That's right, 'extern' is unnecessary, I'll remove it soon.

Looking forward for more advise.

Thanks.

quoted

  
+extern struct workqueue_struct	*smc_tcp_ls_wq;	/* wq for tcp listen work */

I don't think this extern is needed, the work queue is only used within af_smc.c, right?
Even the smc_hs_wq would not need to be extern, but this would be a future cleanup.

quoted

  extern struct workqueue_struct	*smc_hs_wq;	/* wq for handshake work */
  extern struct workqueue_struct	*smc_close_wq;	/* wq for close work */