--- zzzz-none-000/linux-3.10.107/drivers/md/dm-delay.c	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/drivers/md/dm-delay.c	2021-02-04 17:41:59.000000000 +0000
@@ -24,7 +24,6 @@
 	struct work_struct flush_expired_bios;
 	struct list_head delayed_bios;
 	atomic_t may_delay;
-	mempool_t *delayed_pool;
 
 	struct dm_dev *dev_read;
 	sector_t start_read;
@@ -40,14 +39,11 @@
 struct dm_delay_info {
 	struct delay_c *context;
 	struct list_head list;
-	struct bio *bio;
 	unsigned long expires;
 };
 
 static DEFINE_MUTEX(delayed_bios_lock);
 
-static struct kmem_cache *delayed_cache;
-
 static void handle_delayed_timer(unsigned long data)
 {
 	struct delay_c *dc = (struct delay_c *)data;
@@ -87,13 +83,14 @@
 	mutex_lock(&delayed_bios_lock);
 	list_for_each_entry_safe(delayed, next, &dc->delayed_bios, list) {
 		if (flush_all || time_after_eq(jiffies, delayed->expires)) {
+			struct bio *bio = dm_bio_from_per_bio_data(delayed,
+						sizeof(struct dm_delay_info));
 			list_del(&delayed->list);
-			bio_list_add(&flush_bios, delayed->bio);
-			if ((bio_data_dir(delayed->bio) == WRITE))
+			bio_list_add(&flush_bios, bio);
+			if ((bio_data_dir(bio) == WRITE))
 				delayed->context->writes--;
 			else
 				delayed->context->reads--;
-			mempool_free(delayed, dc->delayed_pool);
 			continue;
 		}
 
@@ -125,6 +122,7 @@
  *    <device> <offset> <delay> [<write_device> <write_offset> <write_delay>]
  *
  * With separate write parameters, the first set is only used for reads.
+ * Offsets are specified in sectors.
  * Delays are specified in milliseconds.
  */
 static int delay_ctr(struct dm_target *ti, unsigned int argc, char **argv)
@@ -132,9 +130,10 @@
 	struct delay_c *dc;
 	unsigned long long tmpll;
 	char dummy;
+	int ret;
 
 	if (argc != 3 && argc != 6) {
-		ti->error = "requires exactly 3 or 6 arguments";
+		ti->error = "Requires exactly 3 or 6 arguments";
 		return -EINVAL;
 	}
 
@@ -146,6 +145,7 @@
 
 	dc->reads = dc->writes = 0;
 
+	ret = -EINVAL;
 	if (sscanf(argv[1], "%llu%c", &tmpll, &dummy) != 1) {
 		ti->error = "Invalid device sector";
 		goto bad;
@@ -157,12 +157,14 @@
 		goto bad;
 	}
 
-	if (dm_get_device(ti, argv[0], dm_table_get_mode(ti->table),
-			  &dc->dev_read)) {
+	ret = dm_get_device(ti, argv[0], dm_table_get_mode(ti->table),
+			    &dc->dev_read);
+	if (ret) {
 		ti->error = "Device lookup failed";
 		goto bad;
 	}
 
+	ret = -EINVAL;
 	dc->dev_write = NULL;
 	if (argc == 3)
 		goto out;
@@ -178,19 +180,15 @@
 		goto bad_dev_read;
 	}
 
-	if (dm_get_device(ti, argv[3], dm_table_get_mode(ti->table),
-			  &dc->dev_write)) {
+	ret = dm_get_device(ti, argv[3], dm_table_get_mode(ti->table),
+			    &dc->dev_write);
+	if (ret) {
 		ti->error = "Write device lookup failed";
 		goto bad_dev_read;
 	}
 
 out:
-	dc->delayed_pool = mempool_create_slab_pool(128, delayed_cache);
-	if (!dc->delayed_pool) {
-		DMERR("Couldn't create delayed bio pool.");
-		goto bad_dev_write;
-	}
-
+	ret = -EINVAL;
 	dc->kdelayd_wq = alloc_workqueue("kdelayd", WQ_MEM_RECLAIM, 0);
 	if (!dc->kdelayd_wq) {
 		DMERR("Couldn't start kdelayd");
@@ -206,19 +204,18 @@
 
 	ti->num_flush_bios = 1;
 	ti->num_discard_bios = 1;
+	ti->per_bio_data_size = sizeof(struct dm_delay_info);
 	ti->private = dc;
 	return 0;
 
 bad_queue:
-	mempool_destroy(dc->delayed_pool);
-bad_dev_write:
 	if (dc->dev_write)
 		dm_put_device(ti, dc->dev_write);
 bad_dev_read:
 	dm_put_device(ti, dc->dev_read);
 bad:
 	kfree(dc);
-	return -EINVAL;
+	return ret;
 }
 
 static void delay_dtr(struct dm_target *ti)
@@ -232,7 +229,6 @@
 	if (dc->dev_write)
 		dm_put_device(ti, dc->dev_write);
 
-	mempool_destroy(dc->delayed_pool);
 	kfree(dc);
 }
 
@@ -242,13 +238,12 @@
 	unsigned long expires = 0;
 
 	if (!delay || !atomic_read(&dc->may_delay))
-		return 1;
+		return DM_MAPIO_REMAPPED;
 
-	delayed = mempool_alloc(dc->delayed_pool, GFP_NOIO);
+	delayed = dm_per_bio_data(bio, sizeof(struct dm_delay_info));
 
 	delayed->context = dc;
-	delayed->bio = bio;
-	delayed->expires = expires = jiffies + (delay * HZ / 1000);
+	delayed->expires = expires = jiffies + msecs_to_jiffies(delay);
 
 	mutex_lock(&delayed_bios_lock);
 
@@ -263,7 +258,7 @@
 
 	queue_timeout(dc, expires);
 
-	return 0;
+	return DM_MAPIO_SUBMITTED;
 }
 
 static void delay_presuspend(struct dm_target *ti)
@@ -289,14 +284,15 @@
 	if ((bio_data_dir(bio) == WRITE) && (dc->dev_write)) {
 		bio->bi_bdev = dc->dev_write->bdev;
 		if (bio_sectors(bio))
-			bio->bi_sector = dc->start_write +
-					 dm_target_offset(ti, bio->bi_sector);
+			bio->bi_iter.bi_sector = dc->start_write +
+				dm_target_offset(ti, bio->bi_iter.bi_sector);
 
 		return delay_bio(dc, dc->write_delay, bio);
 	}
 
 	bio->bi_bdev = dc->dev_read->bdev;
-	bio->bi_sector = dc->start_read + dm_target_offset(ti, bio->bi_sector);
+	bio->bi_iter.bi_sector = dc->start_read +
+		dm_target_offset(ti, bio->bi_iter.bi_sector);
 
 	return delay_bio(dc, dc->read_delay, bio);
 }
@@ -356,13 +352,7 @@
 
 static int __init dm_delay_init(void)
 {
-	int r = -ENOMEM;
-
-	delayed_cache = KMEM_CACHE(dm_delay_info, 0);
-	if (!delayed_cache) {
-		DMERR("Couldn't create delayed bio cache.");
-		goto bad_memcache;
-	}
+	int r;
 
 	r = dm_register_target(&delay_target);
 	if (r < 0) {
@@ -373,15 +363,12 @@
 	return 0;
 
 bad_register:
-	kmem_cache_destroy(delayed_cache);
-bad_memcache:
 	return r;
 }
 
 static void __exit dm_delay_exit(void)
 {
 	dm_unregister_target(&delay_target);
-	kmem_cache_destroy(delayed_cache);
 }
 
 /* Module hooks */