aufs: debug, several checks only once

Simple checks when the module is loaded.
This feature is compiled when CONFIG_AUFS_DEBUG is enabled.
Signed-off-by: J. R. Okajima <hooanon05g@gmail.com>

fs/aufs/debug.c

@@ -406,3 +406,23 @@ void au_dbg_verify_kthread(void)
 		/* WARN_ON(1); */
 	}
 }
+
+/* ---------------------------------------------------------------------- */
+
+int __init au_debug_init(void)
+{
+	aufs_bindex_t bindex;
+	struct au_vdir_destr destr;
+
+	bindex = -1;
+	AuDebugOn(bindex >= 0);
+
+	destr.len = -1;
+	AuDebugOn(destr.len < NAME_MAX);
+
+#ifdef CONFIG_4KSTACKS
+	pr_warn("CONFIG_4KSTACKS is defined.\n");
+#endif
+
+	return 0;
+}

fs/aufs/debug.h

@@ -115,6 +115,8 @@ void __au_dbg_verify_dinode(struct dentry *dentry, const char *func, int line);
 void au_dbg_verify_gen(struct dentry *parent, unsigned int sigen);
 void au_dbg_verify_kthread(void);
 
+int __init au_debug_init(void);
+
 #define AuDbgWhlist(w) do { \
 	mutex_lock(&au_dbg_mtx); \
 	AuDbg(#w "\n"); \
@@ -173,6 +175,7 @@ void au_dbg_verify_kthread(void);
 AuStubVoid(au_dbg_verify_dinode, struct dentry *dentry)
 AuStubVoid(au_dbg_verify_gen, struct dentry *parent, unsigned int sigen)
 AuStubVoid(au_dbg_verify_kthread, void)
+AuStubInt0(__init au_debug_init, void)
 
 #define AuDbgWhlist(w)		do {} while (0)
 #define AuDbgVdir(v)		do {} while (0)

fs/aufs/module.c

@@ -179,6 +179,7 @@ static int __init aufs_init(void)
 
 	au_sbilist_init();
 	sysaufs_brs_init();
+	au_debug_init();
 	au_dy_init();
 	err = sysaufs_init();
 	if (unlikely(err))