From a0b8e597e5b0575c09efb04177e21842f907e42e Mon Sep 17 00:00:00 2001
From: Konstantin Belousov <kib@FreeBSD.org>
Date: Sun, 2 May 2010 19:25:22 +0000
Subject: [PATCH] Lock the page around hold_count access.

Reviewed by:	alc
---
 sys/kern/uipc_syscalls.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/sys/kern/uipc_syscalls.c b/sys/kern/uipc_syscalls.c
index a14be72064e..3271235a6f9 100644
--- a/sys/kern/uipc_syscalls.c
+++ b/sys/kern/uipc_syscalls.c
@@ -2108,6 +2108,7 @@ retry_space:
 				mbstat.sf_iocnt++;
 			}
 			if (error) {
+				vm_page_lock(pg);
 				vm_page_lock_queues();
 				vm_page_unwire(pg, 0);
 				/*
@@ -2121,6 +2122,7 @@ retry_space:
 					vm_page_free(pg);
 				}
 				vm_page_unlock_queues();
+				vm_page_unlock(pg);
 				VM_OBJECT_UNLOCK(obj);
 				if (error == EAGAIN)
 					error = 0;	/* not a real error */