From f0b270f4c777815cbff9a8f6b641d9d0b84a3923 Mon Sep 17 00:00:00 2001
From: Eric Schwartz <eschwartz1991@gmail.com>
Date: Fri, 11 Oct 2019 17:40:38 +0000
Subject: [PATCH] address pipe remove on reload and add pipe reuse

---
 proxy/logging/LogFile.cc   | 25 ++++++++++++++++++-------
 proxy/logging/LogObject.cc |  3 +--
 2 files changed, 19 insertions(+), 9 deletions(-)

diff --git a/proxy/logging/LogFile.cc b/proxy/logging/LogFile.cc
index 1d7d0a1c8cd..aeb567b2d11 100644
--- a/proxy/logging/LogFile.cc
+++ b/proxy/logging/LogFile.cc
@@ -170,14 +170,25 @@ LogFile::open_file()
   bool file_exists = LogFile::exists(m_name);
 
   if (m_file_format == LOG_FILE_PIPE) {
-    // setup pipe
-    if (mkfifo(m_name, S_IRUSR | S_IWUSR | S_IRGRP) < 0) {
-      if (errno != EEXIST) {
-        Error("Could not create named pipe %s for logging: %s", m_name, strerror(errno));
-        return LOG_FILE_COULD_NOT_CREATE_PIPE;
+    bool pipe_exists = false;
+    // reuse existing pipe if available
+    struct stat stat_p;
+    stat(m_name, &stat_p);
+    if (S_ISREG(stat_p.st_mode) && S_ISFIFO(stat_p.st_mode)) {
+      pipe_exists = true; // pipe exists try to reuse
+      Debug("log-file", "Reusing existing pipe %s for logging", m_name);
+    }
+
+    // setup pipe if not there
+    if (!pipe_exists) {
+      if (mkfifo(m_name, S_IRUSR | S_IWUSR | S_IRGRP) < 0) {
+        if (errno != EEXIST) {
+          Error("Could not create named pipe %s for logging: %s", m_name, strerror(errno));
+          return LOG_FILE_COULD_NOT_CREATE_PIPE;
+        }
+      } else {
+        Debug("log-file", "Created named pipe %s for logging", m_name);
       }
-    } else {
-      Debug("log-file", "Created named pipe %s for logging", m_name);
     }
 
     // now open the pipe
diff --git a/proxy/logging/LogObject.cc b/proxy/logging/LogObject.cc
index f1c2337b01d..45d826b165a 100644
--- a/proxy/logging/LogObject.cc
+++ b/proxy/logging/LogObject.cc
@@ -966,7 +966,7 @@ LogObjectManager::_solve_filename_conflicts(LogObject *log_object, int maxConfli
         // roll old filename so the new object can use the filename
         // it requested (previously we used to rename the NEW file
         // but now we roll the OLD file), or if the log object writes
-        // to a pipe, just remove the file if it was open as a pipe
+        // to a pipe, just don't roll
 
         bool roll_file = true;
 
@@ -988,7 +988,6 @@ LogObjectManager::_solve_filename_conflicts(LogObject *log_object, int maxConfli
             roll_file = false;
           } else {
             if (S_ISFIFO(s.st_mode)) {
-              unlink(filename);
               roll_file = false;
             }
           }