Index: sys/miscfs/specfs/spec_vnops.c
===================================================================
RCS file: /cvsroot/src/sys/miscfs/specfs/spec_vnops.c,v
retrieving revision 1.218
diff -p -u -r1.218 spec_vnops.c
--- sys/miscfs/specfs/spec_vnops.c	22 Apr 2023 15:32:49 -0000	1.218
+++ sys/miscfs/specfs/spec_vnops.c	22 Feb 2024 08:54:16 -0000
@@ -727,11 +727,11 @@ spec_open(void *v)
 	enum kauth_device_req req;
 	specnode_t *sn, *sn1;
 	specdev_t *sd;
+	int dtype;
 	spec_ioctl_t ioctl;
 	u_int gen = 0;
 	const char *name = NULL;
 	bool needclose = false;
-	struct partinfo pi;
 
 	KASSERT(VOP_ISLOCKED(vp) == LK_EXCLUSIVE);
 	KASSERTMSG(vp->v_type == VBLK || vp->v_type == VCHR, "type=%d",
@@ -1038,11 +1038,23 @@ spec_open(void *v)
 	 * forbidden to devsw_detach until closed).  So it is safe to
 	 * query cdev_type unconditionally here.
 	 */
-	if (cdev_type(dev) == D_DISK) {
-		ioctl = vp->v_type == VCHR ? cdev_ioctl : bdev_ioctl;
-		if ((*ioctl)(dev, DIOCGPARTINFO, &pi, FREAD, curlwp) == 0)
-			uvm_vnp_setsize(vp,
-			    (voff_t)pi.pi_secsize * pi.pi_size);
+	switch (vp->v_type) {
+	case VCHR:
+		ioctl = bdev_ioctl;
+		dtype = cdev_type(dev);
+		break;
+	default:
+		ioctl = bdev_ioctl;
+		dtype = bdev_type(dev);
+		break;
+	}
+	if (dtype == D_DISK) {
+		off_t count;
+		u_int sz;
+
+		if ((*ioctl)(dev, DIOCGMEDIASIZE, &count, FREAD, curlwp) == 0
+		    && (*ioctl)(dev, DIOCGSECTORSIZE, &sz, FREAD, curlwp) == 0)
+			uvm_vnp_setsize(vp, (voff_t)count * sz);
 	}
 
 	/* Success!  */