osd: Add interface for new EC to determine the acting recovery backfill shard id set.

This is used to optimise the set of shards that will be written to by
EC writes.

Signed-off-by: Alex Ainscow <[email protected]>

Author: aainscow

src/osd/ECListener.h

@@ -148,6 +148,7 @@ struct ECListener {
   // RMWPipeline
   virtual const pg_pool_t &get_pool() const = 0;
   virtual const std::set<pg_shard_t> &get_acting_recovery_backfill_shards() const = 0;
+  virtual const shard_id_set &get_acting_recovery_backfill_shard_id_set() const = 0;
   // XXX
   virtual bool should_send_op(
     pg_shard_t peer,

src/osd/PrimaryLogPG.h

@@ -392,6 +392,9 @@ class PrimaryLogPG : public PG,
   const std::set<pg_shard_t> &get_acting_recovery_backfill_shards() const override {
     return get_acting_recovery_backfill();
   }
+  const shard_id_set &get_acting_recovery_backfill_shard_id_set() const override {
+    return PG::get_acting_recovery_backfill_shard_id_set();
+  }
   const std::set<pg_shard_t> &get_acting_shards() const override {
     return recovery_state.get_actingset();
   }