From: Mike Snitzer <snitzer@redhat.com>

Have the error target respond to a discard request with a hard -EIO
rather than fail the request with -EOPNOTSUPP.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

---
 drivers/md/dm-target.c |    5 +++++
 1 file changed, 5 insertions(+)

Index: linux-2.6.35/drivers/md/dm-target.c
===================================================================
--- linux-2.6.35.orig/drivers/md/dm-target.c
+++ linux-2.6.35/drivers/md/dm-target.c
@@ -113,6 +113,11 @@ void dm_unregister_target(struct target_
  */
 static int io_err_ctr(struct dm_target *tt, unsigned int argc, char **args)
 {
+	/*
+	 * Return error for discards instead of -EOPNOTSUPP
+	 */
+	tt->num_discard_requests = 1;
+
 	return 0;
 }