Add option for autounmount

Even though filesystem notifications aren't implemented for FUSE, I decided to
try my hand at implementing the autounmount feature (#128). I based it on the
EncFS autounmount code, which records filesystem accesses and checks every X
seconds whether it's idled long enough to unmount.

I've tested the feature locally, but I haven't added any tests for this flag.
I also haven't worked with Go before. So please let me know if there's
anything that should be done differently.

One particular concern: I worked from the assumption that the open files table
is unique per-filesystem. If that's not true, I'll need to add an open file
count and associated lock to the Filesystem type instead.

https://github.com/rfjakob/gocryptfs/pull/265

1 files changed, 1 insertions, 0 deletions

diff --git a/help.go b/help.go
index 714fcbf..6216a9b 100644
--- a/help.go
+++ b/help.go
@@ -19,6 +19,7 @@ func helpShort() {
 Common Options (use -hh to show all):
   -aessiv            Use AES-SIV encryption (with -init)
   -allow_other       Allow other users to access the mount
+  -i, -idle          Unmount automatically after specified idle duration
   -config            Custom path to config file
   -ctlsock           Create control socket at location
   -extpass           Call external program to prompt for the password