This commit adds the function cgroupv2_subtree_control().
cgroupv2_subtree_control() can be used to enable or disable a
controller in the subtree_control file. The equivalent command
line is:
echo +{ctrl_name} > {path}/cgroup.subtree_control
echo -{ctrl_name} > {path}/cgroup.subtree_control
Signed-off-by: Tom Hromatka <tom.hroma...@oracle.com>
---
src/api.c | 52 +++++++++++++++++++++++++++++++++++++++-
src/libcgroup-internal.h | 3 +++
2 files changed, 54 insertions(+), 1 deletion(-)
diff --git a/src/api.c b/src/api.c
index c4870046e8c2..d16b79c8e8e1 100644
--- a/src/api.c
+++ b/src/api.c
@@ -63,8 +63,9 @@ static __thread char errtext[MAXLEN];
/* Task command name length */
#define TASK_COMM_LEN 16
-/* cgroup v2 controllers file */
+/* cgroup v2 files */
#define CGV2_CONTROLLERS_FILE "cgroup.controllers"
+#define CGV2_SUBTREE_CTRL_FILE "cgroup.subtree_control"
/* maximum line length when reading the cgroup.controllers file */
#define LL_MAX 100
@@ -1835,6 +1836,55 @@ err:
return error;
}
+/**
+ * Enable/Disable a controller in the cgroup v2 subtree_control file
+ *
+ * @param path Directory that contains the subtree_control file
+ * @param ctrl_name Name of the controller to be enabled/disabled
+ * @param enable Enable/Disable the given controller
+ */
+STATIC int cgroupv2_subtree_control(const char *path, const char *ctrl_name,
+ bool enable)
+{
+ char *path_copy = NULL;
+ char *value = NULL;
+ int ret, error = ECGOTHER;
+
+ if (!path || !ctrl_name)
+ return ECGOTHER;
+
+ value = (char *)malloc(FILENAME_MAX);
+ if (!value)
+ goto out;
+
+ path_copy = (char *)malloc(FILENAME_MAX);
+ if (!path_copy)
+ goto out;
+
+ ret = snprintf(path_copy, FILENAME_MAX, "%s/%s", path,
+ CGV2_SUBTREE_CTRL_FILE);
+ if (ret < 0)
+ goto out;
+
+ if (enable)
+ ret = snprintf(value, FILENAME_MAX, "+%s", ctrl_name);
+ else
+ ret = snprintf(value, FILENAME_MAX, "-%s", ctrl_name);
+ if (ret < 0)
+ goto out;
+
+ error = cg_set_control_value(path_copy, value);
+ if (error)
+ goto out;
+
+out:
+ if (value)
+ free(value);
+ if (path_copy)
+ free(path_copy);
+ return error;
+}
+
/** 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
diff --git a/src/libcgroup-internal.h b/src/libcgroup-internal.h
index 57c870a8c41f..38a17e0ab251 100644
--- a/src/libcgroup-internal.h
+++ b/src/libcgroup-internal.h
@@ -340,6 +340,9 @@ int cgroup_set_values_recursive(const char * const base,
int cgroup_chown_chmod_tasks(const char * const cg_path,
uid_t uid, gid_t gid, mode_t fperm);
+int cgroupv2_subtree_control(const char *path, const char *ctrl_name,
+ bool enable);
+
#endif /* UNIT_TEST */
__END_DECLS
--
2.25.3
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