diff --git a/block/bio.c b/block/bio.c
index f66a4eae16ee..117da319afb6 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -270,7 +270,7 @@ void bio_init(struct bio *bio)
 {
 	memset(bio, 0, sizeof(*bio));
 	bio->bi_flags = 1 << BIO_UPTODATE;
-	atomic_set(&bio->bi_remaining, 1);
+	atomic_set(&bio->__bi_remaining, 1);
 	atomic_set(&bio->bi_cnt, 1);
 }
 EXPORT_SYMBOL(bio_init);
@@ -292,8 +292,8 @@ void bio_reset(struct bio *bio)
 	__bio_free(bio);
 
 	memset(bio, 0, BIO_RESET_BYTES);
-	bio->bi_flags = flags|(1 << BIO_UPTODATE);
-	atomic_set(&bio->bi_remaining, 1);
+	bio->bi_flags = flags | (1 << BIO_UPTODATE);
+	atomic_set(&bio->__bi_remaining, 1);
 }
 EXPORT_SYMBOL(bio_reset);
 
@@ -320,7 +320,7 @@ void bio_chain(struct bio *bio, struct bio *parent)
 
 	bio->bi_private = parent;
 	bio->bi_end_io	= bio_chain_endio;
-	atomic_inc(&parent->bi_remaining);
+	bio_inc_remaining(parent);
 }
 EXPORT_SYMBOL(bio_chain);
 
@@ -1741,6 +1741,23 @@ void bio_flush_dcache_pages(struct bio *bi)
 EXPORT_SYMBOL(bio_flush_dcache_pages);
 #endif
 
+static inline bool bio_remaining_done(struct bio *bio)
+{
+	/*
+	 * If we're not chaining, then ->__bi_remaining is always 1 and
+	 * we always end io on the first invocation.
+	 */
+	if (!bio_flagged(bio, BIO_CHAIN))
+		return true;
+
+	BUG_ON(atomic_read(&bio->__bi_remaining) <= 0);
+
+	if (atomic_dec_and_test(&bio->__bi_remaining))
+		return true;
+
+	return false;
+}
+
 /**
  * bio_endio - end I/O on a bio
  * @bio:	bio
@@ -1758,15 +1775,13 @@ EXPORT_SYMBOL(bio_flush_dcache_pages);
 void bio_endio(struct bio *bio, int error)
 {
 	while (bio) {
-		BUG_ON(atomic_read(&bio->bi_remaining) <= 0);
-
 		if (error)
 			clear_bit(BIO_UPTODATE, &bio->bi_flags);
 		else if (!test_bit(BIO_UPTODATE, &bio->bi_flags))
 			error = -EIO;
 
-		if (!atomic_dec_and_test(&bio->bi_remaining))
-			return;
+		if (unlikely(!bio_remaining_done(bio)))
+			break;
 
 		/*
 		 * Need to have a real endio function for chained bios,
@@ -1799,7 +1814,12 @@ EXPORT_SYMBOL(bio_endio);
  **/
 void bio_endio_nodec(struct bio *bio, int error)
 {
-	atomic_inc(&bio->bi_remaining);
+	/*
+	 * If it's not flagged as a chain, we are not going to dec the count
+	 */
+	if (bio_flagged(bio, BIO_CHAIN))
+		bio_inc_remaining(bio);
+
 	bio_endio(bio, error);
 }
 EXPORT_SYMBOL(bio_endio_nodec);
diff --git a/drivers/md/dm-cache-target.c b/drivers/md/dm-cache-target.c
index 7755af351867..705eb7b99d69 100644
--- a/drivers/md/dm-cache-target.c
+++ b/drivers/md/dm-cache-target.c
@@ -91,7 +91,7 @@ static void dm_unhook_bio(struct dm_hook_info *h, struct bio *bio)
 	 * Must bump bi_remaining to allow bio to complete with
 	 * restored bi_end_io.
 	 */
-	atomic_inc(&bio->bi_remaining);
+	bio_inc_remaining(bio);
 }
 
 /*----------------------------------------------------------------*/
diff --git a/drivers/md/dm-raid1.c b/drivers/md/dm-raid1.c
index 089d62751f7f..d6a1c096b777 100644
--- a/drivers/md/dm-raid1.c
+++ b/drivers/md/dm-raid1.c
@@ -1254,7 +1254,7 @@ static int mirror_end_io(struct dm_target *ti, struct bio *bio, int error)
 			dm_bio_restore(bd, bio);
 			bio_record->details.bi_bdev = NULL;
 
-			atomic_inc(&bio->bi_remaining);
+			bio_inc_remaining(bio);
 
 			queue_bio(ms, bio, rw);
 			return DM_ENDIO_INCOMPLETE;
diff --git a/drivers/md/dm-snap.c b/drivers/md/dm-snap.c
index f83a0f3fc365..8bfeae218531 100644
--- a/drivers/md/dm-snap.c
+++ b/drivers/md/dm-snap.c
@@ -1478,7 +1478,7 @@ out:
 	if (full_bio) {
 		full_bio->bi_end_io = pe->full_bio_end_io;
 		full_bio->bi_private = pe->full_bio_private;
-		atomic_inc(&full_bio->bi_remaining);
+		bio_inc_remaining(full_bio);
 	}
 	increment_pending_exceptions_done_count();
 
diff --git a/drivers/md/dm-thin.c b/drivers/md/dm-thin.c
index 921aafd12aee..342dbdad6131 100644
--- a/drivers/md/dm-thin.c
+++ b/drivers/md/dm-thin.c
@@ -795,7 +795,7 @@ static void process_prepared_mapping_fail(struct dm_thin_new_mapping *m)
 {
 	if (m->bio) {
 		m->bio->bi_end_io = m->saved_bi_end_io;
-		atomic_inc(&m->bio->bi_remaining);
+		bio_inc_remaining(m->bio);
 	}
 	cell_error(m->tc->pool, m->cell);
 	list_del(&m->list);
@@ -812,7 +812,7 @@ static void process_prepared_mapping(struct dm_thin_new_mapping *m)
 	bio = m->bio;
 	if (bio) {
 		bio->bi_end_io = m->saved_bi_end_io;
-		atomic_inc(&bio->bi_remaining);
+		bio_inc_remaining(bio);
 	}
 
 	if (m->err) {
diff --git a/include/linux/bio.h b/include/linux/bio.h
index da3a127c9958..8bfe9eee6d1a 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -644,6 +644,17 @@ static inline struct bio *bio_list_get(struct bio_list *bl)
 	return bio;
 }
 
+/*
+ * Increment chain count for the bio. Make sure the CHAIN flag update
+ * is visible before the raised count.
+ */
+static inline void bio_inc_remaining(struct bio *bio)
+{
+	bio->bi_flags |= (1 << BIO_CHAIN);
+	smp_mb__before_atomic();
+	atomic_inc(&bio->__bi_remaining);
+}
+
 /*
  * bio_set is used to allow other portions of the IO system to
  * allocate their own private memory pools for bio and iovec structures.
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index a1b25e35ea5f..8b07e0603887 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -65,7 +65,7 @@ struct bio {
 	unsigned int		bi_seg_front_size;
 	unsigned int		bi_seg_back_size;
 
-	atomic_t		bi_remaining;
+	atomic_t		__bi_remaining;
 
 	bio_end_io_t		*bi_end_io;
 
@@ -122,6 +122,7 @@ struct bio {
 #define BIO_NULL_MAPPED 8	/* contains invalid user pages */
 #define BIO_QUIET	9	/* Make BIO Quiet */
 #define BIO_SNAP_STABLE	10	/* bio data must be snapshotted during write */
+#define BIO_CHAIN	11	/* chained bio, ->bi_remaining in effect */
 
 /*
  * Flags starting here get preserved by bio_reset() - this includes