Commit graph

225 commits

Author SHA1 Message Date
Wen Gu
ddefb2d205 net/smc: Extend SMC-R link group netlink attribute
Extend SMC-R link group netlink attribute SMC_GEN_LGR_SMCR.
Introduce SMC_NLA_LGR_R_BUF_TYPE to show the buffer type of
SMC-R link group.

Signed-off-by: Wen Gu <guwen@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-07-18 11:19:17 +01:00
Wen Gu
b8d199451c net/smc: Allow virtually contiguous sndbufs or RMBs for SMC-R
On long-running enterprise production servers, high-order contiguous
memory pages are usually very rare and in most cases we can only get
fragmented pages.

When replacing TCP with SMC-R in such production scenarios, attempting
to allocate high-order physically contiguous sndbufs and RMBs may result
in frequent memory compaction, which will cause unexpected hung issue
and further stability risks.

So this patch is aimed to allow SMC-R link group to use virtually
contiguous sndbufs and RMBs to avoid potential issues mentioned above.
Whether to use physically or virtually contiguous buffers can be set
by sysctl smcr_buf_type.

Note that using virtually contiguous buffers will bring an acceptable
performance regression, which can be mainly divided into two parts:

1) regression in data path, which is brought by additional address
   translation of sndbuf by RNIC in Tx. But in general, translating
   address through MTT is fast.

   Taking 256KB sndbuf and RMB as an example, the comparisons in qperf
   latency and bandwidth test with physically and virtually contiguous
   buffers are as follows:

- client:
  smc_run taskset -c <cpu> qperf <server> -oo msg_size:1:64K:*2\
  -t 5 -vu tcp_{bw|lat}
- server:
  smc_run taskset -c <cpu> qperf

   [latency]
   msgsize              tcp            smcr        smcr-use-virt-buf
   1               11.17 us         7.56 us         7.51 us (-0.67%)
   2               10.65 us         7.74 us         7.56 us (-2.31%)
   4               11.11 us         7.52 us         7.59 us ( 0.84%)
   8               10.83 us         7.55 us         7.51 us (-0.48%)
   16              11.21 us         7.46 us         7.51 us ( 0.71%)
   32              10.65 us         7.53 us         7.58 us ( 0.61%)
   64              10.95 us         7.74 us         7.80 us ( 0.76%)
   128             11.14 us         7.83 us         7.87 us ( 0.47%)
   256             10.97 us         7.94 us         7.92 us (-0.28%)
   512             11.23 us         7.94 us         8.20 us ( 3.25%)
   1024            11.60 us         8.12 us         8.20 us ( 0.96%)
   2048            14.04 us         8.30 us         8.51 us ( 2.49%)
   4096            16.88 us         9.13 us         9.07 us (-0.64%)
   8192            22.50 us        10.56 us        11.22 us ( 6.26%)
   16384           28.99 us        12.88 us        13.83 us ( 7.37%)
   32768           40.13 us        16.76 us        16.95 us ( 1.16%)
   65536           68.70 us        24.68 us        24.85 us ( 0.68%)
   [bandwidth]
   msgsize                tcp              smcr          smcr-use-virt-buf
   1                1.65 MB/s         1.59 MB/s         1.53 MB/s (-3.88%)
   2                3.32 MB/s         3.17 MB/s         3.08 MB/s (-2.67%)
   4                6.66 MB/s         6.33 MB/s         6.09 MB/s (-3.85%)
   8               13.67 MB/s        13.45 MB/s        11.97 MB/s (-10.99%)
   16              25.36 MB/s        27.15 MB/s        24.16 MB/s (-11.01%)
   32              48.22 MB/s        54.24 MB/s        49.41 MB/s (-8.89%)
   64             106.79 MB/s       107.32 MB/s        99.05 MB/s (-7.71%)
   128            210.21 MB/s       202.46 MB/s       201.02 MB/s (-0.71%)
   256            400.81 MB/s       416.81 MB/s       393.52 MB/s (-5.59%)
   512            746.49 MB/s       834.12 MB/s       809.99 MB/s (-2.89%)
   1024          1292.33 MB/s      1641.96 MB/s      1571.82 MB/s (-4.27%)
   2048          2007.64 MB/s      2760.44 MB/s      2717.68 MB/s (-1.55%)
   4096          2665.17 MB/s      4157.44 MB/s      4070.76 MB/s (-2.09%)
   8192          3159.72 MB/s      4361.57 MB/s      4270.65 MB/s (-2.08%)
   16384         4186.70 MB/s      4574.13 MB/s      4501.17 MB/s (-1.60%)
   32768         4093.21 MB/s      4487.42 MB/s      4322.43 MB/s (-3.68%)
   65536         4057.14 MB/s      4735.61 MB/s      4555.17 MB/s (-3.81%)

2) regression in buffer initialization and destruction path, which is
   brought by additional MR operations of sndbufs. But thanks to link
   group buffer reuse mechanism, the impact of this kind of regression
   decreases as times of buffer reuse increases.

   Taking 256KB sndbuf and RMB as an example, latency of some key SMC-R
   buffer-related function obtained by bpftrace are as follows:

   Function                         Phys-bufs           Virt-bufs
   smcr_new_buf_create()             67154 ns            79164 ns
   smc_ib_buf_map_sg()                 525 ns              928 ns
   smc_ib_get_memory_region()       162294 ns           161191 ns
   smc_wr_reg_send()                  9957 ns             9635 ns
   smc_ib_put_memory_region()       203548 ns           198374 ns
   smc_ib_buf_unmap_sg()               508 ns             1158 ns

------------
Test environment notes:
1. Above tests run on 2 VMs within the same Host.
2. The NIC is ConnectX-4Lx, using SRIOV and passing through 2 VFs to
   the each VM respectively.
3. VMs' vCPUs are binded to different physical CPUs, and the binded
   physical CPUs are isolated by `isolcpus=xxx` cmdline.
4. NICs' queue number are set to 1.

Signed-off-by: Wen Gu <guwen@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-07-18 11:19:17 +01:00
Wen Gu
b984f370ed net/smc: Use sysctl-specified types of buffers in new link group
This patch introduces a new SMC-R specific element buf_type
in struct smc_link_group, for recording the value of sysctl
smcr_buf_type when link group is created.

New created link group will create and reuse buffers of the
type specified by buf_type.

Signed-off-by: Wen Gu <guwen@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-07-18 11:19:17 +01:00
Guangguan Wang
0ef69e7884 net/smc: optimize for smc_sndbuf_sync_sg_for_device and smc_rmb_sync_sg_for_cpu
Some CPU, such as Xeon, can guarantee DMA cache coherency.
So it is no need to use dma sync APIs to flush cache on such CPUs.
In order to avoid calling dma sync APIs on the IO path, use the
dma_need_sync to check whether smc_buf_desc needs dma sync when
creating smc_buf_desc.

Signed-off-by: Guangguan Wang <guangguan.wang@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-07-18 11:19:17 +01:00
Guangguan Wang
6d52e2de64 net/smc: remove redundant dma sync ops
smc_ib_sync_sg_for_cpu/device are the ops used for dma memory cache
consistency. Smc sndbufs are dma buffers, where CPU writes data to
it and PCIE device reads data from it. So for sndbufs,
smc_ib_sync_sg_for_device is needed and smc_ib_sync_sg_for_cpu is
redundant as PCIE device will not write the buffers. Smc rmbs
are dma buffers, where PCIE device write data to it and CPU read
data from it. So for rmbs, smc_ib_sync_sg_for_cpu is needed and
smc_ib_sync_sg_for_device is redundant as CPU will not write the buffers.

Signed-off-by: Guangguan Wang <guangguan.wang@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-07-18 11:19:16 +01:00
Jakub Kicinski
80901bff81 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
net/batman-adv/hard-interface.c
  commit 690bb6fb64 ("batman-adv: Request iflink once in batadv-on-batadv check")
  commit 6ee3c393ee ("batman-adv: Demote batadv-on-batadv skip error message")
https://lore.kernel.org/all/20220302163049.101957-1-sw@simonwunderlich.de/

net/smc/af_smc.c
  commit 4d08b7b57e ("net/smc: Fix cleanup when register ULP fails")
  commit 462791bbfa ("net/smc: add sysctl interface for SMC")
https://lore.kernel.org/all/20220302112209.355def40@canb.auug.org.au/

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-03-03 11:55:12 -08:00
D. Wythe
4940a1fdf3 net/smc: fix unexpected SMC_CLC_DECL_ERR_REGRMB error cause by server
The problem of SMC_CLC_DECL_ERR_REGRMB on the server is very clear.
Based on the fact that whether a new SMC connection can be accepted or
not depends on not only the limit of conn nums, but also the available
entries of rtoken. Since the rtoken release is trigger by peer, while
the conn nums is decrease by local, tons of thing can happen in this
time difference.

This only thing that needs to be mentioned is that now all connection
creations are completely protected by smc_server_lgr_pending lock, it's
enough to check only the available entries in rtokens_used_mask.

Fixes: cd6851f303 ("smc: remote memory buffers (RMBs)")
Signed-off-by: D. Wythe <alibuda@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-03-03 10:34:18 +00:00
D. Wythe
0537f0a215 net/smc: fix unexpected SMC_CLC_DECL_ERR_REGRMB error generated by client
The main reason for this unexpected SMC_CLC_DECL_ERR_REGRMB in client
dues to following execution sequence:

Server Conn A:           Server Conn B:			Client Conn B:

smc_lgr_unregister_conn
                        smc_lgr_register_conn
                        smc_clc_send_accept     ->
                                                        smc_rtoken_add
smcr_buf_unuse
		->		Client Conn A:
				smc_rtoken_delete

smc_lgr_unregister_conn() makes current link available to assigned to new
incoming connection, while smcr_buf_unuse() has not executed yet, which
means that smc_rtoken_add may fail because of insufficient rtoken_entry,
reversing their execution order will avoid this problem.

Fixes: 3e034725c0 ("net/smc: common functions for RMBs and send buffers")
Signed-off-by: D. Wythe <alibuda@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-03-03 10:34:18 +00:00
Dust Li
6bf536eb5c net/smc: correct settings of RMB window update limit
rmbe_update_limit is used to limit announcing receive
window updating too frequently. RFC7609 request a minimal
increase in the window size of 10% of the receive buffer
space. But current implementation used:

  min_t(int, rmbe_size / 10, SOCK_MIN_SNDBUF / 2)

and SOCK_MIN_SNDBUF / 2 == 2304 Bytes, which is almost
always less then 10% of the receive buffer space.

This causes the receiver always sending CDC message to
update its consumer cursor when it consumes more then 2K
of data. And as a result, we may encounter something like
"TCP silly window syndrome" when sending 2.5~8K message.

This patch fixes this using max(rmbe_size / 10, SOCK_MIN_SNDBUF / 2).

With this patch and SMC autocorking enabled, qperf 2K/4K/8K
tcp_bw test shows 45%/75%/40% increase in throughput respectively.

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
Wen Gu
56d99e81ec net/smc: Fix hung_task when removing SMC-R devices
A hung_task is observed when removing SMC-R devices. Suppose that
a link group has two active links(lnk_A, lnk_B) associated with two
different SMC-R devices(dev_A, dev_B). When dev_A is removed, the
link group will be removed from smc_lgr_list and added into
lgr_linkdown_list. lnk_A will be cleared and smcibdev(A)->lnk_cnt
will reach to zero. However, when dev_B is removed then, the link
group can't be found in smc_lgr_list and lnk_B won't be cleared,
making smcibdev->lnk_cnt never reaches zero, which causes a hung_task.

This patch fixes this issue by restoring the implementation of
smc_smcr_terminate_all() to what it was before commit 349d43127d
("net/smc: fix kernel panic caused by race of smc_sock"). The original
implementation also satisfies the intention that make sure QP destroy
earlier than CQ destroy because we will always wait for smcibdev->lnk_cnt
reaches zero, which guarantees QP has been destroyed.

Fixes: 349d43127d ("net/smc: fix kernel panic caused by race of smc_sock")
Signed-off-by: Wen Gu <guwen@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-01-16 12:30:28 +00:00
Wen Gu
20c9398d33 net/smc: Resolve the race between SMC-R link access and clear
We encountered some crashes caused by the race between SMC-R
link access and link clear that triggered by abnormal link
group termination, such as port error.

Here is an example of this kind of crashes:

 BUG: kernel NULL pointer dereference, address: 0000000000000000
 Workqueue: smc_hs_wq smc_listen_work [smc]
 RIP: 0010:smc_llc_flow_initiate+0x44/0x190 [smc]
 Call Trace:
  <TASK>
  ? __smc_buf_create+0x75a/0x950 [smc]
  smcr_lgr_reg_rmbs+0x2a/0xbf [smc]
  smc_listen_work+0xf72/0x1230 [smc]
  ? process_one_work+0x25c/0x600
  process_one_work+0x25c/0x600
  worker_thread+0x4f/0x3a0
  ? process_one_work+0x600/0x600
  kthread+0x15d/0x1a0
  ? set_kthread_struct+0x40/0x40
  ret_from_fork+0x1f/0x30
  </TASK>

smc_listen_work()                     __smc_lgr_terminate()
---------------------------------------------------------------
                                    | smc_lgr_free()
                                    |  |- smcr_link_clear()
                                    |      |- memset(lnk, 0)
smc_listen_rdma_reg()               |
 |- smcr_lgr_reg_rmbs()             |
     |- smc_llc_flow_initiate()     |
         |- access lnk->lgr (panic) |

These crashes are similarly caused by clearing SMC-R link
resources when some functions is still accessing to them.
This patch tries to fix the issue by introducing reference
count of SMC-R links and ensuring that the sensitive resources
of links won't be cleared until reference count reaches zero.

The operation to the SMC-R link reference count can be concluded
as follows:

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

Through this way, the clear of SMC-R links is later than the
free of all the smc connections above it, thus avoiding the
unsafe reference to SMC-R links.

Signed-off-by: Wen Gu <guwen@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-01-13 13:14:53 +00:00
Wen Gu
ea89c6c098 net/smc: Introduce a new conn->lgr validity check helper
It is no longer suitable to identify whether a smc connection
is registered in a link group through checking if conn->lgr
is NULL, because conn->lgr won't be reset even the connection
is unregistered from a link group.

So this patch introduces a new helper smc_conn_lgr_valid() and
replaces all the check of conn->lgr in original implementation
with the new helper to judge if conn->lgr is valid to use.

Signed-off-by: Wen Gu <guwen@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-01-13 13:14:53 +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
Jakub Kicinski
8aaaf2f3af Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Merge in fixes directly in prep for the 5.17 merge window.
No conflicts.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-01-09 17:00:17 -08:00
Wen Gu
36595d8ad4 net/smc: Reset conn->lgr when link group registration fails
SMC connections might fail to be registered in a link group due to
unable to find a usable link during its creation. As a result,
smc_conn_create() will return a failure and most resources related
to the connection won't be applied or initialized, such as
conn->abort_work or conn->lnk.

If smc_conn_free() is invoked later, it will try to access the
uninitialized resources related to the connection, thus causing
a warning or crash.

This patch tries to fix this by resetting conn->lgr to NULL if an
abnormal exit occurs in smc_lgr_register_conn(), thus avoiding the
access to uninitialized resources in smc_conn_free().

Meanwhile, the new created link group should be terminated if smc
connections can't be registered in it. So smc_lgr_cleanup_early() is
modified to take care of link group only and invoked to terminate
unusable link group by smc_conn_create(). The call to smc_conn_free()
is moved out from smc_lgr_cleanup_early() to smc_conn_abort().

Fixes: 56bc3b2094 ("net/smc: assign link to a new connection")
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>
2022-01-06 13:54:06 +00:00
Tony Lu
de2fea7b39 net/smc: Print net namespace in log
This adds net namespace ID to the kernel log, net_cookie is unique in
the whole system. It is useful in container environment.

Signed-off-by: Tony Lu <tonylu@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-01-02 12:07:39 +00:00
Tony Lu
79d39fc503 net/smc: Add netlink net namespace support
This adds net namespace ID to diag of linkgroup, helps us to distinguish
different namespaces, and net_cookie is unique in the whole system.

Signed-off-by: Tony Lu <tonylu@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-01-02 12:07:39 +00:00
Tony Lu
0237a3a683 net/smc: Introduce net namespace support for linkgroup
Currently, rdma device supports exclusive net namespace isolation,
however linkgroup doesn't know and support ibdev net namespace.
Applications in the containers don't want to share the nics if we
enabled rdma exclusive mode. Every net namespaces should have their own
linkgroups.

This patch introduce a new field net for linkgroup, which is standing
for the ibdev net namespace in the linkgroup. The net in linkgroup is
initialized with the net namespace of link's ibdev. It compares the net
of linkgroup and sock or ibdev before choose it, if no matched, create
new one in current net namespace. If rdma net namespace exclusive mode
is not enabled, it behaves as before.

Signed-off-by: Tony Lu <tonylu@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-01-02 12:07:39 +00:00
Jakub Kicinski
aec53e60e0 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
  commit 077cdda764 ("net/mlx5e: TC, Fix memory leak with rules with internal port")
  commit 31108d142f ("net/mlx5: Fix some error handling paths in 'mlx5e_tc_add_fdb_flow()'")
  commit 4390c6edc0 ("net/mlx5: Fix some error handling paths in 'mlx5e_tc_add_fdb_flow()'")
  https://lore.kernel.org/all/20211229065352.30178-1-saeed@kernel.org/

net/smc/smc_wr.c
  commit 49dc9013e3 ("net/smc: Use the bitmap API when applicable")
  commit 349d43127d ("net/smc: fix kernel panic caused by race of smc_sock")
  bitmap_zero()/memset() is removed by the fix

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-12-30 12:12:12 -08:00
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
Dust Li
90cee52f2e net/smc: don't send CDC/LLC message if link not ready
We found smc_llc_send_link_delete_all() sometimes wait
for 2s timeout when testing with RDMA link up/down.
It is possible when a smc_link is in ACTIVATING state,
the underlaying QP is still in RESET or RTR state, which
cannot send any messages out.

smc_llc_send_link_delete_all() use smc_link_usable() to
checks whether the link is usable, if the QP is still in
RESET or RTR state, but the smc_link is in ACTIVATING, this
LLC message will always fail without any CQE entering the
CQ, and we will always wait 2s before timeout.

Since we cannot send any messages through the QP before
the QP enter RTS. I add a wrapper smc_link_sendable()
which checks the state of QP along with the link state.
And replace smc_link_usable() with smc_link_sendable()
in all LLC & CDC message sending routine.

Fixes: 5f08318f61 ("smc: connection data control (CDC)")
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
Tony Lu
1c5526968e net/smc: Clear memory when release and reuse buffer
Currently, buffers are cleared when smc connections are created and
buffers are reused. This slows down the speed of establishing new
connections. In most cases, the applications want to establish
connections as quickly as possible.

This patch moves memset() from connection creation path to release and
buffer unuse path, this trades off between speed of establishing and
release.

Test environments:
- CPU Intel Xeon Platinum 8 core, mem 32 GiB, nic Mellanox CX4
- socket sndbuf / rcvbuf: 16384 / 131072 bytes
- w/o first round, 5 rounds, avg, 100 conns batch per round
- smc_buf_create() use bpftrace kprobe, introduces extra latency

Latency benchmarks for smc_buf_create():
  w/o patch : 19040.0 ns
  w/  patch :  1932.6 ns
  ratio :        10.2% (-89.8%)

Latency benchmarks for socket create and connect:
  w/o patch :   143.3 us
  w/  patch :   102.2 us
  ratio :        71.3% (-28.7%)

The latency of establishing connections is reduced by 28.7%.

Signed-off-by: Tony Lu <tonylu@linux.alibaba.com>
Reviewed-by: Wen Gu <guwen@linux.alibaba.com>
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Link: https://lore.kernel.org/r/20211203113331.2818873-1-kgraul@linux.ibm.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-12-06 17:01:28 -08:00
Dust Li
789b6cc2a5 net/smc: fix wrong list_del in smc_lgr_cleanup_early
smc_lgr_cleanup_early() meant to delete the link
group from the link group list, but it deleted
the list head by mistake.

This may cause memory corruption since we didn't
remove the real link group from the list and later
memseted the link group structure.
We got a list corruption panic when testing:

[  231.277259] list_del corruption. prev->next should be ffff8881398a8000, but was 0000000000000000
[  231.278222] ------------[ cut here ]------------
[  231.278726] kernel BUG at lib/list_debug.c:53!
[  231.279326] invalid opcode: 0000 [#1] SMP NOPTI
[  231.279803] CPU: 0 PID: 5 Comm: kworker/0:0 Not tainted 5.10.46+ #435
[  231.280466] Hardware name: Alibaba Cloud ECS, BIOS 8c24b4c 04/01/2014
[  231.281248] Workqueue: events smc_link_down_work
[  231.281732] RIP: 0010:__list_del_entry_valid+0x70/0x90
[  231.282258] Code: 4c 60 82 e8 7d cc 6a 00 0f 0b 48 89 fe 48 c7 c7 88 4c
60 82 e8 6c cc 6a 00 0f 0b 48 89 fe 48 c7 c7 c0 4c 60 82 e8 5b cc 6a 00 <0f>
0b 48 89 fe 48 c7 c7 00 4d 60 82 e8 4a cc 6a 00 0f 0b cc cc cc
[  231.284146] RSP: 0018:ffffc90000033d58 EFLAGS: 00010292
[  231.284685] RAX: 0000000000000054 RBX: ffff8881398a8000 RCX: 0000000000000000
[  231.285415] RDX: 0000000000000001 RSI: ffff88813bc18040 RDI: ffff88813bc18040
[  231.286141] RBP: ffffffff8305ad40 R08: 0000000000000003 R09: 0000000000000001
[  231.286873] R10: ffffffff82803da0 R11: ffffc90000033b90 R12: 0000000000000001
[  231.287606] R13: 0000000000000000 R14: ffff8881398a8000 R15: 0000000000000003
[  231.288337] FS:  0000000000000000(0000) GS:ffff88813bc00000(0000) knlGS:0000000000000000
[  231.289160] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  231.289754] CR2: 0000000000e72058 CR3: 000000010fa96006 CR4: 00000000003706f0
[  231.290485] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  231.291211] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[  231.291940] Call Trace:
[  231.292211]  smc_lgr_terminate_sched+0x53/0xa0
[  231.292677]  smc_switch_conns+0x75/0x6b0
[  231.293085]  ? update_load_avg+0x1a6/0x590
[  231.293517]  ? ttwu_do_wakeup+0x17/0x150
[  231.293907]  ? update_load_avg+0x1a6/0x590
[  231.294317]  ? newidle_balance+0xca/0x3d0
[  231.294716]  smcr_link_down+0x50/0x1a0
[  231.295090]  ? __wake_up_common_lock+0x77/0x90
[  231.295534]  smc_link_down_work+0x46/0x60
[  231.295933]  process_one_work+0x18b/0x350

Fixes: a0a62ee15a ("net/smc: separate locks for SMCD and SMCR link group lists")
Signed-off-by: Dust Li <dust.li@linux.alibaba.com>
Acked-by: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Tony Lu <tonylu@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-12-02 12:07:46 +00:00
Karsten Graul
587acad41f net/smc: Fix NULL pointer dereferencing in smc_vlan_by_tcpsk()
Coverity reports a possible NULL dereferencing problem:

in smc_vlan_by_tcpsk():
6. returned_null: netdev_lower_get_next returns NULL (checked 29 out of 30 times).
7. var_assigned: Assigning: ndev = NULL return value from netdev_lower_get_next.
1623                ndev = (struct net_device *)netdev_lower_get_next(ndev, &lower);
CID 1468509 (#1 of 1): Dereference null return value (NULL_RETURNS)
8. dereference: Dereferencing a pointer that might be NULL ndev when calling is_vlan_dev.
1624                if (is_vlan_dev(ndev)) {

Remove the manual implementation and use netdev_walk_all_lower_dev() to
iterate over the lower devices. While on it remove an obsolete function
parameter comment.

Fixes: cb9d43f677 ("net/smc: determine vlan_id of stacked net_device")
Suggested-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-11-24 19:02:21 -08:00
Wen Gu
cf4f5530bb net/smc: Make sure the link_id is unique
The link_id is supposed to be unique, but smcr_next_link_id() doesn't
skip the used link_id as expected. So the patch fixes this.

Fixes: 026c381fb4 ("net/smc: introduce link_idx for link group array")
Signed-off-by: Wen Gu <guwen@linux.alibaba.com>
Reviewed-by: Tony Lu <tonylu@linux.alibaba.com>
Acked-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-11-15 14:42:24 +00:00
Tony Lu
a3a0e81b6f net/smc: Introduce tracepoint for smcr link down
SMC-R link down event is important to help us find links' issues, we
should track this event, especially in the single nic mode, which means
upper layer connection would be shut down. Then find out the direct
link-down reason in time, not only increased the counter, also the
location of the code who triggered this event.

Signed-off-by: Tony Lu <tonylu@linux.alibaba.com>
Reviewed-by: Wen Gu <guwen@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-11-01 13:39:14 +00:00
Karsten Graul
b0539f5edd net/smc: add netlink support for SMC-Rv2
Implement the netlink support for SMC-Rv2 related attributes that are
provided to user space.

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
8799e310fb net/smc: add v2 support to the work request layer
In the work request layer define one large v2 buffer for each link group
that is used to transmit and receive large LLC control messages.
Add the completion queue handling for this buffer.

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
24fb68111d net/smc: retrieve v2 gid from IB device
In smc_ib.c, scan for RoCE devices that support UDP encapsulation.
Find an eligible device and check that there is a route to the
remote peer.

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
e49300a6bf net/smc: add listen processing for SMC-Rv2
Implement the server side of the SMC-Rv2 processing. Process incoming
CLC messages, find eligible devices and check for a valid route to the
remote peer.

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
Jakub Kicinski
e15f5972b8 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
tools/testing/selftests/net/ioam6.sh
  7b1700e009 ("selftests: net: modify IOAM tests for undef bits")
  bf77b1400a ("selftests: net: Test for the IOAM encapsulation with IPv6")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-10-14 16:50:14 -07:00
Karsten Graul
95f7f3e7dc net/smc: improved fix wait on already cleared link
Commit 8f3d65c166 ("net/smc: fix wait on already cleared link")
introduced link refcounting to avoid waits on already cleared links.
This patch extents and improves the refcounting to cover all
remaining possible cases for this kind of error situation.

Fixes: 15e1b99aad ("net/smc: no WR buffer wait for terminating link group")
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-10-08 17:00:16 +01:00
Jakub Kicinski
2fcd14d0f7 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
net/mptcp/protocol.c
  977d293e23 ("mptcp: ensure tx skbs always have the MPTCP ext")
  efe686ffce ("mptcp: ensure tx skbs always have the MPTCP ext")

same patch merged in both trees, keep net-next.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-09-23 11:19:49 -07:00
Karsten Graul
a18cee4791 net/smc: fix 'workqueue leaked lock' in smc_conn_abort_work
The abort_work is scheduled when a connection was detected to be
out-of-sync after a link failure. The work calls smc_conn_kill(),
which calls smc_close_active_abort() and that might end up calling
smc_close_cancel_work().
smc_close_cancel_work() cancels any pending close_work and tx_work but
needs to release the sock_lock before and acquires the sock_lock again
afterwards. So when the sock_lock was NOT acquired before then it may
be held after the abort_work completes. Thats why the sock_lock is
acquired before the call to smc_conn_kill() in __smc_lgr_terminate(),
but this is missing in smc_conn_abort_work().

Fix that by acquiring the sock_lock first and release it after the
call to smc_conn_kill().

Fixes: b286a0651e ("net/smc: handle incoming CDC validation message")
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-09-21 10:54:16 +01:00
Karsten Graul
11a26c59fc net/smc: keep static copy of system EID
The system EID is retrieved using an registered ISM device each time
when needed. This adds some unnecessary complexity at all places where
the system EID is needed, but no ISM device is at hand.
Simplify the code and save the system EID in a static variable in
smc_ism.c.

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
Jakub Kicinski
f4083a752a Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Conflicts:

drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.h
  9e26680733 ("bnxt_en: Update firmware call to retrieve TX PTP timestamp")
  9e518f2580 ("bnxt_en: 1PPS functions to configure TSIO pins")
  099fdeda65 ("bnxt_en: Event handler for PPS events")

kernel/bpf/helpers.c
include/linux/bpf-cgroup.h
  a2baf4e8bb ("bpf: Fix potentially incorrect results with bpf_get_local_storage()")
  c7603cfa04 ("bpf: Add ambient BPF runtime context stored in current")

drivers/net/ethernet/mellanox/mlx5/core/pci_irq.c
  5957cc557d ("net/mlx5: Set all field of mlx5_irq before inserting it to the xarray")
  2d0b41a376 ("net/mlx5: Refcount mlx5_irq with integer")

MAINTAINERS
  7b637cd52f ("MAINTAINERS: fix Microchip CAN BUS Analyzer Tool entry typo")
  7d901a1e87 ("net: phy: add Maxlinear GPY115/21x/24x driver")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-08-13 06:41:22 -07:00
Stefan Raspl
67161779a9 net/smc: Allow SMC-D 1MB DMB allocations
Commit a3fe3d01bd ("net/smc: introduce sg-logic for RMBs") introduced
a restriction for RMB allocations as used by SMC-R. However, SMC-D does
not use scatter-gather lists to back its DMBs, yet it was limited by
this restriction, still.
This patch exempts SMC, but limits allocations to the maximum RMB/DMB
size respectively.

Signed-off-by: Stefan Raspl <raspl@linux.ibm.com>
Signed-off-by: Guvenc Gulce <guvenc@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-09 10:57:04 +01:00
Guvenc Gulce
64513d269e net/smc: Correct smc link connection counter in case of smc client
SMC clients may be assigned to a different link after the initial
connection between two peers was established. In such a case,
the connection counter was not correctly set.

Update the connection counter correctly when a smc client connection
is assigned to a different smc link.

Fixes: 07d51580ff ("net/smc: Add connection counters for links")
Signed-off-by: Guvenc Gulce <guvenc@linux.ibm.com>
Tested-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-09 10:46:59 +01:00
Guvenc Gulce
194730a9be net/smc: Make SMC statistics network namespace aware
Make the gathered SMC statistics network namespace aware, for each
namespace collect an own set of statistic information.

Signed-off-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>
2021-06-16 12:54:02 -07:00
Guvenc Gulce
e0e4b8fa53 net/smc: Add SMC statistics support
Add the ability to collect SMC statistics information. Per-cpu
variables are used to collect the statistic information for better
performance and for reducing concurrency pitfalls. The code that is
collecting statistic data is implemented in macros to increase code
reuse and readability.

Signed-off-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>
2021-06-16 12:54:02 -07:00
Karsten Graul
f8e0a68bab net/smc: avoid possible duplicate dmb unregistration
smc_lgr_cleanup() calls smcd_unregister_all_dmbs() as part of the link
group termination process. This is a leftover from the times when
smc_lgr_cleanup() scheduled a worker to actually free the link group.
Nowadays smc_lgr_cleanup() directly calls smc_lgr_free() without any
delay so an earlier dmb unregistration is no longer needed.
So remove smcd_unregister_all_dmbs() and the call to it.

Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-03 13:54:49 -07:00
Guvenc Gulce
8a44653689 net/smc: use memcpy instead of snprintf to avoid out of bounds read
Using snprintf() to convert not null-terminated strings to null
terminated strings may cause out of bounds read in the source string.
Therefore use memcpy() and terminate the target string with a null
afterwards.

Fixes: a3db10efcc ("net/smc: Add support for obtaining SMCR device list")
Signed-off-by: Guvenc Gulce <guvenc@linux.ibm.com>
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-01-12 20:22:01 -08:00
Jakub Kicinski
25fe2c9c4c smc: fix out of bound access in smc_nl_get_sys_info()
smc_clc_get_hostname() sets the host pointer to a buffer
which is not NULL-terminated (see smc_clc_init()).

Reported-by: syzbot+f4708c391121cfc58396@syzkaller.appspotmail.com
Fixes: 099b990bd1 ("net/smc: Add support for obtaining system information")
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-01-12 20:22:01 -08:00
Guvenc Gulce
a3db10efcc net/smc: Add support for obtaining SMCR device list
Deliver SMCR device information via netlink based
diagnostic interface.

Signed-off-by: Guvenc Gulce <guvenc@linux.ibm.com>
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-01 17:56:13 -08:00
Guvenc Gulce
8f9dde4bf2 net/smc: Add SMC-D Linkgroup diagnostic support
Deliver SMCD Linkgroup information via netlink based
diagnostic interface.

Signed-off-by: Guvenc Gulce <guvenc@linux.ibm.com>
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-01 17:56:13 -08:00
Guvenc Gulce
5a7e09d58f net/smc: Introduce SMCR get link command
Introduce get link command which loops through
all available links of all available link groups. It
uses the SMC-R linkgroup list as entry point, not
the socket list, which makes linkgroup diagnosis
possible, in case linkgroup does not contain active
connections anymore.

Signed-off-by: Guvenc Gulce <guvenc@linux.ibm.com>
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-01 17:56:13 -08:00
Guvenc Gulce
e9b8c845cb net/smc: Introduce SMCR get linkgroup command
Introduce get linkgroup command which loops through
all available SMCR linkgroups. It uses the SMC-R linkgroup
list as entry point, not the socket list, which makes
linkgroup diagnosis possible, in case linkgroup does not
contain active connections anymore.

Signed-off-by: Guvenc Gulce <guvenc@linux.ibm.com>
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-01 17:56:13 -08:00
Guvenc Gulce
099b990bd1 net/smc: Add support for obtaining system information
Add new netlink command to obtain system information
of the smc module.

Signed-off-by: Guvenc Gulce <guvenc@linux.ibm.com>
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-01 17:56:13 -08:00
Guvenc Gulce
6443b2f60e net/smc: Add diagnostic information to link structure
During link creation add net-device ifindex and ib-device
name to link structure. This is needed for diagnostic purposes.

When diagnostic information is gathered, we need to traverse
device, linkgroup and link structures, to be able to do that
we need to hold a spinlock for the linkgroup list, without this
diagnostic information in link structure, another device list
mutex holding would be necessary to dereference the device
pointer in the link structure which would be impossible when
holding a spinlock already.

Signed-off-by: Guvenc Gulce <guvenc@linux.ibm.com>
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-01 17:56:12 -08:00
Guvenc Gulce
ddc992866f net/smc: Add link counters for IB device ports
Add link counters to the structure of the smc ib device, one counter per
ib port. Increase/decrease the counters as needed in the corresponding
routines.

Signed-off-by: Guvenc Gulce <guvenc@linux.ibm.com>
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-01 17:56:12 -08:00