cgroup: refactor cgroup_masks_read() in the debug controller

Factor out cgroup_masks_read_one() out of cgroup_masks_read() for
simplicity.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Waiman Long <longman@redhat.com>

kernel/cgroup/debug.c

@@ -200,27 +200,16 @@ static int cgroup_subsys_states_read(struct seq_file *seq, void *v)
 	return 0;
 }
 
-static int cgroup_masks_read(struct seq_file *seq, void *v)
+static void cgroup_masks_read_one(struct seq_file *seq, const char *name,
+				  u16 mask)
 {
-	struct cgroup *cgrp = seq_css(seq)->cgroup;
 	struct cgroup_subsys *ss;
-	int i, j;
-	struct {
-		u16  *mask;
-		char *name;
-	} mask_list[] = {
-		{ &cgrp->subtree_control,  "subtree_control"  },
-		{ &cgrp->subtree_ss_mask,  "subtree_ss_mask"  },
-	};
-
-	mutex_lock(&cgroup_mutex);
-	for (i = 0; i < ARRAY_SIZE(mask_list); i++) {
-		u16 mask = *mask_list[i].mask;
+	int ssid;
 	bool first = true;
 
-		seq_printf(seq, "%-17s: ", mask_list[i].name);
-		for_each_subsys(ss, j) {
-			if (!(mask & (1 << ss->id)))
+	seq_printf(seq, "%-17s: ", name);
+	for_each_subsys(ss, ssid) {
+		if (!(mask & (1 << ssid)))
 			continue;
 		if (!first)
 			seq_puts(seq, ", ");
@@ -228,8 +217,15 @@ static int cgroup_masks_read(struct seq_file *seq, void *v)
 		first = false;
 	}
 	seq_putc(seq, '\n');
-	}
+}
 
+static int cgroup_masks_read(struct seq_file *seq, void *v)
+{
+	struct cgroup *cgrp = seq_css(seq)->cgroup;
+
+	mutex_lock(&cgroup_mutex);
+	cgroup_masks_read_one(seq, "subtree_control", cgrp->subtree_control);
+	cgroup_masks_read_one(seq, "subtree_ss_mask", cgrp->subtree_ss_mask);
 	mutex_unlock(&cgroup_mutex);
 	return 0;
 }