100644
--- a/src/api.c
+++ b/src/api.c
@@ -1432,6 +1432,8 @@ static int cg_set_control_value(char *path, const char *val)
 	return 0;
 }
 
+
+
 /** cgroup_modify_cgroup modifies the cgroup control files.
  * struct cgroup *cgroup: The name will be the cgroup to be modified.
  * The values will be the values to be modified, those not mentioned
@@ -1449,6 +1451,9 @@ int cgroup_modify_cgroup(struct cgroup *cgroup)
 	int i;
 	int error = 0;
 	int ret;
+	int retry_list[CG_CONTROLLER_MAX];
+	int retry_index;
+	struct control_value **cvalues;
 
 	if (!cgroup_initialized)
 		return ECGROUPNOTINITIALIZED;
@@ -1469,6 +1474,8 @@ int cgroup_modify_cgroup(struct cgroup *cgroup)
 		if (!cg_build_path(cgroup->name, base,
 			cgroup->controller[i]->name))
 			continue;
+
+		retry_index = -1;
 		for (j = 0; j < cgroup->controller[i]->index; j++) {
 			ret = asprintf(&path, "%s%s", base,
 				cgroup->controller[i]->values[j]->name);
@@ -1485,12 +1492,40 @@ int cgroup_modify_cgroup(struct cgroup *cgroup)
 			 * the user as fatal */
 			if (error && !cgroup->controller[i]->values[j]->dirty) {
 				error = 0;
+				/* Let's retry to set it in the second round */
+				++retry_index;
+				retry_list[retry_index] = j;
 				continue;
 			}
 			if (error)
 				goto err;
 			cgroup->controller[i]->values[j]->dirty = false;
 		}
+		if (retry_index > -1) {
+			for (j = 0; j <= retry_index; j++) {
+				cvalues = cgroup->controller[i]->values;
+				ret = asprintf(&path, "%s%s", base,
+					cvalues[retry_list[j]]->name);
+				if (ret < 0) {
+					last_errno = errno;
+					error = ECGOTHER;
+					goto err;
+				}
+				error = cg_set_control_value(path,
+					cvalues[retry_list[j]]->value);
+				free(path);
+				path = NULL;
+				/* don't consider error in files directly
+				 * written by the user as fatal */
+				if (error && !cvalues[retry_list[j]]->dirty) {
+					error = 0;
+					continue;
+				}
+				if (error)
+					goto err;
+				cvalues[retry_list[j]]->dirty = false;
+			}
+		}
 	}
 err:
 	return error;
-- 
1.9.3