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2017-08-03rds: reduce memory footprint for RDS when transport is RDMASowmini Varadhan
RDS over IB does not use multipath RDS, so the array of additional rds_conn_path structures is always superfluous in this case. Reduce the memory footprint of the rds module by making this a dynamic allocation predicated on whether the transport is mp_capable. Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com> Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com> Tested-by: Efrain Galaviz <efrain.galaviz@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-16rds: cancel send/recv work before queuing connection shutdownSowmini Varadhan
We could end up executing rds_conn_shutdown before the rds_recv_worker thread, then rds_conn_shutdown -> rds_tcp_conn_shutdown can do a sock_release and set sock->sk to null, which may interleave in bad ways with rds_recv_worker, e.g., it could result in: "BUG: unable to handle kernel NULL pointer dereference at 0000000000000078" [ffff881769f6fd70] release_sock at ffffffff815f337b [ffff881769f6fd90] rds_tcp_recv at ffffffffa043c888 [rds_tcp] [ffff881769f6fdb0] rds_recv_worker at ffffffffa04a4810 [rds] [ffff881769f6fde0] process_one_work at ffffffff810a14c1 [ffff881769f6fe40] worker_thread at ffffffff810a1940 [ffff881769f6fec0] kthread at ffffffff810a6b1e Also, do not enqueue any new shutdown workq items when the connection is shutting down (this may happen for rds-tcp in softirq mode, if a FIN or CLOSE is received while the modules is in the middle of an unload) Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-22rds: tcp: set linger to 1 when unloading a rds-tcpSowmini Varadhan
If we are unloading the rds_tcp module, we can set linger to 1 and drop pending packets to accelerate reconnect. The peer will end up resetting the connection based on new generation numbers of the new incarnation, so hanging on to unsent TCP packets via linger is mostly pointless in this case. Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com> Tested-by: Jenny Xu <jenny.x.xu@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-16rds: tcp: remove cp_outgoingSowmini Varadhan
After commit 1a0e100fb2c9 ("RDS: TCP: Force every connection to be initiated by numerically smaller IP address") we no longer need the logic associated with cp_outgoing, so clean up usage of this field. Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com> Tested-by: Imanti Mendez <imanti.mendez@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-02rds: tcp: allow progress of rds_conn_shutdown if the rds_connection is ↵Sowmini Varadhan
marked ERROR by an intervening FIN rds_conn_shutdown() runs in workq context, and marks the rds_connection as DISCONNECTING before quiescing Tx/Rx paths. However, after all I/O has quiesced, we may still find the rds_connection state to be RDS_CONN_ERROR if an intervening FIN was processed in softirq context. This is not a fatal error: rds_conn_shutdown() should continue the shutdown, and there is no need to log noisy messages about this event. Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com> Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-07rds: tcp: Take explicit refcounts on struct netSowmini Varadhan
It is incorrect for the rds_connection to piggyback on the sock_net() refcount for the netns because this gives rise to a chicken-and-egg problem during rds_conn_destroy. Instead explicitly take a ref on the net, and hold the netns down till the connection tear-down is complete. Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-02RDS: mark few internal functions static to make sparse build happySantosh Shilimkar
Fixes below warnings: warning: symbol 'rds_send_probe' was not declared. Should it be static? warning: symbol 'rds_send_ping' was not declared. Should it be static? warning: symbol 'rds_tcp_accept_one_path' was not declared. Should it be static? warning: symbol 'rds_walk_conn_path_info' was not declared. Should it be static? Signed-off-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
2016-11-17RDS: TCP: Force every connection to be initiated by numerically smaller IP ↵Sowmini Varadhan
address When 2 RDS peers initiate an RDS-TCP connection simultaneously, there is a potential for "duelling syns" on either/both sides. See commit 241b271952eb ("RDS-TCP: Reset tcp callbacks if re-using an outgoing socket in rds_tcp_accept_one()") for a description of this condition, and the arbitration logic which ensures that the numerically large IP address in the TCP connection is bound to the RDS_TCP_PORT ("canonical ordering"). The rds_connection should not be marked as RDS_CONN_UP until the arbitration logic has converged for the following reason. The sender may start transmitting RDS datagrams as soon as RDS_CONN_UP is set, and since the sender removes all datagrams from the rds_connection's cp_retrans queue based on TCP acks. If the TCP ack was sent from a tcp socket that got reset as part of duel aribitration (but before data was delivered to the receivers RDS socket layer), the sender may end up prematurely freeing the datagram, and the datagram is no longer reliably deliverable. This patch remedies that condition by making sure that, upon receipt of 3WH completion state change notification of TCP_ESTABLISHED in rds_tcp_state_change, we mark the rds_connection as RDS_CONN_UP if, and only if, the IP addresses and ports for the connection are canonically ordered. In all other cases, rds_tcp_state_change will force an rds_conn_path_drop(), and rds_queue_reconnect() on both peers will restart the connection to ensure canonical ordering. A side-effect of enforcing this condition in rds_tcp_state_change() is that rds_tcp_accept_one_path() can now be refactored for simplicity. It is also no longer possible to encounter an RDS_CONN_UP connection in the arbitration logic in rds_tcp_accept_one(). Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com> Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-17RDS: TCP: Track peer's connection generation numberSowmini Varadhan
The RDS transport has to be able to distinguish between two types of failure events: (a) when the transport fails (e.g., TCP connection reset) but the RDS socket/connection layer on both sides stays the same (b) when the peer's RDS layer itself resets (e.g., due to module reload or machine reboot at the peer) In case (a) both sides must reconnect and continue the RDS messaging without any message loss or disruption to the message sequence numbers, and this is achieved by rds_send_path_reset(). In case (b) we should reset all rds_connection state to the new incarnation of the peer. Examples of state that needs to be reset are next expected rx sequence number from, or messages to be retransmitted to, the new incarnation of the peer. To achieve this, the RDS handshake probe added as part of commit 5916e2c1554f ("RDS: TCP: Enable multipath RDS for TCP") is enhanced so that sender and receiver of the RDS ping-probe will add a generation number as part of the RDS_EXTHDR_GEN_NUM extension header. Each peer stores local and remote generation numbers as part of each rds_connection. Changes in generation number will be detected via incoming handshake probe ping request or response and will allow the receiver to reset rds_connection state. Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com> Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-17rds: Remove unused rds_conn_errorJoe Perches
This macro's last use was removed in commit d769ef81d5b59 ("RDS: Update rds_conn_shutdown to work with rds_conn_path") so make the macro and the __rds_conn_error function definition and declaration disappear. Signed-off-by: Joe Perches <joe@perches.com> Acked-by: Sowmini Varadhan <sowmini.varadhan@oracle.com> Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-07-15RDS: TCP: Enable multipath RDS for TCPSowmini Varadhan
Use RDS probe-ping to compute how many paths may be used with the peer, and to synchronously start the multiple paths. If mprds is supported, hash outgoing traffic to one of multiple paths in rds_sendmsg() when multipath RDS is supported by the transport. CC: Santosh Shilimkar <santosh.shilimkar@oracle.com> Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com> Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-07-01RDS: TCP: Simplify reconnect to avoid duelling reconnnect attemptsSowmini Varadhan
When reconnecting, the peer with the smaller IP address will initiate the reconnect, to avoid needless duelling SYN issues. Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com> Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-07-01RDS: TCP: Make rds_tcp_connection track the rds_conn_pathSowmini Varadhan
The struct rds_tcp_connection is the transport-specific private data structure that tracks TCP information per rds_conn_path. Modify this structure to have a back-pointer to the rds_conn_path for which it is the ->cp_transport_data. Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com> Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-07-01RDS: Rework path specific indirectionsSowmini Varadhan
Refactor code to avoid separate indirections for single-path and multipath transports. All transports (both single and mp-capable) will get a pointer to the rds_conn_path, and can trivially derive the rds_connection from the ->cp_conn. Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com> Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-14RDS: Update rds_conn_destroy to be MP capableSowmini Varadhan
Refactor rds_conn_destroy() so that the per-path dismantling is done in rds_conn_path_destroy, and then iterate as needed over rds_conn_path_destroy(). Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-14RDS: Update rds_conn_shutdown to work with rds_conn_pathSowmini Varadhan
This commit changes rds_conn_shutdown to take a rds_conn_path * argument, allowing it to shutdown paths other than c_path[0] for MP-capable transports. Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-14RDS: Initialize all RDS_MPATH_WORKERS in __rds_conn_createSowmini Varadhan
Add a for() loop in __rds_conn_create to initialize all the conn_paths, in preparate for MP capable transports. Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-14RDS: Add rds_conn_path_error()Sowmini Varadhan
rds_conn_path_error() is the MP-aware analog of rds_conn_error, to be used by multipath-capable callers. Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-14RDS: update rds-info related functions to traverse multiple conn_pathsSowmini Varadhan
This commit updates the callbacks related to the rds-info command so that they walk through all the rds_conn_path structures and report the requested info. Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-14RDS: Add rds_conn_path_connect_if_down() for MP-aware callersSowmini Varadhan
rds_conn_path_connect_if_down() works on the rds_conn_path that it is passed. Callers who are not t_m_capable may continue calling rds_conn_connect_if_down, which will invoke rds_conn_path_connect_if_down() with the default c_path[0]. Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-14RDS: split out connection specific state from rds_connection to rds_conn_pathSowmini Varadhan
In preparation for multipath RDS, split the rds_connection structure into a base structure, and a per-path struct rds_conn_path. The base structure tracks information and locks common to all paths. The workqs for send/recv/shutdown etc are tracked per rds_conn_path. Thus the workq callbacks now work with rds_conn_path. This commit allows for one rds_conn_path per rds_connection, and will be extended into multiple conn_paths in subsequent commits. Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-11-24RDS: fix race condition when sending a message on unbound socketQuentin Casasnovas
Sasha's found a NULL pointer dereference in the RDS connection code when sending a message to an apparently unbound socket. The problem is caused by the code checking if the socket is bound in rds_sendmsg(), which checks the rs_bound_addr field without taking a lock on the socket. This opens a race where rs_bound_addr is temporarily set but where the transport is not in rds_bind(), leading to a NULL pointer dereference when trying to dereference 'trans' in __rds_conn_create(). Vegard wrote a reproducer for this issue, so kindly ask him to share if you're interested. I cannot reproduce the NULL pointer dereference using Vegard's reproducer with this patch, whereas I could without. Complete earlier incomplete fix to CVE-2015-6937: 74e98eb08588 ("RDS: verify the underlying transport exists before creating a connection") Cc: David S. Miller <davem@davemloft.net> Cc: stable@vger.kernel.org Reviewed-by: Vegard Nossum <vegard.nossum@oracle.com> Reviewed-by: Sasha Levin <sasha.levin@oracle.com> Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com> Signed-off-by: Quentin Casasnovas <quentin.casasnovas@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-05RDS: Use a single TCP socket for both send and receive.Sowmini Varadhan
Commit f711a6ae062c ("net/rds: RDS-TCP: Always create a new rds_sock for an incoming connection.") modified rds-tcp so that an incoming SYN would ignore an existing "client" TCP connection which had the local port set to the transient port. The motivation for ignoring the existing "client" connection in f711a6ae was to avoid race conditions and an endless duel of reconnect attempts triggered by a restart/abort of one of the nodes in the TCP connection. However, having separate sockets for active and passive sides is avoidable, and the simpler model of a single TCP socket for both send and receives of all RDS connections associated with that tcp socket makes for easier observability. We avoid the race conditions from f711a6ae by attempting reconnects in rds_conn_shutdown if, and only if, the (new) c_outgoing bit is set for RDS_TRANS_TCP. The c_outgoing bit is initialized in __rds_conn_create(). A side-effect of re-using the client rds_connection for an incoming SYN is the potential of encountering duelling SYNs, i.e., we have an outgoing RDS_CONN_CONNECTING socket when we get the incoming SYN. The logic to arbitrate this criss-crossing SYN exchange in rds_tcp_accept_one() has been modified to emulate the BGP state machine: the smaller IP address should back off from the connection attempt. Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-09RDS: verify the underlying transport exists before creating a connectionSasha Levin
There was no verification that an underlying transport exists when creating a connection, this would cause dereferencing a NULL ptr. It might happen on sockets that weren't properly bound before attempting to send a message, which will cause a NULL ptr deref: [135546.047719] kasan: GPF could be caused by NULL-ptr deref or user memory accessgeneral protection fault: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC KASAN [135546.051270] Modules linked in: [135546.051781] CPU: 4 PID: 15650 Comm: trinity-c4 Not tainted 4.2.0-next-20150902-sasha-00041-gbaa1222-dirty #2527 [135546.053217] task: ffff8800835bc000 ti: ffff8800bc708000 task.ti: ffff8800bc708000 [135546.054291] RIP: __rds_conn_create (net/rds/connection.c:194) [135546.055666] RSP: 0018:ffff8800bc70fab0 EFLAGS: 00010202 [135546.056457] RAX: dffffc0000000000 RBX: 0000000000000f2c RCX: ffff8800835bc000 [135546.057494] RDX: 0000000000000007 RSI: ffff8800835bccd8 RDI: 0000000000000038 [135546.058530] RBP: ffff8800bc70fb18 R08: 0000000000000001 R09: 0000000000000000 [135546.059556] R10: ffffed014d7a3a23 R11: ffffed014d7a3a21 R12: 0000000000000000 [135546.060614] R13: 0000000000000001 R14: ffff8801ec3d0000 R15: 0000000000000000 [135546.061668] FS: 00007faad4ffb700(0000) GS:ffff880252000000(0000) knlGS:0000000000000000 [135546.062836] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [135546.063682] CR2: 000000000000846a CR3: 000000009d137000 CR4: 00000000000006a0 [135546.064723] Stack: [135546.065048] ffffffffafe2055c ffffffffafe23fc1 ffffed00493097bf ffff8801ec3d0008 [135546.066247] 0000000000000000 00000000000000d0 0000000000000000 ac194a24c0586342 [135546.067438] 1ffff100178e1f78 ffff880320581b00 ffff8800bc70fdd0 ffff880320581b00 [135546.068629] Call Trace: [135546.069028] ? __rds_conn_create (include/linux/rcupdate.h:856 net/rds/connection.c:134) [135546.069989] ? rds_message_copy_from_user (net/rds/message.c:298) [135546.071021] rds_conn_create_outgoing (net/rds/connection.c:278) [135546.071981] rds_sendmsg (net/rds/send.c:1058) [135546.072858] ? perf_trace_lock (include/trace/events/lock.h:38) [135546.073744] ? lockdep_init (kernel/locking/lockdep.c:3298) [135546.074577] ? rds_send_drop_to (net/rds/send.c:976) [135546.075508] ? __might_fault (./arch/x86/include/asm/current.h:14 mm/memory.c:3795) [135546.076349] ? __might_fault (mm/memory.c:3795) [135546.077179] ? rds_send_drop_to (net/rds/send.c:976) [135546.078114] sock_sendmsg (net/socket.c:611 net/socket.c:620) [135546.078856] SYSC_sendto (net/socket.c:1657) [135546.079596] ? SYSC_connect (net/socket.c:1628) [135546.080510] ? trace_dump_stack (kernel/trace/trace.c:1926) [135546.081397] ? ring_buffer_unlock_commit (kernel/trace/ring_buffer.c:2479 kernel/trace/ring_buffer.c:2558 kernel/trace/ring_buffer.c:2674) [135546.082390] ? trace_buffer_unlock_commit (kernel/trace/trace.c:1749) [135546.083410] ? trace_event_raw_event_sys_enter (include/trace/events/syscalls.h:16) [135546.084481] ? do_audit_syscall_entry (include/trace/events/syscalls.h:16) [135546.085438] ? trace_buffer_unlock_commit (kernel/trace/trace.c:1749) [135546.085515] rds_ib_laddr_check(): addr 36.74.25.172 ret -99 node type -1 Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com> Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-05RDS: rds_conn_lookup() should factor in the struct net for a matchSowmini Varadhan
Only return a conn if the rds_conn_net(conn) matches the struct net passed to rds_conn_lookup(). Fixes: 467fa15356ac ("RDS-TCP: Support multiple RDS-TCP listen endpoints, one per netns.") Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com> Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-25RDS: make sure we post recv bufferssantosh.shilimkar@oracle.com
If we get an ENOMEM during rds_ib_recv_refill, we might never come back and refill again later. Patch makes sure to kick krdsd into helping out. To achieve this we add RDS_RECV_REFILL flag and update in the refill path based on that so that at least some therad will keep posting receive buffers. Since krdsd and softirq both might race for refill, we decide to schedule on work queue based on ring_low instead of ring_empty. Reviewed-by: Ajaykumar Hotchandani <ajaykumar.hotchandani@oracle.com> Signed-off-by: Santosh Shilimkar <ssantosh@kernel.org> Signed-off-by: Santosh Shilimkar <santosh.shilimkar@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-07RDS-TCP: Make RDS-TCP work correctly when it is set up in a netns other than ↵Sowmini Varadhan
init_net Open the sockets calling sock_create_kern() with the correct struct net pointer, and use that struct net pointer when verifying the address passed to rds_bind(). Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-09net/rds: RDS-TCP: only initiate reconnect attempt on outgoing TCP socket.Sowmini Varadhan
When the peer of an RDS-TCP connection restarts, a reconnect attempt should only be made from the active side of the TCP connection, i.e. the side that has a transient TCP port number. Do not add the passive side of the TCP connection to the c_hash_node and thus avoid triggering rds_queue_reconnect() for passive rds connections. Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-09net/rds: RDS-TCP: Always create a new rds_sock for an incoming connection.Sowmini Varadhan
When running RDS over TCP, the active (client) side connects to the listening ("passive") side at the RDS_TCP_PORT. After the connection is established, if the client side reboots (potentially without even sending a FIN) the server still has a TCP socket in the esablished state. If the server-side now gets a new SYN comes from the client with a different client port, TCP will create a new socket-pair, but the RDS layer will incorrectly pull up the old rds_connection (which is still associated with the stale t_sock and RDS socket state). This patch corrects this behavior by having rds_tcp_accept_one() always create a new connection for an incoming TCP SYN. The rds and tcp state associated with the old socket-pair is cleaned up via the rds_tcp_state_change() callback which would typically be invoked in most cases when the client-TCP sends a FIN on TCP restart, triggering a transition to CLOSE_WAIT state. In the rarer event of client death without a FIN, TCP_KEEPALIVE probes on the socket will detect the stale socket, and the TCP transition to CLOSE state will trigger the RDS state cleanup. Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-04-08RDS: make sure not to loop forever inside rds_send_xmitSowmini Varadhan
If a determined set of concurrent senders keep the send queue full, we can loop forever inside rds_send_xmit. This fix has two parts. First we are dropping out of the while(1) loop after we've processed a large batch of messages. Second we add a generation number that gets bumped each time the xmit bit lock is acquired. If someone else has jumped in and made progress in the queue, we skip our goto restart. Original patch by Chris Mason. Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-04-08RDS: only use passive connections when addresses matchSowmini Varadhan
Passive connections were added for the case where one loopback IB connection between identical addresses needs another connection to store the second QP. Unfortunately, they were also created in the case where the addesses differ and we already have both QPs. This lead to a message reordering bug. - two different IB interfaces and addresses on a machine: A B - traffic is sent from A to B - connection from A-B is created, connect request sent - listening accepts connect request, B-A is created - traffic flows, next_rx is incremented - unacked messages exist on the retrans list - connection A-B is shut down, new connect request sent - listen sees existing loopback B-A, creates new passive B-A - retrans messages are sent and delivered because of 0 next_rx The problem is that the second connection request saw the previously existing parent connection. Instead of using it, and using the existing next_rx_seq state for the traffic between those IPs, it mistakenly thought that it had to create a passive connection. We fix this by only using passive connections in the special case where laddr and faddr match. In this case we'll only ever have one parent sending connection requests and one passive connection created as the listening path sees the existing parent connection which initiated the request. Original patch by Zach Brown Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-10-19inet: convert inet_ehash_secret and ipv6_hash_secret to net_get_random_onceHannes Frederic Sowa
Initialize the ehash and ipv6_hash_secrets with net_get_random_once. Each compilation unit gets its own secret now: ipv4/inet_hashtables.o ipv4/udp.o ipv6/inet6_hashtables.o ipv6/udp.o rds/connection.o The functions still get inlined into the hashing functions. In the fast path we have at most two (needed in ipv6) if (unlikely(...)). Cc: Eric Dumazet <edumazet@google.com> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-10-19ipv4: split inet_ehashfn to hash functions per compilation unitHannes Frederic Sowa
This duplicates a bit of code but let's us easily introduce separate secret keys later. The separate compilation units are ipv4/inet_hashtabbles.o, ipv4/udp.o and rds/connection.o. Cc: Eric Dumazet <edumazet@google.com> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-02-27hlist: drop the node parameter from iteratorsSasha Levin
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>
2011-10-31net: Add export.h for EXPORT_SYMBOL/THIS_MODULE to non-modulesPaul Gortmaker
These files are non modular, but need to export symbols using the macros now living in export.h -- call out the include so that things won't break when we remove the implicit presence of module.h from everywhere. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2010-10-21rds: make local functions/variables staticstephen hemminger
The RDS protocol has lots of functions that should be declared static. rds_message_get/add_version_extension is removed since it defined but never used. Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-09-08RDS: cancel connection work structs as we shut downZach Brown
Nothing was canceling the send and receive work that might have been queued as a conn was being destroyed. Signed-off-by: Zach Brown <zach.brown@oracle.com>
2010-09-08RDS: don't call rds_conn_shutdown() from rds_conn_destroy()Zach Brown
rds_conn_shutdown() can return before the connection is shut down when it encounters an existing state that it doesn't understand. This lets rds_conn_destroy() then start tearing down the conn from under paths that are still using it. It's more reliable the shutdown work and wait for krdsd to complete the shutdown callback. This stopped some hangs I was seeing where krdsd was trying to shut down a freed conn. Signed-off-by: Zach Brown <zach.brown@oracle.com>
2010-09-08RDS: have sockets get transport module referencesZach Brown
Right now there's nothing to stop the various paths that use rs->rs_transport from racing with rmmod and executing freed transport code. The simple fix is to have binding to a transport also hold a reference to the transport's module, removing this class of races. We already had an unused t_owner field which was set for the modular transports and which wasn't set for the built-in loop transport. Signed-off-by: Zach Brown <zach.brown@oracle.com>
2010-09-08RDS: lock rds_conn_count decrement in rds_conn_destroy()Zach Brown
rds_conn_destroy() can race with all other modifications of the rds_conn_count but it was modifying the count without locking. Signed-off-by: Zach Brown <zach.brown@oracle.com>
2010-09-08RDS: remove __init and __exit annotationZach Brown
The trivial amount of memory saved isn't worth the cost of dealing with section mismatches. Signed-off-by: Zach Brown <zach.brown@oracle.com>
2010-09-08RDS: whitespaceAndy Grover
2010-09-08rds: fix rds_send_xmit() serializationZach Brown
rds_send_xmit() was changed to hold an interrupt masking spinlock instead of a mutex so that it could be called from the IB receive tasklet path. This broke the TCP transport because its xmit method can block and masks and unmasks interrupts. This patch serializes callers to rds_send_xmit() with a simple bit instead of the current spinlock or previous mutex. This enables rds_send_xmit() to be called from any context and to call functions which block. Getting rid of the c_send_lock exposes the bare c_lock acquisitions which are changed to block interrupts. A waitqueue is added so that rds_conn_shutdown() can wait for callers to leave rds_send_xmit() before tearing down partial send state. This lets us get rid of c_senders. rds_send_xmit() is changed to check the conn state after acquiring the RDS_IN_XMIT bit to resolve races with the shutdown path. Previously both worked with the conn state and then the lock in the same order, allowing them to race and execute the paths concurrently. rds_send_reset() isn't racing with rds_send_xmit() now that rds_conn_shutdown() properly ensures that rds_send_xmit() can't start once the conn state has been changed. We can remove its previous use of the spinlock. Finally, c_send_generation is redundant. Callers can race to test the c_flags bit by simply retrying instead of racing to test the c_send_generation atomic. Signed-off-by: Zach Brown <zach.brown@oracle.com>
2010-09-08rds: block ints when acquiring c_lock in rds_conn_message_info()Zach Brown
conn->c_lock is acquired in interrupt context. rds_conn_message_info() is called from user context and was acquiring c_lock without blocking interrupts, leading to possible deadlocks. Signed-off-by: Zach Brown <zach.brown@oracle.com>
2010-09-08RDS: introduce rds_conn_connect_if_down()Zach Brown
A few paths had the same block of code to queue a connection's connect work if it was in the right state. Let's move this in to a helper function. Signed-off-by: Zach Brown <zach.brown@oracle.com>
2010-09-08rds: use RCU to protect the connection hashChris Mason
The connection hash was almost entirely RCU ready, this just makes the final couple of changes to use RCU instead of spinlocks for everything. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-09-08RDS: use locking on the connection hash listChris Mason
rds_conn_destroy really needs locking while it changes the connection hash. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-09-08rds: don't let RDS shutdown a connection while senders are presentChris Mason
This is the first in a long line of patches that tries to fix races between RDS connection shutdown and RDS traffic. Here we are maintaining a count of active senders to make sure the connection doesn't go away while they are using it. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-09-08RDS: Use a generation counter to avoid rds_send_xmit loopChris Mason
rds_send_xmit is required to loop around after it releases the lock because someone else could done a trylock, found someone working on the list and backed off. But, once we drop our lock, it is possible that someone else does come in and make progress on the list. We should detect this and not loop around if another process is actually working on the list. This patch adds a generation counter that is bumped every time we get the lock and do some send work. If the retry notices someone else has bumped the generation counter, it does not need to loop around and continue working. Signed-off-by: Chris Mason <chris.mason@oracle.com> Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08RDS: Change send lock from a mutex to a spinlockAndy Grover
This change allows us to call rds_send_xmit() from a tasklet, which is crucial to our new operating model. * Change c_send_lock to a spinlock * Update stats fields "sem_" to "_lock" * Remove unneeded rds_conn_is_sending() About locking between shutdown and send -- send checks if the connection is up. Shutdown puts the connection into DISCONNECTING. After this, all threads entering send will exit immediately. However, a thread could be *in* send_xmit(), so shutdown acquires the c_send_lock to ensure everyone is out before proceeding with connection shutdown. Signed-off-by: Andy Grover <andy.grover@oracle.com>