From 99afd20ce5420eed51b50d2ea4806d864724cf2c Mon Sep 17 00:00:00 2001
From: Jan-Simon Pendry <pendry@ucbvax.Berkeley.EDU>
Date: Wed, 17 May 1995 18:43:35 -0800
Subject: [PATCH] expand vput inline so that locking is managed properly

SCCS-vsn: sys/kern/vfs_subr.c 8.25
---
 usr/src/sys/kern/vfs_subr.c | 29 ++++++++++++++++++++++++++---
 1 file changed, 26 insertions(+), 3 deletions(-)

diff --git a/usr/src/sys/kern/vfs_subr.c b/usr/src/sys/kern/vfs_subr.c
index 00cd9bb2fa..cc599a5ed1 100644
--- a/usr/src/sys/kern/vfs_subr.c
+++ b/usr/src/sys/kern/vfs_subr.c
@@ -9,7 +9,7 @@
  *
  * %sccs.include.redist.c%
  *
- *	@(#)vfs_subr.c	8.24 (Berkeley) %G%
+ *	@(#)vfs_subr.c	8.25 (Berkeley) %G%
  */
 
 /*
@@ -813,8 +813,31 @@ vput(vp)
 {
 	struct proc *p = curproc;	/* XXX */
 
-	VOP_UNLOCK(vp, 0, p);
-	vrele(vp);
+#ifdef DIGANOSTIC
+	if (vp == NULL)
+		panic("vput: null vp");
+#endif
+	simple_lock(&vp->v_interlock);
+	vp->v_usecount--;
+	if (vp->v_usecount > 0) {
+		simple_unlock(&vp->v_interlock);
+		VOP_UNLOCK(vp, 0, p);
+		return;
+	}
+#ifdef DIAGNOSTIC
+	if (vp->v_usecount < 0 || vp->v_writecount != 0) {
+		vprint("vput: bad ref count", vp);
+		panic("vput: ref cnt");
+	}
+#endif
+	/*
+	 * insert at tail of LRU list
+	 */
+	simple_lock(&vnode_free_list_slock);
+	TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist);
+	simple_unlock(&vnode_free_list_slock);
+	simple_unlock(&vp->v_interlock);
+	VOP_INACTIVE(vp, p);
 }
 
 /*
-- 
2.20.1