From e9b9e4ace294230c6b8eb010eda564a2541c4564 Mon Sep 17 00:00:00 2001
From: Kir Kolyshkin <kolyshkin@gmail.com>
Date: Tue, 30 Jan 2018 15:01:45 -0800
Subject: [PATCH] daemon.cleanupContainer: nullify container RWLayer upon
 release

ReleaseRWLayer can and should only be called once (unless it returns
an error), but might be called twice in case of a failure from
`system.EnsureRemoveAll(container.Root)`. This results in the
following error:

> Error response from daemon: driver "XXX" failed to remove root filesystem for YYY: layer not retained

The obvious fix is to set container.RWLayer to nil as soon as
ReleaseRWLayer() succeeds.

Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
---
 daemon/delete.go | 1 +
 1 file changed, 1 insertion(+)

diff --git a/daemon/delete.go b/daemon/delete.go
index f16d38beb3..c6f8efec45 100644
--- a/daemon/delete.go
+++ b/daemon/delete.go
@@ -128,6 +128,7 @@ func (daemon *Daemon) cleanupContainer(container *container.Container, forceRemo
 			container.SetRemovalError(e)
 			return e
 		}
+		container.RWLayer = nil
 	}
 
 	if err := system.EnsureRemoveAll(container.Root); err != nil {