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2024-01-26net/smc: fix incorrect SMC-D link group matching logicWen Gu
The logic to determine if SMC-D link group matches is incorrect. The correct logic should be that it only returns true when the GID is the same, and the SMC-D device is the same and the extended GID is the same (in the case of virtual ISM). It can be fixed by adding brackets around the conditional (or ternary) operator expression. But for better readability and maintainability, it has been changed to an if-else statement. Reported-by: Matthew Rosato <mjrosato@linux.ibm.com> Closes: https://lore.kernel.org/r/13579588-eb9d-4626-a063-c0b77ed80f11@linux.ibm.com Fixes: b40584d14570 ("net/smc: compatible with 128-bits extended GID of virtual ISM device") Link: https://lore.kernel.org/r/13579588-eb9d-4626-a063-c0b77ed80f11@linux.ibm.com Signed-off-by: Wen Gu <guwen@linux.alibaba.com> Reviewed-by: Alexandra Winter <wintera@linux.ibm.com> Link: https://lore.kernel.org/r/20240125123916.77928-1-guwen@linux.alibaba.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-12-26net/smc: support extended GID in SMC-D lgr netlink attributeWen Gu
Virtual ISM devices introduced in SMCv2.1 requires a 128 bit extended GID vs. the existing ISM 64bit GID. So the 2nd 64 bit of extended GID should be included in SMC-D linkgroup netlink attribute as well. Signed-off-by: Wen Gu <guwen@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-12-26net/smc: compatible with 128-bits extended GID of virtual ISM deviceWen Gu
According to virtual ISM support feature defined by SMCv2.1, GIDs of virtual ISM device are UUIDs defined by RFC4122, which are 128-bits long. So some adaptation work is required. And note that the GIDs of existing platform firmware ISM devices still remain 64-bits long. Signed-off-by: Wen Gu <guwen@linux.alibaba.com> Reviewed-by: Alexandra Winter <wintera@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-09-10net/smc: use smc_lgr_list.lock to protect smc_lgr_list.list iterate in ↵Guangguan Wang
smcr_port_add While doing smcr_port_add, there maybe linkgroup add into or delete from smc_lgr_list.list at the same time, which may result kernel crash. So, use smc_lgr_list.lock to protect smc_lgr_list.list iterate in smcr_port_add. The crash calltrace show below: BUG: kernel NULL pointer dereference, address: 0000000000000000 PGD 0 P4D 0 Oops: 0000 [#1] SMP NOPTI CPU: 0 PID: 559726 Comm: kworker/0:92 Kdump: loaded Tainted: G Hardware name: Alibaba Cloud Alibaba Cloud ECS, BIOS 449e491 04/01/2014 Workqueue: events smc_ib_port_event_work [smc] RIP: 0010:smcr_port_add+0xa6/0xf0 [smc] RSP: 0000:ffffa5a2c8f67de0 EFLAGS: 00010297 RAX: 0000000000000001 RBX: ffff9935e0650000 RCX: 0000000000000000 RDX: 0000000000000010 RSI: ffff9935e0654290 RDI: ffff9935c8560000 RBP: 0000000000000000 R08: 0000000000000000 R09: ffff9934c0401918 R10: 0000000000000000 R11: ffffffffb4a5c278 R12: ffff99364029aae4 R13: ffff99364029aa00 R14: 00000000ffffffed R15: ffff99364029ab08 FS: 0000000000000000(0000) GS:ffff994380600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 0000000f06a10003 CR4: 0000000002770ef0 PKRU: 55555554 Call Trace: smc_ib_port_event_work+0x18f/0x380 [smc] process_one_work+0x19b/0x340 worker_thread+0x30/0x370 ? process_one_work+0x340/0x340 kthread+0x114/0x130 ? __kthread_cancel_work+0x50/0x50 ret_from_fork+0x1f/0x30 Fixes: 1f90a05d9ff9 ("net/smc: add smcr_port_add() and smcr_link_up() processing") Signed-off-by: Guangguan Wang <guangguan.wang@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-08-19net/smc: Extend SMCR v2 linkgroup netlink attributeGuangguan Wang
Add SMC_NLA_LGR_R_V2_MAX_CONNS and SMC_NLA_LGR_R_V2_MAX_LINKS to SMCR v2 linkgroup netlink attribute SMC_NLA_LGR_R_V2 for linkgroup's detail info showing. Signed-off-by: Guangguan Wang <guangguan.wang@linux.alibaba.com> Reviewed-by: Jan Karcher <jaka@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-08-19net/smc: support max links per lgr negotiation in clc handshakeGuangguan Wang
Support max links per lgr negotiation in clc handshake for SMCR v2.1, which is one of smc v2.1 features. Server makes decision for the final value of max links based on the client preferred max links and self-preferred max links. Here use the minimum value of the client preferred max links and server preferred max links. Client Server Proposal(max links(client preferred)) --------------------------------------> Accept(max links(accepted value)) accepted value=min(client preferred, server preferred) <------------------------------------- Confirm(max links(accepted value)) -------------------------------------> Signed-off-by: Guangguan Wang <guangguan.wang@linux.alibaba.com> Reviewed-by: Tony Lu <tonylu@linux.alibaba.com> Reviewed-by: Jan Karcher <jaka@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-08-19net/smc: support max connections per lgr negotiationGuangguan Wang
Support max connections per lgr negotiation for SMCR v2.1, which is one of smc v2.1 features. Server makes decision for the final value of max conns based on the client preferred max conns and self-preferred max conns. Here use the minimum value of client preferred max conns and server preferred max conns. Client Server Proposal(max conns(client preferred)) ------------------------------------> Accept(max conns(accepted value)) accepted value=min(client preferred, server preferred) <----------------------------------- Confirm(max conns(accepted value)) -----------------------------------> Signed-off-by: Guangguan Wang <guangguan.wang@linux.alibaba.com> Reviewed-by: Tony Lu <tonylu@linux.alibaba.com> Reviewed-by: Jan Karcher <jaka@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-08-09net/smc: Fix setsockopt and sysctl to specify same buffer size againGerd Bayer
Commit 0227f058aa29 ("net/smc: Unbind r/w buffer size from clcsock and make them tunable") introduced the net.smc.rmem and net.smc.wmem sysctls to specify the size of buffers to be used for SMC type connections. This created a regression for users that specified the buffer size via setsockopt() as the effective buffer size was now doubled. Re-introduce the division by 2 in the SMC buffer create code and level this out by duplicating the net.smc.[rw]mem values used for initializing sk_rcvbuf/sk_sndbuf at socket creation time. This gives users of both methods (setsockopt or sysctl) the effective buffer size that they expect. Initialize net.smc.[rw]mem from its own constant of 64kB, respectively. Internal performance tests show that this value is a good compromise between throughput/latency and memory consumption. Also, this decouples it from any tuning that was done to net.ipv4.tcp_[rw]mem[1] before the module for SMC protocol was loaded. Check that no more than INT_MAX / 2 is assigned to net.smc.[rw]mem, in order to avoid any overflow condition when that is doubled for use in sk_sndbuf or sk_rcvbuf. While at it, drop the confusing sk_buf_size variable from __smc_buf_create and name "compressed" buffer size variables more consistently. Background: Before the commit mentioned above, SMC's buffer allocator in __smc_buf_create() always used half of the sockets' sk_rcvbuf/sk_sndbuf value as initial value to search for appropriate buffers. If the search resorted to using a bigger buffer when all buffers of the specified size were busy, the duplicate of the used effective buffer size is stored back to sk_rcvbuf/sk_sndbuf. When available, buffers of exactly the size that a user had specified as input to setsockopt() were used, despite setsockopt()'s documentation in "man 7 socket" talking of a mandatory duplication: [...] SO_SNDBUF Sets or gets the maximum socket send buffer in bytes. The kernel doubles this value (to allow space for book‐ keeping overhead) when it is set using setsockopt(2), and this doubled value is returned by getsockopt(2). The default value is set by the /proc/sys/net/core/wmem_default file and the maximum allowed value is set by the /proc/sys/net/core/wmem_max file. The minimum (doubled) value for this option is 2048. [...] Fixes: 0227f058aa29 ("net/smc: Unbind r/w buffer size from clcsock and make them tunable") Co-developed-by: Jan Karcher <jaka@linux.ibm.com> Signed-off-by: Jan Karcher <jaka@linux.ibm.com> Reviewed-by: Wenjia Zhang <wenjia@linux.ibm.com> Reviewed-by: Tony Lu <tonylu@linux.alibaba.com> Signed-off-by: Gerd Bayer <gbayer@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-05-19net/smc: Reset connection when trying to use SMCRv2 fails.Wen Gu
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>
2023-03-15net/smc: fix deadlock triggered by cancel_delayed_work_syn()Wenjia Zhang
The following LOCKDEP was detected: Workqueue: events smc_lgr_free_work [smc] WARNING: possible circular locking dependency detected 6.1.0-20221027.rc2.git8.56bc5b569087.300.fc36.s390x+debug #1 Not tainted ------------------------------------------------------ kworker/3:0/176251 is trying to acquire lock: 00000000f1467148 ((wq_completion)smc_tx_wq-00000000#2){+.+.}-{0:0}, at: __flush_workqueue+0x7a/0x4f0 but task is already holding lock: 0000037fffe97dc8 ((work_completion)(&(&lgr->free_work)->work)){+.+.}-{0:0}, at: process_one_work+0x232/0x730 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #4 ((work_completion)(&(&lgr->free_work)->work)){+.+.}-{0:0}: __lock_acquire+0x58e/0xbd8 lock_acquire.part.0+0xe2/0x248 lock_acquire+0xac/0x1c8 __flush_work+0x76/0xf0 __cancel_work_timer+0x170/0x220 __smc_lgr_terminate.part.0+0x34/0x1c0 [smc] smc_connect_rdma+0x15e/0x418 [smc] __smc_connect+0x234/0x480 [smc] smc_connect+0x1d6/0x230 [smc] __sys_connect+0x90/0xc0 __do_sys_socketcall+0x186/0x370 __do_syscall+0x1da/0x208 system_call+0x82/0xb0 -> #3 (smc_client_lgr_pending){+.+.}-{3:3}: __lock_acquire+0x58e/0xbd8 lock_acquire.part.0+0xe2/0x248 lock_acquire+0xac/0x1c8 __mutex_lock+0x96/0x8e8 mutex_lock_nested+0x32/0x40 smc_connect_rdma+0xa4/0x418 [smc] __smc_connect+0x234/0x480 [smc] smc_connect+0x1d6/0x230 [smc] __sys_connect+0x90/0xc0 __do_sys_socketcall+0x186/0x370 __do_syscall+0x1da/0x208 system_call+0x82/0xb0 -> #2 (sk_lock-AF_SMC){+.+.}-{0:0}: __lock_acquire+0x58e/0xbd8 lock_acquire.part.0+0xe2/0x248 lock_acquire+0xac/0x1c8 lock_sock_nested+0x46/0xa8 smc_tx_work+0x34/0x50 [smc] process_one_work+0x30c/0x730 worker_thread+0x62/0x420 kthread+0x138/0x150 __ret_from_fork+0x3c/0x58 ret_from_fork+0xa/0x40 -> #1 ((work_completion)(&(&smc->conn.tx_work)->work)){+.+.}-{0:0}: __lock_acquire+0x58e/0xbd8 lock_acquire.part.0+0xe2/0x248 lock_acquire+0xac/0x1c8 process_one_work+0x2bc/0x730 worker_thread+0x62/0x420 kthread+0x138/0x150 __ret_from_fork+0x3c/0x58 ret_from_fork+0xa/0x40 -> #0 ((wq_completion)smc_tx_wq-00000000#2){+.+.}-{0:0}: check_prev_add+0xd8/0xe88 validate_chain+0x70c/0xb20 __lock_acquire+0x58e/0xbd8 lock_acquire.part.0+0xe2/0x248 lock_acquire+0xac/0x1c8 __flush_workqueue+0xaa/0x4f0 drain_workqueue+0xaa/0x158 destroy_workqueue+0x44/0x2d8 smc_lgr_free+0x9e/0xf8 [smc] process_one_work+0x30c/0x730 worker_thread+0x62/0x420 kthread+0x138/0x150 __ret_from_fork+0x3c/0x58 ret_from_fork+0xa/0x40 other info that might help us debug this: Chain exists of: (wq_completion)smc_tx_wq-00000000#2 --> smc_client_lgr_pending --> (work_completion)(&(&lgr->free_work)->work) Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock((work_completion)(&(&lgr->free_work)->work)); lock(smc_client_lgr_pending); lock((work_completion) (&(&lgr->free_work)->work)); lock((wq_completion)smc_tx_wq-00000000#2); *** DEADLOCK *** 2 locks held by kworker/3:0/176251: #0: 0000000080183548 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x232/0x730 #1: 0000037fffe97dc8 ((work_completion) (&(&lgr->free_work)->work)){+.+.}-{0:0}, at: process_one_work+0x232/0x730 stack backtrace: CPU: 3 PID: 176251 Comm: kworker/3:0 Not tainted Hardware name: IBM 8561 T01 701 (z/VM 7.2.0) Call Trace: [<000000002983c3e4>] dump_stack_lvl+0xac/0x100 [<0000000028b477ae>] check_noncircular+0x13e/0x160 [<0000000028b48808>] check_prev_add+0xd8/0xe88 [<0000000028b49cc4>] validate_chain+0x70c/0xb20 [<0000000028b4bd26>] __lock_acquire+0x58e/0xbd8 [<0000000028b4cf6a>] lock_acquire.part.0+0xe2/0x248 [<0000000028b4d17c>] lock_acquire+0xac/0x1c8 [<0000000028addaaa>] __flush_workqueue+0xaa/0x4f0 [<0000000028addf9a>] drain_workqueue+0xaa/0x158 [<0000000028ae303c>] destroy_workqueue+0x44/0x2d8 [<000003ff8029af26>] smc_lgr_free+0x9e/0xf8 [smc] [<0000000028adf3d4>] process_one_work+0x30c/0x730 [<0000000028adf85a>] worker_thread+0x62/0x420 [<0000000028aeac50>] kthread+0x138/0x150 [<0000000028a63914>] __ret_from_fork+0x3c/0x58 [<00000000298503da>] ret_from_fork+0xa/0x40 INFO: lockdep is turned off. =================================================================== This deadlock occurs because cancel_delayed_work_sync() waits for the work(&lgr->free_work) to finish, while the &lgr->free_work waits for the work(lgr->tx_wq), which needs the sk_lock-AF_SMC, that is already used under the mutex_lock. The solution is to use cancel_delayed_work() instead, which kills off a pending work. Fixes: a52bcc919b14 ("net/smc: improve termination processing") Signed-off-by: Wenjia Zhang <wenjia@linux.ibm.com> Reviewed-by: Jan Karcher <jaka@linux.ibm.com> Reviewed-by: Karsten Graul <kgraul@linux.ibm.com> Reviewed-by: Tony Lu <tonylu@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-02-21Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
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>
2023-02-20net/smc: fix application data exceptionD. Wythe
There is a certain probability that following exceptions will occur in the wrk benchmark test: Running 10s test @ http://11.213.45.6:80 8 threads and 64 connections Thread Stats Avg Stdev Max +/- Stdev Latency 3.72ms 13.94ms 245.33ms 94.17% Req/Sec 1.96k 713.67 5.41k 75.16% 155262 requests in 10.10s, 23.10MB read Non-2xx or 3xx responses: 3 We will find that the error is HTTP 400 error, which is a serious exception in our test, which means the application data was corrupted. Consider the following scenarios: CPU0 CPU1 buf_desc->used = 0; cmpxchg(buf_desc->used, 0, 1) deal_with(buf_desc) memset(buf_desc->cpu_addr,0); This will cause the data received by a victim connection to be cleared, thus triggering an HTTP 400 error in the server. This patch exchange the order between clear used and memset, add barrier to ensure memory consistency. Fixes: 1c5526968e27 ("net/smc: Clear memory when release and reuse buffer") Signed-off-by: D. Wythe <alibuda@linux.alibaba.com> Reviewed-by: Wenjia Zhang <wenjia@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-02-04net/smc: replace mutex rmbs_lock and sndbufs_lock with rw_semaphoreD. Wythe
It's clear that rmbs_lock and sndbufs_lock are aims to protect the rmbs list or the sndbufs list. During connection establieshment, smc_buf_get_slot() will always be invoked, and it only performs read semantics in rmbs list and sndbufs list. Based on the above considerations, we replace mutex with rw_semaphore. Only smc_buf_get_slot() use down_read() to allow smc_buf_get_slot() run concurrently, other part use down_write() to keep exclusive semantics. Signed-off-by: D. Wythe <alibuda@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-02-04net/smc: use read semaphores to reduce unnecessary blocking in ↵D. Wythe
smc_buf_create() & smcr_buf_unuse() Following is part of Off-CPU graph during frequent SMC-R short-lived processing: process_one_work (51.19%) smc_close_passive_work (28.36%) smcr_buf_unuse (28.34%) rwsem_down_write_slowpath (28.22%) smc_listen_work (22.83%) smc_clc_wait_msg (1.84%) smc_buf_create (20.45%) smcr_buf_map_usable_links rwsem_down_write_slowpath (20.43%) smcr_lgr_reg_rmbs (0.53%) rwsem_down_write_slowpath (0.43%) smc_llc_do_confirm_rkey (0.08%) We can clearly see that during the connection establishment time, waiting time of connections is not on IO, but on llc_conf_mutex. What is more important, the core critical area (smcr_buf_unuse() & smc_buf_create()) only perfroms read semantics on links, we can easily replace it with read semaphore. Signed-off-by: D. Wythe <alibuda@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-02-04net/smc: llc_conf_mutex refactor, replace it with rw_semaphoreD. Wythe
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>
2023-01-25net/smc: De-tangle ism and smc device initializationStefan Raspl
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>
2023-01-25net/smc: Separate SMC-D and ISM APIsStefan Raspl
We separate the code implementing the struct smcd_ops API in the ISM device driver from the functions that may be used by other exploiters of ISM devices. Note: We start out small, and don't offer the whole breadth of the ISM device for public use, as many functions are specific to or likely only ever used in the context of SMC-D. This is the third 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>
2023-01-25net/smc: Register SMC-D as ISM clientStefan Raspl
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>
2022-10-15net/smc: Fix an error code in smc_lgr_create()Dan Carpenter
If smc_wr_alloc_lgr_mem() fails then return an error code. Don't return success. Fixes: 8799e310fb3f ("net/smc: add v2 support to the work request layer") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Reviewed-by: Wenjia Zhang <wenjia@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-09-22Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
drivers/net/ethernet/freescale/fec.h 7b15515fc1ca ("Revert "fec: Restart PPS after link state change"") 40c79ce13b03 ("net: fec: add stop mode support for imx8 platform") https://lore.kernel.org/all/20220921105337.62b41047@canb.auug.org.au/ drivers/pinctrl/pinctrl-ocelot.c c297561bc98a ("pinctrl: ocelot: Fix interrupt controller") 181f604b33cd ("pinctrl: ocelot: add ability to be used in a non-mmio configuration") https://lore.kernel.org/all/20220921110032.7cd28114@canb.auug.org.au/ tools/testing/selftests/drivers/net/bonding/Makefile bbb774d921e2 ("net: Add tests for bonding and team address list management") 152e8ec77640 ("selftests/bonding: add a test for bonding lladdr target") https://lore.kernel.org/all/20220921110437.5b7dbd82@canb.auug.org.au/ drivers/net/can/usb/gs_usb.c 5440428b3da6 ("can: gs_usb: gs_can_open(): fix race dev->can.state condition") 45dfa45f52e6 ("can: gs_usb: add RX and TX hardware timestamp support") https://lore.kernel.org/all/84f45a7d-92b6-4dc5-d7a1-072152fab6ff@tessares.net/ Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-09-22net/smc: Unbind r/w buffer size from clcsock and make them tunableTony Lu
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>
2022-09-22net/smc: Stop the CLC flow if no link to map buffers onWen Gu
There might be a potential race between SMC-R buffer map and link group termination. smc_smcr_terminate_all() | smc_connect_rdma() -------------------------------------------------------------- | smc_conn_create() for links in smcibdev | schedule links down | | smc_buf_create() | \- smcr_buf_map_usable_links() | \- no usable links found, | (rmb->mr = NULL) | | smc_clc_send_confirm() | \- access conn->rmb_desc->mr[]->rkey | (panic) During reboot and IB device module remove, all links will be set down and no usable links remain in link groups. In such situation smcr_buf_map_usable_links() should return an error and stop the CLC flow accessing to uninitialized mr. Fixes: b9247544c1bc ("net/smc: convert static link ID instances to support multiple links") Signed-off-by: Wen Gu <guwen@linux.alibaba.com> Link: https://lore.kernel.org/r/1663656189-32090-1-git-send-email-guwen@linux.alibaba.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-09-07net/smc: Fix possible access to freed memory in link clearYacan Liu
After modifying the QP to the Error state, all RX WR would be completed with WC in IB_WC_WR_FLUSH_ERR status. Current implementation does not wait for it is done, but destroy the QP and free the link group directly. So there is a risk that accessing the freed memory in tasklet context. Here is a crash example: BUG: unable to handle page fault for address: ffffffff8f220860 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD f7300e067 P4D f7300e067 PUD f7300f063 PMD 8c4e45063 PTE 800ffff08c9df060 Oops: 0002 [#1] SMP PTI CPU: 1 PID: 0 Comm: swapper/1 Kdump: loaded Tainted: G S OE 5.10.0-0607+ #23 Hardware name: Inspur NF5280M4/YZMB-00689-101, BIOS 4.1.20 07/09/2018 RIP: 0010:native_queued_spin_lock_slowpath+0x176/0x1b0 Code: f3 90 48 8b 32 48 85 f6 74 f6 eb d5 c1 ee 12 83 e0 03 83 ee 01 48 c1 e0 05 48 63 f6 48 05 00 c8 02 00 48 03 04 f5 00 09 98 8e <48> 89 10 8b 42 08 85 c0 75 09 f3 90 8b 42 08 85 c0 74 f7 48 8b 32 RSP: 0018:ffffb3b6c001ebd8 EFLAGS: 00010086 RAX: ffffffff8f220860 RBX: 0000000000000246 RCX: 0000000000080000 RDX: ffff91db1f86c800 RSI: 000000000000173c RDI: ffff91db62bace00 RBP: ffff91db62bacc00 R08: 0000000000000000 R09: c00000010000028b R10: 0000000000055198 R11: ffffb3b6c001ea58 R12: ffff91db80e05010 R13: 000000000000000a R14: 0000000000000006 R15: 0000000000000040 FS: 0000000000000000(0000) GS:ffff91db1f840000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffff8f220860 CR3: 00000001f9580004 CR4: 00000000003706e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <IRQ> _raw_spin_lock_irqsave+0x30/0x40 mlx5_ib_poll_cq+0x4c/0xc50 [mlx5_ib] smc_wr_rx_tasklet_fn+0x56/0xa0 [smc] tasklet_action_common.isra.21+0x66/0x100 __do_softirq+0xd5/0x29c asm_call_irq_on_stack+0x12/0x20 </IRQ> do_softirq_own_stack+0x37/0x40 irq_exit_rcu+0x9d/0xa0 sysvec_call_function_single+0x34/0x80 asm_sysvec_call_function_single+0x12/0x20 Fixes: bd4ad57718cc ("smc: initialize IB transport incl. PD, MR, QP, CQ, event, WR") Signed-off-by: Yacan Liu <liuyacan@corp.netease.com> Reviewed-by: Tony Lu <tonylu@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-07-18net/smc: Extend SMC-R link group netlink attributeWen Gu
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>
2022-07-18net/smc: Allow virtually contiguous sndbufs or RMBs for SMC-RWen Gu
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>
2022-07-18net/smc: Use sysctl-specified types of buffers in new link groupWen Gu
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>
2022-07-18net/smc: optimize for smc_sndbuf_sync_sg_for_device and smc_rmb_sync_sg_for_cpuGuangguan Wang
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>
2022-07-18net/smc: remove redundant dma sync opsGuangguan Wang
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>
2022-03-03Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
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>
2022-03-03net/smc: fix unexpected SMC_CLC_DECL_ERR_REGRMB error cause by serverD. Wythe
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: cd6851f30386 ("smc: remote memory buffers (RMBs)") Signed-off-by: D. Wythe <alibuda@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-03-03net/smc: fix unexpected SMC_CLC_DECL_ERR_REGRMB error generated by clientD. Wythe
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: 3e034725c0d8 ("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>
2022-03-01net/smc: correct settings of RMB window update limitDust Li
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>
2022-01-16net/smc: Fix hung_task when removing SMC-R devicesWen Gu
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 349d43127dac ("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: 349d43127dac ("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>
2022-01-13net/smc: Resolve the race between SMC-R link access and clearWen Gu
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>
2022-01-13net/smc: Introduce a new conn->lgr validity check helperWen Gu
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>
2022-01-13net/smc: Resolve the race between link group access and terminationWen Gu
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>
2022-01-09Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Merge in fixes directly in prep for the 5.17 merge window. No conflicts. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-01-06net/smc: Reset conn->lgr when link group registration failsWen Gu
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: 56bc3b2094b4 ("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>
2022-01-02net/smc: Print net namespace in logTony Lu
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>
2022-01-02net/smc: Add netlink net namespace supportTony Lu
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>
2022-01-02net/smc: Introduce net namespace support for linkgroupTony Lu
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>
2021-12-30Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
drivers/net/ethernet/mellanox/mlx5/core/en_tc.c commit 077cdda764c7 ("net/mlx5e: TC, Fix memory leak with rules with internal port") commit 31108d142f36 ("net/mlx5: Fix some error handling paths in 'mlx5e_tc_add_fdb_flow()'") commit 4390c6edc0fb ("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 49dc9013e34b ("net/smc: Use the bitmap API when applicable") commit 349d43127dac ("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>
2021-12-28net/smc: fix kernel panic caused by race of smc_sockDust Li
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: 5f08318f617b ("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>
2021-12-28net/smc: don't send CDC/LLC message if link not readyDust Li
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: 5f08318f617b ("smc: connection data control (CDC)") Signed-off-by: Dust Li <dust.li@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-12-06net/smc: Clear memory when release and reuse bufferTony Lu
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>
2021-12-02net/smc: fix wrong list_del in smc_lgr_cleanup_earlyDust Li
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: a0a62ee15a829 ("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>
2021-11-24net/smc: Fix NULL pointer dereferencing in smc_vlan_by_tcpsk()Karsten Graul
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: cb9d43f67754 ("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>
2021-11-15net/smc: Make sure the link_id is uniqueWen Gu
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: 026c381fb477 ("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>
2021-11-01net/smc: Introduce tracepoint for smcr link downTony Lu
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>
2021-10-16net/smc: add netlink support for SMC-Rv2Karsten Graul
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>
generated by cgit (git 2.34.1) at 2024-05-03 06:22:10 +0000