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authorDavid S. Miller <davem@davemloft.net>2014-01-07 18:44:35 -0500
committerDavid S. Miller <davem@davemloft.net>2014-01-07 18:44:35 -0500
commit8752b5caed54baa36c056b5c279ccdcf2805b9f6 (patch)
treea60f322078d1d53319ef2ece706ac96470bf3cc0 /net
parentfd44b93cb5eee218231f6ce5883df937b3b9c3eb (diff)
parent581465fa285863344efc233bc546823bfabd295f (diff)
Merge branch 'tipc'
Jon Maloy says: ==================== tipc: link setup and failover improvements This series consists of four unrelated commits with different purposes. - Commit #1 is purely cosmetic and pedagogic, hopefully making the failover/tunneling logics slightly easier to understand. - Commit #2 fixes a bug that has always been in the code, but was not discovered until very recently. - Commit #3 fixes a non-fatal race issue in the neighbour discovery code. - Commit #4 removes an unnecessary indirection step during link startup. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/tipc/bcast.c2
-rw-r--r--net/tipc/bearer.c2
-rw-r--r--net/tipc/bearer.h3
-rw-r--r--net/tipc/discover.c11
-rw-r--r--net/tipc/link.c96
-rw-r--r--net/tipc/link.h17
-rw-r--r--net/tipc/node.c4
-rw-r--r--net/tipc/node.h2
8 files changed, 73 insertions, 64 deletions
diff --git a/net/tipc/bcast.c b/net/tipc/bcast.c
index 4c2a80b3c01e..bf860d9e75af 100644
--- a/net/tipc/bcast.c
+++ b/net/tipc/bcast.c
@@ -794,7 +794,7 @@ void tipc_bclink_init(void)
void tipc_bclink_stop(void)
{
spin_lock_bh(&bc_lock);
- tipc_link_stop(bcl);
+ tipc_link_purge_queues(bcl);
spin_unlock_bh(&bc_lock);
memset(bclink, 0, sizeof(*bclink));
diff --git a/net/tipc/bearer.c b/net/tipc/bearer.c
index 07ed5cc8235d..2d456ab0e843 100644
--- a/net/tipc/bearer.c
+++ b/net/tipc/bearer.c
@@ -541,7 +541,7 @@ static int tipc_l2_rcv_msg(struct sk_buff *buf, struct net_device *dev,
if (likely(b_ptr)) {
if (likely(buf->pkt_type <= PACKET_BROADCAST)) {
buf->next = NULL;
- tipc_recv_msg(buf, b_ptr);
+ tipc_rcv(buf, b_ptr);
rcu_read_unlock();
return NET_RX_SUCCESS;
}
diff --git a/net/tipc/bearer.h b/net/tipc/bearer.h
index 410efb1e930b..4f5db9ad5bf6 100644
--- a/net/tipc/bearer.h
+++ b/net/tipc/bearer.h
@@ -161,8 +161,7 @@ extern struct tipc_bearer tipc_bearers[];
* TIPC routines available to supported media types
*/
-void tipc_recv_msg(struct sk_buff *buf, struct tipc_bearer *tb_ptr);
-
+void tipc_rcv(struct sk_buff *buf, struct tipc_bearer *tb_ptr);
int tipc_enable_bearer(const char *bearer_name, u32 disc_domain, u32 priority);
int tipc_disable_bearer(const char *name);
diff --git a/net/tipc/discover.c b/net/tipc/discover.c
index bc849f1efa16..412ff41b8611 100644
--- a/net/tipc/discover.c
+++ b/net/tipc/discover.c
@@ -50,6 +50,7 @@
* @dest: destination address for request messages
* @domain: network domain to which links can be established
* @num_nodes: number of nodes currently discovered (i.e. with an active link)
+ * @lock: spinlock for controlling access to requests
* @buf: request message to be (repeatedly) sent
* @timer: timer governing period between requests
* @timer_intv: current interval between requests (in ms)
@@ -59,6 +60,7 @@ struct tipc_link_req {
struct tipc_media_addr dest;
u32 domain;
int num_nodes;
+ spinlock_t lock;
struct sk_buff *buf;
struct timer_list timer;
unsigned int timer_intv;
@@ -274,7 +276,9 @@ static void disc_update(struct tipc_link_req *req)
*/
void tipc_disc_add_dest(struct tipc_link_req *req)
{
+ spin_lock_bh(&req->lock);
req->num_nodes++;
+ spin_unlock_bh(&req->lock);
}
/**
@@ -283,8 +287,10 @@ void tipc_disc_add_dest(struct tipc_link_req *req)
*/
void tipc_disc_remove_dest(struct tipc_link_req *req)
{
+ spin_lock_bh(&req->lock);
req->num_nodes--;
disc_update(req);
+ spin_unlock_bh(&req->lock);
}
/**
@@ -297,7 +303,7 @@ static void disc_timeout(struct tipc_link_req *req)
{
int max_delay;
- spin_lock_bh(&req->bearer->lock);
+ spin_lock_bh(&req->lock);
/* Stop searching if only desired node has been found */
if (tipc_node(req->domain) && req->num_nodes) {
@@ -325,7 +331,7 @@ static void disc_timeout(struct tipc_link_req *req)
k_start_timer(&req->timer, req->timer_intv);
exit:
- spin_unlock_bh(&req->bearer->lock);
+ spin_unlock_bh(&req->lock);
}
/**
@@ -356,6 +362,7 @@ int tipc_disc_create(struct tipc_bearer *b_ptr, struct tipc_media_addr *dest,
req->domain = dest_domain;
req->num_nodes = 0;
req->timer_intv = TIPC_LINK_REQ_INIT;
+ spin_lock_init(&req->lock);
k_init_timer(&req->timer, (Handler)disc_timeout, (unsigned long)req);
k_start_timer(&req->timer, req->timer_intv);
b_ptr->link_req = req;
diff --git a/net/tipc/link.c b/net/tipc/link.c
index 131a32a7b174..471973ff134f 100644
--- a/net/tipc/link.c
+++ b/net/tipc/link.c
@@ -1,7 +1,7 @@
/*
* net/tipc/link.c: TIPC link code
*
- * Copyright (c) 1996-2007, 2012, Ericsson AB
+ * Copyright (c) 1996-2007, 2012-2014, Ericsson AB
* Copyright (c) 2004-2007, 2010-2013, Wind River Systems
* All rights reserved.
*
@@ -78,8 +78,8 @@ static const char *link_unk_evt = "Unknown link event ";
static void link_handle_out_of_seq_msg(struct tipc_link *l_ptr,
struct sk_buff *buf);
static void link_recv_proto_msg(struct tipc_link *l_ptr, struct sk_buff *buf);
-static int link_recv_changeover_msg(struct tipc_link **l_ptr,
- struct sk_buff **buf);
+static int tipc_link_tunnel_rcv(struct tipc_link **l_ptr,
+ struct sk_buff **buf);
static void link_set_supervision_props(struct tipc_link *l_ptr, u32 tolerance);
static int link_send_sections_long(struct tipc_port *sender,
struct iovec const *msg_sect,
@@ -87,7 +87,6 @@ static int link_send_sections_long(struct tipc_port *sender,
static void link_state_event(struct tipc_link *l_ptr, u32 event);
static void link_reset_statistics(struct tipc_link *l_ptr);
static void link_print(struct tipc_link *l_ptr, const char *str);
-static void link_start(struct tipc_link *l_ptr);
static int link_send_long_buf(struct tipc_link *l_ptr, struct sk_buff *buf);
static void tipc_link_send_sync(struct tipc_link *l);
static void tipc_link_recv_sync(struct tipc_node *n, struct sk_buff *buf);
@@ -278,9 +277,11 @@ struct tipc_link *tipc_link_create(struct tipc_node *n_ptr,
tipc_node_attach_link(n_ptr, l_ptr);
- k_init_timer(&l_ptr->timer, (Handler)link_timeout, (unsigned long)l_ptr);
+ k_init_timer(&l_ptr->timer, (Handler)link_timeout,
+ (unsigned long)l_ptr);
list_add_tail(&l_ptr->link_list, &b_ptr->links);
- tipc_k_signal((Handler)link_start, (unsigned long)l_ptr);
+
+ link_state_event(l_ptr, STARTING_EVT);
return l_ptr;
}
@@ -305,19 +306,13 @@ void tipc_link_delete(struct tipc_link *l_ptr)
tipc_node_lock(l_ptr->owner);
tipc_link_reset(l_ptr);
tipc_node_detach_link(l_ptr->owner, l_ptr);
- tipc_link_stop(l_ptr);
+ tipc_link_purge_queues(l_ptr);
list_del_init(&l_ptr->link_list);
tipc_node_unlock(l_ptr->owner);
k_term_timer(&l_ptr->timer);
kfree(l_ptr);
}
-static void link_start(struct tipc_link *l_ptr)
-{
- tipc_node_lock(l_ptr->owner);
- link_state_event(l_ptr, STARTING_EVT);
- tipc_node_unlock(l_ptr->owner);
-}
/**
* link_schedule_port - schedule port for deferred sending
@@ -403,10 +398,10 @@ void tipc_link_reset_fragments(struct tipc_link *l_ptr)
}
/**
- * tipc_link_stop - purge all inbound and outbound messages associated with link
+ * tipc_link_purge_queues - purge all pkt queues associated with link
* @l_ptr: pointer to link
*/
-void tipc_link_stop(struct tipc_link *l_ptr)
+void tipc_link_purge_queues(struct tipc_link *l_ptr)
{
kfree_skb_list(l_ptr->oldest_deferred_in);
kfree_skb_list(l_ptr->first_out);
@@ -437,8 +432,7 @@ void tipc_link_reset(struct tipc_link *l_ptr)
tipc_node_link_down(l_ptr->owner, l_ptr);
tipc_bearer_remove_dest(l_ptr->b_ptr, l_ptr->addr);
- if (was_active_link && tipc_node_active_links(l_ptr->owner) &&
- l_ptr->owner->permit_changeover) {
+ if (was_active_link && tipc_node_active_links(l_ptr->owner)) {
l_ptr->reset_checkpoint = checkpoint;
l_ptr->exp_msg_count = START_CHANGEOVER;
}
@@ -1422,14 +1416,14 @@ static int link_recv_buf_validate(struct sk_buff *buf)
}
/**
- * tipc_recv_msg - process TIPC messages arriving from off-node
+ * tipc_rcv - process TIPC packets/messages arriving from off-node
* @head: pointer to message buffer chain
* @tb_ptr: pointer to bearer message arrived on
*
* Invoked with no locks held. Bearer pointer must point to a valid bearer
* structure (i.e. cannot be NULL), but bearer can be inactive.
*/
-void tipc_recv_msg(struct sk_buff *head, struct tipc_bearer *b_ptr)
+void tipc_rcv(struct sk_buff *head, struct tipc_bearer *b_ptr)
{
read_lock_bh(&tipc_net_lock);
while (head) {
@@ -1603,7 +1597,7 @@ deliver:
continue;
case CHANGEOVER_PROTOCOL:
type = msg_type(msg);
- if (link_recv_changeover_msg(&l_ptr, &buf)) {
+ if (tipc_link_tunnel_rcv(&l_ptr, &buf)) {
msg = buf_msg(buf);
seq_no = msg_seqno(msg);
if (type == ORIGINAL_MSG)
@@ -1837,8 +1831,6 @@ static void link_recv_proto_msg(struct tipc_link *l_ptr, struct sk_buff *buf)
if (tipc_own_addr > msg_prevnode(msg))
l_ptr->b_ptr->net_plane = msg_net_plane(msg);
- l_ptr->owner->permit_changeover = msg_redundant_link(msg);
-
switch (msg_type(msg)) {
case RESET_MSG:
@@ -1954,13 +1946,13 @@ exit:
}
-/*
- * tipc_link_tunnel(): Send one message via a link belonging to
- * another bearer. Owner node is locked.
+/* tipc_link_tunnel_xmit(): Tunnel one packet via a link belonging to
+ * a different bearer. Owner node is locked.
*/
-static void tipc_link_tunnel(struct tipc_link *l_ptr,
- struct tipc_msg *tunnel_hdr, struct tipc_msg *msg,
- u32 selector)
+static void tipc_link_tunnel_xmit(struct tipc_link *l_ptr,
+ struct tipc_msg *tunnel_hdr,
+ struct tipc_msg *msg,
+ u32 selector)
{
struct tipc_link *tunnel;
struct sk_buff *buf;
@@ -1983,12 +1975,13 @@ static void tipc_link_tunnel(struct tipc_link *l_ptr,
}
-
-/*
- * changeover(): Send whole message queue via the remaining link
- * Owner node is locked.
+/* tipc_link_failover_send_queue(): A link has gone down, but a second
+ * link is still active. We can do failover. Tunnel the failing link's
+ * whole send queue via the remaining link. This way, we don't lose
+ * any packets, and sequence order is preserved for subsequent traffic
+ * sent over the remaining link. Owner node is locked.
*/
-void tipc_link_changeover(struct tipc_link *l_ptr)
+void tipc_link_failover_send_queue(struct tipc_link *l_ptr)
{
u32 msgcount = l_ptr->out_queue_size;
struct sk_buff *crs = l_ptr->first_out;
@@ -1999,11 +1992,6 @@ void tipc_link_changeover(struct tipc_link *l_ptr)
if (!tunnel)
return;
- if (!l_ptr->owner->permit_changeover) {
- pr_warn("%speer did not permit changeover\n", link_co_err);
- return;
- }
-
tipc_msg_init(&tunnel_hdr, CHANGEOVER_PROTOCOL,
ORIGINAL_MSG, INT_H_SIZE, l_ptr->addr);
msg_set_bearer_id(&tunnel_hdr, l_ptr->peer_bearer_id);
@@ -2037,20 +2025,30 @@ void tipc_link_changeover(struct tipc_link *l_ptr)
msgcount = msg_msgcnt(msg);
while (msgcount--) {
msg_set_seqno(m, msg_seqno(msg));
- tipc_link_tunnel(l_ptr, &tunnel_hdr, m,
- msg_link_selector(m));
+ tipc_link_tunnel_xmit(l_ptr, &tunnel_hdr, m,
+ msg_link_selector(m));
pos += align(msg_size(m));
m = (struct tipc_msg *)pos;
}
} else {
- tipc_link_tunnel(l_ptr, &tunnel_hdr, msg,
- msg_link_selector(msg));
+ tipc_link_tunnel_xmit(l_ptr, &tunnel_hdr, msg,
+ msg_link_selector(msg));
}
crs = crs->next;
}
}
-void tipc_link_send_duplicate(struct tipc_link *l_ptr, struct tipc_link *tunnel)
+/* tipc_link_dup_send_queue(): A second link has become active. Tunnel a
+ * duplicate of the first link's send queue via the new link. This way, we
+ * are guaranteed that currently queued packets from a socket are delivered
+ * before future traffic from the same socket, even if this is using the
+ * new link. The last arriving copy of each duplicate packet is dropped at
+ * the receiving end by the regular protocol check, so packet cardinality
+ * and sequence order is preserved per sender/receiver socket pair.
+ * Owner node is locked.
+ */
+void tipc_link_dup_send_queue(struct tipc_link *l_ptr,
+ struct tipc_link *tunnel)
{
struct sk_buff *iter;
struct tipc_msg tunnel_hdr;
@@ -2106,12 +2104,14 @@ static struct sk_buff *buf_extract(struct sk_buff *skb, u32 from_pos)
return eb;
}
-/*
- * link_recv_changeover_msg(): Receive tunneled packet sent
- * via other link. Node is locked. Return extracted buffer.
+/* tipc_link_tunnel_rcv(): Receive a tunneled packet, sent
+ * via other link as result of a failover (ORIGINAL_MSG) or
+ * a new active link (DUPLICATE_MSG). Failover packets are
+ * returned to the active link for delivery upwards.
+ * Owner node is locked.
*/
-static int link_recv_changeover_msg(struct tipc_link **l_ptr,
- struct sk_buff **buf)
+static int tipc_link_tunnel_rcv(struct tipc_link **l_ptr,
+ struct sk_buff **buf)
{
struct sk_buff *tunnel_buf = *buf;
struct tipc_link *dest_link;
diff --git a/net/tipc/link.h b/net/tipc/link.h
index 0636ca95be36..3b6aa65b608c 100644
--- a/net/tipc/link.h
+++ b/net/tipc/link.h
@@ -216,15 +216,20 @@ 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(struct tipc_link *l_ptr);
-void tipc_link_changeover(struct tipc_link *l_ptr);
-void tipc_link_send_duplicate(struct tipc_link *l_ptr, struct tipc_link *dest);
+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);
void tipc_link_reset_fragments(struct tipc_link *l_ptr);
int tipc_link_is_up(struct tipc_link *l_ptr);
int tipc_link_is_active(struct tipc_link *l_ptr);
-void tipc_link_stop(struct tipc_link *l_ptr);
-struct sk_buff *tipc_link_cmd_config(const void *req_tlv_area, int req_tlv_space, u16 cmd);
-struct sk_buff *tipc_link_cmd_show_stats(const void *req_tlv_area, int req_tlv_space);
-struct sk_buff *tipc_link_cmd_reset_stats(const void *req_tlv_area, int req_tlv_space);
+void tipc_link_purge_queues(struct tipc_link *l_ptr);
+struct sk_buff *tipc_link_cmd_config(const void *req_tlv_area,
+ int req_tlv_space,
+ u16 cmd);
+struct sk_buff *tipc_link_cmd_show_stats(const void *req_tlv_area,
+ int req_tlv_space);
+struct sk_buff *tipc_link_cmd_reset_stats(const void *req_tlv_area,
+ int req_tlv_space);
void tipc_link_reset(struct tipc_link *l_ptr);
int tipc_link_send(struct sk_buff *buf, u32 dest, u32 selector);
void tipc_link_send_names(struct list_head *message_list, u32 dest);
diff --git a/net/tipc/node.c b/net/tipc/node.c
index e167d2615569..efe4d41bf11b 100644
--- a/net/tipc/node.c
+++ b/net/tipc/node.c
@@ -162,7 +162,7 @@ void tipc_node_link_up(struct tipc_node *n_ptr, struct tipc_link *l_ptr)
pr_info("New link <%s> becomes standby\n", l_ptr->name);
return;
}
- tipc_link_send_duplicate(active[0], l_ptr);
+ tipc_link_dup_send_queue(active[0], l_ptr);
if (l_ptr->priority == active[0]->priority) {
active[0] = l_ptr;
return;
@@ -225,7 +225,7 @@ void tipc_node_link_down(struct tipc_node *n_ptr, struct tipc_link *l_ptr)
if (active[0] == l_ptr)
node_select_active_links(n_ptr);
if (tipc_node_is_up(n_ptr))
- tipc_link_changeover(l_ptr);
+ tipc_link_failover_send_queue(l_ptr);
else
node_lost_contact(n_ptr);
}
diff --git a/net/tipc/node.h b/net/tipc/node.h
index d4bb654c858d..63e2e8ead2fe 100644
--- a/net/tipc/node.h
+++ b/net/tipc/node.h
@@ -64,7 +64,6 @@
* @working_links: number of working links to node (both active and standby)
* @block_setup: bit mask of conditions preventing link establishment to node
* @link_cnt: number of links to node
- * @permit_changeover: non-zero if node has redundant links to this system
* @signature: node instance identifier
* @bclink: broadcast-related info
* @acked: sequence # of last outbound b'cast message acknowledged by node
@@ -89,7 +88,6 @@ struct tipc_node {
int link_cnt;
int working_links;
int block_setup;
- int permit_changeover;
u32 signature;
struct {
u32 acked;

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