diff --git a/drivers/md/bcache/bcache.h b/drivers/md/bcache/bcache.h
index 5c74d55..93b8484 100644
--- a/drivers/md/bcache/bcache.h
+++ b/drivers/md/bcache/bcache.h
@@ -679,9 +679,9 @@
 	unsigned		error_decay;
 
 	unsigned short		journal_delay_ms;
+	bool			expensive_debug_checks;
 	unsigned		verify:1;
 	unsigned		key_merging_disabled:1;
-	unsigned		expensive_debug_checks:1;
 	unsigned		gc_always_rewrite:1;
 	unsigned		shrinker_disabled:1;
 	unsigned		copy_gc_enabled:1;
diff --git a/drivers/md/bcache/bset.c b/drivers/md/bcache/bset.c
index c2c42cb..f34ef56 100644
--- a/drivers/md/bcache/bset.c
+++ b/drivers/md/bcache/bset.c
@@ -149,33 +149,33 @@
 #define BSET_CACHELINE		128
 
 /* Space required for the btree node keys */
-static inline size_t btree_keys_bytes(struct btree *b)
+static inline size_t btree_keys_bytes(struct btree_keys *b)
 {
 	return PAGE_SIZE << b->page_order;
 }
 
-static inline size_t btree_keys_cachelines(struct btree *b)
+static inline size_t btree_keys_cachelines(struct btree_keys *b)
 {
 	return btree_keys_bytes(b) / BSET_CACHELINE;
 }
 
 /* Space required for the auxiliary search trees */
-static inline size_t bset_tree_bytes(struct btree *b)
+static inline size_t bset_tree_bytes(struct btree_keys *b)
 {
 	return btree_keys_cachelines(b) * sizeof(struct bkey_float);
 }
 
 /* Space required for the prev pointers */
-static inline size_t bset_prev_bytes(struct btree *b)
+static inline size_t bset_prev_bytes(struct btree_keys *b)
 {
 	return btree_keys_cachelines(b) * sizeof(uint8_t);
 }
 
 /* Memory allocation */
 
-void bch_btree_keys_free(struct btree *b)
+void bch_btree_keys_free(struct btree_keys *b)
 {
-	struct bset_tree *t = b->sets;
+	struct bset_tree *t = b->set;
 
 	if (bset_prev_bytes(b) < PAGE_SIZE)
 		kfree(t->prev);
@@ -195,10 +195,11 @@
 	t->tree = NULL;
 	t->data = NULL;
 }
+EXPORT_SYMBOL(bch_btree_keys_free);
 
-int bch_btree_keys_alloc(struct btree *b, unsigned page_order, gfp_t gfp)
+int bch_btree_keys_alloc(struct btree_keys *b, unsigned page_order, gfp_t gfp)
 {
-	struct bset_tree *t = b->sets;
+	struct bset_tree *t = b->set;
 
 	BUG_ON(t->data);
 
@@ -225,6 +226,29 @@
 	bch_btree_keys_free(b);
 	return -ENOMEM;
 }
+EXPORT_SYMBOL(bch_btree_keys_alloc);
+
+void bch_btree_keys_init(struct btree_keys *b, const struct btree_keys_ops *ops,
+			 bool *expensive_debug_checks)
+{
+	unsigned i;
+
+	b->ops = ops;
+	b->expensive_debug_checks = expensive_debug_checks;
+	b->nsets = 0;
+	b->last_set_unwritten = 0;
+
+	/* XXX: shouldn't be needed */
+	for (i = 0; i < MAX_BSETS; i++)
+		b->set[i].size = 0;
+	/*
+	 * Second loop starts at 1 because b->keys[0]->data is the memory we
+	 * allocated
+	 */
+	for (i = 1; i < MAX_BSETS; i++)
+		b->set[i].data = NULL;
+}
+EXPORT_SYMBOL(bch_btree_keys_init);
 
 /* Binary tree stuff for auxiliary search trees */
 
@@ -448,9 +472,9 @@
 		f->exponent = 127;
 }
 
-static void bset_alloc_tree(struct btree *b, struct bset_tree *t)
+static void bset_alloc_tree(struct btree_keys *b, struct bset_tree *t)
 {
-	if (t != b->sets) {
+	if (t != b->set) {
 		unsigned j = roundup(t[-1].size,
 				     64 / sizeof(struct bkey_float));
 
@@ -458,27 +482,30 @@
 		t->prev = t[-1].prev + j;
 	}
 
-	while (t < b->sets + MAX_BSETS)
+	while (t < b->set + MAX_BSETS)
 		t++->size = 0;
 }
 
-static void bch_bset_build_unwritten_tree(struct btree *b)
+static void bch_bset_build_unwritten_tree(struct btree_keys *b)
 {
 	struct bset_tree *t = bset_tree_last(b);
 
+	BUG_ON(b->last_set_unwritten);
+	b->last_set_unwritten = 1;
+
 	bset_alloc_tree(b, t);
 
-	if (t->tree != b->sets->tree + btree_keys_cachelines(b)) {
+	if (t->tree != b->set->tree + btree_keys_cachelines(b)) {
 		t->prev[0] = bkey_to_cacheline_offset(t->data->start);
 		t->size = 1;
 	}
 }
 
-void bch_bset_init_next(struct btree *b, struct bset *i, uint64_t magic)
+void bch_bset_init_next(struct btree_keys *b, struct bset *i, uint64_t magic)
 {
-	if (i != b->sets->data) {
-		b->sets[++b->nsets].data = i;
-		i->seq = b->sets->data->seq;
+	if (i != b->set->data) {
+		b->set[++b->nsets].data = i;
+		i->seq = b->set->data->seq;
 	} else
 		get_random_bytes(&i->seq, sizeof(uint64_t));
 
@@ -488,18 +515,21 @@
 
 	bch_bset_build_unwritten_tree(b);
 }
+EXPORT_SYMBOL(bch_bset_init_next);
 
-static void bset_build_written_tree(struct btree *b)
+void bch_bset_build_written_tree(struct btree_keys *b)
 {
 	struct bset_tree *t = bset_tree_last(b);
 	struct bkey *k = t->data->start;
 	unsigned j, cacheline = 1;
 
+	b->last_set_unwritten = 0;
+
 	bset_alloc_tree(b, t);
 
 	t->size = min_t(unsigned,
 			bkey_to_cacheline(t, bset_bkey_last(t->data)),
-			b->sets->tree + btree_keys_cachelines(b) - t->tree);
+			b->set->tree + btree_keys_cachelines(b) - t->tree);
 
 	if (t->size < 2) {
 		t->size = 0;
@@ -532,13 +562,14 @@
 	     j = inorder_next(j, t->size))
 		make_bfloat(t, j);
 }
+EXPORT_SYMBOL(bch_bset_build_written_tree);
 
-void bch_bset_fix_invalidated_key(struct btree *b, struct bkey *k)
+void bch_bset_fix_invalidated_key(struct btree_keys *b, struct bkey *k)
 {
 	struct bset_tree *t;
 	unsigned inorder, j = 1;
 
-	for (t = b->sets; t <= bset_tree_last(b); t++)
+	for (t = b->set; t <= bset_tree_last(b); t++)
 		if (k < bset_bkey_last(t->data))
 			goto found_set;
 
@@ -577,8 +608,9 @@
 			j = j * 2 + 1;
 		} while (j < t->size);
 }
+EXPORT_SYMBOL(bch_bset_fix_invalidated_key);
 
-static void bch_bset_fix_lookup_table(struct btree *b,
+static void bch_bset_fix_lookup_table(struct btree_keys *b,
 				      struct bset_tree *t,
 				      struct bkey *k)
 {
@@ -613,7 +645,7 @@
 		}
 	}
 
-	if (t->size == b->sets->tree + btree_keys_cachelines(b) - t->tree)
+	if (t->size == b->set->tree + btree_keys_cachelines(b) - t->tree)
 		return;
 
 	/* Possibly add a new entry to the end of the lookup table */
@@ -627,12 +659,12 @@
 		}
 }
 
-void bch_bset_insert(struct btree *b, struct bkey *where,
+void bch_bset_insert(struct btree_keys *b, struct bkey *where,
 		     struct bkey *insert)
 {
 	struct bset_tree *t = bset_tree_last(b);
 
-	BUG_ON(t->data != write_block(b));
+	BUG_ON(!b->last_set_unwritten);
 	BUG_ON(bset_byte_offset(b, t->data) +
 	       __set_bytes(t->data, t->data->keys + bkey_u64s(insert)) >
 	       PAGE_SIZE << b->page_order);
@@ -645,20 +677,17 @@
 	bkey_copy(where, insert);
 	bch_bset_fix_lookup_table(b, t, where);
 }
+EXPORT_SYMBOL(bch_bset_insert);
 
 struct bset_search_iter {
 	struct bkey *l, *r;
 };
 
-static struct bset_search_iter bset_search_write_set(struct btree *b,
-						     struct bset_tree *t,
+static struct bset_search_iter bset_search_write_set(struct bset_tree *t,
 						     const struct bkey *search)
 {
 	unsigned li = 0, ri = t->size;
 
-	BUG_ON(!b->nsets &&
-	       t->size < bkey_to_cacheline(t, bset_bkey_last(t->data)));
-
 	while (li + 1 != ri) {
 		unsigned m = (li + ri) >> 1;
 
@@ -674,8 +703,7 @@
 	};
 }
 
-static struct bset_search_iter bset_search_tree(struct btree *b,
-						struct bset_tree *t,
+static struct bset_search_iter bset_search_tree(struct bset_tree *t,
 						const struct bkey *search)
 {
 	struct bkey *l, *r;
@@ -759,7 +787,7 @@
 	if (unlikely(!t->size)) {
 		i.l = t->data->start;
 		i.r = bset_bkey_last(t->data);
-	} else if (bset_written(b, t)) {
+	} else if (bset_written(&b->keys, t)) {
 		/*
 		 * Each node in the auxiliary search tree covers a certain range
 		 * of bits, and keys above and below the set it covers might
@@ -773,12 +801,16 @@
 		if (unlikely(bkey_cmp(search, t->data->start) < 0))
 			return t->data->start;
 
-		i = bset_search_tree(b, t, search);
-	} else
-		i = bset_search_write_set(b, t, search);
+		i = bset_search_tree(t, search);
+	} else {
+		BUG_ON(!b->keys.nsets &&
+		       t->size < bkey_to_cacheline(t, bset_bkey_last(t->data)));
+
+		i = bset_search_write_set(t, search);
+	}
 
 	if (expensive_debug_checks(b->c)) {
-		BUG_ON(bset_written(b, t) &&
+		BUG_ON(bset_written(&b->keys, t) &&
 		       i.l != t->data->start &&
 		       bkey_cmp(tree_to_prev_bkey(t,
 			  inorder_to_tree(bkey_to_cacheline(t, i.l), t)),
@@ -794,6 +826,7 @@
 
 	return i.l;
 }
+EXPORT_SYMBOL(__bch_bset_search);
 
 /* Btree iterator */
 
@@ -833,7 +866,7 @@
 	iter->b = b;
 #endif
 
-	for (; start <= &b->sets[b->nsets]; start++) {
+	for (; start <= bset_tree_last(&b->keys); start++) {
 		ret = bch_bset_search(b, start, search);
 		bch_btree_iter_push(iter, ret, bset_bkey_last(start->data));
 	}
@@ -845,8 +878,9 @@
 				 struct btree_iter *iter,
 				 struct bkey *search)
 {
-	return __bch_btree_iter_init(b, iter, search, b->sets);
+	return __bch_btree_iter_init(b, iter, search, b->keys.set);
 }
+EXPORT_SYMBOL(bch_btree_iter_init);
 
 static inline struct bkey *__bch_btree_iter_next(struct btree_iter *iter,
 						 btree_iter_cmp_fn *cmp)
@@ -879,9 +913,10 @@
 	return __bch_btree_iter_next(iter, btree_iter_cmp);
 
 }
+EXPORT_SYMBOL(bch_btree_iter_next);
 
 struct bkey *bch_btree_iter_next_filter(struct btree_iter *iter,
-					struct btree *b, ptr_filter_fn fn)
+					struct btree_keys *b, ptr_filter_fn fn)
 {
 	struct bkey *ret;
 
@@ -913,15 +948,16 @@
 
 	return 0;
 }
+EXPORT_SYMBOL(bch_bset_sort_state_init);
 
-static void btree_mergesort(struct btree *b, struct bset *out,
+static void btree_mergesort(struct btree_keys *b, struct bset *out,
 			    struct btree_iter *iter,
 			    bool fixup, bool remove_stale)
 {
 	int i;
 	struct bkey *k, *last = NULL;
 	BKEY_PADDED(k) tmp;
-	bool (*bad)(struct btree *, const struct bkey *) = remove_stale
+	bool (*bad)(struct btree_keys *, const struct bkey *) = remove_stale
 		? bch_ptr_bad
 		: bch_ptr_invalid;
 
@@ -955,7 +991,7 @@
 	pr_debug("sorted %i keys", out->keys);
 }
 
-static void __btree_sort(struct btree *b, struct btree_iter *iter,
+static void __btree_sort(struct btree_keys *b, struct btree_iter *iter,
 			 unsigned start, unsigned order, bool fixup,
 			 struct bset_sort_state *state)
 {
@@ -968,7 +1004,7 @@
 
 		out = page_address(mempool_alloc(state->pool, GFP_NOIO));
 		used_mempool = true;
-		order = ilog2(bucket_pages(b->c));
+		order = state->page_order;
 	}
 
 	start_time = local_clock();
@@ -983,13 +1019,13 @@
 		 * memcpy()
 		 */
 
-		out->magic	= bset_magic(&b->c->sb);
-		out->seq	= b->sets[0].data->seq;
-		out->version	= b->sets[0].data->version;
-		swap(out, b->sets[0].data);
+		out->magic	= b->set->data->magic;
+		out->seq	= b->set->data->seq;
+		out->version	= b->set->data->version;
+		swap(out, b->set->data);
 	} else {
-		b->sets[start].data->keys = out->keys;
-		memcpy(b->sets[start].data->start, out->start,
+		b->set[start].data->keys = out->keys;
+		memcpy(b->set[start].data->start, out->start,
 		       (void *) bset_bkey_last(out) - (void *) out->start);
 	}
 
@@ -998,7 +1034,7 @@
 	else
 		free_pages((unsigned long) out, order);
 
-	bset_build_written_tree(b);
+	bch_bset_build_written_tree(b);
 
 	if (!start)
 		bch_time_stats_update(&state->time, start_time);
@@ -1007,34 +1043,32 @@
 void bch_btree_sort_partial(struct btree *b, unsigned start,
 			    struct bset_sort_state *state)
 {
-	size_t order = b->page_order, keys = 0;
+	size_t order = b->keys.page_order, keys = 0;
 	struct btree_iter iter;
 	int oldsize = bch_count_data(b);
 
-	__bch_btree_iter_init(b, &iter, NULL, &b->sets[start]);
-
-	BUG_ON(!bset_written(b, bset_tree_last(b)) &&
-	       (bset_tree_last(b)->size || b->nsets));
+	__bch_btree_iter_init(b, &iter, NULL, &b->keys.set[start]);
 
 	if (start) {
 		unsigned i;
 
-		for (i = start; i <= b->nsets; i++)
-			keys += b->sets[i].data->keys;
+		for (i = start; i <= b->keys.nsets; i++)
+			keys += b->keys.set[i].data->keys;
 
-		order = roundup_pow_of_two(__set_bytes(b->sets->data,
+		order = roundup_pow_of_two(__set_bytes(b->keys.set->data,
 						       keys)) / PAGE_SIZE;
 		if (order)
 			order = ilog2(order);
 	}
 
-	__btree_sort(b, &iter, start, order, false, state);
+	__btree_sort(&b->keys, &iter, start, order, false, state);
 
 	EBUG_ON(b->written && oldsize >= 0 && bch_count_data(b) != oldsize);
 }
 EXPORT_SYMBOL(bch_btree_sort_partial);
 
-void bch_btree_sort_and_fix_extents(struct btree *b, struct btree_iter *iter,
+void bch_btree_sort_and_fix_extents(struct btree_keys *b,
+				    struct btree_iter *iter,
 				    struct bset_sort_state *state)
 {
 	__btree_sort(b, iter, 0, b->page_order, true, state);
@@ -1048,11 +1082,11 @@
 	struct btree_iter iter;
 	bch_btree_iter_init(b, &iter, NULL);
 
-	btree_mergesort(b, new->sets->data, &iter, false, true);
+	btree_mergesort(&b->keys, new->keys.set->data, &iter, false, true);
 
 	bch_time_stats_update(&state->time, start_time);
 
-	new->sets->size = 0;
+	new->keys.set->size = 0; // XXX: why?
 }
 
 #define SORT_CRIT	(4096 / sizeof(uint64_t))
@@ -1062,28 +1096,31 @@
 	unsigned crit = SORT_CRIT;
 	int i;
 
+	b->keys.last_set_unwritten = 0;
+
 	/* Don't sort if nothing to do */
-	if (!b->nsets)
+	if (!b->keys.nsets)
 		goto out;
 
-	for (i = b->nsets - 1; i >= 0; --i) {
+	for (i = b->keys.nsets - 1; i >= 0; --i) {
 		crit *= state->crit_factor;
 
-		if (b->sets[i].data->keys < crit) {
+		if (b->keys.set[i].data->keys < crit) {
 			bch_btree_sort_partial(b, i, state);
 			return;
 		}
 	}
 
 	/* Sort if we'd overflow */
-	if (b->nsets + 1 == MAX_BSETS) {
+	if (b->keys.nsets + 1 == MAX_BSETS) {
 		bch_btree_sort(b, state);
 		return;
 	}
 
 out:
-	bset_build_written_tree(b);
+	bch_bset_build_written_tree(&b->keys);
 }
+EXPORT_SYMBOL(bch_btree_sort_lazy);
 
 /* Sysfs stuff */
 
@@ -1102,12 +1139,12 @@
 
 	stats->nodes++;
 
-	for (i = 0; i <= b->nsets; i++) {
-		struct bset_tree *t = &b->sets[i];
+	for (i = 0; i <= b->keys.nsets; i++) {
+		struct bset_tree *t = &b->keys.set[i];
 		size_t bytes = t->data->keys * sizeof(uint64_t);
 		size_t j;
 
-		if (bset_written(b, t)) {
+		if (bset_written(&b->keys, t)) {
 			stats->sets_written++;
 			stats->bytes_written += bytes;
 
diff --git a/drivers/md/bcache/bset.h b/drivers/md/bcache/bset.h
index b579712..87da828 100644
--- a/drivers/md/bcache/bset.h
+++ b/drivers/md/bcache/bset.h
@@ -145,6 +145,9 @@
  */
 
 struct btree;
+struct btree_keys;
+struct btree_iter;
+struct btree_iter_set;
 struct bkey_float;
 
 #define MAX_BSETS		4U
@@ -181,6 +184,74 @@
 	struct bset		*data;
 };
 
+struct btree_keys_ops {
+	bool		(*sort_cmp)(struct btree_iter_set,
+				    struct btree_iter_set);
+	struct bkey	*(*sort_fixup)(struct btree_iter *, struct bkey *);
+	bool		(*key_invalid)(struct btree_keys *,
+				       const struct bkey *);
+	bool		(*key_bad)(struct btree_keys *, const struct bkey *);
+	bool		(*key_merge)(struct btree_keys *,
+				     struct bkey *, struct bkey *);
+
+	/*
+	 * Only used for deciding whether to use START_KEY(k) or just the key
+	 * itself in a couple places
+	 */
+	bool		is_extents;
+};
+
+struct btree_keys {
+	const struct btree_keys_ops	*ops;
+	uint8_t			page_order;
+	uint8_t			nsets;
+	unsigned		last_set_unwritten:1;
+	bool			*expensive_debug_checks;
+
+	/*
+	 * Sets of sorted keys - the real btree node - plus a binary search tree
+	 *
+	 * set[0] is special; set[0]->tree, set[0]->prev and set[0]->data point
+	 * to the memory we have allocated for this btree node. Additionally,
+	 * set[0]->data points to the entire btree node as it exists on disk.
+	 */
+	struct bset_tree	set[MAX_BSETS];
+};
+
+static inline struct bset_tree *bset_tree_last(struct btree_keys *b)
+{
+	return b->set + b->nsets;
+}
+
+static inline bool bset_written(struct btree_keys *b, struct bset_tree *t)
+{
+	return t <= b->set + b->nsets - b->last_set_unwritten;
+}
+
+static inline bool bkey_written(struct btree_keys *b, struct bkey *k)
+{
+	return !b->last_set_unwritten || k < b->set[b->nsets].data->start;
+}
+
+static inline unsigned bset_byte_offset(struct btree_keys *b, struct bset *i)
+{
+	return ((size_t) i) - ((size_t) b->set->data);
+}
+
+static inline unsigned bset_sector_offset(struct btree_keys *b, struct bset *i)
+{
+	return bset_byte_offset(b, i) >> 9;
+}
+
+static inline bool btree_keys_expensive_checks(struct btree_keys *b)
+{
+#ifdef CONFIG_BCACHE_DEBUG
+	return *b->expensive_debug_checks;
+#else
+	return false;
+#endif
+}
+
 #define __set_bytes(i, k)	(sizeof(*(i)) + (k) * sizeof(uint64_t))
 #define set_bytes(i)		__set_bytes(i, i->keys)
 
@@ -189,12 +260,34 @@
 #define set_blocks(i, block_bytes)				\
 	__set_blocks(i, (i)->keys, block_bytes)
 
-void bch_btree_keys_free(struct btree *);
-int bch_btree_keys_alloc(struct btree *, unsigned, gfp_t);
+static inline struct bset *bset_next_set(struct btree_keys *b,
+					 unsigned block_bytes)
+{
+	struct bset *i = bset_tree_last(b)->data;
 
-void bch_bset_fix_invalidated_key(struct btree *, struct bkey *);
-void bch_bset_init_next(struct btree *, struct bset *, uint64_t);
-void bch_bset_insert(struct btree *, struct bkey *, struct bkey *);
+	return ((void *) i) + roundup(set_bytes(i), block_bytes);
+}
+
+void bch_btree_keys_free(struct btree_keys *);
+int bch_btree_keys_alloc(struct btree_keys *, unsigned, gfp_t);
+void bch_btree_keys_init(struct btree_keys *, const struct btree_keys_ops *,
+			 bool *);
+
+void bch_bset_init_next(struct btree_keys *, struct bset *, uint64_t);
+void bch_bset_build_written_tree(struct btree_keys *);
+void bch_bset_fix_invalidated_key(struct btree_keys *, struct bkey *);
+void bch_bset_insert(struct btree_keys *, struct bkey *, struct bkey *);
+
+/*
+ * Tries to merge l and r: l should be lower than r
+ * Returns true if we were able to merge. If we did merge, l will be the merged
+ * key, r will be untouched.
+ */
+static inline bool bch_bkey_try_merge(struct btree_keys *b,
+				      struct bkey *l, struct bkey *r)
+{
+	return b->ops->key_merge ?  b->ops->key_merge(b, l, r) : false;
+}
 
 /* Btree key iteration */
 
@@ -208,11 +301,11 @@
 	} data[MAX_BSETS];
 };
 
-typedef bool (*ptr_filter_fn)(struct btree *, const struct bkey *);
+typedef bool (*ptr_filter_fn)(struct btree_keys *, const struct bkey *);
 
 struct bkey *bch_btree_iter_next(struct btree_iter *);
 struct bkey *bch_btree_iter_next_filter(struct btree_iter *,
-					struct btree *, ptr_filter_fn);
+					struct btree_keys *, ptr_filter_fn);
 
 void bch_btree_iter_push(struct btree_iter *, struct bkey *, struct bkey *);
 struct bkey *bch_btree_iter_init(struct btree *, struct btree_iter *,
@@ -246,7 +339,7 @@
 void bch_btree_sort_lazy(struct btree *, struct bset_sort_state *);
 void bch_btree_sort_into(struct btree *, struct btree *,
 			 struct bset_sort_state *);
-void bch_btree_sort_and_fix_extents(struct btree *, struct btree_iter *,
+void bch_btree_sort_and_fix_extents(struct btree_keys *, struct btree_iter *,
 				    struct bset_sort_state *);
 void bch_btree_sort_partial(struct btree *, unsigned,
 			    struct bset_sort_state *);
@@ -311,6 +404,16 @@
 	_ret;							\
 })
 
+static inline bool bch_ptr_invalid(struct btree_keys *b, const struct bkey *k)
+{
+	return b->ops->key_invalid(b, k);
+}
+
+static inline bool bch_ptr_bad(struct btree_keys *b, const struct bkey *k)
+{
+	return b->ops->key_bad(b, k);
+}
+
 /* Keylists */
 
 struct keylist {
diff --git a/drivers/md/bcache/btree.c b/drivers/md/bcache/btree.c
index 6734e27..5d7dee8 100644
--- a/drivers/md/bcache/btree.c
+++ b/drivers/md/bcache/btree.c
@@ -107,14 +107,6 @@
 
 static struct workqueue_struct *btree_io_wq;
 
-static inline bool should_split(struct btree *b)
-{
-	struct bset *i = write_block(b);
-	return b->written >= btree_blocks(b) ||
-		(b->written + __set_blocks(i, i->keys + 15, block_bytes(b->c))
-		 > btree_blocks(b));
-}
-
 #define insert_lock(s, b)	((b)->level <= (s)->lock)
 
 /*
@@ -182,6 +174,19 @@
 	_r;								\
 })
 
+static inline struct bset *write_block(struct btree *b)
+{
+	return ((void *) btree_bset_first(b)) + b->written * block_bytes(b->c);
+}
+
+static inline bool should_split(struct btree *b)
+{
+	struct bset *i = write_block(b);
+	return b->written >= btree_blocks(b) ||
+		(b->written + __set_blocks(i, i->keys + 15, block_bytes(b->c))
+		 > btree_blocks(b));
+}
+
 /* Btree key manipulation */
 
 void bkey_put(struct cache_set *c, struct bkey *k)
@@ -222,7 +227,7 @@
 		goto err;
 
 	for (;
-	     b->written < btree_blocks(b) && i->seq == b->sets[0].data->seq;
+	     b->written < btree_blocks(b) && i->seq == b->keys.set[0].data->seq;
 	     i = write_block(b)) {
 		err = "unsupported bset version";
 		if (i->version > BCACHE_BSET_VERSION)
@@ -250,7 +255,7 @@
 		}
 
 		err = "empty set";
-		if (i != b->sets[0].data && !i->keys)
+		if (i != b->keys.set[0].data && !i->keys)
 			goto err;
 
 		bch_btree_iter_push(iter, i->start, bset_bkey_last(i));
@@ -260,21 +265,22 @@
 
 	err = "corrupted btree";
 	for (i = write_block(b);
-	     bset_sector_offset(b, i) < KEY_SIZE(&b->key);
+	     bset_sector_offset(&b->keys, i) < KEY_SIZE(&b->key);
 	     i = ((void *) i) + block_bytes(b->c))
-		if (i->seq == b->sets[0].data->seq)
+		if (i->seq == b->keys.set[0].data->seq)
 			goto err;
 
-	bch_btree_sort_and_fix_extents(b, iter, &b->c->sort);
+	bch_btree_sort_and_fix_extents(&b->keys, iter, &b->c->sort);
 
-	i = b->sets[0].data;
+	i = b->keys.set[0].data;
 	err = "short btree key";
-	if (b->sets[0].size &&
-	    bkey_cmp(&b->key, &b->sets[0].end) < 0)
+	if (b->keys.set[0].size &&
+	    bkey_cmp(&b->key, &b->keys.set[0].end) < 0)
 		goto err;
 
 	if (b->written < btree_blocks(b))
-		bch_bset_init_next(b, write_block(b), bset_magic(&b->c->sb));
+		bch_bset_init_next(&b->keys, write_block(b),
+				   bset_magic(&b->c->sb));
 out:
 	mempool_free(iter, b->c->fill_iter);
 	return;
@@ -308,7 +314,7 @@
 	bio->bi_end_io	= btree_node_read_endio;
 	bio->bi_private	= &cl;
 
-	bch_bio_map(bio, b->sets[0].data);
+	bch_bio_map(bio, b->keys.set[0].data);
 
 	bch_submit_bbio(bio, b->c, &b->key, 0);
 	closure_sync(&cl);
@@ -427,7 +433,7 @@
 
 	bkey_copy(&k.key, &b->key);
 	SET_PTR_OFFSET(&k.key, 0, PTR_OFFSET(&k.key, 0) +
-		       bset_sector_offset(b, i));
+		       bset_sector_offset(&b->keys, i));
 
 	if (!bio_alloc_pages(b->bio, GFP_NOIO)) {
 		int j;
@@ -475,12 +481,13 @@
 
 	do_btree_node_write(b);
 
-	b->written += set_blocks(i, block_bytes(b->c));
 	atomic_long_add(set_blocks(i, block_bytes(b->c)) * b->c->sb.block_size,
 			&PTR_CACHE(b->c, &b->key, 0)->btree_sectors_written);
 
+	b->written += set_blocks(i, block_bytes(b->c));
+
 	/* If not a leaf node, always sort */
-	if (b->level && b->nsets)
+	if (b->level && b->keys.nsets)
 		bch_btree_sort(b, &b->c->sort);
 	else
 		bch_btree_sort_lazy(b, &b->c->sort);
@@ -489,11 +496,12 @@
 	 * do verify if there was more than one set initially (i.e. we did a
 	 * sort) and we sorted down to a single set:
 	 */
-	if (i != b->sets->data && !b->nsets)
+	if (i != b->keys.set->data && !b->keys.nsets)
 		bch_btree_verify(b);
 
 	if (b->written < btree_blocks(b))
-		bch_bset_init_next(b, write_block(b), bset_magic(&b->c->sb));
+		bch_bset_init_next(&b->keys, write_block(b),
+				   bset_magic(&b->c->sb));
 }
 
 static void bch_btree_node_write_sync(struct btree *b)
@@ -553,24 +561,6 @@
  * mca -> memory cache
  */
 
-static void mca_reinit(struct btree *b)
-{
-	unsigned i;
-
-	b->flags	= 0;
-	b->written	= 0;
-	b->nsets	= 0;
-
-	for (i = 0; i < MAX_BSETS; i++)
-		b->sets[i].size = 0;
-	/*
-	 * Second loop starts at 1 because b->sets[0]->data is the memory we
-	 * allocated
-	 */
-	for (i = 1; i < MAX_BSETS; i++)
-		b->sets[i].data = NULL;
-}
-
 #define mca_reserve(c)	(((c->root && c->root->level)		\
 			  ? c->root->level : 1) * 8 + 16)
 #define mca_can_free(c)						\
@@ -580,7 +570,7 @@
 {
 	BUG_ON(b->io_mutex.count != 1);
 
-	bch_btree_keys_free(b);
+	bch_btree_keys_free(&b->keys);
 
 	b->c->bucket_cache_used--;
 	list_move(&b->list, &b->c->btree_cache_freed);
@@ -602,7 +592,7 @@
 
 static void mca_data_alloc(struct btree *b, struct bkey *k, gfp_t gfp)
 {
-	if (!bch_btree_keys_alloc(b,
+	if (!bch_btree_keys_alloc(&b->keys,
 				  max_t(unsigned,
 					ilog2(b->c->btree_pages),
 					btree_order(k)),
@@ -642,9 +632,9 @@
 	if (!down_write_trylock(&b->lock))
 		return -ENOMEM;
 
-	BUG_ON(btree_node_dirty(b) && !b->sets[0].data);
+	BUG_ON(btree_node_dirty(b) && !b->keys.set[0].data);
 
-	if (b->page_order < min_order)
+	if (b->keys.page_order < min_order)
 		goto out_unlock;
 
 	if (!flush) {
@@ -809,7 +799,7 @@
 	c->verify_data = mca_bucket_alloc(c, &ZERO_KEY, GFP_KERNEL);
 
 	if (c->verify_data &&
-	    c->verify_data->sets[0].data)
+	    c->verify_data->keys.set->data)
 		list_del_init(&c->verify_data->list);
 	else
 		c->verify_data = NULL;
@@ -907,7 +897,7 @@
 	list_for_each_entry(b, &c->btree_cache_freed, list)
 		if (!mca_reap(b, 0, false)) {
 			mca_data_alloc(b, k, __GFP_NOWARN|GFP_NOIO);
-			if (!b->sets[0].data)
+			if (!b->keys.set[0].data)
 				goto err;
 			else
 				goto out;
@@ -918,7 +908,7 @@
 		goto err;
 
 	BUG_ON(!down_write_trylock(&b->lock));
-	if (!b->sets->data)
+	if (!b->keys.set->data)
 		goto err;
 out:
 	BUG_ON(b->io_mutex.count != 1);
@@ -929,15 +919,17 @@
 	hlist_add_head_rcu(&b->hash, mca_hash(c, k));
 
 	lock_set_subclass(&b->lock.dep_map, level + 1, _THIS_IP_);
-	b->level	= level;
 	b->parent	= (void *) ~0UL;
+	b->flags	= 0;
+	b->written	= 0;
+	b->level	= level;
 
 	if (!b->level)
-		b->ops	= &bch_extent_keys_ops;
+		bch_btree_keys_init(&b->keys, &bch_extent_keys_ops,
+				    &b->c->expensive_debug_checks);
 	else
-		b->ops	= &bch_btree_keys_ops;
-
-	mca_reinit(b);
+		bch_btree_keys_init(&b->keys, &bch_btree_keys_ops,
+				    &b->c->expensive_debug_checks);
 
 	return b;
 err:
@@ -998,13 +990,13 @@
 
 	b->accessed = 1;
 
-	for (; i <= b->nsets && b->sets[i].size; i++) {
-		prefetch(b->sets[i].tree);
-		prefetch(b->sets[i].data);
+	for (; i <= b->keys.nsets && b->keys.set[i].size; i++) {
+		prefetch(b->keys.set[i].tree);
+		prefetch(b->keys.set[i].data);
 	}
 
-	for (; i <= b->nsets; i++)
-		prefetch(b->sets[i].data);
+	for (; i <= b->keys.nsets; i++)
+		prefetch(b->keys.set[i].data);
 
 	if (btree_node_io_error(b)) {
 		rw_unlock(write, b);
@@ -1084,7 +1076,7 @@
 	}
 
 	b->accessed = 1;
-	bch_bset_init_next(b, b->sets->data, bset_magic(&b->c->sb));
+	bch_bset_init_next(&b->keys, b->keys.set->data, bset_magic(&b->c->sb));
 
 	mutex_unlock(&c->bucket_lock);
 
@@ -1215,7 +1207,7 @@
 		stale = max(stale, btree_mark_key(b, k));
 		keys++;
 
-		if (bch_ptr_bad(b, k))
+		if (bch_ptr_bad(&b->keys, k))
 			continue;
 
 		gc->key_bytes += bkey_u64s(k);
@@ -1225,9 +1217,9 @@
 		gc->data += KEY_SIZE(k);
 	}
 
-	for (t = b->sets; t <= &b->sets[b->nsets]; t++)
+	for (t = b->keys.set; t <= &b->keys.set[b->keys.nsets]; t++)
 		btree_bug_on(t->size &&
-			     bset_written(b, t) &&
+			     bset_written(&b->keys, t) &&
 			     bkey_cmp(&b->key, &t->end) < 0,
 			     b, "found short btree key in gc");
 
@@ -1271,7 +1263,7 @@
 	blocks = btree_default_blocks(b->c) * 2 / 3;
 
 	if (nodes < 2 ||
-	    __set_blocks(b->sets[0].data, keys,
+	    __set_blocks(b->keys.set[0].data, keys,
 			 block_bytes(b->c)) > blocks * (nodes - 1))
 		return 0;
 
@@ -1428,7 +1420,7 @@
 		r[i].b = ERR_PTR(-EINTR);
 
 	while (1) {
-		k = bch_btree_iter_next_filter(&iter, b, bch_ptr_bad);
+		k = bch_btree_iter_next_filter(&iter, &b->keys, bch_ptr_bad);
 		if (k) {
 			r->b = bch_btree_node_get(b->c, k, b->level - 1, true);
 			if (IS_ERR(r->b)) {
@@ -1764,7 +1756,8 @@
 		bch_btree_iter_init(b, &iter, NULL);
 
 		do {
-			k = bch_btree_iter_next_filter(&iter, b, bch_ptr_bad);
+			k = bch_btree_iter_next_filter(&iter, &b->keys,
+						       bch_ptr_bad);
 			if (k)
 				btree_node_prefetch(b->c, k, b->level - 1);
 
@@ -1894,7 +1887,7 @@
 
 			subtract_dirty(k, KEY_START(insert), KEY_SIZE(insert));
 
-			if (bkey_written(b, k)) {
+			if (bkey_written(&b->keys, k)) {
 				/*
 				 * We insert a new key to cover the top of the
 				 * old key, and the old key is modified in place
@@ -1907,19 +1900,20 @@
 				 * depends on us inserting a new key for the top
 				 * here.
 				 */
-				top = bch_bset_search(b, bset_tree_last(b),
+				top = bch_bset_search(b,
+						      bset_tree_last(&b->keys),
 						      insert);
-				bch_bset_insert(b, top, k);
+				bch_bset_insert(&b->keys, top, k);
 			} else {
 				BKEY_PADDED(key) temp;
 				bkey_copy(&temp.key, k);
-				bch_bset_insert(b, k, &temp.key);
+				bch_bset_insert(&b->keys, k, &temp.key);
 				top = bkey_next(k);
 			}
 
 			bch_cut_front(insert, top);
 			bch_cut_back(&START_KEY(insert), k);
-			bch_bset_fix_invalidated_key(b, k);
+			bch_bset_fix_invalidated_key(&b->keys, k);
 			return false;
 		}
 
@@ -1929,7 +1923,7 @@
 			if (bkey_cmp(&START_KEY(insert), &START_KEY(k)) > 0)
 				old_offset = KEY_START(insert);
 
-			if (bkey_written(b, k) &&
+			if (bkey_written(&b->keys, k) &&
 			    bkey_cmp(&START_KEY(insert), &START_KEY(k)) <= 0) {
 				/*
 				 * Completely overwrote, so we don't have to
@@ -1938,7 +1932,7 @@
 				bch_cut_front(k, k);
 			} else {
 				__bch_cut_back(&START_KEY(insert), k);
-				bch_bset_fix_invalidated_key(b, k);
+				bch_bset_fix_invalidated_key(&b->keys, k);
 			}
 		}
 
@@ -1979,7 +1973,8 @@
 		 * the previous key.
 		 */
 		prev = NULL;
-		m = bch_btree_iter_init(b, &iter, PRECEDING_KEY(&START_KEY(k)));
+		m = bch_btree_iter_init(b, &iter,
+					PRECEDING_KEY(&START_KEY(k)));
 
 		if (fix_overlapping_extents(b, k, &iter, replace_key)) {
 			op->insert_collision = true;
@@ -2000,7 +1995,7 @@
 		/* prev is in the tree, if we merge we're done */
 		status = BTREE_INSERT_STATUS_BACK_MERGE;
 		if (prev &&
-		    bch_bkey_try_merge(b, prev, k))
+		    bch_bkey_try_merge(&b->keys, prev, k))
 			goto merged;
 
 		status = BTREE_INSERT_STATUS_OVERWROTE;
@@ -2010,14 +2005,14 @@
 
 		status = BTREE_INSERT_STATUS_FRONT_MERGE;
 		if (m != bset_bkey_last(i) &&
-		    bch_bkey_try_merge(b, k, m))
+		    bch_bkey_try_merge(&b->keys, k, m))
 			goto copy;
 	} else {
 		BUG_ON(replace_key);
-		m = bch_bset_search(b, bset_tree_last(b), k);
+		m = bch_bset_search(b, bset_tree_last(&b->keys), k);
 	}
 
-insert:	bch_bset_insert(b, m, k);
+insert:	bch_bset_insert(&b->keys, m, k);
 copy:	bkey_copy(m, k);
 merged:
 	bch_check_keys(b, "%u for %s", status,
@@ -2362,7 +2357,7 @@
 
 		bch_btree_iter_init(b, &iter, from);
 
-		while ((k = bch_btree_iter_next_filter(&iter, b,
+		while ((k = bch_btree_iter_next_filter(&iter, &b->keys,
 						       bch_ptr_bad))) {
 			ret = btree(map_nodes_recurse, k, b,
 				    op, from, fn, flags);
@@ -2395,7 +2390,7 @@
 
 	bch_btree_iter_init(b, &iter, from);
 
-	while ((k = bch_btree_iter_next_filter(&iter, b, bch_ptr_bad))) {
+	while ((k = bch_btree_iter_next_filter(&iter, &b->keys, bch_ptr_bad))) {
 		ret = !b->level
 			? fn(op, b, k)
 			: btree(map_keys_recurse, k, b, op, from, fn, flags);
diff --git a/drivers/md/bcache/btree.h b/drivers/md/bcache/btree.h
index 0b43607..04e81f8 100644
--- a/drivers/md/bcache/btree.h
+++ b/drivers/md/bcache/btree.h
@@ -113,28 +113,7 @@
 	int			prio_blocked;
 };
 
-struct btree_keys_ops {
-	bool			(*sort_cmp)(struct btree_iter_set,
-					    struct btree_iter_set);
-	struct bkey		*(*sort_fixup)(struct btree_iter *,
-					       struct bkey *);
-	bool			(*key_invalid)(struct btree *,
-					       const struct bkey *);
-	bool			(*key_bad)(struct btree *,
-					   const struct bkey *);
-	bool			(*key_merge)(struct btree *,
-					     struct bkey *, struct bkey *);
-
-
-	/*
-	 * Only used for deciding whether to use START_KEY(k) or just the key
-	 * itself in a couple places
-	 */
-	bool		is_extents;
-};
-
 struct btree {
-	const struct btree_keys_ops	*ops;
 	/* Hottest entries first */
 	struct hlist_node	hash;
 
@@ -151,17 +130,8 @@
 	unsigned long		flags;
 	uint16_t		written;	/* would be nice to kill */
 	uint8_t			level;
-	uint8_t			nsets;
-	uint8_t			page_order;
 
-	/*
-	 * Set of sorted keys - the real btree node - plus a binary search tree
-	 *
-	 * sets[0] is special; set[0]->tree, set[0]->prev and set[0]->data point
-	 * to the memory we have allocated for this btree node. Additionally,
-	 * set[0]->data points to the entire btree node as it exists on disk.
-	 */
-	struct bset_tree	sets[MAX_BSETS];
+	struct btree_keys	keys;
 
 	/* For outstanding btree writes, used as a lock - protects write_idx */
 	struct closure		io;
@@ -201,49 +171,19 @@
 	return b->writes + (btree_node_write_idx(b) ^ 1);
 }
 
-static inline struct bset_tree *bset_tree_last(struct btree *b)
-{
-	return b->sets + b->nsets;
-}
-
 static inline struct bset *btree_bset_first(struct btree *b)
 {
-	return b->sets->data;
+	return b->keys.set->data;
 }
 
 static inline struct bset *btree_bset_last(struct btree *b)
 {
-	return bset_tree_last(b)->data;
-}
-
-static inline unsigned bset_byte_offset(struct btree *b, struct bset *i)
-{
-	return ((size_t) i) - ((size_t) b->sets->data);
-}
-
-static inline unsigned bset_sector_offset(struct btree *b, struct bset *i)
-{
-	return (((void *) i) - ((void *) btree_bset_first(b))) >> 9;
+	return bset_tree_last(&b->keys)->data;
 }
 
 static inline unsigned bset_block_offset(struct btree *b, struct bset *i)
 {
-	return bset_sector_offset(b, i) >> b->c->block_bits;
-}
-
-static inline struct bset *write_block(struct btree *b)
-{
-	return ((void *) b->sets[0].data) + b->written * block_bytes(b->c);
-}
-
-static inline bool bset_written(struct btree *b, struct bset_tree *t)
-{
-	return t->data < write_block(b);
-}
-
-static inline bool bkey_written(struct btree *b, struct bkey *k)
-{
-	return k < write_block(b)->start;
+	return bset_sector_offset(&b->keys, i) >> b->c->block_bits;
 }
 
 static inline void set_gc_sectors(struct cache_set *c)
@@ -251,27 +191,6 @@
 	atomic_set(&c->sectors_to_gc, c->sb.bucket_size * c->nbuckets / 16);
 }
 
-static inline bool bch_ptr_invalid(struct btree *b, const struct bkey *k)
-{
-	return b->ops->key_invalid(b, k);
-}
-
-static inline bool bch_ptr_bad(struct btree *b, const struct bkey *k)
-{
-	return b->ops->key_bad(b, k);
-}
-
-/*
- * Tries to merge l and r: l should be lower than r
- * Returns true if we were able to merge. If we did merge, l will be the merged
- * key, r will be untouched.
- */
-static inline bool bch_bkey_try_merge(struct btree *b,
-				      struct bkey *l, struct bkey *r)
-{
-	return b->ops->key_merge ?  b->ops->key_merge(b, l, r) : false;
-}
-
 void bkey_put(struct cache_set *c, struct bkey *k);
 
 /* Looping macros */
@@ -284,7 +203,7 @@
 
 #define for_each_key_filter(b, k, iter, filter)				\
 	for (bch_btree_iter_init((b), (iter), NULL);			\
-	     ((k) = bch_btree_iter_next_filter((iter), b, filter));)
+	     ((k) = bch_btree_iter_next_filter((iter), &(b)->keys, filter));)
 
 #define for_each_key(b, k, iter)					\
 	for (bch_btree_iter_init((b), (iter), NULL);			\
diff --git a/drivers/md/bcache/debug.c b/drivers/md/bcache/debug.c
index 2c6587d..8acc18a 100644
--- a/drivers/md/bcache/debug.c
+++ b/drivers/md/bcache/debug.c
@@ -113,9 +113,9 @@
 	unsigned i;
 
 	console_lock();
-	for (i = 0; i <= b->nsets; i++)
-		dump_bset(b, b->sets[i].data,
-			  bset_block_offset(b, b->sets[i].data));
+	for (i = 0; i <= b->keys.nsets; i++)
+		dump_bset(b, b->keys.set[i].data,
+			  bset_block_offset(b, b->keys.set[i].data));
 	console_unlock();
 }
 
@@ -139,13 +139,13 @@
 	mutex_lock(&b->c->verify_lock);
 
 	ondisk = b->c->verify_ondisk;
-	sorted = b->c->verify_data->sets->data;
-	inmemory = b->sets->data;
+	sorted = b->c->verify_data->keys.set->data;
+	inmemory = b->keys.set->data;
 
 	bkey_copy(&v->key, &b->key);
 	v->written = 0;
 	v->level = b->level;
-	v->ops = b->ops;
+	v->keys.ops = b->keys.ops;
 
 	bio = bch_bbio_alloc(b->c);
 	bio->bi_bdev		= PTR_CACHE(b->c, &b->key, 0)->bdev;
@@ -159,7 +159,7 @@
 	memcpy(ondisk, sorted, KEY_SIZE(&v->key) << 9);
 
 	bch_btree_node_read_done(v);
-	sorted = v->sets->data;
+	sorted = v->keys.set->data;
 
 	if (inmemory->keys != sorted->keys ||
 	    memcmp(inmemory->start,
@@ -264,14 +264,14 @@
 			if (p && bkey_cmp(&START_KEY(p), &START_KEY(k)) > 0)
 				goto bug;
 
-			if (bch_ptr_invalid(b, k))
+			if (bch_ptr_invalid(&b->keys, k))
 				continue;
 
 			err =  "Overlapping keys";
 			if (p && bkey_cmp(p, &START_KEY(k)) > 0)
 				goto bug;
 		} else {
-			if (bch_ptr_bad(b, k))
+			if (bch_ptr_bad(&b->keys, k))
 				continue;
 
 			err = "Duplicate keys";
diff --git a/drivers/md/bcache/extents.c b/drivers/md/bcache/extents.c
index 8fe6aae..ba30211 100644
--- a/drivers/md/bcache/extents.c
+++ b/drivers/md/bcache/extents.c
@@ -81,8 +81,9 @@
 	return true;
 }
 
-static bool bch_btree_ptr_invalid(struct btree *b, const struct bkey *k)
+static bool bch_btree_ptr_invalid(struct btree_keys *bk, const struct bkey *k)
 {
+	struct btree *b = container_of(bk, struct btree, keys);
 	return __bch_btree_ptr_invalid(b->c, k);
 }
 
@@ -118,13 +119,14 @@
 	return true;
 }
 
-static bool bch_btree_ptr_bad(struct btree *b, const struct bkey *k)
+static bool bch_btree_ptr_bad(struct btree_keys *bk, const struct bkey *k)
 {
+	struct btree *b = container_of(bk, struct btree, keys);
 	unsigned i;
 
 	if (!bkey_cmp(k, &ZERO_KEY) ||
 	    !KEY_PTRS(k) ||
-	    bch_ptr_invalid(b, k))
+	    bch_ptr_invalid(bk, k))
 		return true;
 
 	for (i = 0; i < KEY_PTRS(k); i++)
@@ -209,8 +211,9 @@
 	return NULL;
 }
 
-static bool bch_extent_invalid(struct btree *b, const struct bkey *k)
+static bool bch_extent_invalid(struct btree_keys *bk, const struct bkey *k)
 {
+	struct btree *b = container_of(bk, struct btree, keys);
 	char buf[80];
 
 	if (!KEY_SIZE(k))
@@ -259,13 +262,14 @@
 	return true;
 }
 
-static bool bch_extent_bad(struct btree *b, const struct bkey *k)
+static bool bch_extent_bad(struct btree_keys *bk, const struct bkey *k)
 {
+	struct btree *b = container_of(bk, struct btree, keys);
 	struct bucket *g;
 	unsigned i, stale;
 
 	if (!KEY_PTRS(k) ||
-	    bch_extent_invalid(b, k))
+	    bch_extent_invalid(bk, k))
 		return true;
 
 	for (i = 0; i < KEY_PTRS(k); i++)
@@ -303,8 +307,9 @@
 		~((uint64_t)1 << 63);
 }
 
-static bool bch_extent_merge(struct btree *b, struct bkey *l, struct bkey *r)
+static bool bch_extent_merge(struct btree_keys *bk, struct bkey *l, struct bkey *r)
 {
+	struct btree *b = container_of(bk, struct btree, keys);
 	unsigned i;
 
 	if (key_merging_disabled(b->c))
diff --git a/drivers/md/bcache/sysfs.c b/drivers/md/bcache/sysfs.c
index 206c80f..7e175dbc 100644
--- a/drivers/md/bcache/sysfs.c
+++ b/drivers/md/bcache/sysfs.c
@@ -433,7 +433,7 @@
 
 		mutex_lock(&c->bucket_lock);
 		list_for_each_entry(b, &c->btree_cache, list)
-			ret += 1 << (b->page_order + PAGE_SHIFT);
+			ret += 1 << (b->keys.page_order + PAGE_SHIFT);
 
 		mutex_unlock(&c->bucket_lock);
 		return ret;