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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>
2016-11-17RDS: TCP: set RDS_FLAG_RETRANSMITTED in cp_retrans listSowmini Varadhan
As noted in rds_recv_incoming() sequence numbers on data packets can decreas for the failover case, and the Rx path is equipped to recover from this, if the RDS_FLAG_RETRANSMITTED is set on the rds header of an incoming message with a suspect sequence number. The RDS_FLAG_RETRANSMITTED is predicated on the RDS_FLAG_RETRANSMITTED flag in the rds_message, so make sure the flag is set on messages queued for retransmission. 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>
2016-11-09RDS: TCP: start multipath acceptor loop at 0Sowmini Varadhan
The for() loop in rds_tcp_accept_one() assumes that the 0'th rds_tcp_conn_path is UP and starts multipath accepts at index 1. But this assumption may not always be true: if the 0'th path has failed (ERROR or DOWN state) an incoming connection request should be used to resurrect this path. 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>
2016-11-09RDS: TCP: report addr/port info based on TCP socket in rds-infoSowmini Varadhan
The socket argument passed to rds_tcp_tc_info() is a PF_RDS socket, so it is incorrect to report the address port info based on rds_getname() as part of TCP state report. Invoke inet_getname() for the t_sock associated with the rds_tcp_connection instead. 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>
2016-10-30Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Mostly simple overlapping changes. For example, David Ahern's adjacency list revamp in 'net-next' conflicted with an adjacency list traversal bug fix in 'net'. Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-29rds: debug messages are enabled by defaultshamir rabinovitch
rds use Kconfig option called "RDS_DEBUG" to enable rds debug messages. This option cause the rds Makefile to add -DDEBUG to the rds gcc command line. When CONFIG_DYNAMIC_DEBUG is enabled, the "DEBUG" macro is used by include/linux/dynamic_debug.h to decide if dynamic debug prints should be sent by default to the kernel log. rds should not enable this macro for production builds. rds dynamic debug work as expected follow this fix. Signed-off-by: Shamir Rabinovitch <shamir.rabinovitch@oracle.com> Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com> Reviewed-by: Wengang Wang <wen.gang.wang@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-17rds: Remove duplicate prefix from rds_conn_path_error useJoe Perches
rds_conn_path_error already prefixes "RDS:" to the output. 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>
2016-10-17rds: 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>
2016-09-23IB/core: add support to create a unsafe global rkey to ib_create_pdChristoph Hellwig
Instead of exposing ib_get_dma_mr to ULPs and letting them use it more or less unchecked, this moves the capability of creating a global rkey into the RDMA core, where it can be easily audited. It also prints a warning everytime this feature is used as well. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Reviewed-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com> Reviewed-by: Steve Wise <swise@opengridcomputing.com> Signed-off-by: Doug Ledford <dledford@redhat.com>
2016-08-08RDS: add __printf format attribute to error reporting functionsNicolas Iooss
This is helpful to detect at compile-time errors related to format strings. Signed-off-by: Nicolas Iooss <nicolas.iooss_linux@m4x.org> 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>
2016-07-15RDS: TCP: Reduce code duplication in rds_tcp_reset_callbacks()Sowmini Varadhan
Some code duplication in rds_tcp_reset_callbacks() can be avoided by having the function call rds_tcp_restore_callbacks() and rds_tcp_set_callbacks(). 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>
2016-07-15RDS: TCP: avoid bad page reference in rds_tcp_listen_data_readySowmini Varadhan
As the existing comments in rds_tcp_listen_data_ready() indicate, it is possible under some race-windows to get to this function with the accept() socket. If that happens, we could run into a sequence whereby thread 1 thread 2 rds_tcp_accept_one() thread sets up new_sock via ->accept(). The sk_user_data is now sock_def_readable data comes in for new_sock, ->sk_data_ready is called, and we land in rds_tcp_listen_data_ready rds_tcp_set_callbacks() takes the sk_callback_lock and sets up sk_user_data to be the cp read_lock sk_callback_lock ready = cp unlock sk_callback_lock page fault on ready In the above sequence, we end up with a panic on a bad page reference when trying to execute (*ready)(). Instead we need to call sock_def_readable() safely, which is what this patch achieves. 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>
2016-07-06Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Conflicts: drivers/net/ethernet/mellanox/mlx5/core/en.h drivers/net/ethernet/mellanox/mlx5/core/en_main.c drivers/net/usb/r8152.c All three conflicts were overlapping changes. Signed-off-by: David S. Miller <davem@davemloft.net>
2016-07-04RDS: fix rds_tcp_init() error pathVegard Nossum
If register_pernet_subsys() fails, we shouldn't try to call unregister_pernet_subsys(). Fixes: 467fa15356 ("RDS-TCP: Support multiple RDS-TCP listen endpoints, one per netns.") Cc: stable@vger.kernel.org Cc: Sowmini Varadhan <sowmini.varadhan@oracle.com> Cc: David S. Miller <davem@davemloft.net> Signed-off-by: Vegard Nossum <vegard.nossum@oracle.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>
2016-07-01RDS: Do not send a pong to an incoming ping with 0 src portSowmini Varadhan
RDS ping messages are sent with a non-zero src port to a zero dst port, so that the rds pong messages can be sent back to the originators src port. However if a confused/malicious sender sends a ping with a 0 src port, we'd have an infinite ping-pong loop. To avoid this, the receiver should ignore ping messages with a 0 src port. 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: 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: Hooks to set up a single connection pathSowmini Varadhan
This patch adds ->conn_path_connect callbacks in the rds_transport that are used to set up a single connection path. 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 receive path use the rds_conn_pathSowmini Varadhan
The ->sk_user_data contains a pointer to the rds_conn_path for the socket. Use this consistently in the rds_tcp_data_ready callbacks to get the rds_conn_path for rds_recv_incoming. 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 ->sk_user_data point to a rds_conn_pathSowmini Varadhan
The socket callbacks should all operate on a struct rds_conn_path, in preparation for a MP capable RDS-TCP. 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: Refactor connection destruction to handle multiple pathsSowmini Varadhan
A single rds_connection may have multiple rds_conn_paths that have to be carefully and correctly destroyed, for both rmmod and netns-delete cases. For both cases, we extract a single rds_tcp_connection for each conn into a temporary list, and then invoke rds_conn_destroy() which iteratively dismantles every path in the rds_connection. For the netns deletion case, we additionally have to make sure that we do not leave a socket in TIME_WAIT state, as this will hold up the netns deletion. Thus we call rds_tcp_conn_paths_destroy() to reset state quickly. 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: TCP: Remove dead logic around c_passive in rds-tcpSowmini Varadhan
The c_passive bit is only intended for the IB transport and will never be encountered in rds-tcp, so remove the dead logic that predicates on this bit. 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>
2016-06-30Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Several cases of overlapping changes, except the packet scheduler conflicts which deal with the addition of the free list parameter to qdisc_enqueue(). Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-18net: rds: fix coding style issuesJoshua Houghton
Fix coding style issues in the following files: ib_cm.c: add space loop.c: convert spaces to tabs sysctl.c: add space tcp.h: convert spaces to tabs tcp_connect.c:remove extra indentation in switch statement tcp_recv.c: convert spaces to tabs tcp_send.c: convert spaces to tabs transport.c: move brace up one line on for statement Signed-off-by: Joshua Houghton <josh@awful.name> Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-17RDS: TCP: rds_tcp_accept_one() should transition socket from RESETTING to UPSowmini Varadhan
The state of the rds_connection after rds_tcp_reset_callbacks() would be RDS_CONN_RESETTING and this is the value that should be passed by rds_tcp_accept_one() to rds_connect_path_complete() to transition the socket to RDS_CONN_UP. Fixes: b5c21c0947c1 ("RDS: TCP: fix race windows in send-path quiescence by 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>
2016-06-17RDS: TCP: Fix non static symbol warningsWei Yongjun
Fixes the following sparse warnings: net/rds/tcp.c:59:5: warning: symbol 'rds_tcp_min_sndbuf' was not declared. Should it be static? net/rds/tcp.c:60:5: warning: symbol 'rds_tcp_min_rcvbuf' was not declared. Should it be static? Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn> 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>
2016-06-14RDS: 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: Make rds_send_pong() take a rds_conn_path argumentSowmini Varadhan
This commit allows rds_send_pong() callers to send back the rds pong message on some path other than c_path[0] by passing in a struct rds_conn_path * argument. It also removes the last dependency on the #defines in rds_single.h from send.c Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-14RDS: Extract rds_conn_path from i_conn_path in rds_send_drop_to() for ↵Sowmini Varadhan
MP-capable transports Explicitly set up rds_conn_path, either from i_conn_path (for MP capable transpots) or as c_path[0], and use this in rds_send_drop_to() Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-14RDS: Pass rds_conn_path to rds_send_xmit()Sowmini Varadhan
Pass a struct rds_conn_path to rds_send_xmit so that MP capable transports can transmit packets on something other than c_path[0]. The eventual goal for MP capable transports is to hash the rds socket to a path based on the bound local address/port, and use this path as the argument to rds_send_xmit() Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-14RDS: Make rds_send_queue_rm() rds_conn_path awareSowmini Varadhan
Pass the rds_conn_path to rds_send_queue_rm, and use it to initialize the i_conn_path field in struct rds_incoming. This commit also makes rds_send_queue_rm() MP capable, because it now takes locks specific to the rds_conn_path passed in, instead of defaulting to the c_path[0] based defines from rds_single_path.h Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-14RDS: Remove stale function rds_send_get_message()Sowmini Varadhan
The only caller of rds_send_get_message() was rds_iw_send_cq_comp_handler() which was removed as part of commit dcdede0406d3 ("RDS: Drop stale iWARP RDMA transport"), so remove rds_send_get_message() for the same reason. Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-14RDS: Add rds_send_path_drop_acked()Sowmini Varadhan
rds_send_path_drop_acked() is the path-specific version of rds_send_drop_acked() to be invoked by MP capable callers. Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-14RDS: Add rds_send_path_reset()Sowmini Varadhan
rds_send_path_reset() is the path specific version of rds_send_reset() intended for MP capable callers. Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-14RDS: rds_inc_path_init() helper function for MP capable transportsSowmini Varadhan
t_mp_capable transports can use rds_inc_path_init to initialize all fields in struct rds_incoming, including the i_conn_path. Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-14RDS: recv path gets the conn_path from rds_incoming for MP capable transportsSowmini Varadhan
Transports that are t_mp_capable should set the rds_conn_path on which the datagram was recived in the ->i_conn_path field of struct rds_incoming. Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-14RDS: add t_mp_capable bit to be set by MP capable transportsSowmini Varadhan
The t_mp_capable bit will be used in the core rds module to support multipathing logic when the transport supports it. 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>
2016-06-10RDS: IB: Remove deprecated create_workqueueBhaktipriya Shridhar
alloc_workqueue replaces deprecated create_workqueue(). Since the driver is infiniband which can be used as block device and the workqueue seems involved in regular operation of the device, so a dedicated workqueue has been used with WQ_MEM_RECLAIM set to guarantee forward progress under memory pressure. Since there are only a fixed number of work items, explicit concurrency limit is unnecessary here. Signed-off-by: Bhaktipriya Shridhar <bhaktipriya96@gmail.com> Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-07RDS: TCP: fix race windows in send-path quiescence by rds_tcp_accept_one()Sowmini Varadhan
The send path needs to be quiesced before resetting callbacks from rds_tcp_accept_one(), and commit eb192840266f ("RDS:TCP: Synchronize rds_tcp_accept_one with rds_send_xmit when resetting t_sock") achieves this using the c_state and RDS_IN_XMIT bit following the pattern used by rds_conn_shutdown(). However this leaves the possibility of a race window as shown in the sequence below take t_conn_lock in rds_tcp_conn_connect send outgoing syn to peer drop t_conn_lock in rds_tcp_conn_connect incoming from peer triggers rds_tcp_accept_one, conn is marked CONNECTING wait for RDS_IN_XMIT to quiesce any rds_send_xmit threads call rds_tcp_reset_callbacks [.. race-window where incoming syn-ack can cause the conn to be marked UP from rds_tcp_state_change ..] lock_sock called from rds_tcp_reset_callbacks, and we set t_sock to null As soon as the conn is marked UP in the race-window above, rds_send_xmit() threads will proceed to rds_tcp_xmit and may encounter a null-pointer deref on the t_sock. Given that rds_tcp_state_change() is invoked in softirq context, whereas rds_tcp_reset_callbacks() is in workq context, and testing for RDS_IN_XMIT after lock_sock could result in a deadlock with tcp_sendmsg, this commit fixes the race by using a new c_state, RDS_TCP_RESETTING, which will prevent a transition to RDS_CONN_UP from rds_tcp_state_change(). 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>
2016-06-07RDS: TCP: Retransmit half-sent datagrams when switching sockets in ↵Sowmini Varadhan
rds_tcp_reset_callbacks When we switch a connection's sockets in rds_tcp_rest_callbacks, any partially sent datagram must be retransmitted on the new socket so that the receiver can correctly reassmble the RDS datagram. Use rds_send_reset() which is designed for this purpose. 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>
2016-06-07RDS: TCP: Add/use rds_tcp_reset_callbacks to reset tcp socket safelySowmini Varadhan
When rds_tcp_accept_one() has to replace the existing tcp socket with a newer tcp socket (duelling-syn resolution), it must lock_sock() to suppress the rds_tcp_data_recv() path while callbacks are being changed. Also, existing RDS datagram reassembly state must be reset, so that the next datagram on the new socket does not have corrupted state. Similarly when resetting the newly accepted socket, appropriate locks and synchronization is needed. This commit ensures correct synchronization by invoking kernel_sock_shutdown to reset a newly accepted sock, and by taking appropriate lock_sock()s (for old and new sockets) when resetting existing callbacks. 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>
2016-06-02rds: fix an infoleak in rds_inc_info_copyKangjie Lu
The last field "flags" of object "minfo" is not initialized. Copying this object out may leak kernel stack data. Assign 0 to it to avoid leak. Signed-off-by: Kangjie Lu <kjlu@gatech.edu> Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>