From 8e31b510b050a60e0efc2cf0f63e08cfd9263ac4 Mon Sep 17 00:00:00 2001
From: Bryan Drewery <bdrewery@FreeBSD.org>
Date: Sat, 18 Feb 2017 05:07:53 +0000
Subject: [PATCH] Fix panic with unlocked vnode to vrecycle().

MFC after:	2 weeks
---
 sys/kern/uipc_mqueue.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/sys/kern/uipc_mqueue.c b/sys/kern/uipc_mqueue.c
index 488650190a3..354564b080f 100644
--- a/sys/kern/uipc_mqueue.c
+++ b/sys/kern/uipc_mqueue.c
@@ -714,7 +714,9 @@ do_recycle(void *context, int pending __unused)
 {
 	struct vnode *vp = (struct vnode *)context;
 
+	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
 	vrecycle(vp);
+	VOP_UNLOCK(vp, 0);
 	vdrop(vp);
 }