os/bluestore: 0-length zero should not change object size

Fixes: http://tracker.ceph.com/issues/21712
Signed-off-by: Sage Weil <sage@redhat.com>
(cherry picked from commit b588eaf2b0fdf06c94104d5a542bd571499f2b85)

diff --git a/src/os/bluestore/BlueStore.cc b/src/os/bluestore/BlueStore.cc
index 47eb571b426ca2680eeadaa129b091439019e818..541b000478dadf659715fb762336d96dabb4ba74 100644 (file)
--- a/src/os/bluestore/BlueStore.cc
+++ b/src/os/bluestore/BlueStore.cc
@@ -10568,7 +10568,7 @@ int BlueStore::_do_zero(TransContext *txc,
   o->extent_map.dirty_range(offset, length);
   _wctx_finish(txc, c, o, &wctx);
 
-  if (offset + length > o->onode.size) {
+  if (length > 0 && offset + length > o->onode.size) {
     o->onode.size = offset + length;
     dout(20) << __func__ << " extending size to " << offset + length
             << dendl;