rgw: fetch_remote_obj() applies olh even if object is current

even if we already have the latest version of an object, it may have
synced without a valid olh epoch. so we still need to apply its olh
modifications with this epoch. this change also has to be added to the
data changes log

Signed-off-by: Casey Bodley <cbodley@redhat.com>
(cherry picked from commit b5ecc4e)

src/rgw/rgw_rados.cc

@@ -8168,7 +8168,16 @@ int RGWRados::fetch_remote_obj(RGWObjectCtx& obj_ctx,
   return 0;
 set_err_state:
   if (copy_if_newer && ret == -ERR_NOT_MODIFIED) {
-    ret = 0;
+    // we may have already fetched during sync of OP_ADD, but were waiting
+    // for OP_LINK_OLH to call set_olh() with a real olh_epoch
+    if (olh_epoch && *olh_epoch > 0) {
+      constexpr bool log_data_change = true;
+      ret = set_olh(obj_ctx, dest_bucket_info, dest_obj, false, nullptr,
+                    *olh_epoch, real_time(), false, zones_trace, log_data_change);
+    } else {
+      // we already have the latest copy
+      ret = 0;
+    }
   }
   if (opstate) {
     RGWOpState::OpState state;
@@ -11259,7 +11268,8 @@ int RGWRados::bucket_index_link_olh(const RGWBucketInfo& bucket_info, RGWObjStat
                                     const string& op_tag,
                                     struct rgw_bucket_dir_entry_meta *meta,
                                     uint64_t olh_epoch,
-                                    real_time unmod_since, bool high_precision_time, rgw_zone_set *_zones_trace)
+                                    real_time unmod_since, bool high_precision_time,
+                                    rgw_zone_set *_zones_trace, bool log_data_change)
 {
   rgw_rados_ref ref;
   int r = get_obj_head_ref(bucket_info, obj_instance, &ref);
@@ -11289,6 +11299,10 @@ int RGWRados::bucket_index_link_olh(const RGWBucketInfo& bucket_info, RGWObjStat
     return r;
   }
 
+  if (log_data_change && bucket_info.datasync_flag_enabled()) {
+    data_log->add_entry(bs.bucket, bs.shard_id);
+  }
+
   return 0;
 }
 
@@ -11581,7 +11595,8 @@ int RGWRados::update_olh(RGWObjectCtx& obj_ctx, RGWObjState *state, const RGWBuc
 }
 
 int RGWRados::set_olh(RGWObjectCtx& obj_ctx, RGWBucketInfo& bucket_info, const rgw_obj& target_obj, bool delete_marker, rgw_bucket_dir_entry_meta *meta,
-                      uint64_t olh_epoch, real_time unmod_since, bool high_precision_time, rgw_zone_set *zones_trace)
+                      uint64_t olh_epoch, real_time unmod_since, bool high_precision_time,
+                      rgw_zone_set *zones_trace, bool log_data_change)
 {
   string op_tag;
 
@@ -11612,7 +11627,9 @@ int RGWRados::set_olh(RGWObjectCtx& obj_ctx, RGWBucketInfo& bucket_info, const r
       }
       return ret;
     }
-    ret = bucket_index_link_olh(bucket_info, *state, target_obj, delete_marker, op_tag, meta, olh_epoch, unmod_since, high_precision_time, zones_trace);
+    ret = bucket_index_link_olh(bucket_info, *state, target_obj, delete_marker,
+                                op_tag, meta, olh_epoch, unmod_since, high_precision_time,
+                                zones_trace, log_data_change);
     if (ret < 0) {
       ldout(cct, 20) << "bucket_index_link_olh() target_obj=" << target_obj << " delete_marker=" << (int)delete_marker << " returned " << ret << dendl;
       if (ret == -ECANCELED) {

src/rgw/rgw_rados.h

@@ -3391,7 +3391,9 @@ class RGWRados : public AdminSocketHook
                             const rgw_obj& obj_instance, bool delete_marker,
                             const string& op_tag, struct rgw_bucket_dir_entry_meta *meta,
                             uint64_t olh_epoch,
-                            ceph::real_time unmod_since, bool high_precision_time, rgw_zone_set *zones_trace = nullptr);
+                            ceph::real_time unmod_since, bool high_precision_time,
+                            rgw_zone_set *zones_trace = nullptr,
+                            bool log_data_change = false);
   int bucket_index_unlink_instance(const RGWBucketInfo& bucket_info, const rgw_obj& obj_instance, const string& op_tag, const string& olh_tag, uint64_t olh_epoch, rgw_zone_set *zones_trace = nullptr);
   int bucket_index_read_olh_log(const RGWBucketInfo& bucket_info, RGWObjState& state, const rgw_obj& obj_instance, uint64_t ver_marker,
                                 map<uint64_t, vector<rgw_bucket_olh_log_entry> > *log, bool *is_truncated);
@@ -3402,7 +3404,8 @@ class RGWRados : public AdminSocketHook
                     uint64_t *plast_ver, rgw_zone_set *zones_trace = nullptr);
   int update_olh(RGWObjectCtx& obj_ctx, RGWObjState *state, const RGWBucketInfo& bucket_info, const rgw_obj& obj, rgw_zone_set *zones_trace = nullptr);
   int set_olh(RGWObjectCtx& obj_ctx, RGWBucketInfo& bucket_info, const rgw_obj& target_obj, bool delete_marker, rgw_bucket_dir_entry_meta *meta,
-              uint64_t olh_epoch, ceph::real_time unmod_since, bool high_precision_time, rgw_zone_set *zones_trace = nullptr);
+              uint64_t olh_epoch, ceph::real_time unmod_since, bool high_precision_time,
+              rgw_zone_set *zones_trace = nullptr, bool log_data_change = false);
   int unlink_obj_instance(RGWObjectCtx& obj_ctx, RGWBucketInfo& bucket_info, const rgw_obj& target_obj,
                           uint64_t olh_epoch, rgw_zone_set *zones_trace = nullptr);