Doesn't work with kopia

[yurikoles]

kopia (backup tool) works fine with davfs2, but doesn't work with gcsf. It says that it can't find blob immediately after saving it.

Cross-link: kopia/kopia#77

[yurikoles]

I can provide debug info if you tell me how.

[yurikoles]

@harababurel here is debug log: https://git.io/fjFnC

[yurikoles]

Seems to be related to #60, but I had tried as root too.