os/bluestore: use transparent comparator

so we don't need to create an instance of `std::string` just for looking
up in those maps.

Signed-off-by: Kefu Chai <kchai@redhat.com>
(cherry picked from commit 92665cd93ee6d50d1233e7205f9ffece94e63a20)

diff --git a/src/os/bluestore/BlueFS.h b/src/os/bluestore/BlueFS.h
index fbcb0bbbf77697b05814b468fbae135152b0c7f8..2f1388baea5d0b9a562704cfb46d5c70b6492d12 100644 (file)
--- a/src/os/bluestore/BlueFS.h
+++ b/src/os/bluestore/BlueFS.h
@@ -153,7 +153,7 @@ public:
   struct Dir : public RefCountedObject {
     MEMPOOL_CLASS_HELPERS();
 
-    mempool::bluefs::map<std::string,FileRef> file_map;
+    mempool::bluefs::map<std::string, FileRef, std::less<>> file_map;
 
   private:
     FRIEND_MAKE_REF(Dir);
@@ -309,8 +309,8 @@ private:
   };
 
   // cache
-  mempool::bluefs::map<std::string, DirRef> dir_map;              ///< dirname -> Dir
-  mempool::bluefs::unordered_map<uint64_t,FileRef> file_map; ///< ino -> File
+  mempool::bluefs::map<std::string, DirRef, std::less<>> dir_map;          ///< dirname -> Dir
+  mempool::bluefs::unordered_map<uint64_t, FileRef> file_map; ///< ino -> File
 
   // map of dirty files, files of same dirty_seq are grouped into list.
   std::map<uint64_t, dirty_file_list_t> dirty_files;