From 4c16f2cd95bb5deb36194e85dfc102dfe8af878a Mon Sep 17 00:00:00 2001
From: Vincent Latombe <vincent@latombe.net>
Date: Sat, 23 May 2020 14:16:05 +0200
Subject: [PATCH] Make Computer#getLogDir thread-safe (#4730)

---
 core/src/main/java/hudson/model/Computer.java | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/core/src/main/java/hudson/model/Computer.java b/core/src/main/java/hudson/model/Computer.java
index 073af962c8..94782b6189 100644
--- a/core/src/main/java/hudson/model/Computer.java
+++ b/core/src/main/java/hudson/model/Computer.java
@@ -195,6 +195,8 @@ public /*transient*/ abstract class Computer extends Actionable implements Acces
 
     protected final Object statusChangeLock = new Object();
 
+    private final Object logDirLock = new String("logDirLock");
+
     /**
      * Keeps track of stack traces to track the termination requests for this computer.
      *
@@ -303,10 +305,12 @@ public /*transient*/ abstract class Computer extends Actionable implements Acces
      */
     protected @NonNull File getLogDir() {
         File dir = new File(Jenkins.get().getRootDir(),"logs/slaves/"+nodeName);
-        try {
-            IOUtils.mkdirs(dir);
-        } catch (IOException x) {
-            LOGGER.log(Level.SEVERE, "Failed to create agent log directory " + dir, x);
+        synchronized (logDirLock) {
+            try {
+                IOUtils.mkdirs(dir);
+            } catch (IOException x) {
+                LOGGER.log(Level.SEVERE, "Failed to create agent log directory " + dir, x);
+            }
         }
         return dir;
     }