From c8f780e3d618efb8f42814b3a20e344f4e771371 Mon Sep 17 00:00:00 2001
From: Konstantin Belousov <kib@FreeBSD.org>
Date: Sun, 11 May 2014 18:07:07 +0000
Subject: [PATCH] Fix locking.  The dst_object must remain locked on the retry
 of the loop iteration.

Reported and tested by:	pho
Sponsored by:	The FreeBSD Foundation
MFC after:	6 days
---
 sys/vm/vm_fault.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/sys/vm/vm_fault.c b/sys/vm/vm_fault.c
index 125a5fc2bdd..ff6bca07717 100644
--- a/sys/vm/vm_fault.c
+++ b/sys/vm/vm_fault.c
@@ -1359,6 +1359,7 @@ again:
 					VM_OBJECT_WUNLOCK(dst_object);
 					VM_OBJECT_RUNLOCK(object);
 					VM_WAIT;
+					VM_OBJECT_WLOCK(dst_object);
 					goto again;
 				}
 			} while (dst_m == NULL);