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Commit f20889f7 authored by Jon Maloy's avatar Jon Maloy Committed by David S. Miller
Browse files

tipc: refactor name table translate function 



The function tipc_nametbl_translate() function is ugly and hard to
follow. This can be improved somewhat by introducing a stack variable
for holding the publication list to be used and re-ordering the if-
clauses for selection of algorithm.

Signed-off-by: default avatarJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 218527fe

net/tipc/name_table.c

+25 −36
Original line number Diff line number Diff line
@@ -399,29 +399,32 @@ struct publication *tipc_nametbl_remove_publ(struct net *net, u32 type, 
/**

 * tipc_nametbl_translate - perform service instance to socket translation

 *

 * On entry, 'destnode' is the search domain used during translation.

 * On entry, 'dnode' is the search domain used during translation.

 *

 * On exit:

 * - if name translation is deferred to another node/cluster/zone,

 *   leaves 'destnode' unchanged (will be non-zero) and returns 0

 * - if name translation is attempted and succeeds, sets 'destnode'

 *   to publication node and returns port reference (will be non-zero)

 * - if name translation is attempted and fails, sets 'destnode' to 0

 *   and returns 0

 * - if translation is deferred to another node, leave 'dnode' unchanged and

 *   return 0

 * - if translation is attempted and succeeds, set 'dnode' to the publishing

 *   node and return the published (non-zero) port number

 * - if translation is attempted and fails, set 'dnode' to 0 and return 0

 *

 * Note that for legacy users (node configured with Z.C.N address format) the

 * 'closest-first' lookup algorithm must be maintained, i.e., if dnode is 0

 * we must look in the local binding list first

 */

u32 tipc_nametbl_translate(struct net *net, u32 type, u32 instance,

			   u32 *destnode)

u32 tipc_nametbl_translate(struct net *net, u32 type, u32 instance, u32 *dnode)

{

	struct tipc_net *tn = tipc_net(net);

	bool legacy = tn->legacy_addr_format;

	u32 self = tipc_own_addr(net);

	struct service_range *sr;

	struct tipc_service *sc;

	struct list_head *list;

	struct publication *p;

	u32 port = 0;

	u32 node = 0;



	if (!tipc_in_scope(legacy, *destnode, self))

	if (!tipc_in_scope(legacy, *dnode, self))

		return 0;



	rcu_read_lock();
@@ -434,43 +437,29 @@ u32 tipc_nametbl_translate(struct net *net, u32 type, u32 instance, 
	if (unlikely(!sr))

		goto no_match;



	/* Closest-First Algorithm */

	if (legacy && !*destnode) {

		if (!list_empty(&sr->local_publ)) {

			p = list_first_entry(&sr->local_publ,

					     struct publication,

					     local_publ);

			list_move_tail(&p->local_publ,

				       &sr->local_publ);

		} else {

			p = list_first_entry(&sr->all_publ,

					     struct publication,

					     all_publ);

			list_move_tail(&p->all_publ,

				       &sr->all_publ);

		}

	}



	/* Round-Robin Algorithm */

	else if (*destnode == self) {

		if (list_empty(&sr->local_publ))

	/* Select lookup algorithm: local, closest-first or round-robin */

	if (*dnode == self) {

		list = &sr->local_publ;

		if (list_empty(list))

			goto no_match;

		p = list_first_entry(&sr->local_publ, struct publication,

				     local_publ);

		p = list_first_entry(list, struct publication, local_publ);

		list_move_tail(&p->local_publ, &sr->local_publ);

	} else if (legacy && !*dnode && !list_empty(&sr->local_publ)) {

		list = &sr->local_publ;

		p = list_first_entry(list, struct publication, local_publ);

		list_move_tail(&p->local_publ, &sr->local_publ);

	} else {

		p = list_first_entry(&sr->all_publ, struct publication,

				     all_publ);

		list = &sr->all_publ;

		p = list_first_entry(list, struct publication, all_publ);

		list_move_tail(&p->all_publ, &sr->all_publ);

	}



	port = p->port;

	node = p->node;

no_match:

	spin_unlock_bh(&sc->lock);

not_found:

	rcu_read_unlock();

	*destnode = node;

	*dnode = node;

	return port;

}