From 2175029c9e6ba3a9ecc2a7e13ba8fb335e08c709 Mon Sep 17 00:00:00 2001
From: Michael Eischer <michael.eischer@fau.de>
Date: Fri, 29 Jan 2021 19:02:22 +0100
Subject: [PATCH] Sync directory to disk after upload

After a file was uploaded, also sync its containing directory to disk to
make sure that also the directory entry is persisted after a system
crash.
---
 repo/repo.go | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/repo/repo.go b/repo/repo.go
index fc8e908..8fe1dae 100644
--- a/repo/repo.go
+++ b/repo/repo.go
@@ -627,9 +627,28 @@ func (h *Handler) saveBlob(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
+	if err := syncDir(filepath.Dir(path)); err != nil {
+		// Don't call os.Remove(path) as this is prone to race conditions with parallel upload retries
+		h.internalServerError(w, err)
+		return
+	}
+
 	h.sendMetric(objectType, BlobWrite, uint64(written))
 }
 
+func syncDir(dirname string) error {
+	dir, err := os.Open(dirname)
+	if err != nil {
+		return err
+	}
+	err = dir.Sync()
+	if err != nil {
+		_ = dir.Close()
+		return err
+	}
+	return dir.Close()
+}
+
 // deleteBlob deletes a blob from the repository.
 func (h *Handler) deleteBlob(w http.ResponseWriter, r *http.Request) {
 	if h.opt.Debug {