linux/net/tipc/socket.c, branch v4.0

rhashtable: remove indirection for grow/shrink decision functions

2015-02-27T21:06:02Z

Currently, all real users of rhashtable default their grow and shrink decision functions to rht_grow_above_75() and rht_shrink_below_30(), so that there's currently no need to have this explicitly selectable. It can/should be generic and private inside rhashtable until a real use case pops up. Since we can make this private, we'll save us this additional indirection layer and can improve insertion/deletion time as well. Reference: http://patchwork.ozlabs.org/patch/443040/ Suggested-by: David S. Miller Signed-off-by: Daniel Borkmann Acked-by: Thomas Graf Signed-off-by: David S. Miller

tipc: nl compat add noop and remove legacy nl framework

2015-02-09T21:20:49Z

Add TIPC_CMD_NOOP to compat layer and remove the old framework. All legacy nl commands are now converted to the compat layer in netlink_compat.c. Signed-off-by: Richard Alpe Reviewed-by: Erik Hugne Reviewed-by: Ying Xue Reviewed-by: Jon Maloy Signed-off-by: David S. Miller

tipc: convert legacy nl socket dump to nl compat

2015-02-09T21:20:48Z

Convert socket (port) listing to compat dumpit call. If a socket (port) has publications a second dumpit call is issued to collect them and format then into the legacy buffer before continuing to process the sockets (ports). Command converted in this patch: TIPC_CMD_SHOW_PORTS Signed-off-by: Richard Alpe Reviewed-by: Erik Hugne Reviewed-by: Ying Xue Reviewed-by: Jon Maloy Signed-off-by: David S. Miller

tipc: move and rename the legacy nl api to "nl compat"

2015-02-09T21:20:47Z

The new netlink API is no longer "v2" but rather the standard API and the legacy API is now "nl compat". We split them into separate start/stop and put them in different files in order to further distinguish them. Signed-off-by: Richard Alpe Reviewed-by: Erik Hugne Reviewed-by: Ying Xue Reviewed-by: Jon Maloy Signed-off-by: David S. Miller

tipc: fix bug in socket reception function

2015-02-08T21:09:25Z

In commit c637c1035534867b85b78b453c38c495b58e2c5a ("tipc: resolve race problem at unicast message reception") we introduced a time limit for how long the function tipc_sk_eneque() would be allowed to execute its loop. Unfortunately, the test for when this limit is passed was put in the wrong place, resulting in a lost message when the test is true. We fix this by moving the test to before we dequeue the next buffer from the input queue. Signed-off-by: Jon Maloy Signed-off-by: David S. Miller

tipc: eliminate race condition at multicast reception

2015-02-06T00:00:03Z

In a previous commit in this series we resolved a race problem during unicast message reception. Here, we resolve the same problem at multicast reception. We apply the same technique: an input queue serializing the delivery of arriving buffers. The main difference is that here we do it in two steps. First, the broadcast link feeds arriving buffers into the tail of an arrival queue, which head is consumed at the socket level, and where destination lookup is performed. Second, if the lookup is successful, the resulting buffer clones are fed into a second queue, the input queue. This queue is consumed at reception in the socket just like in the unicast case. Both queues are protected by the same lock, -the one of the input queue. Reviewed-by: Ying Xue Signed-off-by: Jon Maloy Signed-off-by: David S. Miller

tipc: simplify socket multicast reception

2015-02-06T00:00:03Z

The structure 'tipc_port_list' is used to collect port numbers representing multicast destination socket on a receiving node. The list is not based on a standard linked list, and is in reality optimized for the uncommon case that there are more than one multicast destinations per node. This makes the list handling unecessarily complex, and as a consequence, even the socket multicast reception becomes more complex. In this commit, we replace 'tipc_port_list' with a new 'struct tipc_plist', which is based on a standard list. We give the new list stack (push/pop) semantics, someting that simplifies the implementation of the function tipc_sk_mcast_rcv(). Reviewed-by: Ying Xue Signed-off-by: Jon Maloy Signed-off-by: David S. Miller

tipc: resolve race problem at unicast message reception

2015-02-06T00:00:02Z

TIPC handles message cardinality and sequencing at the link layer, before passing messages upwards to the destination sockets. During the upcall from link to socket no locks are held. It is therefore possible, and we see it happen occasionally, that messages arriving in different threads and delivered in sequence still bypass each other before they reach the destination socket. This must not happen, since it violates the sequentiality guarantee. We solve this by adding a new input buffer queue to the link structure. Arriving messages are added safely to the tail of that queue by the link, while the head of the queue is consumed, also safely, by the receiving socket. Sequentiality is secured per socket by only allowing buffers to be dequeued inside the socket lock. Since there may be multiple simultaneous readers of the queue, we use a 'filter' parameter to reduce the risk that they peek the same buffer from the queue, hence also reducing the risk of contention on the receiving socket locks. This solves the sequentiality problem, and seems to cause no measurable performance degradation. A nice side effect of this change is that lock handling in the functions tipc_rcv() and tipc_bcast_rcv() now becomes uniform, something that will enable future simplifications of those functions. Reviewed-by: Ying Xue Signed-off-by: Jon Maloy Signed-off-by: David S. Miller

tipc: use existing sk_write_queue for outgoing packet chain

2015-02-06T00:00:02Z

The list for outgoing traffic buffers from a socket is currently allocated on the stack. This forces us to initialize the queue for each sent message, something costing extra CPU cycles in the most critical data path. Later in this series we will introduce a new safe input buffer queue, something that would force us to initialize even the spinlock of the outgoing queue. A closer analysis reveals that the queue always is filled and emptied within the same lock_sock() session. It is therefore safe to use a queue aggregated in the socket itself for this purpose. Since there already exists a queue for this in struct sock, sk_write_queue, we introduce use of that queue in this commit. Reviewed-by: Ying Xue Signed-off-by: Jon Maloy Signed-off-by: David S. Miller

tipc: split up function tipc_msg_eval()

2015-02-06T00:00:02Z

The function tipc_msg_eval() is in reality doing two related, but different tasks. First it tries to find a new destination for named messages, in case there was no first lookup, or if the first lookup failed. Second, it does what its name suggests, evaluating the validity of the message and its destination, and returning an appropriate error code depending on the result. This is confusing, and in this commit we choose to break it up into two functions. A new function, tipc_msg_lookup_dest(), first attempts to find a new destination, if the message is of the right type. If this lookup fails, or if the message should not be subject to a second lookup, the already existing tipc_msg_reverse() is called. This function performs prepares the message for rejection, if applicable. Reviewed-by: Ying Xue Signed-off-by: Jon Maloy Signed-off-by: David S. Miller