sctp: convert sctp_assoc_set_id() to use idr_alloc_cyclic()

Signed-off-by: Jeff Layton <[e-mail]>
Cc: Vlad Yasevich <[e-mail]>
Cc: Sridhar Samudrala <[e-mail]>
Cc: Neil Horman <[e-mail]>
Cc: "David S. Miller" <[e-mail]>
Cc: Tejun Heo <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

net/sctp/associola.c

···
 static void sctp_assoc_free_asconf_acks(struct sctp_association *asoc);
 static void sctp_assoc_free_asconf_queue(struct sctp_association *asoc);
 
-/* Keep track of the new idr low so that we don't re-use association id
- * numbers too fast.  It is protected by they idr spin lock is in the
- * range of 1 - INT_MAX.
- */
-static u32 idr_low = 1;
-
-
 /* 1st Level Abstractions. */
 
 /* Initialize a new association from provided memory. */
···
 	if (preload)
 		idr_preload(gfp);
 	spin_lock_bh(&sctp_assocs_id_lock);
-	/* 0 is not a valid id, idr_low is always >= 1 */
-	ret = idr_alloc(&sctp_assocs_id, asoc, idr_low, 0, GFP_NOWAIT);
-	if (ret >= 0) {
-		idr_low = ret + 1;
-		if (idr_low == INT_MAX)
-			idr_low = 1;
-	}
+	/* 0 is not a valid assoc_id, must be >= 1 */
+	ret = idr_alloc_cyclic(&sctp_assocs_id, asoc, 1, 0, GFP_NOWAIT);
 	spin_unlock_bh(&sctp_assocs_id_lock);
 	if (preload)
 		idr_preload_end();