[src/trunk]: src/sys/fs/union Handle v_writecount from union_open(), union_cl...

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

details:   https://anonhg.NetBSD.org/src/rev/b7e0372e726c
branches:  trunk
changeset: 351933:b7e0372e726c
user:      hannken <hannken%NetBSD.org@localhost>
date:      Mon Mar 06 10:08:49 2017 +0000

description:
Handle v_writecount from union_open(), union_close() and union_revoke()
so lower file system vnodes get marked as open for writing.

diffstat:

 sys/fs/union/union_vnops.c |  27 ++++++++++++++++++++++++---
 1 files changed, 24 insertions(+), 3 deletions(-)

diffs (70 lines):

diff -r c2afdd6693a1 -r b7e0372e726c sys/fs/union/union_vnops.c
--- a/sys/fs/union/union_vnops.c        Mon Mar 06 10:07:52 2017 +0000
+++ b/sys/fs/union/union_vnops.c        Mon Mar 06 10:08:49 2017 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: union_vnops.c,v 1.63 2015/04/20 23:03:08 riastradh Exp $       */
+/*     $NetBSD: union_vnops.c,v 1.64 2017/03/06 10:08:49 hannken Exp $ */
 
 /*
  * Copyright (c) 1992, 1993, 1994, 1995
@@ -72,7 +72,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: union_vnops.c,v 1.63 2015/04/20 23:03:08 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: union_vnops.c,v 1.64 2017/03/06 10:08:49 hannken Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -616,6 +616,11 @@
                        error = union_copyup(un, (mode&O_TRUNC) == 0, cred, l);
                        if (error == 0)
                                error = VOP_OPEN(un->un_uppervp, mode, cred);
+                       if (error == 0) {
+                               mutex_enter(un->un_uppervp->v_interlock);
+                               un->un_uppervp->v_writecount++;
+                               mutex_exit(un->un_uppervp->v_interlock);
+                       }
                        return (error);
                }
 
@@ -640,6 +645,11 @@
                return ENXIO;
 
        error = VOP_OPEN(tvp, mode, cred);
+       if (error == 0 && (ap->a_mode & FWRITE)) {
+               mutex_enter(tvp->v_interlock);
+               tvp->v_writecount++;
+               mutex_exit(tvp->v_interlock);
+       }
 
        return (error);
 }
@@ -669,6 +679,12 @@
 
        KASSERT(vp != NULLVP);
        ap->a_vp = vp;
+       if ((ap->a_fflag & FWRITE)) {
+               KASSERT(vp == un->un_uppervp);
+               mutex_enter(vp->v_interlock);
+               vp->v_writecount--;
+               mutex_exit(vp->v_interlock);
+       }
        if (do_lock)
                vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
        error = VCALL(vp, VOFFSET(vop_close), ap);
@@ -1048,8 +1064,13 @@
        } */ *ap = v;
        struct vnode *vp = ap->a_vp;
 
-       if (UPPERVP(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);
                VOP_REVOKE(UPPERVP(vp), ap->a_flags);
+       }
        if (LOWERVP(vp))
                VOP_REVOKE(LOWERVP(vp), ap->a_flags);
        vgone(vp);      /* XXXAD?? */