Index: geom_vfs.c
===================================================================
RCS file: /usr/repo/src/sys/geom/geom_vfs.c,v
retrieving revision 1.9
diff -u -p -r1.9 geom_vfs.c
--- geom_vfs.c	19 Feb 2005 11:44:56 -0000	1.9
+++ geom_vfs.c	22 Aug 2005 00:40:24 -0000
@@ -136,26 +136,41 @@ g_vfs_open(struct vnode *vp, struct g_co
 	g_topology_assert();
 
 	*cpp = NULL;
-	pp = g_dev_getprovider(vp->v_rdev);
-	if (pp == NULL)
-		return (ENOENT);
-	gp = g_new_geomf(&g_vfs_class, "%s.%s", fsname, pp->name);
-	cp = g_new_consumer(gp);
-	g_attach(cp, pp);
-	error = g_access(cp, 1, wr, 1);
-	if (error) {
-		g_wither_geom(gp, ENXIO);
-		return (error);
+	bo = &vp->v_bufobj;
+	/* Is this first mount? */
+	if (bo->bo_private == vp) {
+		pp = g_dev_getprovider(vp->v_rdev);
+		if (pp == NULL)
+			return (ENOENT);
+		gp = g_new_geomf(&g_vfs_class, "%s.%s", fsname, pp->name);
+		cp = g_new_consumer(gp);
+		g_attach(cp, pp);
+		error = g_access(cp, 1, wr, 1);
+		if (error) {
+			g_wither_geom(gp, ENXIO);
+			return (error);
+		}
+		cp->private = vp;
+		vnode_create_vobject(vp, pp->mediasize, curthread);
+		bo = &vp->v_bufobj;
+		bo->bo_ops = g_vfs_bufops;
+		bo->bo_private = cp;
+		bo->bo_bsize = pp->sectorsize;
+		gp->softc = bo;
+	} else {
+		cp = bo->bo_private;
+		/*
+		 * Don't allow for mount when already mounted R/W.
+		 * Don't allow for R/W mount when already mounted.
+		 */
+		if (cp->acw > 0 || wr)
+			return (EPERM);
+		error = g_access(cp, 1, wr, 1);
+		if (error)
+			return (error);
 	}
-	vnode_create_vobject(vp, pp->mediasize, curthread);
 	*cpp = cp;
-	bo = &vp->v_bufobj;
-	bo->bo_ops = g_vfs_bufops;
-	bo->bo_private = cp;
-	bo->bo_bsize = pp->sectorsize;
-	gp->softc = bo;
-
-	return (error);
+	return (0);
 }
 
 void
@@ -168,6 +183,20 @@ g_vfs_close(struct g_consumer *cp, struc
 
 	gp = cp->geom;
 	bo = gp->softc;
-	bufobj_invalbuf(bo, V_SAVE, td, 0, 0);
-	g_wither_geom_close(gp, ENXIO);
+	/* Is this last close? */
+	if (cp->acr == 1) {
+		/*
+		 * Put device vnode back into bo_private, so we can mount this
+		 * file system later and first mount will be detected properly.
+		 */
+		bo->bo_private = cp->private;
+		bufobj_invalbuf(bo, V_SAVE, td, 0, 0);
+		g_wither_geom_close(gp, ENXIO);
+	} else {
+		/* It could be open only for reading here. */
+		KASSERT(cp->acr > 1 && cp->acw == 0 && cp->ace > 0,
+		    ("Invalid access for %s (r%dw%de%d).", cp->provider->name,
+		    cp->acr, cp->acw, cp->ace));
+		g_access(cp, -1, 0, -1);
+	}
 }