dm bio record: save/restore bi_end_io and bi_integrity

Also, save/restore __bi_remaining in case the bio was used in a
BIO_CHAIN (e.g. due to blk_queue_split).
Suggested-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

drivers/md/dm-bio-record.h

@@ -20,8 +20,13 @@
 struct dm_bio_details {
 	struct gendisk *bi_disk;
 	u8 bi_partno;
+	int __bi_remaining;
 	unsigned long bi_flags;
 	struct bvec_iter bi_iter;
+	bio_end_io_t *bi_end_io;
+#if defined(CONFIG_BLK_DEV_INTEGRITY)
+	struct bio_integrity_payload *bi_integrity;
+#endif
 };
 
 static inline void dm_bio_record(struct dm_bio_details *bd, struct bio *bio)
@@ -30,6 +35,11 @@ static inline void dm_bio_record(struct dm_bio_details *bd, struct bio *bio)
 	bd->bi_partno = bio->bi_partno;
 	bd->bi_flags = bio->bi_flags;
 	bd->bi_iter = bio->bi_iter;
+	bd->__bi_remaining = atomic_read(&bio->__bi_remaining);
+	bd->bi_end_io = bio->bi_end_io;
+#if defined(CONFIG_BLK_DEV_INTEGRITY)
+	bd->bi_integrity = bio_integrity(bio);
+#endif
 }
 
 static inline void dm_bio_restore(struct dm_bio_details *bd, struct bio *bio)
@@ -38,6 +48,11 @@ static inline void dm_bio_restore(struct dm_bio_details *bd, struct bio *bio)
 	bio->bi_partno = bd->bi_partno;
 	bio->bi_flags = bd->bi_flags;
 	bio->bi_iter = bd->bi_iter;
+	atomic_set(&bio->__bi_remaining, bd->__bi_remaining);
+	bio->bi_end_io = bd->bi_end_io;
+#if defined(CONFIG_BLK_DEV_INTEGRITY)
+	bio->bi_integrity = bd->bi_integrity;
+#endif
 }
 
 #endif