Index: sys/kern/vfs_subr.c
===================================================================
--- sys/kern/vfs_subr.c
+++ sys/kern/vfs_subr.c
@@ -4335,6 +4335,17 @@
  * perform msync on all vnodes under a mount point
  * the mount point must be locked.
  */
+static bool
+vfs_msync_filter(struct vnode *vp, void *arg)
+{
+	struct vm_object *obj;
+	int flags = *(int *)arg;
+
+	obj = vp->v_object;
+	return (obj != NULL && vm_object_mightbedirty(obj) &&
+	    (flags == MNT_WAIT || VOP_ISLOCKED(vp) == 0));
+}
+
 void
 vfs_msync(struct mount *mp, int flags)
 {
@@ -4348,7 +4359,7 @@
 		return;
 
 	td = curthread;
-	MNT_VNODE_FOREACH_ACTIVE(vp, mp, mvp) {
+	MNT_VNODE_FOREACH_ACTIVE_FILTER(vp, mp, mvp, vfs_msync_filter, &flags) {
 		obj = vp->v_object;
 		if (obj != NULL && vm_object_mightbedirty(obj) &&
 		    (flags == MNT_WAIT || VOP_ISLOCKED(vp) == 0)) {
@@ -5959,7 +5970,8 @@
 }
 
 static struct vnode *
-mnt_vnode_next_active(struct vnode **mvp, struct mount *mp)
+mnt_vnode_next_active(struct vnode **mvp, struct mount *mp,
+    bool (*cb)(struct vnode *, void *), void *cbarg)
 {
 	struct vnode *vp, *nvp;
 
@@ -5972,6 +5984,25 @@
 			vp = TAILQ_NEXT(vp, v_actfreelist);
 			continue;
 		}
+		/*
+		 * See if we want to process the vnode. Note we may encounter a
+		 * long string of vnodes we don't care about and hog the list
+		 * as a result. Check for it and requeue the marker.
+		 */
+		if (cb != NULL && !cb(vp, cbarg)) {
+			if (!should_yield()) {
+				vp = TAILQ_NEXT(vp, v_actfreelist);
+				continue;
+			}
+			TAILQ_REMOVE(&mp->mnt_activevnodelist, *mvp,
+			    v_actfreelist);
+			TAILQ_INSERT_AFTER(&mp->mnt_activevnodelist, vp, *mvp,
+			    v_actfreelist);
+			mtx_unlock(&mp->mnt_listmtx);
+			kern_yield(PRI_USER);
+			mtx_lock(&mp->mnt_listmtx);
+			goto restart;
+		}
 		/*
 		 * Try-lock because this is the wrong lock order.  If that does
 		 * not succeed, drop the mount vnode list lock and try to
@@ -6005,17 +6036,19 @@
 }
 
 struct vnode *
-__mnt_vnode_next_active(struct vnode **mvp, struct mount *mp)
+__mnt_vnode_next_active(struct vnode **mvp, struct mount *mp,
+    bool (*cb)(struct vnode *, void *), void *cbarg)
 {
 
 	if (should_yield())
 		kern_yield(PRI_USER);
 	mtx_lock(&mp->mnt_listmtx);
-	return (mnt_vnode_next_active(mvp, mp));
+	return (mnt_vnode_next_active(mvp, mp, cb, cbarg));
 }
 
 struct vnode *
-__mnt_vnode_first_active(struct vnode **mvp, struct mount *mp)
+__mnt_vnode_first_active(struct vnode **mvp, struct mount *mp,
+    bool (*cb)(struct vnode *, void *), void *cbarg)
 {
 	struct vnode *vp;
 
@@ -6034,7 +6067,7 @@
 		return (NULL);
 	}
 	TAILQ_INSERT_BEFORE(vp, *mvp, v_actfreelist);
-	return (mnt_vnode_next_active(mvp, mp));
+	return (mnt_vnode_next_active(mvp, mp, cb, cbarg));
 }
 
 void
Index: sys/sys/mount.h
===================================================================
--- sys/sys/mount.h
+++ sys/sys/mount.h
@@ -256,13 +256,18 @@
 /*
  * Definitions for MNT_VNODE_FOREACH_ACTIVE.
  */
-struct vnode *__mnt_vnode_next_active(struct vnode **mvp, struct mount *mp);
-struct vnode *__mnt_vnode_first_active(struct vnode **mvp, struct mount *mp);
+struct vnode *__mnt_vnode_next_active(struct vnode **mvp, struct mount *mp,
+    bool (*cb)(struct vnode *, void *), void *cbarg);
+struct vnode *__mnt_vnode_first_active(struct vnode **mvp, struct mount *mp,
+    bool (*cb)(struct vnode *, void *), void *cbarg);
 void          __mnt_vnode_markerfree_active(struct vnode **mvp, struct mount *);
 
-#define MNT_VNODE_FOREACH_ACTIVE(vp, mp, mvp) 				\
-	for (vp = __mnt_vnode_first_active(&(mvp), (mp)); 		\
-		(vp) != NULL; vp = __mnt_vnode_next_active(&(mvp), (mp)))
+#define MNT_VNODE_FOREACH_ACTIVE_FILTER(vp, mp, mvp, cb, cbarg)		\
+	for (vp = __mnt_vnode_first_active(&(mvp), (mp), (cb), (cbarg));\
+		(vp) != NULL; vp = __mnt_vnode_next_active(&(mvp), (mp), (cb), (cbarg)))
+
+#define MNT_VNODE_FOREACH_ACTIVE(vp, mp, mvp)				\
+	MNT_VNODE_FOREACH_ACTIVE_FILTER(vp, mp, mvp, NULL, NULL)
 
 #define MNT_VNODE_FOREACH_ACTIVE_ABORT(mp, mvp)				\
 	__mnt_vnode_markerfree_active(&(mvp), (mp))