Debugging calls.

---
 drivers/md/dm-snap.c |   23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

Index: linux-2.6.26-rc5-devel/drivers/md/dm-snap.c
===================================================================
--- linux-2.6.26-rc5-devel.orig/drivers/md/dm-snap.c	2008-06-17 01:21:08.000000000 +0200
+++ linux-2.6.26-rc5-devel/drivers/md/dm-snap.c	2008-06-17 01:21:13.000000000 +0200
@@ -787,6 +787,8 @@
 		goto bad1;
 	}
 
+	printk("%p: %s ctr %s %s\n", ti, is_merge(ti) ? "merge" : "snapshot", argv[0], argv[1]);
+
 	origin_path = argv[0];
 	cow_path = argv[1];
 	persistent = toupper(*argv[2]);
@@ -986,14 +988,18 @@
 	down_write(&_origins_lock);
 	down_write(&s->lock);
 	dup = find_duplicate(s);
+	printk("find duplicate: %p\n", dup);
 	if (dup && dup->handover) {
 		down_write_nested(&dup->lock, SINGLE_DEPTH_NESTING);
+		printk("handover 2\n");
 		handover_exceptions(s, dup);
 		up_write(&dup->lock);
 	}
 	up_write(&s->lock);
 	up_write(&_origins_lock);
 
+	printk("%p: %s dtr %s %s\n", ti, is_merge(ti) ? "merge" : "snapshot", s->origin->name, s->cow->name);
+
 	if (is_merge(ti))
 		stop_merge(s->origin->bdev, 1);
 
@@ -1415,6 +1421,7 @@
 static void snapshot_resume(struct dm_target *ti)
 {
 	struct dm_snapshot *s = ti->private;
+	printk("%p: %s resume: %s %s\n", ti, is_merge(ti) ? "merge" : "snapshot", s->origin->name, s->cow->name);
 
 	down_write(&_origins_lock);
 	down_write(&s->lock);
@@ -1427,6 +1434,7 @@
 			goto ret;
 		}
 		down_write_nested(&dup->lock, SINGLE_DEPTH_NESTING);
+		printk("handover 1\n");
 		handover_exceptions(dup, s);
 		up_write(&dup->lock);
 	}
@@ -1436,6 +1444,12 @@
 	up_write(&_origins_lock);
 }
 
+static void snapshot_suspend(struct dm_target *ti)
+{
+	struct dm_snapshot *s = ti->private;
+	printk("%p: %s suspend: %s %s\n", ti, is_merge(ti) ? "merge" : "snapshot", s->origin->name, s->cow->name);
+}
+
 static int snapshot_status(struct dm_target *ti, status_type_t type,
 			   char *result, unsigned int maxlen)
 {
@@ -1603,6 +1617,8 @@
 		return -EINVAL;
 	}
 
+	printk("%p: origin ctr: %s\n", ti, argv[0]);
+
 	r = dm_get_device(ti, argv[0], 0, ti->len,
 			  dm_table_get_mode(ti->table), &dev);
 	if (r) {
@@ -1618,6 +1634,8 @@
 {
 	struct dm_dev *dev = ti->private;
 
+	printk("%p: origin dtr: %s\n", ti, dev->name);
+
 	stop_merge(dev->bdev, 0);
 	dm_put_device(ti, dev);
 }
@@ -1654,6 +1672,8 @@
 	struct dm_dev *dev = ti->private;
 	struct origin *o;
 
+	printk("%p: origin resume: %s\n", ti, dev->name);
+
 	down_read(&_origins_lock);
 	o = __lookup_origin(dev->bdev);
 	ti->split_io = minimum_chunk_size(o);
@@ -1665,6 +1685,7 @@
 static void origin_postsuspend(struct dm_target *ti)
 {
 	struct dm_dev *dev = ti->private;
+	printk("%p: origin suspend: %s\n", ti, dev->name);
 	stop_merge(dev->bdev, 0);
 }
 
@@ -1707,6 +1728,7 @@
 	.dtr     = snapshot_dtr,
 	.map     = snapshot_map,
 	.end_io  = snapshot_end_io,
+	.presuspend = snapshot_suspend,
 	.resume  = snapshot_resume,
 	.status  = snapshot_status,
 };
@@ -1719,6 +1741,7 @@
 	.dtr     = snapshot_dtr,
 	.map     = snapshot_merge_map,
 	.end_io  = snapshot_end_io,
+	.presuspend = snapshot_suspend,
 	.resume  = snapshot_resume,
 	.status  = snapshot_status,
 };