sctp: remove extern from stream sched

Now each stream sched ops is defined in different .c file and
added into the global ops in another .c file, it uses extern
to make this work.

However extern is not good coding style to get them in and
even make C=2 reports errors for this.

This patch adds sctp_sched_ops_xxx_init for each stream sched
ops in their .c file, then get them into the global ops by
calling them when initializing sctp module.

Fixes: 637784ade221 ("sctp: introduce priority based stream scheduler")
Fixes: ac1ed8b82cd6 ("sctp: introduce round robin stream scheduler")
Signed-off-by: Xin Long <[e-mail]>
Acked-by: Marcelo Ricardo Leitner <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

include/net/sctp/sctp.h

···
 int sctp_offload_init(void);
 
 /*
+ * sctp/stream_sched.c
+ */
+void sctp_sched_ops_init(void);
+
+/*
  * sctp/stream.c
  */
 int sctp_send_reset_streams(struct sctp_association *asoc,

include/net/sctp/stream_sched.h

···
 int sctp_sched_init_sid(struct sctp_stream *stream, __u16 sid, gfp_t gfp);
 struct sctp_sched_ops *sctp_sched_ops_from_stream(struct sctp_stream *stream);
 
+void sctp_sched_ops_register(enum sctp_sched_type sched,
+			     struct sctp_sched_ops *sched_ops);
+void sctp_sched_ops_prio_init(void);
+void sctp_sched_ops_rr_init(void);
+
 #endif /* __sctp_stream_sched_h__ */

net/sctp/protocol.c

···
 	INIT_LIST_HEAD(&sctp_address_families);
 	sctp_v4_pf_init();
 	sctp_v6_pf_init();
+	sctp_sched_ops_init();
 
 	status = register_pernet_subsys(&sctp_defaults_ops);
 	if (status)

net/sctp/stream_sched.c

···
 	.unsched_all = sctp_sched_fcfs_unsched_all,
 };
 
+static void sctp_sched_ops_fcfs_init(void)
+{
+	sctp_sched_ops_register(SCTP_SS_FCFS, &sctp_sched_fcfs);
+}
+
 /* API to other parts of the stack */
 
-extern struct sctp_sched_ops sctp_sched_prio;
-extern struct sctp_sched_ops sctp_sched_rr;
+static struct sctp_sched_ops *sctp_sched_ops[SCTP_SS_MAX + 1];
 
-static struct sctp_sched_ops *sctp_sched_ops[] = {
-	&sctp_sched_fcfs,
-	&sctp_sched_prio,
-	&sctp_sched_rr,
-};
+void sctp_sched_ops_register(enum sctp_sched_type sched,
+			     struct sctp_sched_ops *sched_ops)
+{
+	sctp_sched_ops[sched] = sched_ops;
+}
+
+void sctp_sched_ops_init(void)
+{
+	sctp_sched_ops_fcfs_init();
+	sctp_sched_ops_prio_init();
+	sctp_sched_ops_rr_init();
+}
 
 int sctp_sched_set_sched(struct sctp_association *asoc,
 			 enum sctp_sched_type sched)

net/sctp/stream_sched_prio.c

···
 			sctp_sched_prio_unsched(soute);
 }
 
-struct sctp_sched_ops sctp_sched_prio = {
+static struct sctp_sched_ops sctp_sched_prio = {
 	.set = sctp_sched_prio_set,
 	.get = sctp_sched_prio_get,
 	.init = sctp_sched_prio_init,
···
 	.sched_all = sctp_sched_prio_sched_all,
 	.unsched_all = sctp_sched_prio_unsched_all,
 };
+
+void sctp_sched_ops_prio_init(void)
+{
+	sctp_sched_ops_register(SCTP_SS_PRIO, &sctp_sched_prio);
+}

net/sctp/stream_sched_rr.c

···
 		sctp_sched_rr_unsched(stream, soute);
 }
 
-struct sctp_sched_ops sctp_sched_rr = {
+static struct sctp_sched_ops sctp_sched_rr = {
 	.set = sctp_sched_rr_set,
 	.get = sctp_sched_rr_get,
 	.init = sctp_sched_rr_init,
···
 	.sched_all = sctp_sched_rr_sched_all,
 	.unsched_all = sctp_sched_rr_unsched_all,
 };
+
+void sctp_sched_ops_rr_init(void)
+{
+	sctp_sched_ops_register(SCTP_SS_RR, &sctp_sched_rr);
+}