selinux: Create function for selinuxfs directory cleanup

Separating the cleanup from the creation will simplify two things in
future patches in this series.  First, the creation can be made generic,
to create directories not tied to the selinux_fs_info structure.  Second,
we will ultimately want to reorder creation and deletion so that the
deletions aren't performed until the new directory structures have already
been moved into place.
Signed-off-by: Daniel Burgener <dburgener@linux.microsoft.com>
Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

security/selinux/selinuxfs.c

@@ -355,6 +355,9 @@ static int sel_make_classes(struct selinux_fs_info *fsi,
 static struct dentry *sel_make_dir(struct dentry *dir, const char *name,
 			unsigned long *ino);
 
+/* declaration for sel_remove_old_policy_nodes */
+static void sel_remove_entries(struct dentry *de);
+
 static ssize_t sel_read_mls(struct file *filp, char __user *buf,
 				size_t count, loff_t *ppos)
 {
@@ -509,11 +512,33 @@ static const struct file_operations sel_policy_ops = {
 	.llseek		= generic_file_llseek,
 };
 
+static void sel_remove_old_policy_nodes(struct selinux_fs_info *fsi)
+{
+	u32 i;
+
+	/* bool_dir cleanup */
+	for (i = 0; i < fsi->bool_num; i++)
+		kfree(fsi->bool_pending_names[i]);
+	kfree(fsi->bool_pending_names);
+	kfree(fsi->bool_pending_values);
+	fsi->bool_num = 0;
+	fsi->bool_pending_names = NULL;
+	fsi->bool_pending_values = NULL;
+
+	sel_remove_entries(fsi->bool_dir);
+
+	/* class_dir cleanup */
+	sel_remove_entries(fsi->class_dir);
+
+}
+
 static int sel_make_policy_nodes(struct selinux_fs_info *fsi,
 				struct selinux_policy *newpolicy)
 {
 	int ret;
 
+	sel_remove_old_policy_nodes(fsi);
+
 	ret = sel_make_bools(fsi, newpolicy);
 	if (ret) {
 		pr_err("SELinux: failed to load policy booleans\n");
@@ -1348,17 +1373,6 @@ static int sel_make_bools(struct selinux_fs_info *fsi,
 	int *values = NULL;
 	u32 sid;
 
-	/* remove any existing files */
-	for (i = 0; i < fsi->bool_num; i++)
-		kfree(fsi->bool_pending_names[i]);
-	kfree(fsi->bool_pending_names);
-	kfree(fsi->bool_pending_values);
-	fsi->bool_num = 0;
-	fsi->bool_pending_names = NULL;
-	fsi->bool_pending_values = NULL;
-
-	sel_remove_entries(dir);
-
 	ret = -ENOMEM;
 	page = (char *)get_zeroed_page(GFP_KERNEL);
 	if (!page)
@@ -1873,9 +1887,6 @@ static int sel_make_classes(struct selinux_fs_info *fsi,
 	int rc, nclasses, i;
 	char **classes;
 
-	/* delete any existing entries */
-	sel_remove_entries(fsi->class_dir);
-
 	rc = security_get_classes(newpolicy, &classes, &nclasses);
 	if (rc)
 		return rc;