This function create a new dir in the file system. The provided dir_name must be a full path to the place where you want it to be created.
AFC_ERR_NO_ERROR: no error occurred.
If mkdir fails because the directory you attemped to create already exists, you may get AFC_FILEOPS_ERR_MKDIR, but only if you set that mkdir errors are blocking with afc_fileops_set_tag()
In case mkdir fails for some other reason, you'll get the AFC_FILEOPS_ERR_MKDIR error.
This function may or may not return an error value in case of real errors, depending on the settings you have made using afc_fileops_set_tag() or afc_fileops_set_tags()