Function fsync

packages/computerd/src/fuse/driver.ts:869–873

(path, _fh, _datasync, cb)

    },

    fsync(path, _fh, _datasync, cb) {
      // fsync(2) is the documented user-facing flush. Spill
      // whatever's buffered so subsequent VFS reads see it.
      cb(flushEntry(path));
    },

    fsyncdir(_path, _fh, _datasync, cb) {
      cb(0);