Index: sys/kern/vfs_vnops.c
===================================================================
--- sys/kern/vfs_vnops.c
+++ sys/kern/vfs_vnops.c
@@ -2436,7 +2436,8 @@
 }
 
 int
-vn_bmap_seekhole(struct vnode *vp, u_long cmd, off_t *off, struct ucred *cred)
+vn_bmap_seekhole_locked(struct vnode *vp, u_long cmd, off_t *off,
+    struct ucred *cred)
 {
 	struct vattr va;
 	daddr_t bn, bnp;
@@ -2445,21 +2446,20 @@
 	int error;
 
 	KASSERT(cmd == FIOSEEKHOLE || cmd == FIOSEEKDATA,
-	    ("Wrong command %lu", cmd));
+	    ("%s: Wrong command %lu", __func__, cmd));
+	ASSERT_VOP_LOCKED(vp, "vn_bmap_seekhole_locked");
 
-	if (vn_lock(vp, LK_SHARED) != 0)
-		return (EBADF);
 	if (vp->v_type != VREG) {
 		error = ENOTTY;
-		goto unlock;
+		goto out;
 	}
 	error = VOP_GETATTR(vp, &va, cred);
 	if (error != 0)
-		goto unlock;
+		goto out;
 	noff = *off;
 	if (noff >= va.va_size) {
 		error = ENXIO;
-		goto unlock;
+		goto out;
 	}
 	bsize = vp->v_mount->mnt_stat.f_iosize;
 	for (bn = noff / bsize; noff < va.va_size; bn++, noff += bsize -
@@ -2467,14 +2467,14 @@
 		error = VOP_BMAP(vp, bn, NULL, &bnp, NULL, NULL);
 		if (error == EOPNOTSUPP) {
 			error = ENOTTY;
-			goto unlock;
+			goto out;
 		}
 		if ((bnp == -1 && cmd == FIOSEEKHOLE) ||
 		    (bnp != -1 && cmd == FIOSEEKDATA)) {
 			noff = bn * bsize;
 			if (noff < *off)
 				noff = *off;
-			goto unlock;
+			goto out;
 		}
 	}
 	if (noff > va.va_size)
@@ -2482,13 +2482,27 @@
 	/* noff == va.va_size. There is an implicit hole at the end of file. */
 	if (cmd == FIOSEEKDATA)
 		error = ENXIO;
-unlock:
-	VOP_UNLOCK(vp);
+out:
 	if (error == 0)
 		*off = noff;
 	return (error);
 }
 
+int
+vn_bmap_seekhole(struct vnode *vp, u_long cmd, off_t *off, struct ucred *cred)
+{
+	int error;
+
+	KASSERT(cmd == FIOSEEKHOLE || cmd == FIOSEEKDATA,
+	    ("%s: Wrong command %lu", __func__, cmd));
+
+	if (vn_lock(vp, LK_SHARED) != 0)
+		return (EBADF);
+	error = vn_bmap_seekhole_locked(vp, cmd, off, cred);
+	VOP_UNLOCK(vp);
+	return (error);
+}
+
 int
 vn_seek(struct file *fp, off_t offset, int whence, struct thread *td)
 {
Index: sys/sys/vnode.h
===================================================================
--- sys/sys/vnode.h
+++ sys/sys/vnode.h
@@ -731,6 +731,8 @@
 void	vn_printf(struct vnode *vp, const char *fmt, ...) __printflike(2,3);
 int	vrecycle(struct vnode *vp);
 int	vrecyclel(struct vnode *vp);
+int	vn_bmap_seekhole_locked(struct vnode *vp, u_long cmd, off_t *off,
+	    struct ucred *cred);
 int	vn_bmap_seekhole(struct vnode *vp, u_long cmd, off_t *off,
 	    struct ucred *cred);
 int	vn_close(struct vnode *vp,