From 602d2b481a751e59a57d37475766b841e93357d2 Mon Sep 17 00:00:00 2001
From: David Greenman <dg@FreeBSD.org>
Date: Fri, 23 Dec 1994 04:52:55 +0000
Subject: [PATCH] Protect vnode buffer chain manipulation with splbio to
 prevent list corruption..

---
 sys/kern/vfs_export.c | 9 ++++++++-
 sys/kern/vfs_subr.c   | 9 ++++++++-
 2 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/sys/kern/vfs_export.c b/sys/kern/vfs_export.c
index 6713c73af23..b749976c924 100644
--- a/sys/kern/vfs_export.c
+++ b/sys/kern/vfs_export.c
@@ -36,7 +36,7 @@
  * SUCH DAMAGE.
  *
  *	@(#)vfs_subr.c	8.13 (Berkeley) 4/18/94
- * $Id: vfs_subr.c,v 1.11 1994/10/05 09:48:22 davidg Exp $
+ * $Id: vfs_subr.c,v 1.12 1994/10/06 21:06:37 davidg Exp $
  */
 
 /*
@@ -521,6 +521,7 @@ bgetvp(vp, bp)
 	register struct vnode *vp;
 	register struct buf *bp;
 {
+	int s;
 
 	if (bp->b_vp)
 		panic("bgetvp: not free");
@@ -533,7 +534,9 @@ bgetvp(vp, bp)
 	/*
 	 * Insert onto list for new vnode.
 	 */
+	s = splbio();
 	bufinsvn(bp, &vp->v_cleanblkhd);
+	splx(s);
 }
 
 /*
@@ -544,14 +547,18 @@ brelvp(bp)
 	register struct buf *bp;
 {
 	struct vnode *vp;
+	int s;
 
 	if (bp->b_vp == (struct vnode *) 0)
 		panic("brelvp: NULL");
 	/*
 	 * Delete from old vnode list, if on one.
 	 */
+	s = splbio();
 	if (bp->b_vnbufs.le_next != NOLIST)
 		bufremvn(bp);
+	splx(s);
+
 	vp = bp->b_vp;
 	bp->b_vp = (struct vnode *) 0;
 	HOLDRELE(vp);
diff --git a/sys/kern/vfs_subr.c b/sys/kern/vfs_subr.c
index 6713c73af23..b749976c924 100644
--- a/sys/kern/vfs_subr.c
+++ b/sys/kern/vfs_subr.c
@@ -36,7 +36,7 @@
  * SUCH DAMAGE.
  *
  *	@(#)vfs_subr.c	8.13 (Berkeley) 4/18/94
- * $Id: vfs_subr.c,v 1.11 1994/10/05 09:48:22 davidg Exp $
+ * $Id: vfs_subr.c,v 1.12 1994/10/06 21:06:37 davidg Exp $
  */
 
 /*
@@ -521,6 +521,7 @@ bgetvp(vp, bp)
 	register struct vnode *vp;
 	register struct buf *bp;
 {
+	int s;
 
 	if (bp->b_vp)
 		panic("bgetvp: not free");
@@ -533,7 +534,9 @@ bgetvp(vp, bp)
 	/*
 	 * Insert onto list for new vnode.
 	 */
+	s = splbio();
 	bufinsvn(bp, &vp->v_cleanblkhd);
+	splx(s);
 }
 
 /*
@@ -544,14 +547,18 @@ brelvp(bp)
 	register struct buf *bp;
 {
 	struct vnode *vp;
+	int s;
 
 	if (bp->b_vp == (struct vnode *) 0)
 		panic("brelvp: NULL");
 	/*
 	 * Delete from old vnode list, if on one.
 	 */
+	s = splbio();
 	if (bp->b_vnbufs.le_next != NOLIST)
 		bufremvn(bp);
+	splx(s);
+
 	vp = bp->b_vp;
 	bp->b_vp = (struct vnode *) 0;
 	HOLDRELE(vp);