dm integrity: flush the journal on suspend

This commit flushes the journal on suspend. It is prerequisite for the
next commit that enables activating dm integrity devices in read-only mode.

Note that we deliberately didn't flush the journal on suspend, so that the
journal replay code would be tested. However, the dm-integrity code is 5
years old now, so that journal replay is well-tested, and we can make this
change now.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>

drivers/md/dm-integrity.c

@@ -2591,10 +2591,6 @@ static void integrity_writer(struct work_struct *w)
 
 	unsigned prev_free_sectors;
 
-	/* the following test is not needed, but it tests the replay code */
-	if (unlikely(dm_post_suspending(ic->ti)) && !ic->meta_dev)
-		return;
-
 	spin_lock_irq(&ic->endio_wait.lock);
 	write_start = ic->committed_section;
 	write_sections = ic->n_committed_sections;
@@ -3101,8 +3097,7 @@ static void dm_integrity_postsuspend(struct dm_target *ti)
 	drain_workqueue(ic->commit_wq);
 
 	if (ic->mode == 'J') {
-		if (ic->meta_dev)
-			queue_work(ic->writer_wq, &ic->writer_work);
+		queue_work(ic->writer_wq, &ic->writer_work);
 		drain_workqueue(ic->writer_wq);
 		dm_integrity_flush_buffers(ic, true);
 	}