From: Jason Dillaman <dillaman@redhat.com>
Date: Thu, 4 Feb 2021 16:17:48 +0000 (-0500)
Subject: librbd/io: conditionally disable move optimization
X-Git-Tag: v15.2.13~2^2~15^2
X-Git-Url: http://git.apps.os.sepia.ceph.com/?a=commitdiff_plain;h=22662d7b1d0af8a123b79e9060d692fa7c1fc2fb;p=ceph.git

librbd/io: conditionally disable move optimization

If the requested write length does not match the provided bufferlist
length, disable the move optimization and instead fallback to creating
a new sub-bufferlist for the object request.

Fixes: https://tracker.ceph.com/issues/49173
Signed-off-by: Jason Dillaman <dillaman@redhat.com>
(cherry picked from commit 8dbb4a3d971d9a48c171f161f531956dd0030403)
---

diff --git a/src/librbd/io/ImageRequest.cc b/src/librbd/io/ImageRequest.cc
index 977182eacd1c5..004c41c7dd899 100644
--- a/src/librbd/io/ImageRequest.cc
+++ b/src/librbd/io/ImageRequest.cc
@@ -553,7 +553,8 @@ ObjectDispatchSpec *ImageWriteRequest<I>::create_object_request(
   I &image_ctx = this->m_image_ctx;
 
   bufferlist bl;
-  if (single_extent && object_extent.buffer_extents.size() == 1) {
+  if (single_extent && object_extent.buffer_extents.size() == 1 &&
+      m_bl.length() == object_extent.length) {
     // optimization for single object/buffer extent writes
     bl = std::move(m_bl);
   } else {