From f20889f72bd531cad88fbb571755a52cabf43424 Mon Sep 17 00:00:00 2001 From: Jon Maloy Date: Thu, 29 Mar 2018 23:20:42 +0200 Subject: [PATCH] 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: Jon Maloy Signed-off-by: David S. Miller --- net/tipc/name_table.c | 61 ++++++++++++++++++------------------------- 1 file changed, 25 insertions(+), 36 deletions(-) diff --git a/net/tipc/name_table.c b/net/tipc/name_table.c index e06c7a8907aa..4bdc580c533b 100644 --- a/net/tipc/name_table.c +++ b/net/tipc/name_table.c @@ -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; } -- 2.45.2