rgw: prevent another leftover bucket index olh entry scenario

If a call to bucket_index_link_olh or bucket_index_unlink_instance
fails, its associated pending xattr may have prevented the olh object
from being removed by another thread. We should do a best effort
cleanup attempt for this case by calling update_olh before returning
an error to the caller.

Signed-off-by: Cory Snyder <csnyder@1111systems.com>
(cherry picked from commit 570adec5bb8142f5baf1f05f0040e8afdb11ec05)

diff --git a/src/rgw/driver/rados/rgw_rados.cc b/src/rgw/driver/rados/rgw_rados.cc
index c79275be4034d9bc74dbf7bfc3d0f4c4f076ce45..03a81f03d62079782737abb9e8001ded7475f8d0 100644 (file)
--- a/src/rgw/driver/rados/rgw_rados.cc
+++ b/src/rgw/driver/rados/rgw_rados.cc
@@ -7835,6 +7835,13 @@ int RGWRados::set_olh(const DoutPrefixProvider *dpp, RGWObjectCtx& obj_ctx,
         }
         continue;
       }
+      // it's possible that the pending xattr from this op prevented the olh
+      // object from being cleaned by another thread that was deleting the last
+      // existing version. We invoke a best-effort update_olh here to handle this case.
+      int r = update_olh(dpp, obj_ctx, state, bucket_info, olh_obj);
+      if (r < 0 && r != -ECANCELED) {
+        ldpp_dout(dpp, 20) << "update_olh() target_obj=" << olh_obj << " returned " << r << dendl;
+      }
       return ret;
     }
     break;
@@ -7898,6 +7905,13 @@ int RGWRados::unlink_obj_instance(const DoutPrefixProvider *dpp, RGWObjectCtx& o
       if (ret == -ECANCELED) {
         continue;
       }
+      // it's possible that the pending xattr from this op prevented the olh
+      // object from being cleaned by another thread that was deleting the last
+      // existing version. We invoke a best-effort update_olh here to handle this case.
+      int r = update_olh(dpp, obj_ctx, state, bucket_info, olh_obj, zones_trace);
+      if (r < 0 && r != -ECANCELED) {
+        ldpp_dout(dpp, 20) << "update_olh() target_obj=" << olh_obj << " returned " << r << dendl;
+      }
       return ret;
     }
     break;