merge bitcoin#24079: replace RecursiveMutex cs_SubVer with Mutex (and rename)

src/net.cpp

@@ -648,7 +648,7 @@ void CNode::copyStats(CNodeStats &stats, const std::vector<bool> &m_asmap)
     X(m_addr_name);
     X(nVersion);
     {
-        LOCK(cs_SubVer);
+        LOCK(m_subver_mutex);
         X(cleanSubVer);
     }
     stats.fInbound = IsInboundConn();

src/net.h

@@ -476,12 +476,12 @@ public:
     const bool m_inbound_onion;
     std::atomic<int> nNumWarningsSkipped{0};
     std::atomic<int> nVersion{0};
+    Mutex m_subver_mutex;
     /**
      * cleanSubVer is a sanitized string of the user agent byte array we read
      * from the wire. This cleaned string can safely be logged or displayed.
      */
-    std::string cleanSubVer GUARDED_BY(cs_SubVer){};
-    RecursiveMutex cs_SubVer; // used for both cleanSubVer and strSubVer
+    std::string cleanSubVer GUARDED_BY(m_subver_mutex){};
     bool m_prefer_evict{false}; // This peer is preferred for eviction.
     bool HasPermission(NetPermissionFlags permission) const {
         return NetPermissions::HasFlag(m_permissionFlags, permission);

src/net_processing.cpp

@@ -3357,7 +3357,7 @@ void PeerManagerImpl::ProcessMessage(
         pfrom.nServices = nServices;
         pfrom.SetAddrLocal(addrMe);
         {
-            LOCK(pfrom.cs_SubVer);
+            LOCK(pfrom.m_subver_mutex);
             pfrom.cleanSubVer = cleanSubVer;
         }
         peer->m_starting_height = starting_height;