Merge pull request #12125 from ukernel/wip-17990

mds: properly commit new dirfrag before splitting it

Reviewed-by: Greg Farnum <gfarnum@redhat.com>

diff --cc src/mds/CDir.cc
Simple merge

diff --cc src/mds/CDir.h
Simple merge

diff --cc src/mds/MDCache.cc
Simple merge

diff --cc src/mds/Server.cc
Simple merge