Commit Graph

101 Commits

Author SHA1 Message Date
Sowmini Varadhan
840df162b3 rds: reduce memory footprint for RDS when transport is RDMA
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>
2017-08-03 09:27:59 -07:00
Sowmini Varadhan
aed20a53a7 rds: cancel send/recv work before queuing connection shutdown
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>
2017-07-16 19:07:35 -07:00
Reshetova, Elena
6c5a1c4a2a net, rds: convert rds_message.m_refcount from atomic_t to refcount_t
refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.

Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-04 22:35:18 +01:00
Reshetova, Elena
803ea85053 net, rds: convert rds_mr.r_refcount from atomic_t to refcount_t
refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.

Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-04 22:35:17 +01:00
Reshetova, Elena
b7f0292094 net, rds: convert rds_incoming.i_refcount from atomic_t to refcount_t
refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.

Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-04 22:35:17 +01:00
Sowmini Varadhan
c14b036681 rds: tcp: set linger to 1 when unloading a rds-tcp
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>
2017-06-22 11:34:04 -04:00
Sowmini Varadhan
69b92b5b74 rds: tcp: send handshake ping-probe from passive endpoint
The RDS handshake ping probe added by commit 5916e2c155
("RDS: TCP: Enable multipath RDS for TCP") is sent from rds_sendmsg()
before the first data packet is sent to a peer. If the conversation
is not bidirectional  (i.e., one side is always passive and never
invokes rds_sendmsg()) and the passive side restarts its rds_tcp
module, a new HS ping probe needs to be sent, so that the number
of paths can be re-established.

This patch achieves that by sending a HS ping probe from
rds_tcp_accept_one() when c_npaths is 0 (i.e., we have not done
a handshake probe with this peer yet).

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>
2017-06-22 11:34:04 -04:00
Sowmini Varadhan
00354de577 rds: tcp: various endian-ness fixes
Found when testing between sparc and x86 machines on different
subnets, so the address comparison patterns hit the corner cases and
brought out some bugs fixed by this patch.

Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Tested-by: Imanti Mendez <imanti.mendez@oracle.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-16 12:45:15 -04:00
Sowmini Varadhan
41500c3e2a rds: tcp: remove cp_outgoing
After commit 1a0e100fb2 ("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>
2017-06-16 12:45:14 -04:00
Sowmini Varadhan
8edc3affc0 rds: tcp: Take explicit refcounts on struct net
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>
2017-03-07 14:09:59 -08:00
Linus Torvalds
8d70eeb84a Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Pull networking fixes from David Miller:

 1) Fix double-free in batman-adv, from Sven Eckelmann.

 2) Fix packet stats for fast-RX path, from Joannes Berg.

 3) Netfilter's ip_route_me_harder() doesn't handle request sockets
    properly, fix from Florian Westphal.

 4) Fix sendmsg deadlock in rxrpc, from David Howells.

 5) Add missing RCU locking to transport hashtable scan, from Xin Long.

 6) Fix potential packet loss in mlxsw driver, from Ido Schimmel.

 7) Fix race in NAPI handling between poll handlers and busy polling,
    from Eric Dumazet.

 8) TX path in vxlan and geneve need proper RCU locking, from Jakub
    Kicinski.

 9) SYN processing in DCCP and TCP need to disable BH, from Eric
    Dumazet.

10) Properly handle net_enable_timestamp() being invoked from IRQ
    context, also from Eric Dumazet.

11) Fix crash on device-tree systems in xgene driver, from Alban Bedel.

12) Do not call sk_free() on a locked socket, from Arnaldo Carvalho de
    Melo.

13) Fix use-after-free in netvsc driver, from Dexuan Cui.

14) Fix max MTU setting in bonding driver, from WANG Cong.

15) xen-netback hash table can be allocated from softirq context, so use
    GFP_ATOMIC. From Anoob Soman.

16) Fix MAC address change bug in bgmac driver, from Hari Vyas.

17) strparser needs to destroy strp_wq on module exit, from WANG Cong.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (69 commits)
  strparser: destroy workqueue on module exit
  sfc: fix IPID endianness in TSOv2
  sfc: avoid max() in array size
  rds: remove unnecessary returned value check
  rxrpc: Fix potential NULL-pointer exception
  nfp: correct DMA direction in XDP DMA sync
  nfp: don't tell FW about the reserved buffer space
  net: ethernet: bgmac: mac address change bug
  net: ethernet: bgmac: init sequence bug
  xen-netback: don't vfree() queues under spinlock
  xen-netback: keep a local pointer for vif in backend_disconnect()
  netfilter: nf_tables: don't call nfnetlink_set_err() if nfnetlink_send() fails
  netfilter: nft_set_rbtree: incorrect assumption on lower interval lookups
  netfilter: nf_conntrack_sip: fix wrong memory initialisation
  can: flexcan: fix typo in comment
  can: usb_8dev: Fix memory leak of priv->cmd_msg_buffer
  can: gs_usb: fix coding style
  can: gs_usb: Don't use stack memory for USB transfers
  ixgbe: Limit use of 2K buffers on architectures with 256B or larger cache lines
  ixgbe: update the rss key on h/w, when ethtool ask for it
  ...
2017-03-04 17:31:39 -08:00
Zhu Yanjun
a8d63a53b3 rds: remove unnecessary returned value check
The function rds_trans_register always returns 0. As such, it is not
necessary to check the returned value.

Cc: Joe Jin <joe.jin@oracle.com>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Signed-off-by: Zhu Yanjun <yanjun.zhu@oracle.com>
Reviewed-by: Yuval Shaia <yuval.shaia@oracle.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-03 09:51:22 -08:00
Linus Torvalds
69fd110eb6 Merge branch 'work.sendmsg' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs sendmsg updates from Al Viro:
 "More sendmsg work.

  This is a fairly separate isolated stuff (there's a continuation
  around lustre, but that one was too late to soak in -next), thus the
  separate pull request"

* 'work.sendmsg' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  ncpfs: switch to sock_sendmsg()
  ncpfs: don't mess with manually advancing iovec on send
  ncpfs: sendmsg does *not* bugger iovec these days
  ceph_tcp_sendpage(): use ITER_BVEC sendmsg
  afs_send_pages(): use ITER_BVEC
  rds: remove dead code
  ceph: switch to sock_recvmsg()
  usbip_recv(): switch to sock_recvmsg()
  iscsi_target: deal with short writes on the tx side
  [nbd] pass iov_iter to nbd_xmit()
  [nbd] switch sock_xmit() to sock_{send,recv}msg()
  [drbd] use sock_sendmsg()
2017-03-02 15:16:38 -08:00
Santosh Shilimkar
3289025aed RDS: add receive message trace used by application
Socket option to tap receive path latency in various stages
in nano seconds. It can be enabled on selective sockets using
using SO_RDS_MSG_RXPATH_LATENCY socket option. RDS will return
the data to application with RDS_CMSG_RXPATH_LATENCY in defined
format. Scope is left to add more trace points for future
without need of change in the interface.

Reviewed-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
2017-01-02 14:02:59 -08:00
Avinash Repaka
f9fb69adb6 RDS: make message size limit compliant with spec
RDS support max message size as 1M but the code doesn't check this
in all cases. Patch fixes it for RDMA & non-RDMA and RDS MR size
and its enforced irrespective of underlying transport.

Signed-off-by: Avinash Repaka <avinash.repaka@oracle.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
2017-01-02 14:02:57 -08:00
Venkat Venkatsubra
192a798f52 RDS: add stat for socket recv memory usage
Tracks the receive side memory added to scokets and removed from sockets.

Signed-off-by: Venkat Venkatsubra <venkat.x.venkatsubra@oracle.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
2017-01-02 14:02:56 -08:00
Santosh Shilimkar
941f8d55f6 RDS: RDMA: Fix the composite message user notification
When application sends an RDS RDMA composite message consist of
RDMA transfer to be followed up by non RDMA payload, it expect to
be notified *only* when the full message gets delivered. RDS RDMA
notification doesn't behave this way though.

Thanks to Venkat for debug and root casuing the issue
where only first part of the message(RDMA) was
successfully delivered but remainder payload delivery failed.
In that case, application should not be notified with
a false positive of message delivery success.

Fix this case by making sure the user gets notified only after
the full message delivery.

Reviewed-by: Venkat Venkatsubra <venkat.x.venkatsubra@oracle.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
2017-01-02 14:02:54 -08:00
Al Viro
be6e4d66f0 rds: remove dead code
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-12-26 21:35:39 -05:00
Sowmini Varadhan
905dd4184e RDS: TCP: Track peer's connection generation number
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 5916e2c155 ("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>
2016-11-17 13:35:18 -05:00
David S. Miller
27058af401 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
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>
2016-10-30 12:42:58 -04:00
shamir rabinovitch
ff57087f31 rds: debug messages are enabled by default
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>
2016-10-29 15:55:57 -04:00
Joe Perches
e81c7b69c8 rds: Remove unused rds_conn_error
This macro's last use was removed in commit d769ef81d5
("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>
2016-10-17 11:07:22 -04:00
Nicolas Iooss
6cdaf03f8c RDS: add __printf format attribute to error reporting functions
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>
2016-08-08 16:16:21 -07:00
Sowmini Varadhan
5916e2c155 RDS: TCP: Enable multipath RDS for TCP
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>
2016-07-15 11:36:58 -07:00
Sowmini Varadhan
b04e8554f7 RDS: TCP: Hooks to set up a single connection path
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>
2016-07-01 16:45:17 -04:00
Sowmini Varadhan
2da43c4a1b RDS: TCP: make receive path use the rds_conn_path
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>
2016-07-01 16:45:17 -04:00
Sowmini Varadhan
226f7a7d97 RDS: Rework path specific indirections
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>
2016-07-01 16:45:17 -04:00
Sowmini Varadhan
d769ef81d5 RDS: Update rds_conn_shutdown to work with rds_conn_path
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>
2016-06-14 23:50:44 -07:00
Sowmini Varadhan
fb1b3dc43d RDS: Add rds_conn_path_error()
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>
2016-06-14 23:50:43 -07:00
Sowmini Varadhan
3c0a59001a RDS: Add rds_conn_path_connect_if_down() for MP-aware callers
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>
2016-06-14 23:50:43 -07:00
Sowmini Varadhan
45997e9e2e RDS: Make rds_send_pong() take a rds_conn_path argument
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>
2016-06-14 23:50:43 -07:00
Sowmini Varadhan
1f9ecd7eac RDS: Pass rds_conn_path to rds_send_xmit()
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>
2016-06-14 23:50:43 -07:00
Sowmini Varadhan
7d885d0fc6 RDS: Remove stale function rds_send_get_message()
The only caller of rds_send_get_message() was
rds_iw_send_cq_comp_handler() which was removed as part of
commit dcdede0406 ("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>
2016-06-14 23:50:42 -07:00
Sowmini Varadhan
5c3d274c75 RDS: Add rds_send_path_drop_acked()
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>
2016-06-14 23:50:42 -07:00
Sowmini Varadhan
5e833e025d RDS: rds_inc_path_init() helper function for MP capable transports
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>
2016-06-14 23:50:42 -07:00
Sowmini Varadhan
ef9e62c2e5 RDS: recv path gets the conn_path from rds_incoming for MP capable transports
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>
2016-06-14 23:50:42 -07:00
Sowmini Varadhan
7e8f4413d7 RDS: add t_mp_capable bit to be set by MP capable transports
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>
2016-06-14 23:50:41 -07:00
Sowmini Varadhan
0cb43965d4 RDS: split out connection specific state from rds_connection to rds_conn_path
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>
2016-06-14 23:50:41 -07:00
Sowmini Varadhan
9c79440e2c RDS: TCP: fix race windows in send-path quiescence by rds_tcp_accept_one()
The send path needs to be quiesced before resetting callbacks from
rds_tcp_accept_one(), and commit eb19284026 ("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>
2016-06-07 15:10:15 -07:00
santosh.shilimkar@oracle.com
5711f8b353 RDS: Add support for SO_TIMESTAMP for incoming messages
The SO_TIMESTAMP generates time stamp for each incoming RDS messages
User app can enable it by using SO_TIMESTAMP setsocketopt() at
SOL_SOCKET level. CMSG data of cmsg type SO_TIMESTAMP contains the
time stamp in struct timeval format.

Reviewed-by: Sowmini Varadhan <sowmini.varadhan@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>
2016-03-02 14:13:17 -05:00
santosh.shilimkar@oracle.com
7b5654349e RDS: convert bind hash table to re-sizable hashtable
To further improve the RDS connection scalabilty on massive systems
where number of sockets grows into tens of thousands  of sockets, there
is a need of larger bind hashtable. Pre-allocated 8K or 16K table is
not very flexible in terms of memory utilisation. The rhashtable
infrastructure gives us the flexibility to grow the hashtbable based
on use and also comes up with inbuilt efficient bucket(chain) handling.

Reviewed-by: David Miller <davem@davemloft.net>
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>
2015-11-02 15:36:23 -05:00
David S. Miller
91d2f14bc3 Merge branch 'net/rds/4.3-v3' of git://git.kernel.org/pub/scm/linux/kernel/git/ssantosh/linux
Santosh Shilimkar says:

====================
RDS: connection scalability and performance improvements

[v4]
Re-sending the same patches from v3 again since my repost of
patch 05/14 from v3 was whitespace damaged.

[v3]
Updated patch "[PATCH v2 05/14] RDS: defer the over_batch work to
send worker" as per David Miller's comment [4] to avoid the magic
value usage. Patch now makes use of already available but unused
send_batch_count module parameter. Rest of the patches are same as
earlier version v2 [3]

[v2]:
Dropped "[PATCH 05/15] RDS: increase size of hash-table to 8K" from
earlier version [1]. I plan to address the hash table scalability using
re-sizable hash tables as suggested by David Laight and David Miller [2]

This series addresses RDS connection bottlenecks on massive workloads and
improve the RDMA performance almost by 3X. RDS TCP also gets a small gain
of about 12%.

RDS is being used in massive systems with high scalability where several
hundred thousand end points and tens of thousands of local processes
are operating in tens of thousand sockets. Being RC(reliable connection),
socket bind and release happens very often and any inefficiencies in
bind hash look ups hurts the overall system performance. RDS bin hash-table
uses global spin-lock which is the biggest bottleneck. To make matter worst,
it uses rcu inside global lock for hash buckets.
This is being addressed by simply using per bucket rw lock which makes the
locking simple and very efficient. The hash table size is still an issue and
I plan to address it by using re-sizable hash tables as suggested on the list.

For RDS RDMA improvement, the completion handling is revamped so that we
can do batch completions. Both send and receive completion handlers are
split logically to achieve the same. RDS 8K messages being one of the
key usecase, mr pool is adapted to have the 8K mrs along with default 1M
mrs. And while doing this, few fixes and couple of bottlenecks seen with
rds_sendmsg() are addressed.

Series applies against 4.3-rc1 as well net-next. Its tested on Oracle
hardware with IB fabric for both bcopy as well as RDMA mode. RDS TCP is
tested with iXGB NIC. Like last time, iWARP transport is untested with
these changes. The patchset is also available at below git repo:

git://git.kernel.org/pub/scm/linux/kernel/git/ssantosh/linux.git net/rds/4.3-v3

As a side note, the IB HCA driver I used for testing misses at least 3
important patches in upstream to see the full blown IB performance and
am hoping to get that in mainline with help of them.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-08 04:38:37 -07:00
Sowmini Varadhan
3b20fc3897 RDS: Use a single TCP socket for both send and receive.
Commit f711a6ae06 ("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>
2015-10-05 03:34:51 -07:00
Santosh Shilimkar
9b9acde7e8 RDS: Use per-bucket rw lock for bind hash-table
One global lock protecting hash-tables with 1024 buckets isn't
efficient and it shows up in a massive systems with truck
loads of RDS sockets serving multiple databases. The
perf data clearly highlights the contention on the rw
lock in these massive workloads.

When the contention gets worse, the code gets into a state where
it decides to back off on the lock. So while it has disabled interrupts,
it sits and backs off on this lock get. This causes the system to
become sluggish and eventually all sorts of bad things happen.

The simple fix is to move the lock into the hash bucket and
use per-bucket lock to improve the scalability.

Signed-off-by: Santosh Shilimkar <ssantosh@kernel.org>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
2015-09-30 12:43:25 -04:00
santosh.shilimkar@oracle.com
73ce4317bf RDS: make sure we post recv buffers
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>
2015-08-25 13:35:30 -07:00
Sowmini Varadhan
d5a8ac28a7 RDS-TCP: Make RDS-TCP work correctly when it is set up in a netns other than 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>
2015-08-07 11:29:57 -07:00
Linus Torvalds
e0456717e4 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next
Pull networking updates from David Miller:

 1) Add TX fast path in mac80211, from Johannes Berg.

 2) Add TSO/GRO support to ibmveth, from Thomas Falcon

 3) Move away from cached routes in ipv6, just like ipv4, from Martin
    KaFai Lau.

 4) Lots of new rhashtable tests, from Thomas Graf.

 5) Run ingress qdisc lockless, from Alexei Starovoitov.

 6) Allow servers to fetch TCP packet headers for SYN packets of new
    connections, for fingerprinting.  From Eric Dumazet.

 7) Add mode parameter to pktgen, for testing receive.  From Alexei
    Starovoitov.

 8) Cache access optimizations via simplifications of build_skb(), from
    Alexander Duyck.

 9) Move page frag allocator under mm/, also from Alexander.

10) Add xmit_more support to hv_netvsc, from KY Srinivasan.

11) Add a counter guard in case we try to perform endless reclassify
    loops in the packet scheduler.

12) Extern flow dissector to be programmable and use it in new "Flower"
    classifier.  From Jiri Pirko.

13) AF_PACKET fanout rollover fixes, performance improvements, and new
    statistics.  From Willem de Bruijn.

14) Add netdev driver for GENEVE tunnels, from John W Linville.

15) Add ingress netfilter hooks and filtering, from Pablo Neira Ayuso.

16) Fix handling of epoll edge triggers in TCP, from Eric Dumazet.

17) Add an ECN retry fallback for the initial TCP handshake, from Daniel
    Borkmann.

18) Add tail call support to BPF, from Alexei Starovoitov.

19) Add several pktgen helper scripts, from Jesper Dangaard Brouer.

20) Add zerocopy support to AF_UNIX, from Hannes Frederic Sowa.

21) Favor even port numbers for allocation to connect() requests, and
    odd port numbers for bind(0), in an effort to help avoid
    ip_local_port_range exhaustion.  From Eric Dumazet.

22) Add Cavium ThunderX driver, from Sunil Goutham.

23) Allow bpf programs to access skb_iif and dev->ifindex SKB metadata,
    from Alexei Starovoitov.

24) Add support for T6 chips in cxgb4vf driver, from Hariprasad Shenai.

25) Double TCP Small Queues default to 256K to accomodate situations
    like the XEN driver and wireless aggregation.  From Wei Liu.

26) Add more entropy inputs to flow dissector, from Tom Herbert.

27) Add CDG congestion control algorithm to TCP, from Kenneth Klette
    Jonassen.

28) Convert ipset over to RCU locking, from Jozsef Kadlecsik.

29) Track and act upon link status of ipv4 route nexthops, from Andy
    Gospodarek.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1670 commits)
  bridge: vlan: flush the dynamically learned entries on port vlan delete
  bridge: multicast: add a comment to br_port_state_selection about blocking state
  net: inet_diag: export IPV6_V6ONLY sockopt
  stmmac: troubleshoot unexpected bits in des0 & des1
  net: ipv4 sysctl option to ignore routes when nexthop link is down
  net: track link-status of ipv4 nexthops
  net: switchdev: ignore unsupported bridge flags
  net: Cavium: Fix MAC address setting in shutdown state
  drivers: net: xgene: fix for ACPI support without ACPI
  ip: report the original address of ICMP messages
  net/mlx5e: Prefetch skb data on RX
  net/mlx5e: Pop cq outside mlx5e_get_cqe
  net/mlx5e: Remove mlx5e_cq.sqrq back-pointer
  net/mlx5e: Remove extra spaces
  net/mlx5e: Avoid TX CQE generation if more xmit packets expected
  net/mlx5e: Avoid redundant dev_kfree_skb() upon NOP completion
  net/mlx5e: Remove re-assignment of wq type in mlx5e_enable_rq()
  net/mlx5e: Use skb_shinfo(skb)->gso_segs rather than counting them
  net/mlx5e: Static mapping of netdev priv resources to/from netdev TX queues
  net/mlx4_en: Use HW counters for rx/tx bytes/packets in PF device
  ...
2015-06-24 16:49:49 -07:00
Doug Ledford
b806ef3bbe Merge branch 'for-4.2-misc' into k.o/for-4.2 2015-06-02 09:33:22 -04:00
Wengang Wang
d655a9fbc8 rds: re-entry of rds_ib_xmit/rds_iw_xmit
The BUG_ON at line 452/453 is triggered in function rds_send_xmit.

 441                         while (ret) {
 442                                 tmp = min_t(int, ret, sg->length -
 443                                                       conn->c_xmit_data_off);
 444                                 conn->c_xmit_data_off += tmp;
 445                                 ret -= tmp;
 446                                 if (conn->c_xmit_data_off == sg->length) {
 447                                         conn->c_xmit_data_off = 0;
 448                                         sg++;
 449                                         conn->c_xmit_sg++;
 450                                         if (ret != 0 && conn->c_xmit_sg == rm->data.op_nents)
 451                                                 printk(KERN_ERR "conn %p rm %p sg %p ret %d\n", conn, rm, sg, ret);
 452                                         BUG_ON(ret != 0 &&
 453                                                conn->c_xmit_sg == rm->data.op_nents);
 454                                 }
 455                         }

it is complaining the total sent length is bigger that we want to send.

rds_ib_xmit() is wrong for the second entry for the same rds_message returning
wrong value.

the sg and off passed by rds_send_xmit to rds_ib_xmit is based on
scatterlist.offset/length, but the rds_ib_xmit action is based on
scatterlist.dma_address/dma_length. in case dma_length is larger than length
there is problem. for the 2nd and later entries of rds_ib_xmit for same
rds_message, at least one of the following two is wrong:

1) the scatterlist to start with,  the choosen one can far beyond the correct
   one.
2) the offset to start with within the scatterlist.

fix:
add op_dmasg and op_dmaoff to rm_data_op structure indicating the scatterlist
and offset within the it to start with for rds_ib_xmit respectively. op_dmasg
and op_dmaoff are initialized to zero when doing dma mapping for the first see
of the message and are changed when filling send slots.

the same applies to rds_iw_xmit too.

Signed-off-by: Wengang Wang <wen.gang.wang@oracle.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
2015-06-02 09:22:31 -04:00
Sowmini Varadhan
d97dac54bf net/rds: Add setsockopt support for SO_RDS_TRANSPORT
An application may deterministically attach the underlying transport for
a PF_RDS socket by invoking setsockopt(2) with the SO_RDS_TRANSPORT
option at the SOL_RDS level. The integer argument to setsockopt must be
one of the RDS_TRANS_* transport types, e.g., RDS_TRANS_TCP. The option
must be specified before invoking bind(2) on the socket, and may only
be used once on the socket. An attempt to set the option on a bound
socket, or to invoke the option after a successful SO_RDS_TRANSPORT
attachment, will return EOPNOTSUPP.

Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-31 21:47:23 -07:00