From 651d82e5116a35872ffd11e456a6dc42b347fed0 Mon Sep 17 00:00:00 2001
From: Gilbert Chen <gchen@acrosync.com>
Date: Tue, 20 Jun 2017 14:38:09 -0400
Subject: [PATCH] Check directory existence again when failing to create it to
 avoid erroring out on race condition

---
 integration_tests/test_functions.sh |  1 -
 integration_tests/threaded_test.sh  | 17 +++++++++++++++++
 src/duplicacy_filestorage.go        |  6 +++++-
 src/duplicacy_sftpstorage.go        |  6 +++++-
 4 files changed, 27 insertions(+), 3 deletions(-)
 create mode 100755 integration_tests/threaded_test.sh

diff --git a/integration_tests/test_functions.sh b/integration_tests/test_functions.sh
index 2043356..f517742 100644
--- a/integration_tests/test_functions.sh
+++ b/integration_tests/test_functions.sh
@@ -93,7 +93,6 @@ function add_file()
   FILE_NAME=$1
   pushd ${TEST_REPO}
   dd if=/dev/urandom of=${FILE_NAME} bs=1000 count=20000
-    echo ${FILE_NAME} > "${FILE_NAME}"
   popd
 }
 
diff --git a/integration_tests/threaded_test.sh b/integration_tests/threaded_test.sh
new file mode 100755
index 0000000..6b0bebe
--- /dev/null
+++ b/integration_tests/threaded_test.sh
@@ -0,0 +1,17 @@
+#!/bin/bash
+
+
+. ./test_functions.sh
+
+fixture
+
+pushd ${TEST_REPO}
+${DUPLICACY} init integration-tests $TEST_STORAGE -c 1k
+
+add_file file3
+add_file file4
+
+
+${DUPLICACY} backup -threads 16 
+${DUPLICACY} check --files -stats
+popd
diff --git a/src/duplicacy_filestorage.go b/src/duplicacy_filestorage.go
index 74c289a..db95935 100644
--- a/src/duplicacy_filestorage.go
+++ b/src/duplicacy_filestorage.go
@@ -158,7 +158,11 @@ func (storage *FileStorage) FindChunk(threadIndex int, chunkID string, isFossil
 
             err = os.Mkdir(subDir, 0744)
             if err != nil {
-                return "", false, 0, err
+                // The directory may have been created by other threads so check it again.
+                stat, _ := os.Stat(subDir)
+                if stat == nil || !stat.IsDir() {
+                    return "", false, 0, err
+                }
             }
 
             dir = subDir
diff --git a/src/duplicacy_sftpstorage.go b/src/duplicacy_sftpstorage.go
index d505980..9cfead7 100644
--- a/src/duplicacy_sftpstorage.go
+++ b/src/duplicacy_sftpstorage.go
@@ -215,7 +215,11 @@ func (storage *SFTPStorage) FindChunk(threadIndex int, chunkID string, isFossil
 
             err = storage.client.Mkdir(subDir)
             if err != nil {
-                return "", false, 0, fmt.Errorf("Failed to create the directory %s: %v", subDir, err)
+                // The directory may have been created by other threads so check it again.
+                stat, _ := storage.client.Stat(subDir)
+                if stat == nil || !stat.IsDir() {
+                    return "", false, 0, fmt.Errorf("Failed to create the directory %s: %v", subDir, err)
+                }
             }
 
             dir = subDir