From: Radoslaw Zarzynski <rzarzyns@redhat.com>
Date: Wed, 19 Aug 2020 10:56:21 +0000 (+0200)
Subject: os/bluestore: avoid temporary bufferlist in _flush_range().
X-Git-Tag: v16.1.0~780^2~4
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=b24454abfeb99d962a3f710bb9db357d0e69d2a8;p=ceph.git

os/bluestore: avoid temporary bufferlist in _flush_range().

`bufferlist::splice()` is already piecewise -- it uses the variant
of `bufferlist::appned()` that merges adjacent bptrs.

Signed-off-by: Radoslaw Zarzynski <rzarzyns@redhat.com>
---

diff --git a/src/os/bluestore/BlueFS.cc b/src/os/bluestore/BlueFS.cc
index 15b0c10e8b8..90cb9239efc 100644
--- a/src/os/bluestore/BlueFS.cc
+++ b/src/os/bluestore/BlueFS.cc
@@ -2759,9 +2759,7 @@ ceph::bufferlist BlueFS::FileWriter::flush_buffer(
     /* in case of inital allocation and need to zero, limited flush is unacceptable */
     bl.claim_append_piecewise(buffer);
   } else {
-    bufferlist t;
-    buffer.splice(0, length, &t);
-    bl.claim_append_piecewise(t);
+    buffer.splice(0, length, &bl);
     dout(20) << " leaving 0x" << std::hex << buffer.length() << std::dec
              << " unflushed" << dendl;
   }