- Replace v_flag with v_iflag and v_vflag

 - v_vflag is protected by the vnode lock and is used when synchronization
   with VOP calls is needed.
 - v_iflag is protected by interlock and is used for dealing with vnode
   management issues.  These flags include X/O LOCK, FREE, DOOMED, etc.
 - All accesses to v_iflag and v_vflag have either been locked or marked with
   mp_fixme's.
 - Many ASSERT_VOP_LOCKED calls have been added where the locking was not
   clear.
 - Many functions in vfs_subr.c were restructured to provide for stronger
   locking.

Idea stolen from:	BSD/OS

2 files changed, 7 insertions, 6 deletions

diff --git a/sys/fs/unionfs/union_subr.c b/sys/fs/unionfs/union_subr.c
index d7bbfb4..66a4013 100644
--- a/sys/fs/unionfs/union_subr.c
+++ b/sys/fs/unionfs/union_subr.c
@@ -373,7 +373,7 @@ union_allocvp(vpp, mp, dvp, upperdvp, cnp, uppervp, lowervp, docache)
 			if (lowervp != NULLVP)
 				VREF(lowervp);
 		}
-		vflag = VROOT;
+		vflag = VV_ROOT;
 	}
 
 loop:
@@ -563,7 +563,8 @@ loop:
 	MALLOC((*vpp)->v_data, void *, sizeof(struct union_node),
 		M_TEMP, M_WAITOK);
 
-	(*vpp)->v_flag |= vflag;
+	ASSERT_VOP_LOCKED(*vpp, "union_allocvp");
+	(*vpp)->v_vflag |= vflag;
 	if (uppervp)
 		(*vpp)->v_type = uppervp->v_type;
 	else
diff --git a/sys/fs/unionfs/union_vnops.c b/sys/fs/unionfs/union_vnops.c
index 8035799..227e817 100644
--- a/sys/fs/unionfs/union_vnops.c
+++ b/sys/fs/unionfs/union_vnops.c
@@ -190,7 +190,7 @@ union_lookup1(udvp, pdvp, vpp, cnp)
 	 * hierarchy.
 	 */
 	if (cnp->cn_flags & ISDOTDOT) {
-		while ((dvp != udvp) && (dvp->v_flag & VROOT)) {
+		while ((dvp != udvp) && (dvp->v_vflag & VV_ROOT)) {
 			/*
 			 * Don't do the NOCROSSMOUNT check
 			 * at this level.  By definition,
@@ -1625,7 +1625,7 @@ union_getwritemount(ap)
 
 	if (uvp == NULL) {
 		VI_LOCK(vp);
-		if (vp->v_flag & VFREE) {
+		if (vp->v_iflag & VI_FREE) {
 			VI_UNLOCK(vp);
 			return (EOPNOTSUPP);
 		}
@@ -1788,7 +1788,7 @@ union_createvobject(ap)
 {
 	struct vnode *vp = ap->a_vp;
 
-	vp->v_flag |= VOBJBUF;
+	vp->v_vflag |= VV_OBJBUF;
 	return (0);
 }
 
@@ -1803,7 +1803,7 @@ union_destroyvobject(ap)
 {
 	struct vnode *vp = ap->a_vp;
 
-	vp->v_flag &= ~VOBJBUF;
+	vp->v_vflag &= ~VV_OBJBUF;
 	return (0);
 }