[PATCH 4.9 64/83] dm raid: fix discard support regression

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Heinz Mauelshagen <heinzm@xxxxxxxxxx>

commit 11e2968478edc07a75ee1efb45011b3033c621c2 upstream.

Commit ecbfb9f118 ("dm raid: add raid level takeover support") moved the
configure_discard_support() call from raid_ctr() to raid_preresume().

Enabling/disabling discard _must_ happen during table load (through the
.ctr hook).  Fix this regression by moving the
configure_discard_support() call back to raid_ctr().

Fixes: ecbfb9f118 ("dm raid: add raid level takeover support")
Signed-off-by: Heinz Mauelshagen <heinzm@xxxxxxxxxx>
Signed-off-by: Mike Snitzer <snitzer@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/md/dm-raid.c |    9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

--- a/drivers/md/dm-raid.c
+++ b/drivers/md/dm-raid.c
@@ -2994,6 +2994,9 @@ static int raid_ctr(struct dm_target *ti
 		}
 	}
 
+	/* Disable/enable discard support on raid set. */
+	configure_discard_support(rs);
+
 	mddev_unlock(&rs->md);
 	return 0;
 
@@ -3580,12 +3583,6 @@ static int raid_preresume(struct dm_targ
 	if (test_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags))
 		rs_update_sbs(rs);
 
-	/*
-	 * Disable/enable discard support on raid set after any
-	 * conversion, because devices can have been added
-	 */
-	configure_discard_support(rs);
-
 	/* Load the bitmap from disk unless raid0 */
 	r = __load_dirty_region_bitmap(rs);
 	if (r)