tools: create mdsdir frag in cephfs-data-scan init

MDS used to ignore missing dirfrag objects.  Now that
they're detected and flagged, we need to explicitly
inject them during disaster recovery in order to have
a working filesystem.

(Specifically, this is needed because in CDir::_go_bad
we used to finish_waiting(WAIT_COMPLETE, 0), but now
we finish_waiting(WAIT_COMPLETE, -EIO))

Signed-off-by: John Spray <john.spray@redhat.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/src/tools/cephfs/DataScan.cc b/src/tools/cephfs/DataScan.cc
index 0a992a32e8f..1deabbdd878 100644
--- a/src/tools/cephfs/DataScan.cc
+++ b/src/tools/cephfs/DataScan.cc
@@ -329,6 +329,11 @@ int MetadataDriver::init_roots(int64_t data_pool_id)
   if (r != 0) {
     return r;
   }
+  bool created = false;
+  r = find_or_create_dirfrag(MDS_INO_MDSDIR(0), frag_t(), &created);
+  if (r != 0) {
+    return r;
+  }
 
   return 0;
 }