4 files changed, 81 insertions, 34 deletions

diff --git a/drivers/md/persistent-data/dm-block-manager.c b/drivers/md/persistent-data/dm-block-manager.c
index 81b513890e2b..a7e8bf296388 100644
--- a/drivers/md/persistent-data/dm-block-manager.c
+++ b/drivers/md/persistent-data/dm-block-manager.c
@@ -615,6 +615,11 @@ int dm_bm_flush_and_unlock(struct dm_block_manager *bm,
 }
 EXPORT_SYMBOL_GPL(dm_bm_flush_and_unlock);
 
+void dm_bm_prefetch(struct dm_block_manager *bm, dm_block_t b)
+{
+	dm_bufio_prefetch(bm->bufio, b, 1);
+}
+
 void dm_bm_set_read_only(struct dm_block_manager *bm)
 {
 	bm->read_only = true;
diff --git a/drivers/md/persistent-data/dm-block-manager.h b/drivers/md/persistent-data/dm-block-manager.h
index be5bff61be28..9a82083a66b6 100644
--- a/drivers/md/persistent-data/dm-block-manager.h
+++ b/drivers/md/persistent-data/dm-block-manager.h
@@ -108,6 +108,11 @@ int dm_bm_unlock(struct dm_block *b);
 int dm_bm_flush_and_unlock(struct dm_block_manager *bm,
 			   struct dm_block *superblock);
 
+ /*
+  * Request data be prefetched into the cache.
+  */
+void dm_bm_prefetch(struct dm_block_manager *bm, dm_block_t b);
+
 /*
  * Switches the bm to a read only mode.  Once read-only mode
  * has been entered the following functions will return -EPERM.
diff --git a/drivers/md/persistent-data/dm-btree.c b/drivers/md/persistent-data/dm-btree.c
index 35865425e4b4..468e371ee9b2 100644
--- a/drivers/md/persistent-data/dm-btree.c
+++ b/drivers/md/persistent-data/dm-btree.c
@@ -161,6 +161,7 @@ struct frame {
 };
 
 struct del_stack {
+	struct dm_btree_info *info;
 	struct dm_transaction_manager *tm;
 	int top;
 	struct frame spine[MAX_SPINE_DEPTH];
@@ -183,6 +184,20 @@ static int unprocessed_frames(struct del_stack *s)
 	return s->top >= 0;
 }
 
+static void prefetch_children(struct del_stack *s, struct frame *f)
+{
+	unsigned i;
+	struct dm_block_manager *bm = dm_tm_get_bm(s->tm);
+
+	for (i = 0; i < f->nr_children; i++)
+		dm_bm_prefetch(bm, value64(f->n, i));
+}
+
+static bool is_internal_level(struct dm_btree_info *info, struct frame *f)
+{
+	return f->level < (info->levels - 1);
+}
+
 static int push_frame(struct del_stack *s, dm_block_t b, unsigned level)
 {
 	int r;
@@ -205,6 +220,7 @@ static int push_frame(struct del_stack *s, dm_block_t b, unsigned level)
 		dm_tm_dec(s->tm, b);
 
 	else {
+		uint32_t flags;
 		struct frame *f = s->spine + ++s->top;
 
 		r = dm_tm_read_lock(s->tm, b, &btree_node_validator, &f->b);
@@ -217,6 +233,10 @@ static int push_frame(struct del_stack *s, dm_block_t b, unsigned level)
 		f->level = level;
 		f->nr_children = le32_to_cpu(f->n->header.nr_entries);
 		f->current_child = 0;
+
+		flags = le32_to_cpu(f->n->header.flags);
+		if (flags & INTERNAL_NODE || is_internal_level(s->info, f))
+			prefetch_children(s, f);
 	}
 
 	return 0;
@@ -230,11 +250,6 @@ static void pop_frame(struct del_stack *s)
 	dm_tm_unlock(s->tm, f->b);
 }
 
-static bool is_internal_level(struct dm_btree_info *info, struct frame *f)
-{
-	return f->level < (info->levels - 1);
-}
-
 int dm_btree_del(struct dm_btree_info *info, dm_block_t root)
 {
 	int r;
@@ -243,6 +258,7 @@ int dm_btree_del(struct dm_btree_info *info, dm_block_t root)
 	s = kmalloc(sizeof(*s), GFP_KERNEL);
 	if (!s)
 		return -ENOMEM;
+	s->info = info;
 	s->tm = info->tm;
 	s->top = -1;
 
@@ -287,7 +303,7 @@ int dm_btree_del(struct dm_btree_info *info, dm_block_t root)
 					info->value_type.dec(info->value_type.context,
 							     value_ptr(f->n, i));
 			}
-			f->current_child = f->nr_children;
+			pop_frame(s);
 		}
 	}
 
diff --git a/drivers/md/persistent-data/dm-space-map-common.c b/drivers/md/persistent-data/dm-space-map-common.c
index 3e7a88d99eb0..6058569fe86c 100644
--- a/drivers/md/persistent-data/dm-space-map-common.c
+++ b/drivers/md/persistent-data/dm-space-map-common.c
@@ -292,16 +292,11 @@ int sm_ll_lookup_bitmap(struct ll_disk *ll, dm_block_t b, uint32_t *result)
 	return dm_tm_unlock(ll->tm, blk);
 }
 
-int sm_ll_lookup(struct ll_disk *ll, dm_block_t b, uint32_t *result)
+static int sm_ll_lookup_big_ref_count(struct ll_disk *ll, dm_block_t b,
+				      uint32_t *result)
 {
 	__le32 le_rc;
-	int r = sm_ll_lookup_bitmap(ll, b, result);
-
-	if (r)
-		return r;
-
-	if (*result != 3)
-		return r;
+	int r;
 
 	r = dm_btree_lookup(&ll->ref_count_info, ll->ref_count_root, &b, &le_rc);
 	if (r < 0)
@@ -312,6 +307,19 @@ int sm_ll_lookup(struct ll_disk *ll, dm_block_t b, uint32_t *result)
 	return r;
 }
 
+int sm_ll_lookup(struct ll_disk *ll, dm_block_t b, uint32_t *result)
+{
+	int r = sm_ll_lookup_bitmap(ll, b, result);
+
+	if (r)
+		return r;
+
+	if (*result != 3)
+		return r;
+
+	return sm_ll_lookup_big_ref_count(ll, b, result);
+}
+
 int sm_ll_find_free_block(struct ll_disk *ll, dm_block_t begin,
 			  dm_block_t end, dm_block_t *result)
 {
@@ -372,11 +380,12 @@ int sm_ll_find_free_block(struct ll_disk *ll, dm_block_t begin,
 	return -ENOSPC;
 }
 
-int sm_ll_insert(struct ll_disk *ll, dm_block_t b,
-		 uint32_t ref_count, enum allocation_event *ev)
+static int sm_ll_mutate(struct ll_disk *ll, dm_block_t b,
+			uint32_t (*mutator)(void *context, uint32_t old),
+			void *context, enum allocation_event *ev)
 {
 	int r;
-	uint32_t bit, old;
+	uint32_t bit, old, ref_count;
 	struct dm_block *nb;
 	dm_block_t index = b;
 	struct disk_index_entry ie_disk;
@@ -399,6 +408,14 @@ int sm_ll_insert(struct ll_disk *ll, dm_block_t b,
 	bm_le = dm_bitmap_data(nb);
 	old = sm_lookup_bitmap(bm_le, bit);
 
+	if (old > 2) {
+		r = sm_ll_lookup_big_ref_count(ll, b, &old);
+		if (r < 0)
+			return r;
+	}
+
+	ref_count = mutator(context, old);
+
 	if (ref_count <= 2) {
 		sm_set_bitmap(bm_le, bit, ref_count);
 
@@ -448,31 +465,35 @@ int sm_ll_insert(struct ll_disk *ll, dm_block_t b,
 	return ll->save_ie(ll, index, &ie_disk);
 }
 
-int sm_ll_inc(struct ll_disk *ll, dm_block_t b, enum allocation_event *ev)
+static uint32_t set_ref_count(void *context, uint32_t old)
 {
-	int r;
-	uint32_t rc;
-
-	r = sm_ll_lookup(ll, b, &rc);
-	if (r)
-		return r;
+	return *((uint32_t *) context);
+}
 
-	return sm_ll_insert(ll, b, rc + 1, ev);
+int sm_ll_insert(struct ll_disk *ll, dm_block_t b,
+		 uint32_t ref_count, enum allocation_event *ev)
+{
+	return sm_ll_mutate(ll, b, set_ref_count, &ref_count, ev);
 }
 
-int sm_ll_dec(struct ll_disk *ll, dm_block_t b, enum allocation_event *ev)
+static uint32_t inc_ref_count(void *context, uint32_t old)
 {
-	int r;
-	uint32_t rc;
+	return old + 1;
+}
 
-	r = sm_ll_lookup(ll, b, &rc);
-	if (r)
-		return r;
+int sm_ll_inc(struct ll_disk *ll, dm_block_t b, enum allocation_event *ev)
+{
+	return sm_ll_mutate(ll, b, inc_ref_count, NULL, ev);
+}
 
-	if (!rc)
-		return -EINVAL;
+static uint32_t dec_ref_count(void *context, uint32_t old)
+{
+	return old - 1;
+}
 
-	return sm_ll_insert(ll, b, rc - 1, ev);
+int sm_ll_dec(struct ll_disk *ll, dm_block_t b, enum allocation_event *ev)
+{
+	return sm_ll_mutate(ll, b, dec_ref_count, NULL, ev);
 }
 
 int sm_ll_commit(struct ll_disk *ll)