Revert "storage_service: remove storage_service::_is_bootstrap_mode."

It will be needed by "storage_service: Reject nodetool cleanup when
there is pending ranges"

This reverts commit dbca327b46.

dht/boot_strapper.cc

@@ -62,7 +62,9 @@ future<> boot_strapper::bootstrap() {
         return streamer->add_ranges(keyspace_name, ranges);
     }).then([this, streamer] {
         _abort_source.check();
-        return streamer->stream_async().handle_exception([streamer] (std::exception_ptr eptr) {
+        return streamer->stream_async().then([streamer] () {
+            service::get_local_storage_service().finish_bootstrapping();
+        }).handle_exception([streamer] (std::exception_ptr eptr) {
             blogger.warn("Error during bootstrap: {}", eptr);
             return make_exception_future<>(std::move(eptr));
         });

service/storage_service.cc

@@ -715,6 +715,11 @@ void storage_service::join_token_ring(int delay) {
         db::system_keyspace::update_tokens(_bootstrap_tokens).get();
         bootstrap();
         // bootstrap will block until finished
+        if (_is_bootstrap_mode) {
+            auto err = format("We are not supposed in bootstrap mode any more");
+            slogger.warn("{}", err);
+            throw std::runtime_error(err);
+        }
     } else {
         maybe_start_sys_dist_ks();
         size_t num_tokens = _db.local().get_config().num_tokens();
@@ -819,6 +824,7 @@ void storage_service::mark_existing_views_as_built() {
 
 // Runs inside seastar::async context
 void storage_service::bootstrap() {
+    _is_bootstrap_mode = true;
     if (!db().local().is_replacing()) {
         // Wait until we know tokens of existing node before announcing join status.
         _gossiper.wait_for_range_setup().get();

service/storage_service.hh

@@ -259,6 +259,9 @@ private:
 
     std::optional<inet_address> _removing_node;
 
+    /* Are we starting this node in bootstrap mode? */
+    bool _is_bootstrap_mode;
+
     bool _initialized;
 
     bool _joined = false;
@@ -344,6 +347,10 @@ public:
     sstables::sstable_version_types sstables_format() const { return _sstables_format; }
     void enable_all_features();
 
+    void finish_bootstrapping() {
+        _is_bootstrap_mode = false;
+    }
+
     void set_gossip_tokens(const std::unordered_set<dht::token>& local_tokens);
 #if 0
 
@@ -547,6 +554,10 @@ private:
     void bootstrap();
 
 public:
+    bool is_bootstrap_mode() {
+        return _is_bootstrap_mode;
+    }
+
 #if 0
 
     public TokenMetadata getTokenMetadata()