@@ -35,6 +35,7 @@
*/
#include <net/sock.h>
+#include <linux/list_sort.h>
#include "core.h"
#include "netlink.h"
#include "name_table.h"
@@ -66,6 +67,7 @@ struct service_range {
/**
* struct tipc_service - container for all published instances of a service type
* @type: 32 bit 'type' value for service
+ * @publ_cnt: increasing counter for publications in this service
* @ranges: rb tree containing all service ranges for this service
* @service_list: links to adjacent name ranges in hash chain
* @subscriptions: list of subscriptions for this service type
@@ -74,6 +76,7 @@ struct service_range {
*/
struct tipc_service {
u32 type;
+ unsigned int publ_cnt;
struct rb_root ranges;
struct hlist_node service_list;
struct list_head subscriptions;
@@ -109,6 +112,7 @@ static struct publication *tipc_publ_create(u32 type, u32 lower, u32 upper,
INIT_LIST_HEAD(&publ->binding_node);
INIT_LIST_HEAD(&publ->local_publ);
INIT_LIST_HEAD(&publ->all_publ);
+ INIT_LIST_HEAD(&publ->list);
return publ;
}
@@ -244,6 +248,8 @@ static struct publication *tipc_service_insert_publ(struct net *net,
p = tipc_publ_create(type, lower, upper, scope, node, port, key);
if (!p)
goto err;
+ /* Suppose there shouldn't be a huge gap btw publs i.e. >INT_MAX */
+ p->id = sc->publ_cnt++;
if (in_own_node(net, node))
list_add(&p->local_publ, &sr->local_publ);
list_add(&p->all_publ, &sr->all_publ);
@@ -277,6 +283,22 @@ static struct publication *tipc_service_remove_publ(struct service_range *sr,
return NULL;
}
+static inline int publication_after(struct publication *pa,
+ struct publication *pb)
+{
+ return ((int)(pb->id - pa->id) < 0);
+}
+
+static int tipc_publ_sort(void *priv, struct list_head *a,
+ struct list_head *b)
+{
+ struct publication *pa, *pb;
+
+ pa = container_of(a, struct publication, list);
+ pb = container_of(b, struct publication, list);
+ return publication_after(pa, pb);
+}
+
/**
* tipc_service_subscribe - attach a subscription, and optionally
* issue the prescribed number of events if there is any service
@@ -286,36 +308,51 @@ static void tipc_service_subscribe(struct tipc_service *service,
struct tipc_subscription *sub)
{
struct tipc_subscr *sb = &sub->evt.s;
+ struct publication *p, *first, *tmp;
+ struct list_head publ_list;
struct service_range *sr;
struct tipc_name_seq ns;
- struct publication *p;
struct rb_node *n;
- bool first;
+ u32 filter;
ns.type = tipc_sub_read(sb, seq.type);
ns.lower = tipc_sub_read(sb, seq.lower);
ns.upper = tipc_sub_read(sb, seq.upper);
+ filter = tipc_sub_read(sb, filter);
tipc_sub_get(sub);
list_add(&sub->service_list, &service->subscriptions);
- if (tipc_sub_read(sb, filter) & TIPC_SUB_NO_STATUS)
+ if (filter & TIPC_SUB_NO_STATUS)
return;
+ INIT_LIST_HEAD(&publ_list);
for (n = rb_first(&service->ranges); n; n = rb_next(n)) {
sr = container_of(n, struct service_range, tree_node);
if (sr->lower > ns.upper)
break;
if (!tipc_sub_check_overlap(&ns, sr->lower, sr->upper))
continue;
- first = true;
+ first = NULL;
list_for_each_entry(p, &sr->all_publ, all_publ) {
- tipc_sub_report_overlap(sub, sr->lower, sr->upper,
- TIPC_PUBLISHED, p->port,
- p->node, p->scope, first);
- first = false;
+ if (filter & TIPC_SUB_PORTS)
+ list_add_tail(&p->list, &publ_list);
+ else if (!first || publication_after(first, p))
+ /* Pick this range's *first* publication */
+ first = p;
}
+ if (first)
+ list_add_tail(&first->list, &publ_list);
+ }
+
+ /* Sort the publications before reporting */
+ list_sort(NULL, &publ_list, tipc_publ_sort);
+ list_for_each_entry_safe(p, tmp, &publ_list, list) {
+ tipc_sub_report_overlap(sub, p->lower, p->upper,
+ TIPC_PUBLISHED, p->port, p->node,
+ p->scope, true);
+ list_del_init(&p->list);
}
}
@@ -58,6 +58,7 @@ struct tipc_group;
* @node: network address of publishing socket's node
* @port: publishing port
* @key: publication key, unique across the cluster
+ * @id: publication id
* @binding_node: all publications from the same node which bound this one
* - Remote publications: in node->publ_list
* Used by node/name distr to withdraw publications when node is lost
@@ -69,6 +70,7 @@ struct tipc_group;
* Used by closest_first and multicast receive lookup algorithms
* @all_publ: all publications identical to this one, whatever node and scope
* Used by round-robin lookup algorithm
+ * @list: to form a list of publications in temporal order
* @rcu: RCU callback head used for deferred freeing
*/
struct publication {
@@ -79,10 +81,12 @@ struct publication {
u32 node;
u32 port;
u32 key;
+ unsigned int id;
struct list_head binding_node;
struct list_head binding_sock;
struct list_head local_publ;
struct list_head all_publ;
+ struct list_head list;
struct rcu_head rcu;
};
It is observed that TIPC service binding order will not be kept in the publication event report to user if the service is subscribed after the bindings. For example, services are bound by application in the following order: Server: bound port A to {18888,66,66} scope 2 Server: bound port A to {18888,33,33} scope 2 Now, if a client subscribes to the service range (e.g. {18888, 0-100}), it will get the 'TIPC_PUBLISHED' events in that binding order only when the subscription is started before the bindings. Otherwise, if started after the bindings, the events will arrive in the opposite order: Client: received event for published {18888,33,33} Client: received event for published {18888,66,66} For the latter case, it is clear that the bindings have existed in the name table already, so when reported, the events' order will follow the order of the rbtree binding nodes (- a node with lesser 'lower'/'upper' range value will be first). This is correct as we provide the tracking on a specific service status (available or not), not the relationship between multiple services. However, some users expect to see the same order of arriving events irrespective of when the subscription is issued. This turns out to be easy to fix. We now add functionality to ensure that publication events always are issued in the same temporal order as the corresponding bindings were performed. v2: replace the unnecessary macro - 'publication_after()' with inline function. Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au> --- net/tipc/name_table.c | 53 +++++++++++++++++++++++++++++++++++++++++++-------- net/tipc/name_table.h | 4 ++++ 2 files changed, 49 insertions(+), 8 deletions(-)