[src/trunk]: src/sys Move v_writecount adjustment from revoke to reclaim.

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

details:   https://anonhg.NetBSD.org/src/rev/99d3877c3e20
branches:  trunk
changeset: 823749:99d3877c3e20
user:      hannken <hannken%NetBSD.org@localhost>
date:      Sun May 07 08:21:57 2017 +0000

description:
Move v_writecount adjustment from revoke to reclaim.

diffstat:

 sys/fs/union/union_vnops.c     |  22 +++++++++++++---------
 sys/miscfs/genfs/layer_vnops.c |  17 ++++++++---------
 2 files changed, 21 insertions(+), 18 deletions(-)

diffs (99 lines):

diff -r 6498cd49f7eb -r 99d3877c3e20 sys/fs/union/union_vnops.c
--- a/sys/fs/union/union_vnops.c        Sun May 07 08:21:08 2017 +0000
+++ b/sys/fs/union/union_vnops.c        Sun May 07 08:21:57 2017 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: union_vnops.c,v 1.67 2017/04/26 03:02:48 riastradh Exp $       */
+/*     $NetBSD: union_vnops.c,v 1.68 2017/05/07 08:22:40 hannken Exp $ */
 
 /*
  * Copyright (c) 1992, 1993, 1994, 1995
@@ -72,7 +72,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: union_vnops.c,v 1.67 2017/04/26 03:02:48 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: union_vnops.c,v 1.68 2017/05/07 08:22:40 hannken Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -1064,13 +1064,8 @@
        } */ *ap = v;
        struct vnode *vp = ap->a_vp;
 
-       if (UPPERVP(vp)) {
-               mutex_enter(UPPERVP(vp)->v_interlock);
-               KASSERT(vp->v_interlock == UPPERVP(vp)->v_interlock);
-               UPPERVP(vp)->v_writecount -= vp->v_writecount;
-               mutex_exit(UPPERVP(vp)->v_interlock);
+       if (UPPERVP(vp))
                VOP_REVOKE(UPPERVP(vp), ap->a_flags);
-       }
        if (LOWERVP(vp))
                VOP_REVOKE(LOWERVP(vp), ap->a_flags);
        vgone(vp);      /* XXXAD?? */
@@ -1585,8 +1580,17 @@
        struct vop_reclaim_args /* {
                struct vnode *a_vp;
        } */ *ap = v;
+       struct vnode *vp = ap->a_vp;
+       struct vnode *uvp = UPPERVP(vp);
 
-       union_freevp(ap->a_vp);
+       if (uvp != NULL) {
+               mutex_enter(uvp->v_interlock);
+               KASSERT(vp->v_interlock == uvp->v_interlock);
+               uvp->v_writecount -= vp->v_writecount;
+               mutex_exit(uvp->v_interlock);
+       }
+
+       union_freevp(vp);
 
        return (0);
 }
diff -r 6498cd49f7eb -r 99d3877c3e20 sys/miscfs/genfs/layer_vnops.c
--- a/sys/miscfs/genfs/layer_vnops.c    Sun May 07 08:21:08 2017 +0000
+++ b/sys/miscfs/genfs/layer_vnops.c    Sun May 07 08:21:57 2017 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: layer_vnops.c,v 1.63 2017/04/26 03:02:49 riastradh Exp $       */
+/*     $NetBSD: layer_vnops.c,v 1.64 2017/05/07 08:21:57 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 1.63 2017/04/26 03:02:49 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: layer_vnops.c,v 1.64 2017/05/07 08:21:57 hannken Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -693,15 +693,8 @@
         * We will most likely end up in vclean which uses the v_usecount
         * to determine if a vnode is active.  Take an extra reference on
         * the lower vnode so it will always close and inactivate.
-        * Remove our writecount from the lower vnode.
         */
        vref(lvp);
-
-       mutex_enter(vp->v_interlock);
-       KASSERT(vp->v_interlock == lvp->v_interlock);
-       lvp->v_writecount -= vp->v_writecount;
-       mutex_exit(vp->v_interlock);
-
        error = LAYERFS_DO_BYPASS(vp, ap);
        vrele(lvp);
 
@@ -734,6 +727,12 @@
                 */
                lmp->layerm_rootvp = NULL;
        }
+
+       mutex_enter(vp->v_interlock);
+       KASSERT(vp->v_interlock == lowervp->v_interlock);
+       lowervp->v_writecount -= vp->v_writecount;
+       mutex_exit(vp->v_interlock);
+
        /* After this assignment, this node will not be re-used. */
        xp->layer_lowervp = NULL;
        kmem_free(vp->v_data, lmp->layerm_size);