[src/trunk]: src/sys/miscfs/genfs Layer_revoke(): change previous to always t...

[hannken <hannken%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/ac4ee87901a2
branches:  trunk
changeset: 760803:ac4ee87901a2
user:      hannken <hannken%NetBSD.org@localhost>
date:      Thu Jan 13 10:28:38 2011 +0000

description:
Layer_revoke(): change previous to always take an extra reference on the
lower vnode before passing down the VOP_REVOKE().  This way VOP_REVOKE()
on a layered file system always inactivates and closes the lower vnode.

Should finally fix PR kern/43456.

diffstat:

 sys/miscfs/genfs/layer_vnops.c |  17 +++++++----------
 1 files changed, 7 insertions(+), 10 deletions(-)

diffs (43 lines):

diff -r 7e5731565299 -r ac4ee87901a2 sys/miscfs/genfs/layer_vnops.c
--- a/sys/miscfs/genfs/layer_vnops.c    Thu Jan 13 10:26:47 2011 +0000
+++ b/sys/miscfs/genfs/layer_vnops.c    Thu Jan 13 10:28:38 2011 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: layer_vnops.c,v 1.45 2011/01/10 11:11:03 hannken Exp $ */
+/*     $NetBSD: layer_vnops.c,v 1.46 2011/01/13 10:28:38 hannken Exp $ */
 
 /*
  * Copyright (c) 1999 National Aeronautics & Space Administration
@@ -170,7 +170,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: layer_vnops.c,v 1.45 2011/01/10 11:11:03 hannken Exp $");
+__KERNEL_RCSID(0, "$NetBSD: layer_vnops.c,v 1.46 2011/01/13 10:28:38 hannken Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -658,19 +658,16 @@
        } */ *ap = v;
        struct vnode *vp = ap->a_vp;
        struct vnode *lvp = LAYERVPTOLOWERVP(vp);
-       int i, n, error;
+       int error;
 
        /*
         * We will most likely end up in vclean which uses the v_usecount
-        * to determine if a vnode is active.  So we have to adjust the
-        * lower vp's usecount to be at least as high as our usecount.
+        * to determine if a vnode is active.  Take an extra reference on
+        * the lower vnode so it will always close and inactivate.
         */
-       n = vp->v_usecount - lvp->v_usecount;
-       for (i = 0; i < n; i++)
-               vref(lvp);
+       vref(lvp);
        error = LAYERFS_DO_BYPASS(vp, ap);
-       for (i = 0; i < n; i++)
-               vrele(lvp);
+       vrele(lvp);
 
        return error;
 }