[dm-devel] [PATCH] dm-crypt: fix warning in shutdown path

[Kent Overstreet]

The counter for the number of allocated pages includes pages in the
mempool's reserve, so checking that the number of allocated pages is 0
needs to happen after we exit the mempool.

Signed-off-by: Kent Overstreet <kent.overstreet at gmail.com>
---
 drivers/md/dm-crypt.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index eaf6b279ac..9a000aa955 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -2221,14 +2221,14 @@ static void crypt_dtr(struct dm_target *ti)
 
 	bioset_exit(&cc->bs);
 
-	if (mempool_initialized(&cc->page_pool))
-		WARN_ON(percpu_counter_sum(&cc->n_allocated_pages) != 0);
-	percpu_counter_destroy(&cc->n_allocated_pages);
-
 	mempool_exit(&cc->page_pool);
 	mempool_exit(&cc->req_pool);
 	mempool_exit(&cc->tag_pool);
 
+	if (cc->n_allocated_pages.counters)
+		WARN_ON(percpu_counter_sum(&cc->n_allocated_pages) != 0);
+	percpu_counter_destroy(&cc->n_allocated_pages);
+
 	if (cc->iv_gen_ops && cc->iv_gen_ops->dtr)
 		cc->iv_gen_ops->dtr(cc);
 
-- 
2.17.1