diff --git a/sys/kern/vfs_subr.c b/sys/kern/vfs_subr.c
index 3b931056edf5..2a4a2c19f22c 100644
--- a/sys/kern/vfs_subr.c
+++ b/sys/kern/vfs_subr.c
@@ -171,6 +171,16 @@ vinvalbuf(struct vnode *vp, int flags, kauth_cred_t cred, struct lwp *l,
 	mutex_enter(&bufcache_lock);
 restart:
 	for (bp = LIST_FIRST(&vp->v_dirtyblkhd); bp; bp = nbp) {
+		if (bp->b_vp != vp) {
+			if (bp->b_vp)
+				vprint("bp->b_vp", bp->b_vp);
+			else
+				printf("bp->b_vp is null\n");
+			if (vp)
+				vprint("vp", vp);
+			else
+				printf("vp is null\n");
+		}
 		KASSERT(bp->b_vp == vp);
 		nbp = LIST_NEXT(bp, b_vnbufs);
 		error = bbusy(bp, catch_p, slptimeo, NULL);
@@ -184,6 +194,16 @@ restart:
 	}
 
 	for (bp = LIST_FIRST(&vp->v_cleanblkhd); bp; bp = nbp) {
+		if (bp->b_vp != vp) {
+			if (bp->b_vp)
+				vprint("bp->b_vp", bp->b_vp);
+			else
+				printf("bp->b_vp is null\n");
+			if (vp)
+				vprint("vp", vp);
+			else
+				printf("vp is null\n");
+		}
 		KASSERT(bp->b_vp == vp);
 		nbp = LIST_NEXT(bp, b_vnbufs);
 		error = bbusy(bp, catch_p, slptimeo, NULL);