diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 5fa521b..6434672 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -2426,6 +2426,40 @@
 	return ret;
 }
 
+static void key_search_validate(struct extent_buffer *b,
+				struct btrfs_key *key,
+				int level)
+{
+#ifdef CONFIG_BTRFS_ASSERT
+	struct btrfs_disk_key disk_key;
+
+	btrfs_cpu_key_to_disk(&disk_key, key);
+
+	if (level == 0)
+		ASSERT(!memcmp_extent_buffer(b, &disk_key,
+		    offsetof(struct btrfs_leaf, items[0].key),
+		    sizeof(disk_key)));
+	else
+		ASSERT(!memcmp_extent_buffer(b, &disk_key,
+		    offsetof(struct btrfs_node, ptrs[0].key),
+		    sizeof(disk_key)));
+#endif
+}
+
+static int key_search(struct extent_buffer *b, struct btrfs_key *key,
+		      int level, int *prev_cmp, int *slot)
+{
+	if (*prev_cmp != 0) {
+		*prev_cmp = bin_search(b, key, level, slot);
+		return *prev_cmp;
+	}
+
+	key_search_validate(b, key, level);
+	*slot = 0;
+
+	return 0;
+}
+
 /*
  * look for key in the tree.  path is filled in with nodes along the way
  * if key is found, we return zero and you can find the item in the leaf
@@ -2454,6 +2488,7 @@
 	int write_lock_level = 0;
 	u8 lowest_level = 0;
 	int min_write_lock_level;
+	int prev_cmp;
 
 	lowest_level = p->lowest_level;
 	WARN_ON(lowest_level && ins_len > 0);
@@ -2484,6 +2519,7 @@
 	min_write_lock_level = write_lock_level;
 
 again:
+	prev_cmp = -1;
 	/*
 	 * we try very hard to do read locks on the root
 	 */
@@ -2584,7 +2620,7 @@
 		if (!cow)
 			btrfs_unlock_up_safe(p, level + 1);
 
-		ret = bin_search(b, key, level, &slot);
+		ret = key_search(b, key, level, &prev_cmp, &slot);
 
 		if (level != 0) {
 			int dec = 0;
@@ -2719,6 +2755,7 @@
 	int level;
 	int lowest_unlock = 1;
 	u8 lowest_level = 0;
+	int prev_cmp;
 
 	lowest_level = p->lowest_level;
 	WARN_ON(p->nodes[0] != NULL);
@@ -2729,6 +2766,7 @@
 	}
 
 again:
+	prev_cmp = -1;
 	b = get_old_root(root, time_seq);
 	level = btrfs_header_level(b);
 	p->locks[level] = BTRFS_READ_LOCK;
@@ -2746,7 +2784,7 @@
 		 */
 		btrfs_unlock_up_safe(p, level + 1);
 
-		ret = bin_search(b, key, level, &slot);
+		ret = key_search(b, key, level, &prev_cmp, &slot);
 
 		if (level != 0) {
 			int dec = 0;