From 5795bd7db6d76da5e75d1e4c54297896a54b3f65 Mon Sep 17 00:00:00 2001
From: Nick Craig-Wood <nick@craig-wood.com>
Date: Fri, 2 Mar 2018 16:01:13 +0000
Subject: [PATCH] vfs: update cached copy if we know it has changed even if
 pending opens

This fixes a problem with Caddy serving corrupted files out of the VFS
cache when the file on the remote changed.
---
 vfs/read_write.go | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/vfs/read_write.go b/vfs/read_write.go
index 2b8e9525b..b612fdf1d 100644
--- a/vfs/read_write.go
+++ b/vfs/read_write.go
@@ -112,8 +112,8 @@ func (fh *RWFileHandle) openPending(truncate bool) (err error) {
 	// if not truncating the file, need to read it first
 	if fh.flags&os.O_TRUNC == 0 && !truncate {
 		// If the remote object exists AND its cached file exists locally AND there are no
-		// other handles with it open writers, then attempt to update it.
-		if o != nil && fh.d.vfs.cache.opens(fh.remote) <= 1 {
+		// other RW handles with it open, then attempt to update it.
+		if o != nil && fh.file.rwOpens() == 0 {
 			cacheObj, err := fh.d.vfs.cache.f.NewObject(fh.remote)
 			if err == nil && cacheObj != nil {
 				cacheObj, err = copyObj(fh.d.vfs.cache.f, cacheObj, fh.remote, o)