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* smc: Drop smc_sendpage() in favour of smc_sendmsg() + MSG_SPLICE_PAGESDavid Howells2023-06-241-29/+0
| | | | | | | | | | | | | | | | | | Drop the smc_sendpage() code as smc_sendmsg() just passes the call down to the underlying TCP socket and smc_tx_sendpage() is just a wrapper around its sendmsg implementation. Signed-off-by: David Howells <dhowells@redhat.com> cc: Karsten Graul <kgraul@linux.ibm.com> cc: Wenjia Zhang <wenjia@linux.ibm.com> cc: Jan Karcher <jaka@linux.ibm.com> cc: "D. Wythe" <alibuda@linux.alibaba.com> cc: Tony Lu <tonylu@linux.alibaba.com> cc: Wen Gu <guwen@linux.alibaba.com> cc: Jens Axboe <axboe@kernel.dk> cc: Matthew Wilcox <willy@infradead.org> Link: https://lore.kernel.org/r/20230623225513.2732256-10-dhowells@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
* net/smc: Reset connection when trying to use SMCRv2 fails.Wen Gu2023-05-191-2/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We found a crash when using SMCRv2 with 2 Mellanox ConnectX-4. It can be reproduced by: - smc_run nginx - smc_run wrk -t 32 -c 500 -d 30 http://<ip>:<port> BUG: kernel NULL pointer dereference, address: 0000000000000014 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 8000000108713067 P4D 8000000108713067 PUD 151127067 PMD 0 Oops: 0000 [#1] PREEMPT SMP PTI CPU: 4 PID: 2441 Comm: kworker/4:249 Kdump: loaded Tainted: G W E 6.4.0-rc1+ #42 Workqueue: smc_hs_wq smc_listen_work [smc] RIP: 0010:smc_clc_send_confirm_accept+0x284/0x580 [smc] RSP: 0018:ffffb8294b2d7c78 EFLAGS: 00010a06 RAX: ffff8f1873238880 RBX: ffffb8294b2d7dc8 RCX: 0000000000000000 RDX: 00000000000000b4 RSI: 0000000000000001 RDI: 0000000000b40c00 RBP: ffffb8294b2d7db8 R08: ffff8f1815c5860c R09: 0000000000000000 R10: 0000000000000400 R11: 0000000000000000 R12: ffff8f1846f56180 R13: ffff8f1815c5860c R14: 0000000000000001 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8f1aefd00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000014 CR3: 00000001027a0001 CR4: 00000000003706e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> ? mlx5_ib_map_mr_sg+0xa1/0xd0 [mlx5_ib] ? smcr_buf_map_link+0x24b/0x290 [smc] ? __smc_buf_create+0x4ee/0x9b0 [smc] smc_clc_send_accept+0x4c/0xb0 [smc] smc_listen_work+0x346/0x650 [smc] ? __schedule+0x279/0x820 process_one_work+0x1e5/0x3f0 worker_thread+0x4d/0x2f0 ? __pfx_worker_thread+0x10/0x10 kthread+0xe5/0x120 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x2c/0x50 </TASK> During the CLC handshake, server sequentially tries available SMCRv2 and SMCRv1 devices in smc_listen_work(). If an SMCRv2 device is found. SMCv2 based link group and link will be assigned to the connection. Then assumed that some buffer assignment errors happen later in the CLC handshake, such as RMB registration failure, server will give up SMCRv2 and try SMCRv1 device instead. But the resources assigned to the connection won't be reset. When server tries SMCRv1 device, the connection creation process will be executed again. Since conn->lnk has been assigned when trying SMCRv2, it will not be set to the correct SMCRv1 link in smcr_lgr_conn_assign_link(). So in such situation, conn->lgr points to correct SMCRv1 link group but conn->lnk points to the SMCRv2 link mistakenly. Then in smc_clc_send_confirm_accept(), conn->rmb_desc->mr[link->link_idx] will be accessed. Since the link->link_idx is not correct, the related MR may not have been initialized, so crash happens. | Try SMCRv2 device first | |-> conn->lgr: assign existed SMCRv2 link group; | |-> conn->link: assign existed SMCRv2 link (link_idx may be 1 in SMC_LGR_SYMMETRIC); | |-> sndbuf & RMB creation fails, quit; | | Try SMCRv1 device then | |-> conn->lgr: create SMCRv1 link group and assign; | |-> conn->link: keep SMCRv2 link mistakenly; | |-> sndbuf & RMB creation succeed, only RMB->mr[link_idx = 0] | initialized. | | Then smc_clc_send_confirm_accept() accesses | conn->rmb_desc->mr[conn->link->link_idx, which is 1], then crash. v This patch tries to fix this by cleaning conn->lnk before assigning link. In addition, it is better to reset the connection and clean the resources assigned if trying SMCRv2 failed in buffer creation or registration. Fixes: e49300a6bf62 ("net/smc: add listen processing for SMC-Rv2") Link: https://lore.kernel.org/r/20220523055056.2078994-1-liuyacan@corp.netease.com/ Signed-off-by: Wen Gu <guwen@linux.alibaba.com> Reviewed-by: Tony Lu <tonylu@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* smc: Fix use-after-free in tcp_write_timer_handler().Kuniyuki Iwashima2023-04-121-0/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With Eric's ref tracker, syzbot finally found a repro for use-after-free in tcp_write_timer_handler() by kernel TCP sockets. [0] If SMC creates a kernel socket in __smc_create(), the kernel socket is supposed to be freed in smc_clcsock_release() by calling sock_release() when we close() the parent SMC socket. However, at the end of smc_clcsock_release(), the kernel socket's sk_state might not be TCP_CLOSE. This means that we have not called inet_csk_destroy_sock() in __tcp_close() and have not stopped the TCP timers. The kernel socket's TCP timers can be fired later, so we need to hold a refcnt for net as we do for MPTCP subflows in mptcp_subflow_create_socket(). [0]: leaked reference. sk_alloc (./include/net/net_namespace.h:335 net/core/sock.c:2108) inet_create (net/ipv4/af_inet.c:319 net/ipv4/af_inet.c:244) __sock_create (net/socket.c:1546) smc_create (net/smc/af_smc.c:3269 net/smc/af_smc.c:3284) __sock_create (net/socket.c:1546) __sys_socket (net/socket.c:1634 net/socket.c:1618 net/socket.c:1661) __x64_sys_socket (net/socket.c:1672) do_syscall_64 (arch/x86/entry/common.c:50 arch/x86/entry/common.c:80) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:120) ================================================================== BUG: KASAN: slab-use-after-free in tcp_write_timer_handler (net/ipv4/tcp_timer.c:378 net/ipv4/tcp_timer.c:624 net/ipv4/tcp_timer.c:594) Read of size 1 at addr ffff888052b65e0d by task syzrepro/18091 CPU: 0 PID: 18091 Comm: syzrepro Tainted: G W 6.3.0-rc4-01174-gb5d54eb5899a #7 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.0-1.amzn2022.0.1 04/01/2014 Call Trace: <IRQ> dump_stack_lvl (lib/dump_stack.c:107) print_report (mm/kasan/report.c:320 mm/kasan/report.c:430) kasan_report (mm/kasan/report.c:538) tcp_write_timer_handler (net/ipv4/tcp_timer.c:378 net/ipv4/tcp_timer.c:624 net/ipv4/tcp_timer.c:594) tcp_write_timer (./include/linux/spinlock.h:390 net/ipv4/tcp_timer.c:643) call_timer_fn (./arch/x86/include/asm/jump_label.h:27 ./include/linux/jump_label.h:207 ./include/trace/events/timer.h:127 kernel/time/timer.c:1701) __run_timers.part.0 (kernel/time/timer.c:1752 kernel/time/timer.c:2022) run_timer_softirq (kernel/time/timer.c:2037) __do_softirq (./arch/x86/include/asm/jump_label.h:27 ./include/linux/jump_label.h:207 ./include/trace/events/irq.h:142 kernel/softirq.c:572) __irq_exit_rcu (kernel/softirq.c:445 kernel/softirq.c:650) irq_exit_rcu (kernel/softirq.c:664) sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1107 (discriminator 14)) </IRQ> Fixes: ac7138746e14 ("smc: establish new socket family") Reported-by: syzbot+7e1e1bdb852961150198@syzkaller.appspotmail.com Link: https://lore.kernel.org/netdev/000000000000a3f51805f8bcc43a@google.com/ Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Tony Lu <tonylu@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net/smc: Fix device de-init sequenceStefan Raspl2023-03-151-0/+1
| | | | | | | | | | CLC message initialization was not properly reversed in error handling path. Reported-and-suggested-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Stefan Raspl <raspl@linux.ibm.com> Signed-off-by: Wenjia Zhang <wenjia@linux.ibm.com> Reviewed-by: Tony Lu <tonylu@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net/smc: fix fallback failed while sendmsg with fastopenD. Wythe2023-03-081-5/+8
| | | | | | | | | | | | | | | | | | | | | | | | Before determining whether the msg has unsupported options, it has been prematurely terminated by the wrong status check. For the application, the general usages of MSG_FASTOPEN likes fd = socket(...) /* rather than connect */ sendto(fd, data, len, MSG_FASTOPEN) Hence, We need to check the flag before state check, because the sock state here is always SMC_INIT when applications tries MSG_FASTOPEN. Once we found unsupported options, fallback it to TCP. Fixes: ee9dfbef02d1 ("net/smc: handle sockopts forcing fallback") Signed-off-by: D. Wythe <alibuda@linux.alibaba.com> Signed-off-by: Simon Horman <simon.horman@corigine.com> v2 -> v1: Optimize code style Reviewed-by: Tony Lu <tonylu@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski2023-02-211-0/+2
|\ | | | | | | | | | | | | | | | | | | | | Per-next-PR merge. net/smc/af_smc.c b5dd4d698171 ("net/smc: llc_conf_mutex refactor, replace it with rw_semaphore") e40b801b3603 ("net/smc: fix potential panic dues to unprotected smc_llc_srv_add_link()") https://lore.kernel.org/all/20230221124008.6303c330@canb.auug.org.au/ Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| * net/smc: fix potential panic dues to unprotected smc_llc_srv_add_link()D. Wythe2023-02-201-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is a certain chance to trigger the following panic: PID: 5900 TASK: ffff88c1c8af4100 CPU: 1 COMMAND: "kworker/1:48" #0 [ffff9456c1cc79a0] machine_kexec at ffffffff870665b7 #1 [ffff9456c1cc79f0] __crash_kexec at ffffffff871b4c7a #2 [ffff9456c1cc7ab0] crash_kexec at ffffffff871b5b60 #3 [ffff9456c1cc7ac0] oops_end at ffffffff87026ce7 #4 [ffff9456c1cc7ae0] page_fault_oops at ffffffff87075715 #5 [ffff9456c1cc7b58] exc_page_fault at ffffffff87ad0654 #6 [ffff9456c1cc7b80] asm_exc_page_fault at ffffffff87c00b62 [exception RIP: ib_alloc_mr+19] RIP: ffffffffc0c9cce3 RSP: ffff9456c1cc7c38 RFLAGS: 00010202 RAX: 0000000000000000 RBX: 0000000000000002 RCX: 0000000000000004 RDX: 0000000000000010 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff88c1ea281d00 R8: 000000020a34ffff R9: ffff88c1350bbb20 R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000 R13: 0000000000000010 R14: ffff88c1ab040a50 R15: ffff88c1ea281d00 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 #7 [ffff9456c1cc7c60] smc_ib_get_memory_region at ffffffffc0aff6df [smc] #8 [ffff9456c1cc7c88] smcr_buf_map_link at ffffffffc0b0278c [smc] #9 [ffff9456c1cc7ce0] __smc_buf_create at ffffffffc0b03586 [smc] The reason here is that when the server tries to create a second link, smc_llc_srv_add_link() has no protection and may add a new link to link group. This breaks the security environment protected by llc_conf_mutex. Fixes: 2d2209f20189 ("net/smc: first part of add link processing as SMC server") Signed-off-by: D. Wythe <alibuda@linux.alibaba.com> Reviewed-by: Larysa Zaremba <larysa.zaremba@intel.com> Reviewed-by: Wenjia Zhang <wenjia@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | net: no longer support SOCK_REFCNT_DEBUG featureJason Xing2023-02-151-3/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit e48c414ee61f ("[INET]: Generalise the TCP sock ID lookup routines") commented out the definition of SOCK_REFCNT_DEBUG in 2005 and later another commit 463c84b97f24 ("[NET]: Introduce inet_connection_sock") removed it. Since we could track all of them through bpf and kprobe related tools and the feature could print loads of information which might not be that helpful even under a little bit pressure, the whole feature which has been inactive for many years is no longer supported. Link: https://lore.kernel.org/lkml/20230211065153.54116-1-kerneljasonxing@gmail.com/ Suggested-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: Jason Xing <kernelxing@tencent.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Acked-by: Wenjia Zhang <wenjia@linux.ibm.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Acked-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: David S. Miller <davem@davemloft.net>
* | net/smc: reduce unnecessary blocking in smcr_lgr_reg_rmbs()D. Wythe2023-02-041-2/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Unlike smc_buf_create() and smcr_buf_unuse(), smcr_lgr_reg_rmbs() is exclusive when assigned rmb_desc was not registered, although it can be executed in parallel when assigned rmb_desc was registered already and only performs read semtamics on it. Hence, we can not simply replace it with read semaphore. The idea here is that if the assigned rmb_desc was registered already, use read semaphore to protect the critical section, once the assigned rmb_desc was not registered, keep using keep write semaphore still to keep its exclusivity. Thanks to the reusable features of rmb_desc, which allows us to execute in parallel in most cases. Signed-off-by: D. Wythe <alibuda@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | net/smc: llc_conf_mutex refactor, replace it with rw_semaphoreD. Wythe2023-02-041-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | llc_conf_mutex was used to protect links and link related configurations in the same link group, for example, add or delete links. However, in most cases, the protected critical area has only read semantics and with no write semantics at all, such as obtaining a usable link or an available rmb_desc. This patch do simply code refactoring, replace mutex with rw_semaphore, replace mutex_lock with down_write and replace mutex_unlock with up_write. Theoretically, this replacement is equivalent, but after this patch, we can distinguish lock granularity according to different semantics of critical areas. Signed-off-by: D. Wythe <alibuda@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | net: add missing includes of linux/splice.hJakub Kicinski2023-01-271-0/+1
| | | | | | | | | | | | | | | | Number of files depend on linux/splice.h getting included by linux/skbuff.h which soon will no longer be the case. Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* | net/smc: De-tangle ism and smc device initializationStefan Raspl2023-01-251-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | The struct device for ISM devices was part of struct smcd_dev. Move to struct ism_dev, provide a new API call in struct smcd_ops, and convert existing SMCD code accordingly. Furthermore, remove struct smcd_dev from struct ism_dev. This is the final part of a bigger overhaul of the interfaces between SMC and ISM. Signed-off-by: Stefan Raspl <raspl@linux.ibm.com> Signed-off-by: Jan Karcher <jaka@linux.ibm.com> Signed-off-by: Wenjia Zhang <wenjia@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | net/smc: Register SMC-D as ISM clientStefan Raspl2023-01-251-2/+6
|/ | | | | | | | | | | Register the smc module with the new ism device driver API. This is the second part of a bigger overhaul of the interfaces between SMC and ISM. Signed-off-by: Stefan Raspl <raspl@linux.ibm.com> Signed-off-by: Jan Karcher <jaka@linux.ibm.com> Signed-off-by: Wenjia Zhang <wenjia@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net/smc: Fix possible leaked pernet namespace in smc_init()Chen Zhongjin2022-11-021-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | In smc_init(), register_pernet_subsys(&smc_net_stat_ops) is called without any error handling. If it fails, registering of &smc_net_ops won't be reverted. And if smc_nl_init() fails, &smc_net_stat_ops itself won't be reverted. This leaves wild ops in subsystem linkedlist and when another module tries to call register_pernet_operations() it triggers page fault: BUG: unable to handle page fault for address: fffffbfff81b964c RIP: 0010:register_pernet_operations+0x1b9/0x5f0 Call Trace: <TASK> register_pernet_subsys+0x29/0x40 ebtables_init+0x58/0x1000 [ebtables] ... Fixes: 194730a9beb5 ("net/smc: Make SMC statistics network namespace aware") Signed-off-by: Chen Zhongjin <chenzhongjin@huawei.com> Reviewed-by: Tony Lu <tonylu@linux.alibaba.com> Reviewed-by: Wenjia Zhang <wenjia@linux.ibm.com> Link: https://lore.kernel.org/r/20221101093722.127223-1-chenzhongjin@huawei.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
* net/smc: Support SO_REUSEPORTTony Lu2022-09-271-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This enables SO_REUSEPORT [1] for clcsock when it is set on smc socket, so that some applications which uses it can be transparently replaced with SMC. Also, this helps improve load distribution. Here is a simple test of NGINX + wrk with SMC. The CPU usage is collected on NGINX (server) side as below. Disable SO_REUSEPORT: 05:15:33 PM CPU %usr %nice %sys %iowait %irq %soft %steal %guest %gnice %idle 05:15:34 PM all 7.02 0.00 11.86 0.00 2.04 8.93 0.00 0.00 0.00 70.15 05:15:34 PM 0 0.00 0.00 0.00 0.00 16.00 70.00 0.00 0.00 0.00 14.00 05:15:34 PM 1 11.58 0.00 22.11 0.00 0.00 0.00 0.00 0.00 0.00 66.32 05:15:34 PM 2 1.00 0.00 1.00 0.00 0.00 0.00 0.00 0.00 0.00 98.00 05:15:34 PM 3 16.84 0.00 30.53 0.00 0.00 0.00 0.00 0.00 0.00 52.63 05:15:34 PM 4 28.72 0.00 44.68 0.00 0.00 0.00 0.00 0.00 0.00 26.60 05:15:34 PM 5 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 05:15:34 PM 6 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 05:15:34 PM 7 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 Enable SO_REUSEPORT: 05:15:20 PM CPU %usr %nice %sys %iowait %irq %soft %steal %guest %gnice %idle 05:15:21 PM all 8.56 0.00 14.40 0.00 2.20 9.86 0.00 0.00 0.00 64.98 05:15:21 PM 0 0.00 0.00 4.08 0.00 14.29 76.53 0.00 0.00 0.00 5.10 05:15:21 PM 1 9.09 0.00 16.16 0.00 1.01 0.00 0.00 0.00 0.00 73.74 05:15:21 PM 2 9.38 0.00 16.67 0.00 1.04 0.00 0.00 0.00 0.00 72.92 05:15:21 PM 3 10.42 0.00 17.71 0.00 1.04 0.00 0.00 0.00 0.00 70.83 05:15:21 PM 4 9.57 0.00 15.96 0.00 0.00 0.00 0.00 0.00 0.00 74.47 05:15:21 PM 5 9.18 0.00 15.31 0.00 0.00 1.02 0.00 0.00 0.00 74.49 05:15:21 PM 6 8.60 0.00 15.05 0.00 0.00 0.00 0.00 0.00 0.00 76.34 05:15:21 PM 7 12.37 0.00 14.43 0.00 0.00 0.00 0.00 0.00 0.00 73.20 Using SO_REUSEPORT helps the load distribution of NGINX be more balanced. [1] https://man7.org/linux/man-pages/man7/socket.7.html Signed-off-by: Tony Lu <tonylu@linux.alibaba.com> Acked-by: Wenjia Zhang <wenjia@linux.ibm.com> Link: https://lore.kernel.org/r/20220922121906.72406-1-tonylu@linux.alibaba.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
* net/smc: Unbind r/w buffer size from clcsock and make them tunableTony Lu2022-09-221-3/+2
| | | | | | | | | | | | | | | | | Currently, SMC uses smc->sk.sk_{rcv|snd}buf to create buffers for send buffer and RMB. And the values of buffer size are from tcp_{w|r}mem in clcsock. The buffer size from TCP socket doesn't fit SMC well. Generally, buffers are usually larger than TCP for SMC-R/-D to get higher performance, for they are different underlay devices and paths. So this patch unbinds buffer size from TCP, and introduces two sysctl knobs to tune them independently. Also, these knobs are per net namespace and work for containers. Signed-off-by: Tony Lu <tonylu@linux.alibaba.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
* net/smc: Remove redundant refcount increaseYacan Liu2022-09-011-1/+0
| | | | | | | | | | | For passive connections, the refcount increment has been done in smc_clcsock_accept()-->smc_sock_alloc(). Fixes: 3b2dec2603d5 ("net/smc: restructure client and server code in af_smc") Signed-off-by: Yacan Liu <liuyacan@corp.netease.com> Reviewed-by: Tony Lu <tonylu@linux.alibaba.com> Link: https://lore.kernel.org/r/20220830152314.838736-1-liuyacan@corp.netease.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
* net/smc: Enable module load on netlink usageStefan Raspl2022-07-271-0/+1
| | | | | | | | | | | | | | | Previously, the smc and smc_diag modules were automatically loaded as dependencies of the ism module whenever an ISM device was present. With the pending rework of the ISM API, the smc module will no longer automatically be loaded in presence of an ISM device. Usage of an AF_SMC socket will still trigger loading of the smc modules, but usage of a netlink socket will not. This is addressed by setting the correct module aliases. Signed-off-by: Stefan Raspl <raspl@linux.ibm.com> Signed-off-by: Wenjia Zhang < wenjia@linux.ibm.com> Reviewed-by: Tony Lu <tonylu@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net/smc: Allow virtually contiguous sndbufs or RMBs for SMC-RWen Gu2022-07-181-8/+58
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* net/smc: remove redundant dma sync opsGuangguan Wang2022-07-181-2/+0
| | | | | | | | | | | | | | 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>
* net/smc: set ini->smcrv2.ib_dev_v2 to NULL if SMC-Rv2 is unavailableliuyacan2022-05-251-0/+1
| | | | | | | | | | | | | In the process of checking whether RDMAv2 is available, the current implementation first sets ini->smcrv2.ib_dev_v2, and then allocates smc buf desc and register rmb, but the latter may fail. In this case, the pointer should be reset. Fixes: e49300a6bf62 ("net/smc: add listen processing for SMC-Rv2") Signed-off-by: liuyacan <liuyacan@corp.netease.com> Reviewed-by: Karsten Graul <kgraul@linux.ibm.com> Link: https://lore.kernel.org/r/20220525085408.812273-1-liuyacan@corp.netease.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
* Revert "net/smc: fix listen processing for SMC-Rv2"liuyacan2022-05-241-27/+17
| | | | | | | | | | | | | This reverts commit 8c3b8dc5cc9bf6d273ebe18b16e2d6882bcfb36d. Some rollback issue will be fixed in other patches in the future. Link: https://lore.kernel.org/all/20220523055056.2078994-1-liuyacan@corp.netease.com/ Fixes: 8c3b8dc5cc9b ("net/smc: fix listen processing for SMC-Rv2") Signed-off-by: liuyacan <liuyacan@corp.netease.com> Link: https://lore.kernel.org/r/20220524090230.2140302-1-liuyacan@corp.netease.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski2022-05-231-18/+28
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | drivers/net/ethernet/cadence/macb_main.c 5cebb40bc955 ("net: macb: Fix PTP one step sync support") 138badbc21a0 ("net: macb: use NAPI for TX completion path") https://lore.kernel.org/all/20220523111021.31489367@canb.auug.org.au/ net/smc/af_smc.c 75c1edf23b95 ("net/smc: postpone sk_refcnt increment in connect()") 3aba103006bc ("net/smc: align the connect behaviour with TCP") https://lore.kernel.org/all/20220524114408.4bf1af38@canb.auug.org.au/ Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| * net/smc: fix listen processing for SMC-Rv2liuyacan2022-05-231-17/+27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In the process of checking whether RDMAv2 is available, the current implementation first sets ini->smcrv2.ib_dev_v2, and then allocates smc buf desc, but the latter may fail. Unfortunately, the caller will only check the former. In this case, a NULL pointer reference will occur in smc_clc_send_confirm_accept() when accessing conn->rmb_desc. This patch does two things: 1. Use the return code to determine whether V2 is available. 2. If the return code is NODEV, continue to check whether V1 is available. Fixes: e49300a6bf62 ("net/smc: add listen processing for SMC-Rv2") Signed-off-by: liuyacan <liuyacan@corp.netease.com> Signed-off-by: David S. Miller <davem@davemloft.net>
| * net/smc: postpone sk_refcnt increment in connect()liuyacan2022-05-231-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | Same trigger condition as commit 86434744. When setsockopt runs in parallel to a connect(), and switch the socket into fallback mode. Then the sk_refcnt is incremented in smc_connect(), but its state stay in SMC_INIT (NOT SMC_ACTIVE). This cause the corresponding sk_refcnt decrement in __smc_release() will not be performed. Fixes: 86434744fedf ("net/smc: add fallback check to connect()") Signed-off-by: liuyacan <liuyacan@corp.netease.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | net/smc: align the connect behaviour with TCPGuangguan Wang2022-05-161-4/+46
|/ | | | | | | | | | | | | | Connect with O_NONBLOCK will not be completed immediately and returns -EINPROGRESS. It is possible to use selector/poll for completion by selecting the socket for writing. After select indicates writability, a second connect function call will return 0 to indicate connected successfully as TCP does, but smc returns -EISCONN. Use socket state for smc to indicate connect state, which can help smc aligning the connect behaviour with TCP. Signed-off-by: Guangguan Wang <guangguan.wang@linux.alibaba.com> Acked-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net/smc: Fix slab-out-of-bounds issue in fallbackWen Gu2022-04-251-23/+57
| | | | | | | | | | | | | | | | | | | | syzbot reported a slab-out-of-bounds/use-after-free issue, which was caused by accessing an already freed smc sock in fallback-specific callback functions of clcsock. This patch fixes the issue by restoring fallback-specific callback functions to original ones and resetting clcsock sk_user_data to NULL before freeing smc sock. Meanwhile, this patch introduces sk_callback_lock to make the access and assignment to sk_user_data mutually exclusive. Reported-by: syzbot+b425899ed22c6943e00b@syzkaller.appspotmail.com Fixes: 341adeec9ada ("net/smc: Forward wakeup to smc socket waitqueue after fallback") Link: https://lore.kernel.org/r/00000000000013ca8105d7ae3ada@google.com/ 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>
* net/smc: Only save the original clcsock callback functionsWen Gu2022-04-251-19/+36
| | | | | | | | | | | | | | 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: 341adeec9ada ("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>
* net/smc: sync err code when tcp connection was refusedliuyacan2022-04-251-0/+2
| | | | | | | | | | | | | | In the current implementation, when TCP initiates a connection to an unavailable [ip,port], ECONNREFUSED will be stored in the TCP socket, but SMC will not. However, some apps (like curl) use getsockopt(,,SO_ERROR,,) to get the error information, which makes them miss the error message and behave strangely. Fixes: 50717a37db03 ("net/smc: nonblocking connect rework") Signed-off-by: liuyacan <liuyacan@corp.netease.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>
* net/smc: Fix sock leak when release after smc_shutdown()Tony Lu2022-04-151-1/+3
| | | | | | | | | | | | | | | Since commit e5d5aadcf3cd ("net/smc: fix sk_refcnt underflow on linkdown and fallback"), for a fallback connection, __smc_release() does not call sock_put() if its state is already SMC_CLOSED. When calling smc_shutdown() after falling back, its state is set to SMC_CLOSED but does not call sock_put(), so this patch calls it. Reported-and-tested-by: syzbot+6e29a053eb165bd50de5@syzkaller.appspotmail.com Fixes: e5d5aadcf3cd ("net/smc: fix sk_refcnt underflow on linkdown and fallback") Signed-off-by: Tony Lu <tonylu@linux.alibaba.com> Acked-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net/smc: Fix af_ops of child socket pointing to released memoryKarsten Graul2022-04-111-2/+12
| | | | | | | | | | | | | | | Child sockets may inherit the af_ops from the parent listen socket. When the listen socket is released then the af_ops of the child socket points to released memory. Solve that by restoring the original af_ops for child sockets which inherited the parent af_ops. And clear any inherited user_data of the parent socket. Fixes: 8270d9c21041 ("net/smc: Limit backlog connections") Reviewed-by: Wenjia Zhang <wenjia@linux.ibm.com> Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Reviewed-by: D. Wythe <alibuda@linux.alibaba.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
* net/smc: fix compile warning for smc_sysctlDust Li2022-03-071-9/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | kernel test robot reports multiple warning for smc_sysctl: In file included from net/smc/smc_sysctl.c:17: >> net/smc/smc_sysctl.h:23:5: warning: no previous prototype \ for function 'smc_sysctl_init' [-Wmissing-prototypes] int smc_sysctl_init(void) ^ and >> WARNING: modpost: vmlinux.o(.text+0x12ced2d): Section mismatch \ in reference from the function smc_sysctl_exit() to the variable .init.data:smc_sysctl_ops The function smc_sysctl_exit() references the variable __initdata smc_sysctl_ops. This is often because smc_sysctl_exit lacks a __initdata annotation or the annotation of smc_sysctl_ops is wrong. and net/smc/smc_sysctl.c: In function 'smc_sysctl_init_net': net/smc/smc_sysctl.c:47:17: error: 'struct netns_smc' has no member named 'smc_hdr' 47 | net->smc.smc_hdr = register_net_sysctl(net, "net/smc", table); Since we don't need global sysctl initialization. To make things clean and simple, remove the global pernet_operations and smc_sysctl_{init|exit}. Call smc_sysctl_net_{init|exit} directly from smc_net_{init|exit}. Also initialized sysctl_autocorking_size if CONFIG_SYSCTL it not set, this make sure SMC autocorking is enabled by default if CONFIG_SYSCTL is not set. Fixes: 462791bbfa35 ("net/smc: add sysctl interface for SMC") Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Dust Li <dust.li@linux.alibaba.com> Tested-by: Randy Dunlap <rdunlap@infradead.org> # build-tested Signed-off-by: David S. Miller <davem@davemloft.net>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski2022-03-031-3/+11
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | net/batman-adv/hard-interface.c commit 690bb6fb64f5 ("batman-adv: Request iflink once in batadv-on-batadv check") commit 6ee3c393eeb7 ("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 4d08b7b57ece ("net/smc: Fix cleanup when register ULP fails") commit 462791bbfa35 ("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>
| * net/smc: Fix cleanup when register ULP failsTony Lu2022-02-281-1/+3
| | | | | | | | | | | | | | | | | | This patch calls smc_ib_unregister_client() when tcp_register_ulp() fails, and make sure to clean it up. Fixes: d7cd421da9da ("net/smc: Introduce TCP ULP support") Signed-off-by: Tony Lu <tonylu@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
| * net/smc: fix connection leakD. Wythe2022-02-251-2/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There's a potential leak issue under following execution sequence : smc_release smc_connect_work if (sk->sk_state == SMC_INIT) send_clc_confirim tcp_abort(); ... sk.sk_state = SMC_ACTIVE smc_close_active switch(sk->sk_state) { ... case SMC_ACTIVE: smc_close_final() // then wait peer closed Unfortunately, tcp_abort() may discard CLC CONFIRM messages that are still in the tcp send buffer, in which case our connection token cannot be delivered to the server side, which means that we cannot get a passive close message at all. Therefore, it is impossible for the to be disconnected at all. This patch tries a very simple way to avoid this issue, once the state has changed to SMC_ACTIVE after tcp_abort(), we can actively abort the smc connection, considering that the state is SMC_INIT before tcp_abort(), abandoning the complete disconnection process should not cause too much problem. In fact, this problem may exist as long as the CLC CONFIRM message is not received by the server. Whether a timer should be added after smc_close_final() needs to be discussed in the future. But even so, this patch provides a faster release for connection in above case, it should also be valuable. Fixes: 39f41f367b08 ("net/smc: common release code for non-accepted sockets") Signed-off-by: D. Wythe <alibuda@linux.alibaba.com> Acked-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | net/smc: don't send in the BH context if sock_owned_by_userDust Li2022-03-011-0/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | net/smc: send directly on setting TCP_NODELAYDust Li2022-03-011-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In commit ea785a1a573b("net/smc: Send directly when TCP_CORK is cleared"), we don't use delayed work to implement cork. This patch use the same algorithm, removes the delayed work when setting TCP_NODELAY and send directly in setsockopt(). This also makes the TCP_NODELAY the same as TCP. Cc: Tony Lu <tonylu@linux.alibaba.com> Signed-off-by: Dust Li <dust.li@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | net/smc: add sysctl interface for SMCDust Li2022-03-011-0/+10
| | | | | | | | | | | | | | | | | | | | | | This patch add sysctl interface to support container environment for SMC as we talk in the mail list. Link: https://lore.kernel.org/netdev/20220224020253.GF5443@linux.alibaba.com Co-developed-by: Tony Lu <tonylu@linux.alibaba.com> Signed-off-by: Tony Lu <tonylu@linux.alibaba.com> Signed-off-by: Dust Li <dust.li@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | net/smc: unlock on error paths in __smc_setsockopt()Dan Carpenter2022-02-191-4/+8
| | | | | | | | | | | | | | | | | | These two error paths need to release_sock(sk) before returning. Fixes: a6a6fe27bab4 ("net/smc: Dynamic control handshake limitation by socket options") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Reviewed-by: D. Wythe <alibuda@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski2022-02-171-3/+7
|\| | | | | | | | | | | No conflicts. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| * net/smc: Avoid overwriting the copies of clcsock callback functionsWen Gu2022-02-111-3/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The callback functions of clcsock will be saved and replaced during the fallback. But if the fallback happens more than once, then the copies of these callback functions will be overwritten incorrectly, resulting in a loop call issue: clcsk->sk_error_report |- smc_fback_error_report() <------------------------------| |- smc_fback_forward_wakeup() | (loop) |- clcsock_callback() (incorrectly overwritten) | |- smc->clcsk_error_report() ------------------| So this patch fixes the issue by saving these function pointers only once in the fallback and avoiding overwriting. Reported-by: syzbot+4de3c0e8a263e1e499bc@syzkaller.appspotmail.com Fixes: 341adeec9ada ("net/smc: Forward wakeup to smc socket waitqueue after fallback") Link: https://lore.kernel.org/r/0000000000006d045e05d78776f6@google.com Signed-off-by: Wen Gu <guwen@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | net/smc: return ETIMEDOUT when smc_connect_clc() timeoutD. Wythe2022-02-161-1/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When smc_connect_clc() times out, it will return -EAGAIN(tcp_recvmsg retuns -EAGAIN while timeout), then this value will passed to the application, which is quite confusing to the applications, makes inconsistency with TCP. From the manual of connect, ETIMEDOUT is more suitable, and this patch try convert EAGAIN to ETIMEDOUT in that case. Signed-off-by: D. Wythe <alibuda@linux.alibaba.com> Reviewed-by: Karsten Graul <kgraul@linux.ibm.com> Link: https://lore.kernel.org/r/1644913490-21594-1-git-send-email-alibuda@linux.alibaba.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
* | net/smc: Add global configure for handshake limitation by netlinkD. Wythe2022-02-111-0/+42
| | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | net/smc: Dynamic control handshake limitation by socket optionsD. Wythe2022-02-111-1/+68
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | net/smc: Limit SMC visits when handshake workqueue congestedD. Wythe2022-02-111-0/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch intends to provide a mechanism to put constraint on SMC connections visit according to the pressure of SMC handshake process. At present, frequent visits will cause the incoming connections to be backlogged in SMC handshake queue, raise the connections established time. Which is quite unacceptable for those applications who base on short lived connections. There are two ways to implement this mechanism: 1. Put limitation after TCP established. 2. Put limitation before TCP established. In the first way, we need to wait and receive CLC messages that the client will potentially send, and then actively reply with a decline message, in a sense, which is also a sort of SMC handshake, affect the connections established time on its way. In the second way, the only problem is that we need to inject SMC logic into TCP when it is about to reply the incoming SYN, since we already do that, it's seems not a problem anymore. And advantage is obvious, few additional processes are required to complete the constraint. This patch use the second way. After this patch, connections who beyond constraint will not informed any SMC indication, and SMC will not be involved in any of its subsequent processes. Link: https://lore.kernel.org/all/1641301961-59331-1-git-send-email-alibuda@linux.alibaba.com/ Signed-off-by: D. Wythe <alibuda@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | net/smc: Limit backlog connectionsD. Wythe2022-02-111-0/+45
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | net/smc: Make smc_tcp_listen_work() independentD. Wythe2022-02-111-2/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In multithread and 10K connections benchmark, the backend TCP connection established very slowly, and lots of TCP connections stay in SYN_SENT state. Client: smc_run wrk -c 10000 -t 4 http://server the netstate of server host shows like: 145042 times the listen queue of a socket overflowed 145042 SYNs to LISTEN sockets dropped One reason of this issue is that, since the smc_tcp_listen_work() shared the same workqueue (smc_hs_wq) with smc_listen_work(), while the smc_listen_work() do blocking wait for smc connection established. Once the workqueue became congested, it's will block the accept() from TCP listen. This patch creates a independent workqueue(smc_tcp_ls_wq) for smc_tcp_listen_work(), separate it from smc_listen_work(), which is quite acceptable considering that smc_tcp_listen_work() runs very fast. Signed-off-by: D. Wythe <alibuda@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski2022-02-031-15/+118
|\| | | | | | | | | | | No conflicts. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| * net/smc: Forward wakeup to smc socket waitqueue after fallbackWen Gu2022-01-311-15/+118
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: 2153bd1e3d3d ("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>
* | net/smc: Cork when sendpage with MSG_SENDPAGE_NOTLAST flagTony Lu2022-01-311-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This introduces a new corked flag, MSG_SENDPAGE_NOTLAST, which is involved in syscall sendfile() [1], it indicates this is not the last page. So we can cork the data until the page is not specify this flag. It has the same effect as MSG_MORE, but existed in sendfile() only. This patch adds a option MSG_SENDPAGE_NOTLAST for corking data, try to cork more data before sending when using sendfile(), which acts like TCP's behaviour. Also, this reimplements the default sendpage to inform that it is supported to some extent. [1] https://man7.org/linux/man-pages/man2/sendfile.2.html Signed-off-by: Tony Lu <tonylu@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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