From 6d4ebeb4df0176b1973875840a9f7e91394c0685 Mon Sep 17 00:00:00 2001 From: Ying Xue Date: Thu, 6 Mar 2014 14:40:16 +0100 Subject: tipc: allow connection shutdown callback to be invoked in advance Currently connection shutdown callback function is called when connection instance is released in tipc_conn_kref_release(), and receiving packets and sending packets are running in different threads. Even if connection is closed by the thread of receiving packets, its shutdown callback may not be called immediately as the connection reference count is non-zero at that moment. So, although the connection is shut down by the thread of receiving packets, the thread of sending packets doesn't know it. Before its shutdown callback is invoked to tell the sending thread its connection has been closed, the sending thread may deliver messages by tipc_conn_sendmsg(), this is why the following error information appears: "Sending subscription event failed, no memory" To eliminate it, allow connection shutdown callback function to be called before connection id is removed in tipc_close_conn(), which makes the sending thread know the truth in time that its socket is closed so that it doesn't send message to it. We also remove the "Sending XXX failed..." error reporting for topology and config services. Signed-off-by: Ying Xue Signed-off-by: Erik Hugne Reviewed-by: Jon Maloy Signed-off-by: David S. Miller --- net/tipc/config.c | 9 ++------- net/tipc/server.c | 8 +++----- net/tipc/subscr.c | 8 ++------ 3 files changed, 7 insertions(+), 18 deletions(-) (limited to 'net/tipc') diff --git a/net/tipc/config.c b/net/tipc/config.c index e74eef2e749..e6d721692ae 100644 --- a/net/tipc/config.c +++ b/net/tipc/config.c @@ -376,7 +376,6 @@ static void cfg_conn_msg_event(int conid, struct sockaddr_tipc *addr, struct tipc_cfg_msg_hdr *req_hdr; struct tipc_cfg_msg_hdr *rep_hdr; struct sk_buff *rep_buf; - int ret; /* Validate configuration message header (ignore invalid message) */ req_hdr = (struct tipc_cfg_msg_hdr *)buf; @@ -398,12 +397,8 @@ static void cfg_conn_msg_event(int conid, struct sockaddr_tipc *addr, memcpy(rep_hdr, req_hdr, sizeof(*rep_hdr)); rep_hdr->tcm_len = htonl(rep_buf->len); rep_hdr->tcm_flags &= htons(~TCM_F_REQUEST); - - ret = tipc_conn_sendmsg(&cfgsrv, conid, addr, rep_buf->data, - rep_buf->len); - if (ret < 0) - pr_err("Sending cfg reply message failed, no memory\n"); - + tipc_conn_sendmsg(&cfgsrv, conid, addr, rep_buf->data, + rep_buf->len); kfree_skb(rep_buf); } } diff --git a/net/tipc/server.c b/net/tipc/server.c index 373979789a7..bbaa8f56024 100644 --- a/net/tipc/server.c +++ b/net/tipc/server.c @@ -87,7 +87,6 @@ static void tipc_clean_outqueues(struct tipc_conn *con); static void tipc_conn_kref_release(struct kref *kref) { struct tipc_conn *con = container_of(kref, struct tipc_conn, kref); - struct tipc_server *s = con->server; if (con->sock) { tipc_sock_release_local(con->sock); @@ -95,10 +94,6 @@ static void tipc_conn_kref_release(struct kref *kref) } tipc_clean_outqueues(con); - - if (con->conid) - s->tipc_conn_shutdown(con->conid, con->usr_data); - kfree(con); } @@ -181,6 +176,9 @@ static void tipc_close_conn(struct tipc_conn *con) struct tipc_server *s = con->server; if (test_and_clear_bit(CF_CONNECTED, &con->flags)) { + if (con->conid) + s->tipc_conn_shutdown(con->conid, con->usr_data); + spin_lock_bh(&s->idr_lock); idr_remove(&s->conn_idr, con->conid); s->idr_in_use--; diff --git a/net/tipc/subscr.c b/net/tipc/subscr.c index 7cb0bd5b117..a6ce3bbf3ea 100644 --- a/net/tipc/subscr.c +++ b/net/tipc/subscr.c @@ -96,20 +96,16 @@ static void subscr_send_event(struct tipc_subscription *sub, u32 found_lower, { struct tipc_subscriber *subscriber = sub->subscriber; struct kvec msg_sect; - int ret; msg_sect.iov_base = (void *)&sub->evt; msg_sect.iov_len = sizeof(struct tipc_event); - sub->evt.event = htohl(event, sub->swap); sub->evt.found_lower = htohl(found_lower, sub->swap); sub->evt.found_upper = htohl(found_upper, sub->swap); sub->evt.port.ref = htohl(port_ref, sub->swap); sub->evt.port.node = htohl(node, sub->swap); - ret = tipc_conn_sendmsg(&topsrv, subscriber->conid, NULL, - msg_sect.iov_base, msg_sect.iov_len); - if (ret < 0) - pr_err("Sending subscription event failed, no memory\n"); + tipc_conn_sendmsg(&topsrv, subscriber->conid, NULL, msg_sect.iov_base, + msg_sect.iov_len); } /** -- cgit v1.2.3-18-g5258 From 4652edb70e8a7eebbe47fa931940f65522c36e8f Mon Sep 17 00:00:00 2001 From: Ying Xue Date: Thu, 6 Mar 2014 14:40:17 +0100 Subject: tipc: fix connection refcount leak When tipc_conn_sendmsg() calls tipc_conn_lookup() to query a connection instance, its reference count value is increased if it's found. But subsequently if it's found that the connection is closed, the work of sending message is not queued into its server send workqueue, and the connection reference count is not decreased. This will cause a reference count leak. To reproduce this problem, an application would need to open and closes topology server connections with high intensity. We fix this by immediately decrementing the connection reference count if a send fails due to the connection being closed. Signed-off-by: Ying Xue Acked-by: Erik Hugne Reviewed-by: Jon Maloy Signed-off-by: David S. Miller --- net/tipc/server.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'net/tipc') diff --git a/net/tipc/server.c b/net/tipc/server.c index bbaa8f56024..646a930eefb 100644 --- a/net/tipc/server.c +++ b/net/tipc/server.c @@ -427,10 +427,12 @@ int tipc_conn_sendmsg(struct tipc_server *s, int conid, list_add_tail(&e->list, &con->outqueue); spin_unlock_bh(&con->outqueue_lock); - if (test_bit(CF_CONNECTED, &con->flags)) + if (test_bit(CF_CONNECTED, &con->flags)) { if (!queue_work(s->send_wq, &con->swork)) conn_put(con); - + } else { + conn_put(con); + } return 0; } -- cgit v1.2.3-18-g5258 From fe8e4649397915cf3b2ab0b695929a27e543967e Mon Sep 17 00:00:00 2001 From: Ying Xue Date: Thu, 6 Mar 2014 14:40:18 +0100 Subject: tipc: avoid to unnecessary process switch under non-block mode When messages are received via tipc socket under non-block mode, schedule_timeout() is called in tipc_wait_for_rcvmsg(), that is, the process of receiving messages will be scheduled once although timeout value passed to schedule_timeout() is 0. The same issue exists in accept()/wait_for_accept(). To avoid this unnecessary process switch, we only call schedule_timeout() if the timeout value is non-zero. Signed-off-by: Ying Xue Reviewed-by: Erik Hugne Reviewed-by: Jon Maloy Signed-off-by: David S. Miller --- net/tipc/socket.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'net/tipc') diff --git a/net/tipc/socket.c b/net/tipc/socket.c index a4cf274455a..0ed0eaa62f2 100644 --- a/net/tipc/socket.c +++ b/net/tipc/socket.c @@ -997,7 +997,7 @@ static int tipc_wait_for_rcvmsg(struct socket *sock, long timeo) for (;;) { prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE); - if (skb_queue_empty(&sk->sk_receive_queue)) { + if (timeo && skb_queue_empty(&sk->sk_receive_queue)) { if (sock->state == SS_DISCONNECTING) { err = -ENOTCONN; break; @@ -1623,7 +1623,7 @@ static int tipc_wait_for_accept(struct socket *sock, long timeo) for (;;) { prepare_to_wait_exclusive(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE); - if (skb_queue_empty(&sk->sk_receive_queue)) { + if (timeo && skb_queue_empty(&sk->sk_receive_queue)) { release_sock(sk); timeo = schedule_timeout(timeo); lock_sock(sk); -- cgit v1.2.3-18-g5258 From edcc0511b5ee7235282a688cd604e3ae7f9e1fc9 Mon Sep 17 00:00:00 2001 From: Erik Hugne Date: Thu, 6 Mar 2014 14:40:19 +0100 Subject: tipc: drop subscriber connection id invalidation When a topology server subscriber is disconnected, the associated connection id is set to zero. A check vs zero is then done in the subscription timeout function to see if the subscriber have been shut down. This is unnecessary, because all subscription timers will be cancelled when a subscriber terminates. Setting the connection id to zero is actually harmful because id zero is the identity of the topology server listening socket, and can cause a race that leads to this socket being closed instead. Signed-off-by: Erik Hugne Acked-by: Ying Xue Reviewed-by: Jon Maloy Signed-off-by: David S. Miller --- net/tipc/subscr.c | 11 ----------- 1 file changed, 11 deletions(-) (limited to 'net/tipc') diff --git a/net/tipc/subscr.c b/net/tipc/subscr.c index a6ce3bbf3ea..11c9ae00837 100644 --- a/net/tipc/subscr.c +++ b/net/tipc/subscr.c @@ -149,14 +149,6 @@ static void subscr_timeout(struct tipc_subscription *sub) /* The spin lock per subscriber is used to protect its members */ spin_lock_bh(&subscriber->lock); - /* Validate if the connection related to the subscriber is - * closed (in case subscriber is terminating) - */ - if (subscriber->conid == 0) { - spin_unlock_bh(&subscriber->lock); - return; - } - /* Validate timeout (in case subscription is being cancelled) */ if (sub->timeout == TIPC_WAIT_FOREVER) { spin_unlock_bh(&subscriber->lock); @@ -211,9 +203,6 @@ static void subscr_release(struct tipc_subscriber *subscriber) spin_lock_bh(&subscriber->lock); - /* Invalidate subscriber reference */ - subscriber->conid = 0; - /* Destroy any existing subscriptions for subscriber */ list_for_each_entry_safe(sub, sub_temp, &subscriber->subscription_list, subscription_list) { -- cgit v1.2.3-18-g5258 From 1bb8dce57f4d15233688c68990852a10eb1cd79f Mon Sep 17 00:00:00 2001 From: Erik Hugne Date: Thu, 6 Mar 2014 14:40:20 +0100 Subject: tipc: fix memory leak during module removal When the TIPC module is removed, the tasklet handler is disabled before all other subsystems. This will cause lingering publications in the name table because the node_down tasklets responsible to clean up publications from an unreachable node will never run. When the name table is shut down, these publications are detected and an error message is logged: tipc: nametbl_stop(): orphaned hash chain detected This is actually a memory leak, introduced with commit 993b858e37b3120ee76d9957a901cca22312ffaa ("tipc: correct the order of stopping services at rmmod") Instead of just logging an error and leaking memory, we free the orphaned entries during nametable shutdown. Signed-off-by: Erik Hugne Reviewed-by: Jon Maloy Signed-off-by: David S. Miller --- net/tipc/name_table.c | 37 ++++++++++++++++++++++++++++++++++--- 1 file changed, 34 insertions(+), 3 deletions(-) (limited to 'net/tipc') diff --git a/net/tipc/name_table.c b/net/tipc/name_table.c index 48302be175c..042e8e3cabc 100644 --- a/net/tipc/name_table.c +++ b/net/tipc/name_table.c @@ -941,17 +941,48 @@ int tipc_nametbl_init(void) return 0; } +/** + * tipc_purge_publications - remove all publications for a given type + * + * tipc_nametbl_lock must be held when calling this function + */ +static void tipc_purge_publications(struct name_seq *seq) +{ + struct publication *publ, *safe; + struct sub_seq *sseq; + struct name_info *info; + + if (!seq->sseqs) { + nameseq_delete_empty(seq); + return; + } + sseq = seq->sseqs; + info = sseq->info; + list_for_each_entry_safe(publ, safe, &info->zone_list, zone_list) { + tipc_nametbl_remove_publ(publ->type, publ->lower, publ->node, + publ->ref, publ->key); + } +} + void tipc_nametbl_stop(void) { u32 i; + struct name_seq *seq; + struct hlist_head *seq_head; + struct hlist_node *safe; - /* Verify name table is empty, then release it */ + /* Verify name table is empty and purge any lingering + * publications, then release the name table + */ write_lock_bh(&tipc_nametbl_lock); for (i = 0; i < TIPC_NAMETBL_SIZE; i++) { if (hlist_empty(&table.types[i])) continue; - pr_err("nametbl_stop(): orphaned hash chain detected\n"); - break; + seq_head = &table.types[i]; + hlist_for_each_entry_safe(seq, safe, seq_head, ns_list) { + tipc_purge_publications(seq); + } + continue; } kfree(table.types); table.types = NULL; -- cgit v1.2.3-18-g5258 From 2892505ea170094f982516bb38105eac45f274b1 Mon Sep 17 00:00:00 2001 From: Erik Hugne Date: Thu, 6 Mar 2014 14:40:21 +0100 Subject: tipc: don't log disabled tasklet handler errors Failure to schedule a TIPC tasklet with tipc_k_signal because the tasklet handler is disabled is not an error. It means TIPC is currently in the process of shutting down. We remove the error logging in this case. Signed-off-by: Erik Hugne Reviewed-by: Jon Maloy Signed-off-by: David S. Miller --- net/tipc/handler.c | 1 - 1 file changed, 1 deletion(-) (limited to 'net/tipc') diff --git a/net/tipc/handler.c b/net/tipc/handler.c index e4bc8a29674..1fabf160501 100644 --- a/net/tipc/handler.c +++ b/net/tipc/handler.c @@ -58,7 +58,6 @@ unsigned int tipc_k_signal(Handler routine, unsigned long argument) spin_lock_bh(&qitem_lock); if (!handler_enabled) { - pr_err("Signal request ignored by handler\n"); spin_unlock_bh(&qitem_lock); return -ENOPROTOOPT; } -- cgit v1.2.3-18-g5258