From cc8662b0f9d569bd8da2cb558ccc5a2a38f53198 Mon Sep 17 00:00:00 2001
From: Jeff Roberson <jeff@FreeBSD.org>
Date: Sat, 6 Jul 2002 04:39:48 +0000
Subject: [PATCH] Add "vop_rename_pre" to do pre rename lock verification. 
 This is enabled only with DEBUG_VFS_LOCKS.

---
 sys/kern/vfs_subr.c | 21 ++++++++++++++++++++-
 sys/sys/vnode.h     |  2 ++
 2 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/sys/kern/vfs_subr.c b/sys/kern/vfs_subr.c
index 6662d019aaf9..fb7ba43c21f7 100644
--- a/sys/kern/vfs_subr.c
+++ b/sys/kern/vfs_subr.c
@@ -234,7 +234,26 @@ int (*softdep_process_worklist_hook)(struct mount *);
 int vfs_badlock_print = 1;
 /* Panic on violation */
 int vfs_badlock_panic = 1;
-#endif
+
+void
+vop_rename_pre(void *ap)
+{
+	struct vop_rename_args *a = ap;
+
+	/* Check the source (from) */
+	if (a->a_tdvp != a->a_fdvp)
+		ASSERT_VOP_UNLOCKED(a->a_fdvp, "vop_rename: fdvp locked.\n");
+	if (a->a_tvp != a->a_fvp)
+		ASSERT_VOP_UNLOCKED(a->a_fvp, "vop_rename: tvp locked.\n");
+
+	/* Check the target */
+	if (a->a_tvp)
+		ASSERT_VOP_LOCKED(a->a_tvp, "vop_rename: tvp not locked.\n");
+
+	ASSERT_VOP_LOCKED(a->a_tdvp, "vop_rename: tdvp not locked.\n");
+}
+
+#endif	/* DEBUG_VFS_LOCKS */
 
 void
 v_addpollinfo(struct vnode *vp)
diff --git a/sys/sys/vnode.h b/sys/sys/vnode.h
index 3c7542976440..4e315d70fa6c 100644
--- a/sys/sys/vnode.h
+++ b/sys/sys/vnode.h
@@ -523,6 +523,8 @@ do {									\
 		    str, _vp);						\
 } while (0)
 
+void vop_rename_pre(void *a);
+
 #else
 
 #define ASSERT_VOP_LOCKED(vp, str)