From 14fc705698aaeae25248f0f6ea95e0e4b38ffddc Mon Sep 17 00:00:00 2001
From: Kefu Chai <kchai@redhat.com>
Date: Fri, 28 Apr 2017 14:15:54 +0800
Subject: [PATCH] bluestore: use std::atomic<uint8_t> for min_alloc_size_order

Signed-off-by: Kefu Chai <kchai@redhat.com>
---
 src/os/bluestore/BlueStore.h | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/os/bluestore/BlueStore.h b/src/os/bluestore/BlueStore.h
index f2a32b8b2df..e96c4108257 100644
--- a/src/os/bluestore/BlueStore.h
+++ b/src/os/bluestore/BlueStore.h
@@ -1795,8 +1795,11 @@ private:
   int deferred_batch_ops = 0; ///< deferred batch size
 
   ///< bits for min_alloc_size
-  std::atomic<size_t> min_alloc_size_order = {0};
-  
+  std::atomic<uint8_t> min_alloc_size_order = {0};
+  static_assert(std::numeric_limits<uint8_t>::max() >
+		std::numeric_limits<decltype(min_alloc_size)>::digits,
+		"not enough bits for min_alloc_size");
+
   ///< size threshold for forced deferred writes
   std::atomic<uint64_t> prefer_deferred_size = {0};
 
-- 
2.39.5