Commit Graph

65 Commits

Author SHA1 Message Date
Wen Gu
b40584d145 net/smc: compatible with 128-bits extended GID of virtual ISM device
According to virtual ISM support feature defined by SMCv2.1, GIDs of
virtual ISM device are UUIDs defined by RFC4122, which are 128-bits
long. So some adaptation work is required. And note that the GIDs of
existing platform firmware ISM devices still remain 64-bits long.

Signed-off-by: Wen Gu <guwen@linux.alibaba.com>
Reviewed-by: Alexandra Winter <wintera@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-12-26 20:24:33 +00:00
Wen Gu
00e006a257 net/smc: introduce virtual ISM device support feature
This introduces virtual ISM device support feature to SMCv2.1 as the
first supplemental feature.

Signed-off-by: Wen Gu <guwen@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-12-26 20:24:33 +00:00
Wen Gu
ece60db3a4 net/smc: support SMCv2.x supplemental features negotiation
This patch adds SMCv2.x supplemental features negotiation. Supported
SMCv2.x supplemental features are represented by feature_mask in FCE
field. The negotiation process is as follows.

 Server                                        Client
            Proposal(features(c-mask bits))
      <-----------------------------------------
            Accept(features(s-mask bits))
      ----------------------------------------->
           Confirm(features(s&c-mask bits))
      <-----------------------------------------

Signed-off-by: Wen Gu <guwen@linux.alibaba.com>
Reviewed-and-tested-by: Wenjia Zhang <wenjia@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-12-26 20:24:33 +00:00
Li RongQing
e7bed88e05 net/smc: remove unneeded atomic operations in smc_tx_sndbuf_nonempty
The commit dcd2cf5f2f ("net/smc: add autocorking support") adds an
atomic variable tx_pushing in smc_connection to make sure only one can
send to let it cork more and save CDC slot. since smc_tx_pending can be
called in the soft IRQ without checking sock_owned_by_user() at that
time, which would cause a race condition because bh_lock_sock() did
not honor sock_lock()

After commit 6b88af839d ("net/smc: don't send in the BH context if
sock_owned_by_user"), the transmission is deferred to when sock_lock()
is held by the user. Therefore, we no longer need tx_pending to hold
message.

So remove atomic variable tx_pushing and its operation, and
smc_tx_sndbuf_nonempty becomes a wrapper of __smc_tx_sndbuf_nonempty,
so rename __smc_tx_sndbuf_nonempty back to smc_tx_sndbuf_nonempty

Suggested-by: Alexandra Winter <wintera@linux.ibm.com>
Co-developed-by: Dust Li <dust.li@linux.alibaba.com>
Signed-off-by: Dust Li <dust.li@linux.alibaba.com>
Signed-off-by: Li RongQing <lirongqing@baidu.com>
Reviewed-by: Alexandra Winter <wintera@linux.ibm.com>

diff v4: remove atomic variable tx_pushing
diff v3: improvements in the commit body and comments
diff v2: fix a typo in commit body and add net-next subject-prefix

 net/smc/smc.h    |  1 -
 net/smc/smc_tx.c | 30 +-----------------------------
 2 files changed, 1 insertion(+), 30 deletions(-)

Signed-off-by: David S. Miller <davem@davemloft.net>
2023-11-24 15:00:47 +00:00
D. Wythe
5211c97294 net/smc: fix dangling sock under state SMC_APPFINCLOSEWAIT
Considering scenario:

				smc_cdc_rx_handler
__smc_release
				sock_set_flag
smc_close_active()
sock_set_flag

__set_bit(DEAD)			__set_bit(DONE)

Dues to __set_bit is not atomic, the DEAD or DONE might be lost.
if the DEAD flag lost, the state SMC_CLOSED  will be never be reached
in smc_close_passive_work:

if (sock_flag(sk, SOCK_DEAD) &&
	smc_close_sent_any_close(conn)) {
	sk->sk_state = SMC_CLOSED;
} else {
	/* just shutdown, but not yet closed locally */
	sk->sk_state = SMC_APPFINCLOSEWAIT;
}

Replace sock_set_flags or __set_bit to set_bit will fix this problem.
Since set_bit is atomic.

Fixes: b38d732477 ("smc: socket closing and linkgroup cleanup")
Signed-off-by: D. Wythe <alibuda@linux.alibaba.com>
Reviewed-by: Dust Li <dust.li@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-11-06 10:01:07 +00:00
Guangguan Wang
1e700948c9 net/smc: support smc release version negotiation in clc handshake
Support smc release version negotiation in clc handshake based on
SMC v2, where no negotiation process for different releases, but
for different versions. The latest smc release version was updated
to v2.1. And currently there are two release versions of SMCv2, v2.0
and v2.1. In the release version negotiation, client sends the preferred
release version by CLC Proposal Message, server makes decision for which
release version to use based on the client preferred release version and
self-supported release version (here choose the minimum release version
of the client preferred and server latest supported), then the decision
returns to client by CLC Accept Message. Client confirms the decision by
CLC Confirm Message.

Client                                    Server
      Proposal(preferred release version)
     ------------------------------------>

      Accept(accpeted release version)
 min(client preferred, server latest supported)
     <------------------------------------

      Confirm(accpeted release version)
     ------------------------------------>

Signed-off-by: Guangguan Wang <guangguan.wang@linux.alibaba.com>
Reviewed-by: Tony Lu <tonylu@linux.alibaba.com>
Reviewed-by: Jan Karcher <jaka@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-08-19 12:46:52 +01:00
Gerd Bayer
833bac7ec3 net/smc: Fix setsockopt and sysctl to specify same buffer size again
Commit 0227f058aa ("net/smc: Unbind r/w buffer size from clcsock
and make them tunable") introduced the net.smc.rmem and net.smc.wmem
sysctls to specify the size of buffers to be used for SMC type
connections. This created a regression for users that specified the
buffer size via setsockopt() as the effective buffer size was now
doubled.

Re-introduce the division by 2 in the SMC buffer create code and level
this out by duplicating the net.smc.[rw]mem values used for initializing
sk_rcvbuf/sk_sndbuf at socket creation time. This gives users of both
methods (setsockopt or sysctl) the effective buffer size that they
expect.

Initialize net.smc.[rw]mem from its own constant of 64kB, respectively.
Internal performance tests show that this value is a good compromise
between throughput/latency and memory consumption. Also, this decouples
it from any tuning that was done to net.ipv4.tcp_[rw]mem[1] before the
module for SMC protocol was loaded. Check that no more than INT_MAX / 2
is assigned to net.smc.[rw]mem, in order to avoid any overflow condition
when that is doubled for use in sk_sndbuf or sk_rcvbuf.

While at it, drop the confusing sk_buf_size variable from
__smc_buf_create and name "compressed" buffer size variables more
consistently.

Background:

Before the commit mentioned above, SMC's buffer allocator in
__smc_buf_create() always used half of the sockets' sk_rcvbuf/sk_sndbuf
value as initial value to search for appropriate buffers. If the search
resorted to using a bigger buffer when all buffers of the specified
size were busy, the duplicate of the used effective buffer size is
stored back to sk_rcvbuf/sk_sndbuf.

When available, buffers of exactly the size that a user had specified as
input to setsockopt() were used, despite setsockopt()'s documentation in
"man 7 socket" talking of a mandatory duplication:

[...]
       SO_SNDBUF
              Sets  or  gets the maximum socket send buffer in bytes.
              The kernel doubles this value (to allow space for book‐
              keeping  overhead)  when it is set using setsockopt(2),
              and this doubled value is  returned  by  getsockopt(2).
              The     default     value     is     set     by     the
              /proc/sys/net/core/wmem_default file  and  the  maximum
              allowed value is set by the /proc/sys/net/core/wmem_max
              file.  The minimum (doubled) value for this  option  is
              2048.
[...]

Fixes: 0227f058aa ("net/smc: Unbind r/w buffer size from clcsock and make them tunable")
Co-developed-by: Jan Karcher <jaka@linux.ibm.com>
Signed-off-by: Jan Karcher <jaka@linux.ibm.com>
Reviewed-by: Wenjia Zhang <wenjia@linux.ibm.com>
Reviewed-by: Tony Lu <tonylu@linux.alibaba.com>
Signed-off-by: Gerd Bayer <gbayer@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-08-09 11:20:28 +01:00
Eric Dumazet
407db475d5 smc: preserve const qualifier in smc_sk()
We can change smc_sk() to propagate its argument const qualifier,
thanks to container_of_const().

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Karsten Graul <kgraul@linux.ibm.com>
Cc: Wenjia Zhang <wenjia@linux.ibm.com>
Cc: Jan Karcher <jaka@linux.ibm.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Reviewed-by: Wenjia Zhang <wenjia@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-03-18 12:23:33 +00:00
Wen Gu
97b9af7a70 net/smc: Only save the original clcsock callback functions
Both listen and fallback process will save the current clcsock
callback functions and establish new ones. But if both of them
happen, the saved callback functions will be overwritten.

So this patch introduces some helpers to ensure that only save
the original callback functions of clcsock.

Fixes: 341adeec9a ("net/smc: Forward wakeup to smc socket waitqueue after fallback")
Signed-off-by: Wen Gu <guwen@linux.alibaba.com>
Acked-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-04-25 11:03:48 -07:00
Dust Li
6b88af839d net/smc: don't send in the BH context if sock_owned_by_user
Send data all the way down to the RDMA device is a time
consuming operation(get a new slot, maybe do RDMA Write
and send a CDC, etc). Moving those operations from BH
to user context is good for performance.

If the sock_lock is hold by user, we don't try to send
data out in the BH context, but just mark we should
send. Since the user will release the sock_lock soon, we
can do the sending there.

Add smc_release_cb() which will be called in release_sock()
and try send in the callback if needed.

This patch moves the sending part out from BH if sock lock
is hold by user. In my testing environment, this saves about
20% softirq in the qperf 4K tcp_bw test in the sender side
with no noticeable throughput drop.

Signed-off-by: Dust Li <dust.li@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-03-01 14:25:12 +00:00
Dust Li
dcd2cf5f2f net/smc: add autocorking support
This patch adds autocorking support for SMC which could improve
throughput for small message by x3+.

The main idea is borrowed from TCP autocorking with some RDMA
specific modification:
1. The first message should never cork to make sure we won't
   bring extra latency
2. If we have posted any Tx WRs to the NIC that have not
   completed, cork the new messages until:
   a) Receive CQE for the last Tx WR
   b) We have corked enough message on the connection
3. Try to push the corked data out when we receive CQE of
   the last Tx WR to prevent the corked messages hang in
   the send queue.

Both SMC autocorking and TCP autocorking check the TX completion
to decide whether we should cork or not. The difference is
when we got a SMC Tx WR completion, the data have been confirmed
by the RNIC while TCP TX completion just tells us the data
have been sent out by the local NIC.

Add an atomic variable tx_pushing in smc_connection to make
sure only one can send to let it cork more and save CDC slot.

SMC autocorking should not bring extra latency since the first
message will always been sent out immediately.

The qperf tcp_bw test shows more than x4 increase under small
message size with Mellanox connectX4-Lx, same result with other
throughput benchmarks like sockperf/netperf.
The qperf tcp_lat test shows SMC autocorking has not increase any
ping-pong latency.

Test command:
 client: smc_run taskset -c 1 qperf smc-server -oo msg_size:1:64K:*2 \
			-t 30 -vu tcp_{bw|lat}
 server: smc_run taskset -c 1 qperf

=== Bandwidth ====
MsgSize(Bytes)  SMC-NoCork           TCP                      SMC-AutoCorking
      1         0.578 MB/s       2.392 MB/s(313.57%)        2.647 MB/s(357.72%)
      2         1.159 MB/s       4.780 MB/s(312.53%)        5.153 MB/s(344.71%)
      4         2.283 MB/s      10.266 MB/s(349.77%)       10.363 MB/s(354.02%)
      8         4.668 MB/s      19.040 MB/s(307.86%)       21.215 MB/s(354.45%)
     16         9.147 MB/s      38.904 MB/s(325.31%)       41.740 MB/s(356.32%)
     32        18.369 MB/s      79.587 MB/s(333.25%)       82.392 MB/s(348.52%)
     64        36.562 MB/s     148.668 MB/s(306.61%)      161.564 MB/s(341.89%)
    128        72.961 MB/s     274.913 MB/s(276.80%)      325.363 MB/s(345.94%)
    256       144.705 MB/s     512.059 MB/s(253.86%)      633.743 MB/s(337.96%)
    512       288.873 MB/s     884.977 MB/s(206.35%)     1250.681 MB/s(332.95%)
   1024       574.180 MB/s    1337.736 MB/s(132.98%)     2246.121 MB/s(291.19%)
   2048      1095.192 MB/s    1865.952 MB/s( 70.38%)     2057.767 MB/s( 87.89%)
   4096      2066.157 MB/s    2380.337 MB/s( 15.21%)     2173.983 MB/s(  5.22%)
   8192      3717.198 MB/s    2733.073 MB/s(-26.47%)     3491.223 MB/s( -6.08%)
  16384      4742.221 MB/s    2958.693 MB/s(-37.61%)     4637.692 MB/s( -2.20%)
  32768      5349.550 MB/s    3061.285 MB/s(-42.77%)     5385.796 MB/s(  0.68%)
  65536      5162.919 MB/s    3731.408 MB/s(-27.73%)     5223.890 MB/s(  1.18%)
==== Latency ====
MsgSize(Bytes)   SMC-NoCork         TCP                    SMC-AutoCorking
      1          10.540 us      11.938 us( 13.26%)       10.573 us(  0.31%)
      2          10.996 us      11.992 us(  9.06%)       10.269 us( -6.61%)
      4          10.229 us      11.687 us( 14.25%)       10.240 us(  0.11%)
      8          10.203 us      11.653 us( 14.21%)       10.402 us(  1.95%)
     16          10.530 us      11.313 us(  7.44%)       10.599 us(  0.66%)
     32          10.241 us      11.586 us( 13.13%)       10.223 us( -0.18%)
     64          10.693 us      11.652 us(  8.97%)       10.251 us( -4.13%)
    128          10.597 us      11.579 us(  9.27%)       10.494 us( -0.97%)
    256          10.409 us      11.957 us( 14.87%)       10.710 us(  2.89%)
    512          11.088 us      12.505 us( 12.78%)       10.547 us( -4.88%)
   1024          11.240 us      12.255 us(  9.03%)       10.787 us( -4.03%)
   2048          11.485 us      16.970 us( 47.76%)       11.256 us( -1.99%)
   4096          12.077 us      13.948 us( 15.49%)       12.230 us(  1.27%)
   8192          13.683 us      16.693 us( 22.00%)       13.786 us(  0.75%)
  16384          16.470 us      23.615 us( 43.38%)       16.459 us( -0.07%)
  32768          22.540 us      40.966 us( 81.75%)       23.284 us(  3.30%)
  65536          34.192 us      73.003 us(113.51%)       34.233 us(  0.12%)

With SMC autocorking support, we can archive better throughput
than TCP in most message sizes without any latency trade-off.

Signed-off-by: Dust Li <dust.li@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-03-01 14:25:12 +00:00
D. Wythe
f9496b7c1b net/smc: Add global configure for handshake limitation by netlink
Although we can control SMC handshake limitation through socket options,
which means that applications who need it must modify their code. It's
quite troublesome for many existing applications. This patch modifies
the global default value of SMC handshake limitation through netlink,
providing a way to put constraint on handshake without modifies any code
for applications.

Suggested-by: Tony Lu <tonylu@linux.alibaba.com>
Signed-off-by: D. Wythe <alibuda@linux.alibaba.com>
Reviewed-by: Tony Lu <tonylu@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-02-11 11:14:58 +00:00
D. Wythe
a6a6fe27ba net/smc: Dynamic control handshake limitation by socket options
This patch aims to add dynamic control for SMC handshake limitation for
every smc sockets, in production environment, it is possible for the
same applications to handle different service types, and may have
different opinion on SMC handshake limitation.

This patch try socket options to complete it, since we don't have socket
option level for SMC yet, which requires us to implement it at the same
time.

This patch does the following:

- add new socket option level: SOL_SMC.
- add new SMC socket option: SMC_LIMIT_HS.
- provide getter/setter for SMC socket options.

Link: https://lore.kernel.org/all/20f504f961e1a803f85d64229ad84260434203bd.1644323503.git.alibuda@linux.alibaba.com/
Signed-off-by: D. Wythe <alibuda@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-02-11 11:14:58 +00:00
D. Wythe
8270d9c210 net/smc: Limit backlog connections
Current implementation does not handling backlog semantics, one
potential risk is that server will be flooded by infinite amount
connections, even if client was SMC-incapable.

This patch works to put a limit on backlog connections, referring to the
TCP implementation, we divides SMC connections into two categories:

1. Half SMC connection, which includes all TCP established while SMC not
connections.

2. Full SMC connection, which includes all SMC established connections.

For half SMC connection, since all half SMC connections starts with TCP
established, we can achieve our goal by put a limit before TCP
established. Refer to the implementation of TCP, this limits will based
on not only the half SMC connections but also the full connections,
which is also a constraint on full SMC connections.

For full SMC connections, although we know exactly where it starts, it's
quite hard to put a limit before it. The easiest way is to block wait
before receive SMC confirm CLC message, while it's under protection by
smc_server_lgr_pending, a global lock, which leads this limit to the
entire host instead of a single listen socket. Another way is to drop
the full connections, but considering the cast of SMC connections, we
prefer to keep full SMC connections.

Even so, the limits of full SMC connections still exists, see commits
about half SMC connection below.

After this patch, the limits of backend connection shows like:

For SMC:

1. Client with SMC-capability can makes 2 * backlog full SMC connections
   or 1 * backlog half SMC connections and 1 * backlog full SMC
   connections at most.

2. Client without SMC-capability can only makes 1 * backlog half TCP
   connections and 1 * backlog full TCP connections.

Signed-off-by: D. Wythe <alibuda@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-02-11 11:14:58 +00:00
Wen Gu
341adeec9a net/smc: Forward wakeup to smc socket waitqueue after fallback
When we replace TCP with SMC and a fallback occurs, there may be
some socket waitqueue entries remaining in smc socket->wq, such
as eppoll_entries inserted by userspace applications.

After the fallback, data flows over TCP/IP and only clcsocket->wq
will be woken up. Applications can't be notified by the entries
which were inserted in smc socket->wq before fallback. So we need
a mechanism to wake up smc socket->wq at the same time if some
entries remaining in it.

The current workaround is to transfer the entries from smc socket->wq
to clcsock->wq during the fallback. But this may cause a crash
like this:

 general protection fault, probably for non-canonical address 0xdead000000000100: 0000 [#1] PREEMPT SMP PTI
 CPU: 3 PID: 0 Comm: swapper/3 Kdump: loaded Tainted: G E     5.16.0+ #107
 RIP: 0010:__wake_up_common+0x65/0x170
 Call Trace:
  <IRQ>
  __wake_up_common_lock+0x7a/0xc0
  sock_def_readable+0x3c/0x70
  tcp_data_queue+0x4a7/0xc40
  tcp_rcv_established+0x32f/0x660
  ? sk_filter_trim_cap+0xcb/0x2e0
  tcp_v4_do_rcv+0x10b/0x260
  tcp_v4_rcv+0xd2a/0xde0
  ip_protocol_deliver_rcu+0x3b/0x1d0
  ip_local_deliver_finish+0x54/0x60
  ip_local_deliver+0x6a/0x110
  ? tcp_v4_early_demux+0xa2/0x140
  ? tcp_v4_early_demux+0x10d/0x140
  ip_sublist_rcv_finish+0x49/0x60
  ip_sublist_rcv+0x19d/0x230
  ip_list_rcv+0x13e/0x170
  __netif_receive_skb_list_core+0x1c2/0x240
  netif_receive_skb_list_internal+0x1e6/0x320
  napi_complete_done+0x11d/0x190
  mlx5e_napi_poll+0x163/0x6b0 [mlx5_core]
  __napi_poll+0x3c/0x1b0
  net_rx_action+0x27c/0x300
  __do_softirq+0x114/0x2d2
  irq_exit_rcu+0xb4/0xe0
  common_interrupt+0xba/0xe0
  </IRQ>
  <TASK>

The crash is caused by privately transferring waitqueue entries from
smc socket->wq to clcsock->wq. The owners of these entries, such as
epoll, have no idea that the entries have been transferred to a
different socket wait queue and still use original waitqueue spinlock
(smc socket->wq.wait.lock) to make the entries operation exclusive,
but it doesn't work. The operations to the entries, such as removing
from the waitqueue (now is clcsock->wq after fallback), may cause a
crash when clcsock waitqueue is being iterated over at the moment.

This patch tries to fix this by no longer transferring wait queue
entries privately, but introducing own implementations of clcsock's
callback functions in fallback situation. The callback functions will
forward the wakeup to smc socket->wq if clcsock->wq is actually woken
up and smc socket->wq has remaining entries.

Fixes: 2153bd1e3d ("net/smc: Transfer remaining wait queue entries during fallback")
Suggested-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: Wen Gu <guwen@linux.alibaba.com>
Acked-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-01-31 11:07:13 +00:00
Wen Gu
61f434b028 net/smc: Resolve the race between link group access and termination
We encountered some crashes caused by the race between the access
and the termination of link groups.

Here are some of panic stacks we met:

1) Race between smc_clc_wait_msg() and __smc_lgr_terminate()

 BUG: kernel NULL pointer dereference, address: 00000000000002f0
 Workqueue: smc_hs_wq smc_listen_work [smc]
 RIP: 0010:smc_clc_wait_msg+0x3eb/0x5c0 [smc]
 Call Trace:
  <TASK>
  ? smc_clc_send_accept+0x45/0xa0 [smc]
  ? smc_clc_send_accept+0x45/0xa0 [smc]
  smc_listen_work+0x783/0x1220 [smc]
  ? finish_task_switch+0xc4/0x2e0
  ? process_one_work+0x1ad/0x3c0
  process_one_work+0x1ad/0x3c0
  worker_thread+0x4c/0x390
  ? rescuer_thread+0x320/0x320
  kthread+0x149/0x190
  ? set_kthread_struct+0x40/0x40
  ret_from_fork+0x1f/0x30
  </TASK>

smc_listen_work()                abnormal case like port error
---------------------------------------------------------------
                                | __smc_lgr_terminate()
                                |  |- smc_conn_kill()
                                |      |- smc_lgr_unregister_conn()
                                |          |- set conn->lgr = NULL
smc_clc_wait_msg()              |
 |- access conn->lgr (panic)    |

2) Race between smc_setsockopt() and __smc_lgr_terminate()

 BUG: kernel NULL pointer dereference, address: 00000000000002e8
 RIP: 0010:smc_setsockopt+0x17a/0x280 [smc]
 Call Trace:
  <TASK>
  __sys_setsockopt+0xfc/0x190
  __x64_sys_setsockopt+0x20/0x30
  do_syscall_64+0x34/0x90
  entry_SYSCALL_64_after_hwframe+0x44/0xae
  </TASK>

smc_setsockopt()                 abnormal case like port error
--------------------------------------------------------------
                                | __smc_lgr_terminate()
                                |  |- smc_conn_kill()
                                |      |- smc_lgr_unregister_conn()
                                |          |- set conn->lgr = NULL
mod_delayed_work()              |
 |- access conn->lgr (panic)    |

There are some other panic places and they are caused by the
similar reason as described above, which is accessing link
group after termination, thus getting a NULL pointer or invalid
resource.

Currently, there seems to be no synchronization between the
link group access and a sudden termination of it. This patch
tries to fix this by introducing reference count of link group
and not freeing link group until reference count is zero.

Link group might be referred to by links or smc connections. So
the operation to the link group reference count can be concluded
as follows:

object          [hold or initialized as 1]       [put]
-------------------------------------------------------------------
link group      smc_lgr_create()                 smc_lgr_free()
connections     smc_conn_create()                smc_conn_free()
links           smcr_link_init()                 smcr_link_clear()

Througth this way, we extend the life cycle of link group and
ensure it is longer than the life cycle of connections and links
above it, so that avoid invalid access to link group after its
termination.

Signed-off-by: Wen Gu <guwen@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-01-13 12:55:40 +00:00
Dust Li
349d43127d net/smc: fix kernel panic caused by race of smc_sock
A crash occurs when smc_cdc_tx_handler() tries to access smc_sock
but smc_release() has already freed it.

[ 4570.695099] BUG: unable to handle page fault for address: 000000002eae9e88
[ 4570.696048] #PF: supervisor write access in kernel mode
[ 4570.696728] #PF: error_code(0x0002) - not-present page
[ 4570.697401] PGD 0 P4D 0
[ 4570.697716] Oops: 0002 [#1] PREEMPT SMP NOPTI
[ 4570.698228] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.16.0-rc4+ #111
[ 4570.699013] Hardware name: Alibaba Cloud Alibaba Cloud ECS, BIOS 8c24b4c 04/0
[ 4570.699933] RIP: 0010:_raw_spin_lock+0x1a/0x30
<...>
[ 4570.711446] Call Trace:
[ 4570.711746]  <IRQ>
[ 4570.711992]  smc_cdc_tx_handler+0x41/0xc0
[ 4570.712470]  smc_wr_tx_tasklet_fn+0x213/0x560
[ 4570.712981]  ? smc_cdc_tx_dismisser+0x10/0x10
[ 4570.713489]  tasklet_action_common.isra.17+0x66/0x140
[ 4570.714083]  __do_softirq+0x123/0x2f4
[ 4570.714521]  irq_exit_rcu+0xc4/0xf0
[ 4570.714934]  common_interrupt+0xba/0xe0

Though smc_cdc_tx_handler() checked the existence of smc connection,
smc_release() may have already dismissed and released the smc socket
before smc_cdc_tx_handler() further visits it.

smc_cdc_tx_handler()           |smc_release()
if (!conn)                     |
                               |
                               |smc_cdc_tx_dismiss_slots()
                               |      smc_cdc_tx_dismisser()
                               |
                               |sock_put(&smc->sk) <- last sock_put,
                               |                      smc_sock freed
bh_lock_sock(&smc->sk) (panic) |

To make sure we won't receive any CDC messages after we free the
smc_sock, add a refcount on the smc_connection for inflight CDC
message(posted to the QP but haven't received related CQE), and
don't release the smc_connection until all the inflight CDC messages
haven been done, for both success or failed ones.

Using refcount on CDC messages brings another problem: when the link
is going to be destroyed, smcr_link_clear() will reset the QP, which
then remove all the pending CQEs related to the QP in the CQ. To make
sure all the CQEs will always come back so the refcount on the
smc_connection can always reach 0, smc_ib_modify_qp_reset() was replaced
by smc_ib_modify_qp_error().
And remove the timeout in smc_wr_tx_wait_no_pending_sends() since we
need to wait for all pending WQEs done, or we may encounter use-after-
free when handling CQEs.

For IB device removal routine, we need to wait for all the QPs on that
device been destroyed before we can destroy CQs on the device, or
the refcount on smc_connection won't reach 0 and smc_sock cannot be
released.

Fixes: 5f08318f61 ("smc: connection data control (CDC)")
Reported-by: Wen Gu <guwen@linux.alibaba.com>
Signed-off-by: Dust Li <dust.li@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-12-28 12:42:45 +00:00
Karsten Graul
b4ba4652b3 net/smc: extend LLC layer for SMC-Rv2
Add support for large v2 LLC control messages in smc_llc.c.
The new large work request buffer allows to combine control
messages into one packet that had to be spread over several
packets before.
Add handling of the new v2 LLC messages.

Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-10-16 14:58:13 +01:00
Karsten Graul
fa08666255 net/smc: add support for user defined EIDs
SMC-Dv2 allows users to define EIDs which allows to create separate
name spaces enabling users to cluster their SMC-Dv2 connections.
Add support for user defined EIDs and extent the generic netlink
interface so users can add, remove and dump EIDs.

Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Guvenc Gulce  <guvenc@linux.ibm.com>
Signed-off-by: Guvenc Gulce <guvenc@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-09-14 12:49:10 +01:00
Ursula Braun
b81a5eb789 net/smc: introduce CLC first contact extension
SMC Version 2 defines a first contact extension for CLC accept
and CLC confirm. This patch covers sending and receiving of the
CLC first contact extension.

Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-28 15:19:03 -07:00
Ursula Braun
8c3dca341a net/smc: build and send V2 CLC proposal
The new format of an SMCD V2 CLC proposal is introduced, and
building and checking of SMCD V2 CLC proposals is adapted
accordingly.

Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-28 15:19:03 -07:00
Ursula Braun
d70bf4f7a9 net/smc: determine proposed ISM devices
SMCD Version 2 allows to propose up to 8 additional ISM devices
offered to the peer as candidates for SMCD communication.
This patch covers determination of the ISM devices to be proposed.
ISM devices without PNETID are preferred, since ISM devices with
PNETID are a V1 leftover and will disappear over the time.

Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-28 15:19:03 -07:00
Ursula Braun
3fc6493761 net/smc: prepare for more proposed ISM devices
SMCD Version 2 allows proposing of up to 8 ISM devices in addition
to the native ISM device of SMCD Version 1.
This patch prepares the struct smc_init_info to deal with these
additional 8 ISM devices.

Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-28 15:19:02 -07:00
Karsten Graul
22ef473dbd net/smc: use separate work queues for different worker types
There are 6 types of workers which exist per smc connection. 3 of them
are used for listen and handshake processing, another 2 are used for
close and abort processing and 1 is the tx worker that moves calls to
sleeping functions into a worker.
To prevent flooding of the system work queue when many connections are
opened or closed at the same time (some pattern uperf implements), move
those workers to one of 3 smc-specific work queues. Two work queues are
module-global and used for handshake and close workers. The third work
queue is defined per link group and used by the tx workers that may
sleep waiting for resources of this link group.
And in smc_llc_enqueue() queue the llc_event_work work to the system
prio work queue because its critical that this work is started fast.

Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-10 15:24:27 -07:00
Ursula Braun
5ac54d8768 net/smc: introduce better field names
Field names "srv_first_contact" and "cln_first_contact" are misleading,
since they apply to both, server and client. Rename them to
"first_contact_peer" and "first_contact_local".
Rename "ism_gid" by the more precise name "ism_peer_gid".
Rename version constant "SMC_CLC_V1" into "SMC_V1".
No functional change.

Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-10 15:24:26 -07:00
Ursula Braun
a60a2b1e0a net/smc: reduce active tcp_listen workers
SMC starts a separate tcp_listen worker for every SMC socket in
state SMC_LISTEN, and can accept an incoming connection request only,
if this worker is really running and waiting in kernel_accept(). But
the number of running workers is limited.
This patch reworks the listening SMC code and starts a tcp_listen worker
after the SYN-ACK handshake on the internal clc-socket only.

Suggested-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Reviewed-by: Guvenc Gulce <guvenc@linux.ibm.com>
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-10 15:24:26 -07:00
Karsten Graul
b286a0651e net/smc: handle incoming CDC validation message
Call smc_cdc_msg_validate() when a CDC message with the failover
validation bit enabled was received. Validate that the sequence number
sent with the message is one we already have received. If not, messages
were lost and the connection is terminated using a new abort_work.

Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-04 10:54:39 -07:00
Karsten Graul
f0ec4f1d32 net/smc: save state of last sent CDC message
When a link goes down and all connections of this link need to be
switched to an other link then the producer cursor and the sequence of
the last successfully sent CDC message must be known. Add the two fields
to the SMC connection and update it in the tx completion handler.
And to allow matching of sequences in error cases reset the seqno to the
old value in smc_cdc_msg_send() when the actual send failed.

Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-04 10:54:39 -07:00
Karsten Graul
387707fdf4 net/smc: convert static link ID to dynamic references
As a preparation for the support of multiple links remove the usage of
a static link id (SMC_SINGLE_LINK) and allow dynamic link ids.

Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-29 12:26:32 -07:00
Ursula Braun
b290098092 net/smc: cancel send and receive for terminated socket
The resources for a terminated socket are being cleaned up.
This patch makes sure
* no more data is received for an actively terminated socket
* no more data is sent for an actively or passively terminated socket

Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
2019-10-22 11:23:43 -07:00
Ursula Braun
50717a37db net/smc: nonblocking connect rework
For nonblocking sockets move the kernel_connect() from the connect
worker into the initial smc_connect part to return kernel_connect()
errors other than -EINPROGRESS to user space.

Reviewed-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-12 10:50:56 -07:00
Ursula Braun
d7cf4a3bf3 net/smc: fix smc_poll in SMC_INIT state
smc_poll() returns with mask bit EPOLLPRI if the connection urg_state
is SMC_URG_VALID. Since SMC_URG_VALID is zero, smc_poll signals
EPOLLPRI errorneously if called in state SMC_INIT before the connection
is created, for instance in a non-blocking connect scenario.

This patch switches to non-zero values for the urg states.

Reviewed-by: Karsten Graul <kgraul@linux.ibm.com>
Fixes: de8474eb9d ("net/smc: urgent data support")
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-02-21 10:19:20 -08:00
Myungho Jung
78abe3d0df net/smc: fix TCP fallback socket release
clcsock can be released while kernel_accept() references it in TCP
listen worker. Also, clcsock needs to wake up before released if TCP
fallback is used and the clcsock is blocked by accept. Add a lock to
safely release clcsock and call kernel_sock_shutdown() to wake up
clcsock from accept in smc_release().

Reported-by: syzbot+0bf2e01269f1274b4b03@syzkaller.appspotmail.com
Reported-by: syzbot+e3132895630f957306bc@syzkaller.appspotmail.com
Signed-off-by: Myungho Jung <mhjungk@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-18 22:02:51 -08:00
Karsten Graul
603cc14984 net/smc: provide fallback reason code
Remember the fallback reason code and the peer diagnosis code for
smc sockets, and provide them in smc_diag.c to the netlink interface.
And add more detailed reason codes.

Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-25 22:25:53 -07:00
David S. Miller
5cd3da4ba2 Merge ra.kernel.org:/pub/scm/linux/kernel/git/davem/net
Simple overlapping changes in stmmac driver.

Adjust skb_gro_flush_final_remcsum function signature to make GRO list
changes in net-next, as per Stephen Rothwell's example merge
resolution.

Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-03 10:29:26 +09:00
Hans Wippel
be244f28d2 net/smc: add SMC-D support in data transfer
The data transfer and CDC message headers differ in SMC-R and SMC-D.
This patch adds support for the SMC-D data transfer to the existing SMC
code. It consists of the following:

* SMC-D CDC support
* SMC-D tx support
* SMC-D rx support

The CDC header is stored at the beginning of the receive buffer. Thus, a
rx_offset variable is added for the CDC header offset within the buffer
(0 for SMC-R).

Signed-off-by: Hans Wippel <hwippel@linux.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Suggested-by: Thomas Richter <tmricht@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-30 20:42:26 +09:00
Ursula Braun
be6a3f38ff net/smc: determine port attributes independent from pnet table
For SMC it is important to know the current port state of RoCE devices.
Monitoring port states has been triggered, when a RoCE device was added
to the pnet table. To support future alternatives to the pnet table the
monitoring of ports is made independent of the existence of a pnet table.
It starts once the smc_ib_device is established.

Due to this change smc_ib_remember_port_attr() is now a local function
and shuffling its location and the location of its used functions
makes any forward references obsolete.

And the duplicate SMC_MAX_PORTS definition is removed.

Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-30 20:42:25 +09:00
Ursula Braun
24ac3a08e6 net/smc: rebuild nonblocking connect
The recent poll change may lead to stalls for non-blocking connecting
SMC sockets, since sock_poll_wait is no longer performed on the
internal CLC socket, but on the outer SMC socket.  kernel_connect() on
the internal CLC socket returns with -EINPROGRESS, but the wake up
logic does not work in all cases. If the internal CLC socket is still
in state TCP_SYN_SENT when polled, sock_poll_wait() from sock_poll()
does not sleep. It is supposed to sleep till the state of the internal
CLC socket switches to TCP_ESTABLISHED.

This problem triggered a redesign of the SMC nonblocking connect logic.
This patch introduces a connect worker covering all connect steps
followed by a wake up of socket waiters. It allows to get rid of all
delays and locks in smc_poll().

Fixes: c0129a0614 ("smc: convert to ->poll_mask")
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-28 22:03:55 +09:00
Stefan Raspl
de8474eb9d net/smc: urgent data support
Add support for out of band data send and receive.

Signed-off-by: Stefan Raspl <raspl@linux.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-23 16:02:35 -04:00
Hans Wippel
2f6becaf79 net/smc: move smc_core specific code from smc.h to smc_core
SMC connection and buffer handling belong to smc_core. So, this patch
moves this code from smc.h to smc_core.

Signed-off-by: Hans Wippel <hwippel@linux.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-18 13:15:01 -04:00
Hans Wippel
95d8d26306 net/smc: calculate write offset in RMB only once per connection
Currently, the write offset within the RMB is calculated on each write
operation although it is fixed for each connection. With this patch, the
offset is calculated once and stored in a connection specific variable.

Signed-off-by: Hans Wippel <hwippel@linux.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-18 13:15:01 -04:00
Hans Wippel
92a138e333 net/smc: rename connection index to RMBE index
The connection index is actually a RMBE index. So, this patch changes
the name accordingly.

Signed-off-by: Hans Wippel <hwippel@linux.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-18 13:15:01 -04:00
Hans Wippel
69cb7dc021 net/smc: add common buffer size in send and receive buffer descriptors
In addition to the buffer references, SMC currently stores the sizes of
the receive and send buffers in each connection as separate variables.
This patch introduces a buffer length variable in the common buffer
descriptor and uses this length instead.

Signed-off-by: Hans Wippel <hwippel@linux.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-18 13:15:01 -04:00
Stefan Raspl
9014db202c smc: add support for splice()
Provide an implementation for splice() when we are using SMC. See
smc_splice_read() for further details.

Signed-off-by: Stefan Raspl <raspl@linux.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com><
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-04 11:45:06 -04:00
Ursula Braun
abb190f194 net/smc: handle sockopt TCP_DEFER_ACCEPT
If sockopt TCP_DEFER_ACCEPT is set, the accept is delayed till
data is available.

Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-27 14:02:52 -04:00
Karsten Graul
aaa4d33f6d net/smc: enable ipv6 support for smc
Add ipv6 support to the smc socket layer functions. Make use of the
updated clc layer functions to retrieve and match ipv6 information.
The indicator for ipv4 or ipv6 is the protocol constant that is provided
in the socket() call with address family AF_SMC.

Based-on-patch-by: Takanori Ueda <tkueda@jp.ibm.com>

Signed-off-by: Karsten Graul <kgraul@linux.vnet.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-16 14:57:26 -04:00
Karsten Graul
be6d467b99 net/smc: remove unused fields from smc structures
The daddr field holds the destination IPv4 address. The field was set but
never used and can be removed. The addr field was a left-over from an
earlier version of non-blocking connects and can be removed.
The result of the call to kernel_getpeername is not used, the call can be
removed. Non-blocking connects are working, so remove restriction comment.

Signed-off-by: Karsten Graul <kgraul@linux.vnet.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-01 13:21:31 -05:00
Karsten Graul
696cd30169 net/smc: move netinfo function to file smc_clc.c
The function smc_netinfo_by_tcpsk() belongs to CLC handling.
Move it to smc_clc.c and rename to smc_clc_netinfo_by_tcpsk.

Signed-off-by: Karsten Graul <kgraul@linux.vnet.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-01 13:21:31 -05:00
Gustavo A. R. Silva
a8fbf8e7ec net/smc: return booleans instead of integers
Return statements in functions returning bool should use
true/false instead of 1/0.

This issue was detected with the help of Coccinelle.

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-26 10:41:56 -05:00
Ursula Braun
51f1de79ad net/smc: replace sock_put worker by socket refcounting
Proper socket refcounting makes the sock_put worker obsolete.

Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-26 10:41:56 -05:00