Index: sys/kern/vfs_vnops.c
===================================================================
--- sys/kern/vfs_vnops.c
+++ sys/kern/vfs_vnops.c
@@ -1459,21 +1459,10 @@
 
 /* generic FIOBMAP2 implementation */
 static int
-vn_ioc_bmap2(struct file *fp, struct fiobmap2_arg *arg, struct ucred *cred)
+vn_ioc_bmap2(struct vnode *vp, daddr_t lbn, daddr_t *bn, int *runb, int *runp)
 {
-	struct vnode *vp = fp->f_vnode;
-	daddr_t lbn = arg->bn;
-	int error;
-
-	vn_lock(vp, LK_SHARED | LK_RETRY);
-#ifdef MAC
-	error = mac_vnode_check_read(cred, fp->f_cred, vp);
-	if (error == 0)
-#endif
-		error = VOP_BMAP(vp, lbn, NULL, &arg->bn, &arg->runp,
-			&arg->runb);
-	VOP_UNLOCK(vp, 0);
-	return (error);
+	ASSERT_VOP_LOCKED(vp, "vn_ioc_bmap2 with no vp lock held");
+	return( VOP_BMAP(vp, lbn, NULL, bn, runp, runb));
 }
 
 /*
@@ -1485,6 +1474,7 @@
 {
 	struct vattr vattr;
 	struct vnode *vp;
+	struct fiobmap2_arg *bmarg;
 	int error;
 
 	vp = fp->f_vnode;
@@ -1500,8 +1490,17 @@
 				*(int *)data = vattr.va_size - fp->f_offset;
 			return (error);
 		case FIOBMAP2:
-			return (vn_ioc_bmap2(fp, (struct fiobmap2_arg*)data,
-				active_cred));
+			bmarg = (struct fiobmap2_arg *)data;
+			vn_lock(vp, LK_SHARED | LK_RETRY);
+#ifdef MAC
+			error = mac_vnode_check_read(active_cred, fp->f_cred,
+			    vp);
+			if (error == 0)
+#endif
+			error = vn_ioc_bmap2(vp, bmarg->bn, &bmarg->bn,
+			    &bmarg->runb, &bmarg->runp);
+			VOP_UNLOCK(vp, 0);
+			return (error);
 		case FIONBIO:
 		case FIOASYNC:
 			return (0);