tipc: delay delete of link when failover is needed
When a bearer is disabled, all its attached links are deleted.
Ideally, we should do link failover to redundant links on other bearers,
if there are any, in such cases. This would be consistent with current
behavior when a link is reset, but not deleted. However, due to the
complexity involved, and the (wrongly) perceived low demand for this
feature, it was never implemented until now.
We mark the doomed link for deletion with a new flag, but wait until the
failover process is finished before we actually delete it. With the
improved link tunnelling/failover code introduced earlier in this commit
series, it is now easy to identify a spot in the code where the failover
is finished and it is safe to delete the marked link. Moreover, the test
for the flag and the deletion can be done synchronously, and outside the
most time critical data path.
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Reviewed-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/tipc/bearer.c b/net/tipc/bearer.c
index 4931eea..60caa45 100644
--- a/net/tipc/bearer.c
+++ b/net/tipc/bearer.c
@@ -51,7 +51,7 @@
struct tipc_bearer tipc_bearers[MAX_BEARERS];
-static void bearer_disable(struct tipc_bearer *b_ptr);
+static void bearer_disable(struct tipc_bearer *b_ptr, bool shutting_down);
/**
* tipc_media_find - locates specified media object by name
@@ -331,7 +331,7 @@
res = tipc_disc_create(b_ptr, &b_ptr->bcast_addr, disc_domain);
if (res) {
- bearer_disable(b_ptr);
+ bearer_disable(b_ptr, false);
pr_warn("Bearer <%s> rejected, discovery object creation failed\n",
name);
goto exit;
@@ -363,14 +363,14 @@
*
* Note: This routine assumes caller holds tipc_net_lock.
*/
-static void bearer_disable(struct tipc_bearer *b_ptr)
+static void bearer_disable(struct tipc_bearer *b_ptr, bool shutting_down)
{
struct tipc_link_req *temp_req;
pr_info("Disabling bearer <%s>\n", b_ptr->name);
spin_lock_bh(&b_ptr->lock);
b_ptr->media->disable_media(b_ptr);
- tipc_link_delete_list(b_ptr->identity);
+ tipc_link_delete_list(b_ptr->identity, shutting_down);
temp_req = b_ptr->link_req;
b_ptr->link_req = NULL;
spin_unlock_bh(&b_ptr->lock);
@@ -392,7 +392,7 @@
pr_warn("Attempt to disable unknown bearer <%s>\n", name);
res = -EINVAL;
} else {
- bearer_disable(b_ptr);
+ bearer_disable(b_ptr, false);
res = 0;
}
write_unlock_bh(&tipc_net_lock);
@@ -612,6 +612,6 @@
for (i = 0; i < MAX_BEARERS; i++) {
if (tipc_bearers[i].active)
- bearer_disable(&tipc_bearers[i]);
+ bearer_disable(&tipc_bearers[i], true);
}
}
diff --git a/net/tipc/link.c b/net/tipc/link.c
index 663623c..0307516 100644
--- a/net/tipc/link.c
+++ b/net/tipc/link.c
@@ -281,7 +281,7 @@
}
-void tipc_link_delete_list(unsigned int bearer_id)
+void tipc_link_delete_list(unsigned int bearer_id, bool shutting_down)
{
struct tipc_link *l_ptr;
struct tipc_node *n_ptr;
@@ -291,12 +291,20 @@
l_ptr = n_ptr->links[bearer_id];
if (l_ptr) {
tipc_link_reset(l_ptr);
- tipc_node_detach_link(n_ptr, l_ptr);
- spin_unlock_bh(&n_ptr->lock);
+ if (shutting_down || !tipc_node_is_up(n_ptr)) {
+ tipc_node_detach_link(l_ptr->owner, l_ptr);
+ tipc_link_reset_fragments(l_ptr);
+ spin_unlock_bh(&n_ptr->lock);
- /* Nobody else can access this link now: */
- del_timer_sync(&l_ptr->timer);
- kfree(l_ptr);
+ /* Nobody else can access this link now: */
+ del_timer_sync(&l_ptr->timer);
+ kfree(l_ptr);
+ } else {
+ /* Detach/delete when failover is finished: */
+ l_ptr->flags |= LINK_STOPPED;
+ spin_unlock_bh(&n_ptr->lock);
+ del_timer_sync(&l_ptr->timer);
+ }
continue;
}
spin_unlock_bh(&n_ptr->lock);
@@ -481,6 +489,9 @@
struct tipc_link *other;
u32 cont_intv = l_ptr->continuity_interval;
+ if (l_ptr->flags & LINK_STOPPED)
+ return;
+
if (!(l_ptr->flags & LINK_STARTED) && (event != STARTING_EVT))
return; /* Not yet. */
@@ -2167,8 +2178,11 @@
&buf);
}
}
-
exit:
+ if ((l_ptr->exp_msg_count == 0) && (l_ptr->flags & LINK_STOPPED)) {
+ tipc_node_detach_link(l_ptr->owner, l_ptr);
+ kfree(l_ptr);
+ }
return buf;
}
@@ -2201,7 +2215,6 @@
*buf = tipc_link_failover_rcv(l_ptr, t_buf);
else
pr_warn("%sunknown tunnel pkt received\n", link_co_err);
-
exit:
kfree_skb(t_buf);
return *buf != NULL;
diff --git a/net/tipc/link.h b/net/tipc/link.h
index 3340fc1..45b9cd0 100644
--- a/net/tipc/link.h
+++ b/net/tipc/link.h
@@ -214,7 +214,7 @@
struct tipc_link *tipc_link_create(struct tipc_node *n_ptr,
struct tipc_bearer *b_ptr,
const struct tipc_media_addr *media_addr);
-void tipc_link_delete_list(unsigned int bearer_id);
+void tipc_link_delete_list(unsigned int bearer_id, bool shutting_down);
void tipc_link_failover_send_queue(struct tipc_link *l_ptr);
void tipc_link_dup_send_queue(struct tipc_link *l_ptr,
struct tipc_link *dest);
diff --git a/net/tipc/node.c b/net/tipc/node.c
index efe4d41..833324b 100644
--- a/net/tipc/node.c
+++ b/net/tipc/node.c
@@ -249,7 +249,13 @@
void tipc_node_detach_link(struct tipc_node *n_ptr, struct tipc_link *l_ptr)
{
- n_ptr->links[l_ptr->b_ptr->identity] = NULL;
+ int i;
+
+ for (i = 0; i < MAX_BEARERS; i++) {
+ if (l_ptr == n_ptr->links[i])
+ break;
+ }
+ n_ptr->links[i] = NULL;
atomic_dec(&tipc_num_links);
n_ptr->link_cnt--;
}