From: Matt Benjamin <matt@linuxbox.com>
Date: Thu, 29 May 2014 14:34:20 +0000 (-0400)
Subject: Work around an apparent binding bug (GCC 4.8).
X-Git-Tag: v0.80.6~44
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=ae787cfa88dfd0f5add5932b297258c46af4e333;p=ceph.git

Work around an apparent binding bug (GCC 4.8).

A reference to h->seq passed to std::pair ostensibly could not bind
because the header structure is packed.  At first this looked like
a more general unaligned access problem, but the only location the
compiler rejects is a false positive.

Signed-off-by: Matt Benjamin <matt@linuxbox.com>
(cherry picked from commit c930a1f119069a424af28a618b0abff4947c221f)
---

diff --git a/src/os/FileJournal.cc b/src/os/FileJournal.cc
index c6bd6167aaa4..7eb7927e0412 100644
--- a/src/os/FileJournal.cc
+++ b/src/os/FileJournal.cc
@@ -1758,7 +1758,12 @@ FileJournal::read_entry_result FileJournal::do_read_entry(
   // ok!
   if (seq)
     *seq = h->seq;
-  journalq.push_back(pair<uint64_t,off64_t>(h->seq, pos));
+
+  // works around an apparent GCC 4.8(?) compiler bug about unaligned
+  // bind by reference to (packed) h->seq
+  journalq.push_back(
+    pair<uint64_t,off64_t>(static_cast<uint64_t>(h->seq),
+			   static_cast<off64_t>(pos)));
 
   if (next_pos)
     *next_pos = pos;