rgw: avoid shard recreation during bilog trimming if it doesn't exist

When trimming bilogs, avoid recreating shards that don't exist. Instead,
calling assert_exists() will return ENOENT, and the result will be logged
in handle_result() without unnecessary shard creation.

Signed-off-by: Seena Fallah <[email protected]>

Author: clwluvw

src/rgw/driver/rados/rgw_cr_rados.cc

@@ -704,6 +704,7 @@ int RGWRadosBILogTrimCR::send_request(const DoutPrefixProvider *dpp)
   encode(call, in);
 
   librados::ObjectWriteOperation op;
+  op.assert_exists();
   op.exec(RGW_CLASS, RGW_BI_LOG_TRIM, in);
 
   cn = stack->create_completion_notifier();

src/rgw/driver/rados/rgw_trim_bilog.cc

@@ -791,6 +791,12 @@ int BucketTrimInstanceCR::operate(const DoutPrefixProvider *dpp)
       set_status("trimming bilog shards");
       yield call(new BucketTrimShardCollectCR(dpp, store, *pbucket_info, totrim.layout.in_index,
 					      min_markers));
+      if (retcode == -ENOENT) {
+        // this is not a fatal error to retry, as the shard seems to not exist
+        // anymore. This can happen if the shard was removed unexpectedly.
+        // should be already logged by the BucketTrimShardCollectCR().
+        retcode = 0;
+      }
       if (retcode < 0) {
 	ldpp_dout(dpp, 4) << "failed to trim bilog shards: "
 			  << cpp_strerror(retcode) << dendl;