mount: add --no-seek flag to disable seeking

cmd/mount/file.go

@@ -114,6 +114,9 @@ func (f *File) Open(ctx context.Context, req *fuse.OpenRequest, resp *fuse.OpenR
 
 	switch {
 	case req.Flags.IsReadOnly():
+		if noSeek {
+			resp.Flags |= fuse.OpenNonSeekable
+		}
 		return newReadFileHandle(o)
 	case req.Flags.IsWriteOnly():
 		resp.Flags |= fuse.OpenNonSeekable

cmd/mount/mount.go

@@ -20,6 +20,7 @@ import (
 var (
 	noModTime = false
 	debugFUSE = false
+	noSeek    = false
 	// mount options
 	readOnly                         = false
 	allowNonEmpty                    = false
@@ -43,6 +44,7 @@ func init() {
 	cmd.Root.AddCommand(mountCmd)
 	mountCmd.Flags().BoolVarP(&noModTime, "no-modtime", "", noModTime, "Don't read the modification time (can speed things up).")
 	mountCmd.Flags().BoolVarP(&debugFUSE, "debug-fuse", "", debugFUSE, "Debug the FUSE internals - needs -v.")
+	mountCmd.Flags().BoolVarP(&noSeek, "no-seek", "", noSeek, "Don't allow seeking in files.")
 	// mount options
 	mountCmd.Flags().BoolVarP(&readOnly, "read-only", "", readOnly, "Mount read-only.")
 	mountCmd.Flags().BoolVarP(&allowNonEmpty, "allow-non-empty", "", allowNonEmpty, "Allow mounting over a non-empty directory.")