--- /opt/kernel/linux-2.4.3/drivers/md/lvm.c	Mon Jan 29 01:11:20 2001
+++ drivers/md/lvm.c	Thu Apr  5 16:20:12 2001
@@ -148,6 +148,8 @@
  *                 procfs is always supported now. (JT)
  *    12/01/2001 - avoided flushing logical volume in case of shrinking
  *                 because of unecessary overhead in case of heavy updates
+ *    05/04/2001 - don't use b_blocknr/b_dev in lvm_map, it destroys
+ *		   stacking devices (Jens Axboe)
  *
  */
 
@@ -1480,14 +1482,14 @@
  */
 static int lvm_map(struct buffer_head *bh, int rw)
 {
-	int minor = MINOR(bh->b_dev);
+	int minor = MINOR(bh->b_rdev);
 	int ret = 0;
 	ulong index;
 	ulong pe_start;
 	ulong size = bh->b_size >> 9;
-	ulong rsector_tmp = bh->b_blocknr * size;
+	ulong rsector_tmp = bh->b_rsector;
 	ulong rsector_sav;
-	kdev_t rdev_tmp = bh->b_dev;
+	kdev_t rdev_tmp = bh->b_rdev;
 	kdev_t rdev_sav;
 	vg_t *vg_this = vg[VG_BLK(minor)];
 	lv_t *lv = vg_this->lv[LV_BLK(minor)];