vfs: add --dir-perms and --file-perms flags - fixes #2897

This allows files to be shown with the execute bit which allows
binaries to be run under Windows and Linux.

vfs/vfs.go

@@ -43,7 +43,7 @@ var DefaultOpt = Options{
 	Umask:             0,
 	UID:               ^uint32(0), // these values instruct WinFSP-FUSE to use the current user
 	GID:               ^uint32(0), // overriden for non windows in mount_unix.go
-	DirPerms:          os.FileMode(0777) | os.ModeDir,
+	DirPerms:          os.FileMode(0777),
 	FilePerms:         os.FileMode(0666),
 	CacheMode:         CacheModeOff,
 	CacheMaxAge:       3600 * time.Second,

vfs/vfsflags/filemode.go

@@ -0,0 +1,34 @@
+package vfsflags
+
+import (
+	"fmt"
+	"os"
+	"strconv"
+
+	"github.com/pkg/errors"
+)
+
+// FileMode is a command line friendly os.FileMode
+type FileMode struct {
+	Mode *os.FileMode
+}
+
+// String turns FileMode into a string
+func (x *FileMode) String() string {
+	return fmt.Sprintf("0%3o", *x.Mode)
+}
+
+// Set a FileMode
+func (x *FileMode) Set(s string) error {
+	i, err := strconv.ParseInt(s, 8, 64)
+	if err != nil {
+		return errors.Wrap(err, "Bad FileMode - must be octal digits")
+	}
+	*x.Mode = (os.FileMode)(i)
+	return nil
+}
+
+// Type of the value
+func (x *FileMode) Type() string {
+	return "int"
+}

vfs/vfsflags/vfsflags.go

@@ -11,6 +11,8 @@ import (
 // Options set by command line flags
 var (
 	Opt       = vfs.DefaultOpt
+	DirPerms  = &FileMode{Mode: &Opt.DirPerms}
+	FilePerms = &FileMode{Mode: &Opt.FilePerms}
 )
 
 // AddFlags adds the non filing system specific flags to the command
@@ -27,5 +29,7 @@ func AddFlags(flagSet *pflag.FlagSet) {
 	flags.DurationVarP(flagSet, &Opt.CacheMaxAge, "vfs-cache-max-age", "", Opt.CacheMaxAge, "Max age of objects in the cache.")
 	flags.FVarP(flagSet, &Opt.ChunkSize, "vfs-read-chunk-size", "", "Read the source objects in chunks.")
 	flags.FVarP(flagSet, &Opt.ChunkSizeLimit, "vfs-read-chunk-size-limit", "", "If greater than --vfs-read-chunk-size, double the chunk size after each chunk read, until the limit is reached. 'off' is unlimited.")
+	flags.FVarP(flagSet, DirPerms, "dir-perms", "", "Directory permissions")
+	flags.FVarP(flagSet, FilePerms, "file-perms", "", "File permissions")
 	platformFlags(flagSet)
 }