From 4115f6f36714b0eb883f144cefdadc97c1187cdd Mon Sep 17 00:00:00 2001
From: Aleksandra Martyniuk <aleksandra.martyniuk@scylladb.com>
Date: Tue, 4 Feb 2025 11:42:03 +0100
Subject: [PATCH] repair: do not pass erm to flush_rows_in_working_row_buf when
 unnecessary

When small_table_optimization isn't enabled, flush_rows_in_working_row_buf
does not access erm. Add small_table_optimization_params containing erm and
pass it only when small_table_optimization is enabled.

This is safe as erm is kept by shard_repair_task_impl.

(cherry picked from commit e56bb5b6e22e855709c803c14571b1d2d41da7f6)
---
 repair/row_level.cc | 23 +++++++++++++----------
 repair/row_level.hh |  6 +++++-
 2 files changed, 18 insertions(+), 11 deletions(-)

diff --git a/repair/row_level.cc b/repair/row_level.cc
index da402f8882..45a6f67336 100644
--- a/repair/row_level.cc
+++ b/repair/row_level.cc
@@ -1385,13 +1385,17 @@ public:
 
 public:
     // Must run inside a seastar thread
-    void flush_rows_in_working_row_buf(locator::effective_replication_map_ptr erm, bool small_table_optimization) {
+    void flush_rows_in_working_row_buf(std::optional<small_table_optimization_params> small_table_optimization) {
         if (_dirty_on_master) {
             _dirty_on_master = is_dirty_on_master::no;
         } else {
             return;
         }
-        flush_rows(_schema, _working_row_buf, _repair_writer, erm, small_table_optimization, this);
+        if (small_table_optimization) {
+            flush_rows(_schema, _working_row_buf, _repair_writer, small_table_optimization, this);
+        } else {
+            flush_rows(_schema, _working_row_buf, _repair_writer);
+        }
     }
 
 private:
@@ -1933,14 +1937,13 @@ public:
     }
 };
 
-void flush_rows(schema_ptr s, std::list<repair_row>& rows, lw_shared_ptr<repair_writer>& writer, locator::effective_replication_map_ptr erm, bool small_table_optimization, repair_meta* rm) {
+void flush_rows(schema_ptr s, std::list<repair_row>& rows, lw_shared_ptr<repair_writer>& writer, std::optional<small_table_optimization_params> small_table_optimization, repair_meta* rm) {
     auto cmp = position_in_partition::tri_compare(*s);
     lw_shared_ptr<mutation_fragment> last_mf;
     lw_shared_ptr<const decorated_key_with_hash> last_dk;
-    bool do_small_table_optimization = erm && small_table_optimization;
-    const auto* tm = do_small_table_optimization ? &erm->get_token_metadata() : nullptr;
+    const auto* tm = small_table_optimization ? &small_table_optimization->erm->get_token_metadata() : nullptr;
 
-    if (do_small_table_optimization && rm) {
+    if (small_table_optimization && rm) {
         const auto* tmptr = rm->get_tm_for_small_table_optimization_check(tm).get();
         if (tmptr) {
             tm = tmptr;
@@ -1953,10 +1956,10 @@ void flush_rows(schema_ptr s, std::list<repair_row>& rows, lw_shared_ptr<repair_
             continue;
         }
         const auto& dk = r.get_dk_with_hash()->dk;
-        if (do_small_table_optimization) {
+        if (small_table_optimization) {
             // Check if the token is owned by the node
-            auto eps = erm->get_replication_strategy().calculate_natural_endpoints(dk.token(), *tm).get();
-            if (!eps.contains(erm->get_topology().my_host_id())) {
+            auto eps = small_table_optimization->erm->get_replication_strategy().calculate_natural_endpoints(dk.token(), *tm).get();
+            if (!eps.contains(small_table_optimization->erm->get_topology().my_host_id())) {
                 rlogger.trace("master: ignore row, token={}", dk.token());
                 continue;
             }
@@ -2937,7 +2940,7 @@ private:
             throw;
           }
         }
-        master.flush_rows_in_working_row_buf(get_erm(), _small_table_optimization);
+        master.flush_rows_in_working_row_buf(_small_table_optimization ? std::make_optional(small_table_optimization_params{ .erm = get_erm() }) : std::nullopt);
         return op_status::next_step;
     }
 
diff --git a/repair/row_level.hh b/repair/row_level.hh
index 34ff1bacf1..c14f5d83c4 100644
--- a/repair/row_level.hh
+++ b/repair/row_level.hh
@@ -42,6 +42,10 @@ namespace gms {
     class gossiper;
 }
 
+struct small_table_optimization_params {
+    locator::effective_replication_map_ptr erm;
+};
+
 class repair_meta;
 
 using repair_meta_ptr = shared_ptr<repair_meta>;
@@ -279,4 +283,4 @@ future<> repair_cf_range_row_level(repair::shard_repair_task_impl& shard_task,
 future<std::list<repair_row>> to_repair_rows_list(repair_rows_on_wire rows,
         schema_ptr s, uint64_t seed, repair_master is_master,
         reader_permit permit, repair_hasher hasher);
-void flush_rows(schema_ptr s, std::list<repair_row>& rows, lw_shared_ptr<repair_writer>& writer, locator::effective_replication_map_ptr erm = {}, bool small_table_optimization = false, repair_meta* rm = nullptr);
+void flush_rows(schema_ptr s, std::list<repair_row>& rows, lw_shared_ptr<repair_writer>& writer, std::optional<small_table_optimization_params> small_table_optimization = std::nullopt, repair_meta* rm = nullptr);