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>

diff --git a/src/rgw/driver/rados/rgw_rados.cc b/src/rgw/driver/rados/rgw_rados.cc
index f634df58a52c4f84d5aa4332699d9b0d29641e46..b6e3151295a1e5101d3a55c1180f2689e9cf0d96 100644 (file)
--- a/src/rgw/driver/rados/rgw_rados.cc
+++ b/src/rgw/driver/rados/rgw_rados.cc
@@ -8102,6 +8102,13 @@ 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, y);
+      if (r < 0 && r != -ECANCELED) {
+        ldpp_dout(dpp, 20) << "update_olh() target_obj=" << olh_obj << " returned " << r << dendl;
+      }
       return ret;
     }
     break;
@@ -8170,6 +8177,13 @@ 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, y, zones_trace);
+      if (r < 0 && r != -ECANCELED) {
+        ldpp_dout(dpp, 20) << "update_olh() target_obj=" << olh_obj << " returned " << r << dendl;
+      }
       return ret;
     }
     break;