From: Tom Hromatka <tom.hromatka@oracle.com>
Date: Tue, 20 Dec 2022 22:33:23 +0000 (+0000)
Subject: api: cgroup_get_cgroup() populate the controller list based on the subtree_control... 
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=52f20c4567ea45157112ad765b94f072cf62183f;p=thirdparty%2Flibcgroup.git

api: cgroup_get_cgroup() populate the controller list based on the subtree_control file

In cgroup_get_cgroup(), populate the controller list in the cgroup
only with controllers that are enabled in cgroup.subtree_control.

As part of this change update the error codes from
cgroupv2_get_subtree_control() to better reflect memory allocation
errors

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

diff --git a/src/api.c b/src/api.c
index 5480c7a8..1932832c 100644
--- a/src/api.c
+++ b/src/api.c
@@ -2277,17 +2277,22 @@ STATIC int cgroupv2_get_subtree_control(const char *path, const char *ctrl_name,
 	*enabled = false;
 
 	path_copy = (char *)malloc(FILENAME_MAX);
-	if (!path_copy)
+	if (!path_copy) {
+		error = ECGOTHER;
 		goto out;
+	}
 
 	ret = snprintf(path_copy, FILENAME_MAX, "%s/%s", path, CGV2_SUBTREE_CTRL_FILE);
-	if (ret < 0)
+	if (ret < 0) {
+		error = ECGOTHER;
 		goto out;
+	}
 
 	fp = fopen(path_copy, "re");
 	if (!fp) {
 		cgroup_warn("fopen failed\n");
 		last_errno = errno;
+		error = ECGOTHER;
 		goto out;
 	}
 
@@ -3506,6 +3511,18 @@ int cgroup_get_cgroup(struct cgroup *cgroup)
 			cgroup->tasks_gid = stat_buffer.st_gid;
 
 			free(control_path);
+		} else { /* cgroup v2 */
+			bool enabled;
+
+			error = cgroupv2_get_subtree_control(path, cg_mount_table[i].name,
+							     &enabled);
+			if (error == ECGROUPNOTMOUNTED)
+				continue;
+			if (error)
+				goto unlock_error;
+
+			if (!enabled)
+				continue;
 		}
 
 		cgc = cgroup_add_controller(cgroup, cg_mount_table[i].name);