func main() {
flag.Usage = usage
flag.Parse()
if flag.NArg() != 1 {
usage()
os.Exit(2)
}
mountpoint := flag.Arg(0)
c, err := fuse.Mount(
mountpoint,
fuse.FSName("clock"),
fuse.Subtype("clockfsfs"),
fuse.LocalVolume(),
fuse.VolumeName("Clock filesystem"),
)
if err != nil {
log.Fatal(err)
}
defer c.Close()
srv := fs.New(c, nil)
filesys := &FS{
// We pre-create the clock node so that it's always the same
// object returned from all the Lookups. You could carefully
// track its lifetime between Lookup&Forget, and have the
// ticking & invalidation happen only when active, but let's
// keep this example simple.
clockFile: &File{
fuse: srv,
},
}
filesys.clockFile.tick()
// This goroutine never exits. That's fine for this example.
go filesys.clockFile.update()
if err := srv.Serve(filesys); err != nil {
log.Fatal(err)
}
// Check if the mount process has an error to report.
<-c.Ready
if err := c.MountError; err != nil {
log.Fatal(err)
}
}
// Convert to mount options to be passed to package bazilfuse.
func (c *MountConfig) bazilfuseOptions() (opts []bazilfuse.MountOption) {
isDarwin := runtime.GOOS == "darwin"
// Enable permissions checking in the kernel. See the comments on
// InodeAttributes.Mode.
opts = append(opts, bazilfuse.SetOption("default_permissions", ""))
// HACK(jacobsa): Work around what appears to be a bug in systemd v219, as
// shipped in Ubuntu 15.04, where it automatically unmounts any file system
// that doesn't set an explicit name.
//
// When Ubuntu contains systemd v220, this workaround should be removed and
// the systemd bug reopened if the problem persists.
//
// Cf. https://github.com/bazil/fuse/issues/89
// Cf. https://bugs.freedesktop.org/show_bug.cgi?id=90907
fsname := c.FSName
if runtime.GOOS == "linux" && fsname == "" {
fsname = "some_fuse_file_system"
}
// Special file system name?
if fsname != "" {
opts = append(opts, bazilfuse.FSName(fsname))
}
// Read only?
if c.ReadOnly {
opts = append(opts, bazilfuse.ReadOnly())
}
// OS X: set novncache when appropriate.
if isDarwin && !c.EnableVnodeCaching {
opts = append(opts, bazilfuse.SetOption("novncache", ""))
}
// OS X: disable the use of "Apple Double" (._foo and .DS_Store) files, which
// just add noise to debug output and can have significant cost on
// network-based file systems.
//
// Cf. https://github.com/osxfuse/osxfuse/wiki/Mount-options
if isDarwin {
opts = append(opts, bazilfuse.SetOption("noappledouble", ""))
}
// Ask the Linux kernel for larger read requests.
//
// As of 2015-03-26, the behavior in the kernel is:
//
// * (http://goo.gl/bQ1f1i, http://goo.gl/HwBrR6) Set the local variable
// ra_pages to be init_response->max_readahead divided by the page size.
//
// * (http://goo.gl/gcIsSh, http://goo.gl/LKV2vA) Set
// backing_dev_info::ra_pages to the min of that value and what was sent
// in the request's max_readahead field.
//
// * (http://goo.gl/u2SqzH) Use backing_dev_info::ra_pages when deciding
// how much to read ahead.
//
// * (http://goo.gl/JnhbdL) Don't read ahead at all if that field is zero.
//
// Reading a page at a time is a drag. Ask for a larger size.
const maxReadahead = 1 << 20
opts = append(opts, bazilfuse.MaxReadahead(maxReadahead))
// Last but not least: other user-supplied options.
for k, v := range c.Options {
opts = append(opts, bazilfuse.SetOption(k, v))
}
return
}