From: Kefu Chai <kchai@redhat.com>
Date: Sat, 18 Mar 2017 09:07:48 +0000 (+0800)
Subject: os/bluestore: do not use nullptr to calc the size of bluestore_pextent_t
X-Git-Tag: v12.0.1~14^2
X-Git-Url: http://git.apps.os.sepia.ceph.com/?a=commitdiff_plain;h=79e91733a44d25ecaac78014dbfcdbbe47ce2567;p=ceph-ci.git

os/bluestore: do not use nullptr to calc the size of bluestore_pextent_t

see also #13889, otherwise this segfaults when compiled with -O0.

Signed-off-by: Kefu Chai <kchai@redhat.com>
---

diff --git a/src/os/bluestore/bluestore_types.h b/src/os/bluestore/bluestore_types.h
index a385a6acf2b..57f60afd1f9 100644
--- a/src/os/bluestore/bluestore_types.h
+++ b/src/os/bluestore/bluestore_types.h
@@ -165,9 +165,12 @@ struct denc_traits<PExtentVector> {
   static constexpr bool featured = false;
   static void bound_encode(const PExtentVector& v, size_t& p) {
     p += sizeof(uint32_t);
-    size_t per = 0;
-    denc(*(bluestore_pextent_t*)nullptr, per);
-    p += per * v.size();
+    const auto size = v.size();
+    if (size) {
+      size_t per = 0;
+      denc(v.front(), per);
+      p +=  per * size;
+    }
   }
   static void encode(const PExtentVector& v,
 		     bufferlist::contiguous_appender& p) {