Convert fdLock to an RWMutex and protect the whole transaction

...against concurrent closes.

The testcase

	(set -e; while true; do truncate -s $RANDOM b; done) &
	(set -e; while true; do truncate -s $RANDOM b; done) &

uncovered lots of unnecessary RMW failures that were the result
of concurrent closes.

With this patch, the only remaining error is "Truncate on forgotten file"
that is probably caused by a problem in the go-fuse lib
( https://github.com/hanwen/go-fuse/issues/95 )

1 files changed, 1 insertions, 1 deletions

diff --git a/cryptfs/names_diriv.go b/cryptfs/names_diriv.go
index 9519ebc..45abfce 100644
--- a/cryptfs/names_diriv.go
+++ b/cryptfs/names_diriv.go
@@ -1,9 +1,9 @@
 package cryptfs
 
 import (
-	"os"
 	"fmt"
 	"io/ioutil"
+	"os"
 	"path/filepath"
 	"strings"
 	"sync"