hack to see what clone from journal might look likewip-sim-journal-clone

this is an upper bound, since we aren't touching the extent trees, and
that isn't completely free in btrfs.. but it shouldn't be too far off.

1 files changed, 9 insertions, 1 deletions

diff --git a/src/os/FileStore.cc b/src/os/FileStore.cc
index 44f3b571960..8a5bad74927 100644
--- a/src/os/FileStore.cc
+++ b/src/os/FileStore.cc
@@ -2891,7 +2891,15 @@ int FileStore::_write(coll_t cid, const hobject_t& oid,
   }
 
   // write
-  r = bl.write_fd(fd);
+  if (bl.length() > 65536) {
+    // hack to see what clone-from-journal perf might look like
+    bufferlist f;
+    f.append("blah");
+    ::lseek64(fd, offset + bl.length() - f.length(), SEEK_SET);
+    f.write_fd(fd);
+  } else {
+    r = bl.write_fd(fd);
+  }
   if (r == 0)
     r = bl.length();