--- zzzz-none-000/linux-3.10.107/drivers/md/dm-region-hash.c	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/drivers/md/dm-region-hash.c	2021-02-04 17:41:59.000000000 +0000
@@ -126,7 +126,8 @@
 
 region_t dm_rh_bio_to_region(struct dm_region_hash *rh, struct bio *bio)
 {
-	return dm_rh_sector_to_region(rh, bio->bi_sector - rh->target_begin);
+	return dm_rh_sector_to_region(rh, bio->bi_iter.bi_sector -
+				      rh->target_begin);
 }
 EXPORT_SYMBOL_GPL(dm_rh_bio_to_region);
 
@@ -192,7 +193,7 @@
 	rh->max_recovery = max_recovery;
 	rh->log = log;
 	rh->region_size = region_size;
-	rh->region_shift = ffs(region_size) - 1;
+	rh->region_shift = __ffs(region_size);
 	rwlock_init(&rh->hash_lock);
 	rh->mask = nr_buckets - 1;
 	rh->nr_buckets = nr_buckets;
@@ -248,9 +249,7 @@
 	if (rh->log)
 		dm_dirty_log_destroy(rh->log);
 
-	if (rh->region_pool)
-		mempool_destroy(rh->region_pool);
-
+	mempool_destroy(rh->region_pool);
 	vfree(rh->buckets);
 	kfree(rh);
 }