diff --git a/drivers/md/bcache/features.c b/drivers/md/bcache/features.c
index 6469223f0b77..d636b7b2d070 100644
--- a/drivers/md/bcache/features.c
+++ b/drivers/md/bcache/features.c
@@ -17,7 +17,7 @@ struct feature {
 };
 
 static struct feature feature_list[] = {
-	{BCH_FEATURE_INCOMPAT, BCH_FEATURE_INCOMPAT_LARGE_BUCKET,
+	{BCH_FEATURE_INCOMPAT, BCH_FEATURE_INCOMPAT_LOG_LARGE_BUCKET_SIZE,
 		"large_bucket"},
 	{0, 0, 0 },
 };
diff --git a/drivers/md/bcache/features.h b/drivers/md/bcache/features.h
index e73724c2b49b..84fc2c0f0101 100644
--- a/drivers/md/bcache/features.h
+++ b/drivers/md/bcache/features.h
@@ -13,11 +13,15 @@
 
 /* Feature set definition */
 /* Incompat feature set */
-#define BCH_FEATURE_INCOMPAT_LARGE_BUCKET	0x0001 /* 32bit bucket size */
+/* 32bit bucket size, obsoleted */
+#define BCH_FEATURE_INCOMPAT_OBSO_LARGE_BUCKET		0x0001
+/* real bucket size is (1 << bucket_size) */
+#define BCH_FEATURE_INCOMPAT_LOG_LARGE_BUCKET_SIZE	0x0002
 
 #define BCH_FEATURE_COMPAT_SUPP		0
 #define BCH_FEATURE_RO_COMPAT_SUPP	0
-#define BCH_FEATURE_INCOMPAT_SUPP	BCH_FEATURE_INCOMPAT_LARGE_BUCKET
+#define BCH_FEATURE_INCOMPAT_SUPP	(BCH_FEATURE_INCOMPAT_OBSO_LARGE_BUCKET| \
+					 BCH_FEATURE_INCOMPAT_LOG_LARGE_BUCKET_SIZE)
 
 #define BCH_HAS_COMPAT_FEATURE(sb, mask) \
 		((sb)->feature_compat & (mask))
@@ -77,7 +81,8 @@ static inline void bch_clear_feature_##name(struct cache_sb *sb) \
 		~BCH##_FEATURE_INCOMPAT_##flagname; \
 }
 
-BCH_FEATURE_INCOMPAT_FUNCS(large_bucket, LARGE_BUCKET);
+BCH_FEATURE_INCOMPAT_FUNCS(obso_large_bucket, OBSO_LARGE_BUCKET);
+BCH_FEATURE_INCOMPAT_FUNCS(large_bucket, LOG_LARGE_BUCKET_SIZE);
 
 static inline bool bch_has_unknown_compat_features(struct cache_sb *sb)
 {
diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c
index f4674a3298af..3999641f1775 100644
--- a/drivers/md/bcache/super.c
+++ b/drivers/md/bcache/super.c
@@ -64,9 +64,25 @@ static unsigned int get_bucket_size(struct cache_sb *sb, struct cache_sb_disk *s
 {
 	unsigned int bucket_size = le16_to_cpu(s->bucket_size);
 
-	if (sb->version >= BCACHE_SB_VERSION_CDEV_WITH_FEATURES &&
-	     bch_has_feature_large_bucket(sb))
-		bucket_size |= le16_to_cpu(s->bucket_size_hi) << 16;
+	if (sb->version >= BCACHE_SB_VERSION_CDEV_WITH_FEATURES) {
+		if (bch_has_feature_large_bucket(sb)) {
+			unsigned int max, order;
+
+			max = sizeof(unsigned int) * BITS_PER_BYTE - 1;
+			order = le16_to_cpu(s->bucket_size);
+			/*
+			 * bcache tool will make sure the overflow won't
+			 * happen, an error message here is enough.
+			 */
+			if (order > max)
+				pr_err("Bucket size (1 << %u) overflows\n",
+					order);
+			bucket_size = 1 << order;
+		} else if (bch_has_feature_obso_large_bucket(sb)) {
+			bucket_size +=
+				le16_to_cpu(s->obso_bucket_size_hi) << 16;
+		}
+	}
 
 	return bucket_size;
 }
diff --git a/include/uapi/linux/bcache.h b/include/uapi/linux/bcache.h
index 52e8bcb33981..cf7399f03b71 100644
--- a/include/uapi/linux/bcache.h
+++ b/include/uapi/linux/bcache.h
@@ -213,7 +213,7 @@ struct cache_sb_disk {
 		__le16		keys;
 	};
 	__le64			d[SB_JOURNAL_BUCKETS];	/* journal buckets */
-	__le16			bucket_size_hi;
+	__le16			obso_bucket_size_hi;	/* obsoleted */
 };
 
 /*