Initialize the attribute structure used by the device

/* initialize attribute structure used by the device */
iofunc_attr_init(&attr, S_IFNAM | 0666, 0, 0);

The attribute structure contains information about our particular device associated with the name /dev/sample. It contains at least the following information:

Effectively, this is a per-name data structure. In the POSIX-Layer Data Structures chapter, we'll see how you can extend the structure to include your own per-resource information.