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* tipc: make name table distributor use new send functionJon Paul Maloy2014-07-161-10/+3
| | | | | | | | | | | | | | | | In a previous commit series ("tipc: new unicast transmission code") we introduced a new message sending function, tipc_link_xmit2(), and moved the unicast data users over to use that function. We now let the internal name table distributor do the same. The interaction between the name distributor and the node/link layer also becomes significantly simpler, so we can eliminate the function tipc_link_names_xmit(). Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Reviewed-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: make link mtu easily accessible from socketJon Paul Maloy2014-06-271-4/+21
| | | | | | | | | | | | | | | | | | Message fragmentation is currently performed at link level, inside the protection of node_lock. This potentially binds up the sending link structure for a long time, instead of letting it do other tasks, such as handle reception of new packets. In this commit, we make the MTUs of each active link become easily accessible from the socket level, i.e., without taking any spinlock or dereferencing the target link pointer. This way, we make it possible to perform fragmentation in the sending socket, before sending the whole fragment chain to the link for transport. Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Reviewed-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: rename and move message reassembly functionJon Paul Maloy2014-05-141-4/+3
| | | | | | | | | | | | | | | | The function tipc_link_frag_rcv() is in reality a re-entrant generic message reassemby function that has nothing in particular to do with the link, where it is defined now. This becomes obvious when we see the need to call the function from other places in the code. In this commit rename it to tipc_buf_append() and move it to the file msg.c. We also simplify its signature by moving the tail pointer to the control block of the head buffer, hence making the head buffer self-contained. 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>
* tipc: don't directly overwrite node action_flagsYing Xue2014-05-091-2/+4
| | | | | | | | | | | | Each node action flag should be set or cleared separately, instead we now set the whole flags variable in one shot, and it's turned out to be hard to see which other flags are affected. Therefore, for instance, we explicitly clear TIPC_WAIT_OWN_LINKS_DOWN bit in node_lost_contact(). Signed-off-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: rename enum names of node flagsYing Xue2014-05-091-8/+9
| | | | | | | | | Rename node flags to action_flags as well as its enum names so that they can reflect its real meanings. Signed-off-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: avoid to asynchronously deliver name tables to peer nodeYing Xue2014-05-051-1/+15
| | | | | | | | | | Postpone the actions of delivering name tables until after node lock is released, avoiding to do it under asynchronous context. Signed-off-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: remove TIPC_NAMES_GONE node flagYing Xue2014-05-051-18/+4
| | | | | | | | | | | | | | Since previously what all publications pertaining to the lost node were removed from name table was finished in tasklet context asynchronously, we need to TIPC_NAMES_GONE flag indicating whether the node cleanup work is finished or not. But now as the cleanup work has been finished when node lock is released, the flag becomes meaningless for us. Signed-off-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: avoid to asynchronously notify subscriptionsYing Xue2014-05-051-2/+21
| | | | | | | | | | | Postpone the actions of notifying subscriptions until after node lock is released, avoiding to asynchronously execute registered handlers when node is lost. Signed-off-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: rename setup_blocked variable of node struct to flagsYing Xue2014-05-051-3/+3
| | | | | | | | | | | Rename setup_blocked variable of node struct to a more common name called "flags", which will be used to represent kinds of node states. Signed-off-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: fix out of bounds indexingErik Hugne2014-04-281-1/+1
| | | | | | | | | | | | | Commit 78acb1f9b898e85fa2c1e28e700b54b66b288e8d ("tipc: add ioctl to fetch link names") introduced a buffer overflow bug where specially crafted ioctl requests could cause out-of-bounds indexing of the node->links array. This was caused by an incorrect check vs MAX_BEARERS, and the static code checker complaint is: net/tipc/node.c:459 tipc_node_get_linkname() error: buffer overflow 'node->links' 2 <= 2 Signed-off-by: Erik Hugne <erik.hugne@ericsson.com> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: add ioctl to fetch link namesErik Hugne2014-04-261-0/+27
| | | | | | | | | | | | | We add a new ioctl for AF_TIPC that can be used to fetch the logical name for a link to a remote node on a given bearer. This should be used in combination with link state subscriptions. The logical name size limit definitions are moved to tipc.h, as they are now also needed by the new ioctl. Signed-off-by: Erik Hugne <erik.hugne@ericsson.com> Reviewed-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: add support for link state subscriptionsErik Hugne2014-04-261-1/+5
| | | | | | | | | | | | | When links are established over a bearer plane, we create a node local publication containing information about the peer node and bearer plane. This allows TIPC applications to use the standard TIPC topology server subscription mechanism to get notifications when a link goes up or down. Signed-off-by: Erik Hugne <erik.hugne@ericsson.com> Reviewed-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: purge tipc_net_lock lockYing Xue2014-04-221-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now tipc routing hierarchy comprises the structures 'node', 'link'and 'bearer'. The whole hierarchy is protected by a big read/write lock, tipc_net_lock, to ensure that nothing is added or removed while code is accessing any of these structures. Obviously the locking policy makes node, link and bearer components closely bound together so that their relationship becomes unnecessarily complex. In the worst case, such locking policy not only has a negative influence on performance, but also it's prone to lead to deadlock occasionally. In order o decouple the complex relationship between bearer and node as well as link, the locking policy is adjusted as follows: - Bearer level RTNL lock is used on update side, and RCU is used on read side. Meanwhile, all bearer instances including broadcast bearer are saved into bearer_list array. - Node and link level All node instances are saved into two tipc_node_list and node_htable lists. The two lists are protected by node_list_lock on write side, and they are guarded with RCU lock on read side. All members in node structure including link instances are protected by node spin lock. - The relationship between bearer and node When link accesses bearer, it first needs to find the bearer with its bearer identity from the bearer_list array. When bearer accesses node, it can iterate the node_htable hash list with the node address to find the corresponding node. In the new locking policy, every component has its private locking solution and the relationship between bearer and node is very simple, that is, they can find each other with node address or bearer identity from node_htable hash list or bearer_list array. Until now above all changes have been done, so tipc_net_lock can be removed safely. Signed-off-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Tested-by: Erik Hugne <erik.hugne@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: decouple the relationship between bearer and linkYing Xue2014-04-221-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently on both paths of message transmission and reception, the read lock of tipc_net_lock must be held before bearer is accessed, while the write lock of tipc_net_lock has to be taken before bearer is configured. Although it can ensure that bearer is always valid on the two data paths, link and bearer is closely bound together. So as the part of effort of removing tipc_net_lock, the locking policy of bearer protection will be adjusted as below: on the two data paths, RCU is used, and on the configuration path of bearer, RTNL lock is applied. Now RCU just covers the path of message reception. To make it possible to protect the path of message transmission with RCU, link should not use its stored bearer pointer to access bearer, but it should use the bearer identity of its attached bearer as index to get bearer instance from bearer_list array, which can help us decouple the relationship between bearer and link. As a result, bearer on the path of message transmission can be safely protected by RCU when we access bearer_list array within RCU lock protection. Signed-off-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Tested-by: Erik Hugne <erik.hugne@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: use node list lock to protect tipc_num_links variableYing Xue2014-03-271-10/+11
| | | | | | | | | | | | | | | | Without properly implicit or explicit read memory barrier, it's unsafe to read an atomic variable with atomic_read() from another thread which is different with the thread of changing the atomic variable with atomic_inc() or atomic_dec(). So a stale tipc_num_links may be got with atomic_read() in tipc_node_get_links(). If the tipc_num_links variable type is converted from atomic to unsigned integer and node list lock is used to protect it, the issue would be avoided. Signed-off-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: use node_list_lock to protect tipc_num_nodes variableYing Xue2014-03-271-4/+3
| | | | | | | | | | | | As tipc_node_list is protected by rcu read lock on read side, it's unnecessary to hold node_list_lock to protect tipc_node_list in tipc_node_get_links(). Instead, node_list_lock should just protects tipc_num_nodes in the function. Signed-off-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: tipc: convert node list and node hlist to RCU listsYing Xue2014-03-271-12/+16
| | | | | | | | | | | Convert tipc_node_list list and node_htable hash list to RCU lists. On read side, the two lists are protected with RCU read lock, and on update side, node_list_lock is applied to them. Signed-off-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: rename node create lock to protect node list and hlistYing Xue2014-03-271-29/+30
| | | | | | | | | | | | | | | | | | | | | | When a node is created, tipc_net_lock read lock is first held and then node_create_lock is grabbed in order to prevent the same node from being created and inserted into both node list and hlist twice. But when we query node from the two node lists, we only hold tipc_net_lock read lock without grabbing node_create_lock. Obviously this locking policy is unable to guarantee that the two node lists are always synchronized especially when the operation of changing and accessing them occurs in different contexts like currently doing. Therefore, rename node_create_lock to node_list_lock to protect the two node lists, that is, whenever node is inserted into them or node is queried from them, the node_list_lock should be always held. As a result, tipc_net_lock read lock becomes redundant and then can be removed from the node query functions. Signed-off-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: remove unnecessary checking for node objectYing Xue2014-03-271-6/+0
| | | | | | | | | | | | tipc_node_create routine doesn't need to check whether a node object specified with a node address exists or not because its caller(ie, tipc_disc_recv_msg routine) has checked this before calling it. Signed-off-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: align tipc function names with common naming practice in the networkYing Xue2014-02-181-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Rename the following functions, which are shorter and more in line with common naming practice in the network subsystem. tipc_bclink_send_msg->tipc_bclink_xmit tipc_bclink_recv_pkt->tipc_bclink_rcv tipc_disc_recv_msg->tipc_disc_rcv tipc_link_send_proto_msg->tipc_link_proto_xmit link_recv_proto_msg->tipc_link_proto_rcv link_send_sections_long->tipc_link_iovec_long_xmit tipc_link_send_sections_fast->tipc_link_iovec_xmit_fast tipc_link_send_sync->tipc_link_sync_xmit tipc_link_recv_sync->tipc_link_sync_rcv tipc_link_send_buf->__tipc_link_xmit tipc_link_send->tipc_link_xmit tipc_link_send_names->tipc_link_names_xmit tipc_named_recv->tipc_named_rcv tipc_link_recv_bundle->tipc_link_bundle_rcv tipc_link_dup_send_queue->tipc_link_dup_queue_xmit link_send_long_buf->tipc_link_frag_xmit tipc_multicast->tipc_port_mcast_xmit tipc_port_recv_mcast->tipc_port_mcast_rcv tipc_port_reject_sections->tipc_port_iovec_reject tipc_port_recv_proto_msg->tipc_port_proto_rcv tipc_connect->tipc_port_connect __tipc_connect->__tipc_port_connect __tipc_disconnect->__tipc_port_disconnect tipc_disconnect->tipc_port_disconnect tipc_shutdown->tipc_port_shutdown tipc_port_recv_msg->tipc_port_rcv tipc_port_recv_sections->tipc_port_iovec_rcv release->tipc_release accept->tipc_accept bind->tipc_bind get_name->tipc_getname poll->tipc_poll send_msg->tipc_sendmsg send_packet->tipc_send_packet send_stream->tipc_send_stream recv_msg->tipc_recvmsg recv_stream->tipc_recv_stream connect->tipc_connect listen->tipc_listen shutdown->tipc_shutdown setsockopt->tipc_setsockopt getsockopt->tipc_getsockopt Above changes have no impact on current users of the functions. Signed-off-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: fix a loop style problemJon Paul Maloy2014-02-171-5/+5
| | | | | | | | | | | | | | | | | | In commit 7d33939f475d403e79124e3143d7951dcfe8629f ("tipc: delay delete of link when failover is needed") we introduced a loop for finding and removing a link pointer in an array. The removal is done after we have left the loop, giving the impression that one may remove the wrong pointer if no matching element is found. This is not really a bug, since we know that there will always be a matching element, but it looks wrong, and causes a smatch warning. We fix this loop with this commit. Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: delay delete of link when failover is neededJon Paul Maloy2014-02-131-1/+7
| | | | | | | | | | | | | | | | | | | | | 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>
* tipc: rename functions related to link failover and improve commentsJon Paul Maloy2014-01-071-2/+2
| | | | | | | | | | | | | | | | The functionality related to link addition and failover is unnecessarily hard to understand and maintain. We try to improve this by renaming some of the functions, at the same time adding or improving the explanatory comments around them. Names such as "tipc_rcv()" etc. also align better with what is used in other networking components. The changes in this commit are purely cosmetic, no functional changes are made. Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Reviewed-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: remove unused codestephen hemminger2014-01-041-5/+0
| | | | | | | | | | | | Remove dead code; tipc_bearer_find_interface tipc_node_redundant_links This may break out of tree version of TIPC if there still is one. But that maybe a good thing :-) Signed-off-by: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: eliminate redundant code with kfree_skb_list routineYing Xue2013-12-111-5/+1
| | | | | | | | | | | | sk_buff lists are currently relased by looping over the list and explicitly releasing each buffer. We replace all occurrences of this loop with a call to kfree_skb_list(). Signed-off-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: message reassembly using fragment chainErik Hugne2013-11-071-3/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | When the first fragment of a long data data message is received on a link, a reassembly buffer large enough to hold the data from this and all subsequent fragments of the message is allocated. The payload of each new fragment is copied into this buffer upon arrival. When the last fragment is received, the reassembled message is delivered upwards to the port/socket layer. Not only is this an inefficient approach, but it may also cause bursts of reassembly failures in low memory situations. since we may fail to allocate the necessary large buffer in the first place. Furthermore, after 100 subsequent such failures the link will be reset, something that in reality aggravates the situation. To remedy this problem, this patch introduces a different approach. Instead of allocating a big reassembly buffer, we now append the arriving fragments to a reassembly chain on the link, and deliver the whole chain up to the socket layer once the last fragment has been received. This is safe because the retransmission layer of a TIPC link always delivers packets in strict uninterrupted order, to the reassembly layer as to all other upper layers. Hence there can never be more than one fragment chain pending reassembly at any given time in a link, and we can trust (but still verify) that the fragments will be chained up in the correct order. Signed-off-by: Erik Hugne <erik.hugne@ericsson.com> Reviewed-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* hlist: drop the node parameter from iteratorsSasha Levin2013-02-271-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I'm not sure why, but the hlist for each entry iterators were conceived list_for_each_entry(pos, head, member) The hlist ones were greedy and wanted an extra parameter: hlist_for_each_entry(tpos, pos, head, member) Why did they need an extra pos parameter? I'm not quite sure. Not only they don't really need it, it also prevents the iterator from looking exactly like the list iterator, which is unfortunate. Besides the semantic patch, there was some manual work required: - Fix up the actual hlist iterators in linux/list.h - Fix up the declaration of other iterators based on the hlist ones. - A very small amount of places were using the 'node' parameter, this was modified to use 'obj->member' instead. - Coccinelle didn't handle the hlist_for_each_entry_safe iterator properly, so those had to be fixed up manually. The semantic patch which is mostly the work of Peter Senna Tschudin is here: @@ iterator name hlist_for_each_entry, hlist_for_each_entry_continue, hlist_for_each_entry_from, hlist_for_each_entry_rcu, hlist_for_each_entry_rcu_bh, hlist_for_each_entry_continue_rcu_bh, for_each_busy_worker, ax25_uid_for_each, ax25_for_each, inet_bind_bucket_for_each, sctp_for_each_hentry, sk_for_each, sk_for_each_rcu, sk_for_each_from, sk_for_each_safe, sk_for_each_bound, hlist_for_each_entry_safe, hlist_for_each_entry_continue_rcu, nr_neigh_for_each, nr_neigh_for_each_safe, nr_node_for_each, nr_node_for_each_safe, for_each_gfn_indirect_valid_sp, for_each_gfn_sp, for_each_host; type T; expression a,c,d,e; identifier b; statement S; @@ -T b; <+... when != b ( hlist_for_each_entry(a, - b, c, d) S | hlist_for_each_entry_continue(a, - b, c) S | hlist_for_each_entry_from(a, - b, c) S | hlist_for_each_entry_rcu(a, - b, c, d) S | hlist_for_each_entry_rcu_bh(a, - b, c, d) S | hlist_for_each_entry_continue_rcu_bh(a, - b, c) S | for_each_busy_worker(a, c, - b, d) S | ax25_uid_for_each(a, - b, c) S | ax25_for_each(a, - b, c) S | inet_bind_bucket_for_each(a, - b, c) S | sctp_for_each_hentry(a, - b, c) S | sk_for_each(a, - b, c) S | sk_for_each_rcu(a, - b, c) S | sk_for_each_from -(a, b) +(a) S + sk_for_each_from(a) S | sk_for_each_safe(a, - b, c, d) S | sk_for_each_bound(a, - b, c) S | hlist_for_each_entry_safe(a, - b, c, d, e) S | hlist_for_each_entry_continue_rcu(a, - b, c) S | nr_neigh_for_each(a, - b, c) S | nr_neigh_for_each_safe(a, - b, c, d) S | nr_node_for_each(a, - b, c) S | nr_node_for_each_safe(a, - b, c, d) S | - for_each_gfn_sp(a, c, d, b) S + for_each_gfn_sp(a, c, d) S | - for_each_gfn_indirect_valid_sp(a, c, d, b) S + for_each_gfn_indirect_valid_sp(a, c, d) S | for_each_host(a, - b, c) S | for_each_host_safe(a, - b, c, d) S | for_each_mesh_entry(a, - b, c, d) S ) ...+> [akpm@linux-foundation.org: drop bogus change from net/ipv4/raw.c] [akpm@linux-foundation.org: drop bogus hunk from net/ipv6/raw.c] [akpm@linux-foundation.org: checkpatch fixes] [akpm@linux-foundation.org: fix warnings] [akpm@linux-foudnation.org: redo intrusive kvm changes] Tested-by: Peter Senna Tschudin <peter.senna@gmail.com> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Gleb Natapov <gleb@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* tipc: introduce message to synchronize broadcast linkJon Maloy2012-11-221-3/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Upon establishing a first link between two nodes, there is currently a risk that the two endpoints will disagree on exactly which sequence number reception and acknowleding of broadcast packets should start. The following scenarios may happen: 1: Node A sends an ACTIVATE message to B, telling it to start acking packets from sequence number N. 2: Node A sends out broadcast N, but does not expect an acknowledge from B, since B is not yet in its broadcast receiver's list. 3: Node A receives ACK for N from all nodes except B, and releases packet N. 4: Node B receives the ACTIVATE, activates its link endpoint, and stores the value N as sequence number of first expected packet. 5: Node B sends a NAME_DISTR message to A. 6: Node A receives the NAME_DISTR message, and activates its endpoint. At this moment B is added to A's broadcast receiver's set. Node A also sets sequence number 0 as the first broadcast packet to be received from B. 7: Node A sends broadcast N+1. 8: B receives N+1, determines there is a gap in the sequence, since it is expecting N, and sends a NACK for N back to A. 9: Node A has already released N, so no retransmission is possible. The broadcast link in direction A->B is stale. In addition to, or instead of, 7-9 above, the following may happen: 10: Node B sends broadcast M > 0 to A. 11: Node A receives M, falsely decides there must be a gap, since it is expecting packet 0, and asks for retransmission of packets [0,M-1]. 12: Node B has already released these packets, so the broadcast link is stale in direction B->A. We solve this problem by introducing a new unicast message type, BCAST_PROTOCOL/STATE, to convey the sequence number of the next sent broadcast packet to the other endpoint, at exactly the moment that endpoint is added to the own node's broadcast receivers list, and before any other unicast messages are permitted to be sent. Furthermore, we don't allow any node to start receiving and processing broadcast packets until this new synchronization message has been received. To maintain backwards compatibility, we still open up for broadcast reception if we receive a NAME_DISTR message without any preceding broadcast sync message. In this case, we must assume that the other end has an older code version, and will never send out the new synchronization message. Hence, for mixed old and new nodes, the issue arising in 7-12 of the above may happen with the same probability as before. Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* tipc: rename supported flag to recv_permittedYing Xue2012-11-221-3/+3
| | | | | | | | | | | | Rename the "supported" flag in bclink structure to "recv_permitted" to better reflect what it is used for. When this flag is set for a given node, we are permitted to receive and acknowledge broadcast messages from that node. Convert it to a bool at the same time, since it is not used to store any numerical values. Signed-off-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* tipc: remove supportable flag from bclink structureYing Xue2012-11-221-5/+3
| | | | | | | | | | | | | | The "supportable" flag in bclink structure is a compatibility flag indicating whether a peer node is capable of receiving TIPC broadcast messages. However, all TIPC versions since tipc-1.5, and after the inclusion in the upstream Linux kernel in 2006, support this capability. It is highly unlikely that anybody is still using such an old version of TIPC, let alone that they want to mix it with TIPC-2.0 nodes. Therefore, we now remove the "supportable" flag. Signed-off-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* tipc: use standard printk shortcut macros (pr_err etc.)Erik Hugne2012-07-131-11/+11
| | | | | | | | | | | | | | | | | | | | All messages should go directly to the kernel log. The TIPC specific error, warning, info and debug trace macro's are removed and all references replaced with pr_err, pr_warn, pr_info and pr_debug. Commonly used sub-strings are explicitly declared as a const char to reduce .text size. Note that this means the debug messages (changed to pr_debug), are now enabled through dynamic debugging, instead of a TIPC specific Kconfig option (TIPC_DEBUG). The latter will be phased out completely Signed-off-by: Erik Hugne <erik.hugne@ericsson.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> [PG: use pr_fmt as suggested by Joe Perches <joe@perches.com>] Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* tipc: compress out gratuitous extra carriage returnsPaul Gortmaker2012-04-301-13/+0
| | | | | | | | | | | | | | | Some of the comment blocks are floating in limbo between two functions, or between blocks of code. Delete the extra line feeds between any comment and its associated following block of code, to be consistent with the majority of the rest of the kernel. Also delete trailing newlines at EOF and fix a couple trivial typos in existing comments. This is a 100% cosmetic change with no runtime impact. We get rid of over 500 lines of non-code, and being blank line deletes, they won't even show up as noise in git blame. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* tipc: remove inline instances from C source files.Paul Gortmaker2012-04-241-1/+1
| | | | | | | | | | | Untie gcc's hands and let it do what it wants within the individual source files. There are two files, node.c and port.c -- only the latter effectively changes (gcc-4.5.2). Objdump shows gcc deciding to not inline port_peernode(). Suggested-by: David S. Miller <davem@davemloft.net> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: Add routines for safe checking of node's network addressAllan Stephens2012-04-191-1/+1
| | | | | | | | | | | | | | | | | Introduces routines that test whether a given network address is equal to a node's own network address or if it lies within the node's own network cluster, and which work properly regardless of whether the node is using the default network address <0.0.0> or a non-zero network address that is assigned later on. In essence, these routines ensure that address <0.0.0> is treated as an alias for "this node", regardless of which network address the node is actually using. Old users of the pre-existing more strict match in_own_cluster() have been accordingly redirected to what is now called in_own_cluster_exact() --- which does not extend matching to <0,0,0>. Signed-off-by: Allan Stephens <allan.stephens@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* tipc: Eliminate support for tipc_mode global variableAllan Stephens2012-02-241-1/+1
| | | | | | | | | | | | | | | | Removes all references to the global variable that records whether TIPC is running in "single node" mode or "network" mode, since this information can be easily deduced from the global variable that records TIPC's network address. (i.e. a non-zero network address means that TIPC is running in network mode.) The changes made update most existing mode-based checks to use the network address global variable. A few checks that are no longer needed are removed entirely, along with any associated code lying on non-executable control paths. Signed-off-by: Allan Stephens <allan.stephens@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* tipc: Minor optimization to broadcast link synchronization logicAllan Stephens2012-02-241-3/+1
| | | | | | | | | | Optimizes processing done when contact with a neighboring node is established to avoid recording the current state of outgoing broadcast messages if the neighboring node isn't a valid broadcast link destination, since this state information isn't needed for such nodes. Signed-off-by: Allan Stephens <allan.stephens@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* tipc: Remove obsolete comments about routing table updatesAllan Stephens2012-02-241-46/+0
| | | | | | | | | | | | Eliminates a block of comments that describe how routing table updates are to be handled. These comments no longer apply following the removal of TIPC's prototype multi-cluster support. Note that these changes are essentially cosmetic in nature, and have no impact on the actual operation of TIPC. Signed-off-by: Allan Stephens <allan.stephens@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* tipc: Eliminate trivial buffer manipulation helper routinesAllan Stephens2012-02-241-2/+2
| | | | | | | | | | | | Gets rid of two inlined routines that simply call existing sk_buff manipulation routines, since there is no longer any extra processing done by the helper routines. Note that these changes are essentially cosmetic in nature, and have no impact on the actual operation of TIPC. Signed-off-by: Allan Stephens <allan.stephens@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* tipc: Hide internal details of node table implementationAllan Stephens2012-02-241-0/+13
| | | | | | | | | | | | Relocates information about the size of TIPC's node table index and its associated hash function, since only node subsystem routines need to have access to this information. Note that these changes are essentially cosmetic in nature, and have no impact on the actual operation of TIPC. Signed-off-by: Allan Stephens <allan.stephens@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* tipc: Introduce node signature field in neighbor discovery messageAllan Stephens2012-02-241-0/+1
| | | | | | | | | | | | | | | | | Adds support for the new "node signature" in neighbor discovery messages, which is a 16 bit identifier chosen randomly when TIPC is initialized. This field makes it possible for nodes receiving a neighbor discovery message to detect if multiple neighboring nodes are using the same network address (i.e. <Z.C.N>), even when the messages are arriving on different interfaces. This first phase of node signature support creates the signature, incorporates it into outgoing neighbor discovery messages, and tracks the signature used by valid neighbors. An upcoming patch builds on this foundation to implement the improved duplicate neighbor detection checking. Signed-off-by: Allan Stephens <allan.stephens@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* tipc: Remove obsolete broadcast tag capabilityAllan Stephens2012-02-061-6/+1
| | | | | | | | Eliminates support for the broadcast tag field, which is no longer used by broadcast link NACK messages. Signed-off-by: Allan Stephens <allan.stephens@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* tipc: Major redesign of broadcast link ACK/NACK algorithmsAllan Stephens2012-02-061-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Completely redesigns broadcast link ACK and NACK mechanisms to prevent spurious retransmit requests in dual LAN networks, and to prevent the broadcast link from stalling due to the failure of a receiving node to acknowledge receiving a broadcast message or request its retransmission. Note: These changes only impact the timing of when ACK and NACK messages are sent, and not the basic broadcast link protocol itself, so inter- operability with nodes using the "classic" algorithms is maintained. The revised algorithms are as follows: 1) An explicit ACK message is still sent after receiving 16 in-sequence messages, and implicit ACK information continues to be carried in other unicast link message headers (including link state messages). However, the timing of explicit ACKs is now based on the receiving node's absolute network address rather than its relative network address to ensure that the failure of another node does not delay the ACK beyond its 16 message target. 2) A NACK message is now typically sent only when a message gap persists for two consecutive incoming link state messages; this ensures that a suspected gap is not confirmed until both LANs in a dual LAN network have had an opportunity to deliver the message, thereby preventing spurious NACKs. A NACK message can also be generated by the arrival of a single link state message, if the deferred queue is so big that the current message gap cannot be the result of "normal" mis-ordering due to the use of dual LANs (or one LAN using a bonded interface). Since link state messages typically arrive at different nodes at different times the problem of multiple nodes issuing identical NACKs simultaneously is inherently avoided. 3) Nodes continue to "peek" at NACK messages sent by other nodes. If another node requests retransmission of a message gap suspected (but not yet confirmed) by the peeking node, the peeking node forgets about the gap and does not generate a duplicate retransmit request. (If the peeking node subsequently fails to receive the lost message, later link state messages will cause it to rediscover and confirm the gap and send another NACK.) 4) Message gap "equality" is now determined by the start of the gap only. This is sufficient to deal with the most common cases of message loss, and eliminates the need for complex end of gap computations. 5) A peeking node no longer tries to determine whether it should send a complementary NACK, since the most common cases of message loss don't require it to be sent. Consequently, the node no longer examines the "broadcast tag" field of a NACK message when peeking. Signed-off-by: Allan Stephens <allan.stephens@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* tipc: Ensure broadcast link re-acquires node after link failureAllan Stephens2012-02-061-1/+2
| | | | | | | | | | | | | | | | | | | | | | | Fix a bug that can prevent TIPC from sending broadcast messages to a node if contact with the node is lost and then regained. The problem occurs if the broadcast link first clears the flag indicating the node is part of the link's distribution set (when it loses contact with the node), and later fails to restore the flag (when contact is regained); restoration fails if contact with the node is regained by implicit unicast link activation triggered by the arrival of a data message, rather than explicitly by the arrival of a link activation message. The broadcast link now uses separate fields to track whether a node is theoretically capable of receiving broadcast messages versus whether it is actually part of the link's distribution set. The former member is updated by the receipt of link protocol messages, which can occur at any time; the latter member is updated only when contact with the node is gained or lost. This change also permits the simplification of several conditional expressions since the broadcast link's "supported" field can now only be set if there are working links to the associated node. Signed-off-by: Allan Stephens <allan.stephens@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* tipc: rename struct link* to struct tipc_link*Paul Gortmaker2011-12-291-9/+9
| | | | | | | | | | This converts the following: struct link -> struct tipc_link struct link_req -> struct tipc_link_req struct link_name -> struct tipc_link_name Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* tipc: Ignore broadcast acknowledgements that are out-of-rangeAllan Stephens2011-12-271-2/+1
| | | | | | | | | | | | | | | | Adds checks to TIPC's broadcast link so that it ignores any acknowledgement message containing a sequence number that does not correspond to an unacknowledged message currently in the broadcast link's transmit queue. This change prevents the broadcast link from becoming stalled if a newly booted node receives stale broadcast link acknowledgement information from another node that has not yet fully synchronized its end of the broadcast link to reflect the current state of the new node's end. Signed-off-by: Allan Stephens <allan.stephens@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* tipc: Ensure broadcast link spinlock is held when updating node mapAllan Stephens2011-12-271-2/+2
| | | | | | | | | | Fixes oversight that allowed broadcast link node map to be updated without first taking the broadcast link spinlock that protects the map. As part of this fix the node map has been incorporated into the broadcast link structure to make the need for such protection more evident. Signed-off-by: Allan Stephens <allan.stephens@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* tipc: Ensure both nodes recognize loss of contact between themAllan Stephens2011-09-171-5/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Enhances TIPC to ensure that a node that loses contact with a neighboring node does not allow contact to be re-established until it sees that its peer has also recognized the loss of contact. Previously, nodes that were connected by two or more links could encounter a situation in which node A would lose contact with node B on all of its links, purge its name table of names published by B, and then fail to repopulate those names once contact with B was restored. This would happen because B was able to re-establish one or more links so quickly that it never reached a point where it had no links to A -- meaning that B never saw a loss of contact with A, and consequently didn't re-publish its names to A. This problem is now prevented by enhancing the cleanup done by TIPC following a loss of contact with a neighboring node to ensure that node A ignores all messages sent by B until it receives a LINK_PROTOCOL message that indicates B has lost contact with A, thereby preventing the (re)establishment of links between the nodes. The loss of contact is recognized when a RESET or ACTIVATE message is received that has a "redundant link exists" field of 0, indicating that B's sending link endpoint is in a reset state and that B has no other working links. Additionally, TIPC now suppresses the sending of (most) link protocol messages to a neighboring node while it is cleaning up after an earlier loss of contact with that node. This stops the peer node from prematurely activating its link endpoint, which would prevent TIPC from later activating its own end. TIPC still allows outgoing RESET messages to occur during cleanup, to avoid problems if its own node recognizes the loss of contact first and tries to notify the peer of the situation. Finally, TIPC now recognizes an impending loss of contact with a peer node as soon as it receives a RESET message on a working link that is the peer's only link to the node, and ensures that the link protocol suppression mentioned above goes into effect right away -- that is, even before its own link endpoints have failed. This is necessary to ensure correct operation when there are redundant links between the nodes, since otherwise TIPC would send an ACTIVATE message upon receiving a RESET on its first link and only begin suppressing when a RESET on its second link was received, instead of initiating suppression with the first RESET message as it needs to. Note: The reworked cleanup code also eliminates a check that prevented a link endpoint's discovery object from responding to incoming messages while stale name table entries are being purged. This check is now unnecessary and would have slowed down re-establishment of communication between the nodes in some situations. Signed-off-by: Allan Stephens <allan.stephens@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* tipc: Prevent broadcast link stalling when another node failsAllan Stephens2011-09-011-1/+1
| | | | | | | | | | | | | | | | | | | | Ensure that broadcast link messages that have not been acknowledged by a newly failed node do not get an implied acknowledgement until the failed node is removed from the broadcast link's map of reachable nodes. Previously, a race condition allowed a new broadcast link message to be sent after the implicit acknowledgement processing was completed, but before the map of reachable nodes was updated, resulting in the message having an expected acknowledgement count that required the failed node to explicitly acknowledge the message. Since this would never occur the new message would remain in the broadcast link's transmit queue forever, eventually causing the link to become congested and "stall". Delaying the implicit acknowledgement processing until after the update of the map of reachable nodes eliminates this race condition and prevents stalling. Signed-off-by: Allan Stephens <allan.stephens@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* tipc: Enhance cleanup of broadcast link when contact with node is lostAllan Stephens2011-09-011-14/+18
| | | | | | | | | | | | | | | | | | | Enhances cleanup of broadcast link-related information when contact with a node is lost. 1) All broadcast link-related cleanup now occurs only if the lost node was capable of communicating over the broadcast link. 2) Following cleanup, the lost node is marked as no longer supporting the broadcast link, ensuring that any remaining broadcast messages received from that node prior to the re-establishment of a normal communication link are ignored. Thanks to Surya [Suryanarayana.Garlapati@emerson.com] for contributing a prototype version of this patch. Signed-off-by: Allan Stephens <allan.stephens@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* tipc: Optimizations to link creation codeAllan Stephens2011-03-131-26/+4
| | | | | | | | | | | | | | | | | Enhances link creation code as follows: 1) Detects illegal attempts to add a requested link earlier in the link creation process. This prevents TIPC from wasting time initializing a link object it then throws away, and also eliminates the code needed to do the throwing away. 2) Passes in the node object associated with the requested link. This allows TIPC to eliminate a search to locate the node object, as well as code that attempted to create the node if it doesn't exist. Signed-off-by: Allan Stephens <Allan.Stephens@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
generated by cgit v1.2.3 (git 2.25.1) at 2024-12-19 18:19:11 +0000