From: Kamalesh Babulal <kamalesh.babulal@oracle.com>
Date: Mon, 4 Apr 2022 06:48:44 +0000 (+0530)
Subject: api.c: add check for empty cgroup v2 controller
X-Git-Tag: v3.0~91
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c8e694c6f0a1330cdcd11b3601a2a5c58fc00df9;p=thirdparty%2Flibcgroup.git

api.c: add check for empty cgroup v2 controller

There can be cgroup v2 cgroup with no controllers attached to it and
while checking for enabled controllers always return true in
cgroupv2_controller_enabled() for such cgroups.

Signed-off-by: Kamalesh Babulal <kamalesh.babulal@oracle.com>
Signed-off-by: Tom Hromatka <tom.hromatka@oracle.com>
---

diff --git a/src/api.c b/src/api.c
index ca71ef29..f5b6d303 100644
--- a/src/api.c
+++ b/src/api.c
@@ -1770,6 +1770,10 @@ STATIC int cgroupv2_controller_enabled(const char * const cg_name,
 	if (version != CGROUP_V2)
 		return 0;
 
+	if (ctrl_name == NULL)
+		/* cgroup v2 supports cgroups with no controllers. */
+		return 0;
+
 	if (strncmp(cg_name, "/", strlen(cg_name)) == 0)
 		/*
 		 * The root cgroup has been requested.  All version 2