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2021-10-20net/smc: improved fix wait on already cleared linkKarsten Graul
commit 95f7f3e7dc6bd2e735cb5de11734ea2222b1e05a upstream. Commit 8f3d65c16679 ("net/smc: fix wait on already cleared link") introduced link refcounting to avoid waits on already cleared links. This patch extents and improves the refcounting to cover all remaining possible cases for this kind of error situation. Fixes: 15e1b99aadfb ("net/smc: no WR buffer wait for terminating link group") Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-09-30net/smc: fix 'workqueue leaked lock' in smc_conn_abort_workKarsten Graul
[ Upstream commit a18cee4791b1123d0a6579a7c89f4b87e48abe03 ] The abort_work is scheduled when a connection was detected to be out-of-sync after a link failure. The work calls smc_conn_kill(), which calls smc_close_active_abort() and that might end up calling smc_close_cancel_work(). smc_close_cancel_work() cancels any pending close_work and tx_work but needs to release the sock_lock before and acquires the sock_lock again afterwards. So when the sock_lock was NOT acquired before then it may be held after the abort_work completes. Thats why the sock_lock is acquired before the call to smc_conn_kill() in __smc_lgr_terminate(), but this is missing in smc_conn_abort_work(). Fix that by acquiring the sock_lock first and release it after the call to smc_conn_kill(). Fixes: b286a0651e44 ("net/smc: handle incoming CDC validation message") Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-08-09net/smc: Correct smc link connection counter in case of smc clientGuvenc Gulce
SMC clients may be assigned to a different link after the initial connection between two peers was established. In such a case, the connection counter was not correctly set. Update the connection counter correctly when a smc client connection is assigned to a different smc link. Fixes: 07d51580ff65 ("net/smc: Add connection counters for links") Signed-off-by: Guvenc Gulce <guvenc@linux.ibm.com> Tested-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-16net/smc: Make SMC statistics network namespace awareGuvenc Gulce
Make the gathered SMC statistics network namespace aware, for each namespace collect an own set of statistic information. Signed-off-by: Guvenc Gulce <guvenc@linux.ibm.com> Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-16net/smc: Add SMC statistics supportGuvenc Gulce
Add the ability to collect SMC statistics information. Per-cpu variables are used to collect the statistic information for better performance and for reducing concurrency pitfalls. The code that is collecting statistic data is implemented in macros to increase code reuse and readability. Signed-off-by: Guvenc Gulce <guvenc@linux.ibm.com> Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-03net/smc: avoid possible duplicate dmb unregistrationKarsten Graul
smc_lgr_cleanup() calls smcd_unregister_all_dmbs() as part of the link group termination process. This is a leftover from the times when smc_lgr_cleanup() scheduled a worker to actually free the link group. Nowadays smc_lgr_cleanup() directly calls smc_lgr_free() without any delay so an earlier dmb unregistration is no longer needed. So remove smcd_unregister_all_dmbs() and the call to it. Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-01-12net/smc: use memcpy instead of snprintf to avoid out of bounds readGuvenc Gulce
Using snprintf() to convert not null-terminated strings to null terminated strings may cause out of bounds read in the source string. Therefore use memcpy() and terminate the target string with a null afterwards. Fixes: a3db10efcc4c ("net/smc: Add support for obtaining SMCR device list") Signed-off-by: Guvenc Gulce <guvenc@linux.ibm.com> Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-01-12smc: fix out of bound access in smc_nl_get_sys_info()Jakub Kicinski
smc_clc_get_hostname() sets the host pointer to a buffer which is not NULL-terminated (see smc_clc_init()). Reported-by: syzbot+f4708c391121cfc58396@syzkaller.appspotmail.com Fixes: 099b990bd11a ("net/smc: Add support for obtaining system information") Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-01net/smc: Add support for obtaining SMCR device listGuvenc Gulce
Deliver SMCR device information via netlink based diagnostic interface. Signed-off-by: Guvenc Gulce <guvenc@linux.ibm.com> Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-01net/smc: Add SMC-D Linkgroup diagnostic supportGuvenc Gulce
Deliver SMCD Linkgroup information via netlink based diagnostic interface. Signed-off-by: Guvenc Gulce <guvenc@linux.ibm.com> Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-01net/smc: Introduce SMCR get link commandGuvenc Gulce
Introduce get link command which loops through all available links of all available link groups. It uses the SMC-R linkgroup list as entry point, not the socket list, which makes linkgroup diagnosis possible, in case linkgroup does not contain active connections anymore. Signed-off-by: Guvenc Gulce <guvenc@linux.ibm.com> Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-01net/smc: Introduce SMCR get linkgroup commandGuvenc Gulce
Introduce get linkgroup command which loops through all available SMCR linkgroups. It uses the SMC-R linkgroup list as entry point, not the socket list, which makes linkgroup diagnosis possible, in case linkgroup does not contain active connections anymore. Signed-off-by: Guvenc Gulce <guvenc@linux.ibm.com> Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-01net/smc: Add support for obtaining system informationGuvenc Gulce
Add new netlink command to obtain system information of the smc module. Signed-off-by: Guvenc Gulce <guvenc@linux.ibm.com> Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-01net/smc: Add diagnostic information to link structureGuvenc Gulce
During link creation add net-device ifindex and ib-device name to link structure. This is needed for diagnostic purposes. When diagnostic information is gathered, we need to traverse device, linkgroup and link structures, to be able to do that we need to hold a spinlock for the linkgroup list, without this diagnostic information in link structure, another device list mutex holding would be necessary to dereference the device pointer in the link structure which would be impossible when holding a spinlock already. Signed-off-by: Guvenc Gulce <guvenc@linux.ibm.com> Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-01net/smc: Add link counters for IB device portsGuvenc Gulce
Add link counters to the structure of the smc ib device, one counter per ib port. Increase/decrease the counters as needed in the corresponding routines. Signed-off-by: Guvenc Gulce <guvenc@linux.ibm.com> Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-01net/smc: Add connection counters for linksGuvenc Gulce
Add connection counters to the structure of the link. Increase/decrease the counters as needed in the corresponding routines. Signed-off-by: Guvenc Gulce <guvenc@linux.ibm.com> Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-11-19net/smc: fix matching of existing link groupsKarsten Graul
With the multi-subnet support of SMC-Dv2 the match for existing link groups should not include the vlanid of the network device. Set ini->smcd_version accordingly before the call to smc_conn_create() and use this value in smc_conn_create() to skip the vlanid check. Fixes: 5c21c4ccafe8 ("net/smc: determine accepted ISM devices") Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-10-26net/smc: fix suppressed return codeKarsten Graul
The patch that repaired the invalid return code in smcd_new_buf_create() missed to take care of errno ENOSPC which has a special meaning that no more DMBEs can be registered on the device. Fix that by keeping this errno value during the translation of the return code. Fixes: 6b1bbf94ab36 ("net/smc: fix invalid return code in smcd_new_buf_create()") Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-10-15Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Minor conflicts in net/mptcp/protocol.h and tools/testing/selftests/net/Makefile. In both cases code was added on both sides in the same place so just keep both. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-10-15net/smc: fix invalid return code in smcd_new_buf_create()Karsten Graul
smc_ism_register_dmb() returns error codes set by the ISM driver which are not guaranteed to be negative or in the errno range. Such values would not be handled by ERR_PTR() and finally the return code will be used as a memory address. Fix that by using a valid negative errno value with ERR_PTR(). Fixes: 72b7f6c48708 ("net/smc: unique reason code for exceeded max dmb count") Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-10-15net/smc: fix valid DMBE buffer sizesKarsten Graul
The SMCD_DMBE_SIZES should include all valid DMBE buffer sizes, so the correct value is 6 which means 1MB. With 7 the registration of an ISM buffer would always fail because of the invalid size requested. Fix that and set the value to 6. Fixes: c6ba7c9ba43d ("net/smc: add base infrastructure for SMC-D and ISM") Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-09-28net/smc: introduce CLC first contact extensionUrsula Braun
SMC Version 2 defines a first contact extension for CLC accept and CLC confirm. This patch covers sending and receiving of the CLC first contact extension. Signed-off-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-28net/smc: determine accepted ISM devicesUrsula Braun
SMCD Version 2 allows to propose up to 8 additional ISM devices offered to the peer as candidates for SMCD communication. This patch covers the server side, i.e. selection of an ISM device matching one of the proposed ISM devices, that will be used for CLC accept Signed-off-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-28net/smc: prepare for more proposed ISM devicesUrsula Braun
SMCD Version 2 allows proposing of up to 8 ISM devices in addition to the native ISM device of SMCD Version 1. This patch prepares the struct smc_init_info to deal with these additional 8 ISM devices. Signed-off-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-10net/smc: use separate work queues for different worker typesKarsten Graul
There are 6 types of workers which exist per smc connection. 3 of them are used for listen and handshake processing, another 2 are used for close and abort processing and 1 is the tx worker that moves calls to sleeping functions into a worker. To prevent flooding of the system work queue when many connections are opened or closed at the same time (some pattern uperf implements), move those workers to one of 3 smc-specific work queues. Two work queues are module-global and used for handshake and close workers. The third work queue is defined per link group and used by the tx workers that may sleep waiting for resources of this link group. And in smc_llc_enqueue() queue the llc_event_work work to the system prio work queue because its critical that this work is started fast. Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-10net/smc: immediate freeing in smc_lgr_cleanup_early()Ursula Braun
smc_lgr_cleanup_early() schedules the free worker with delay. DMB unregistering occurs in this delayed worker increasing the risk to reach the SMCD SBA limit without need. Terminate the linkgroup immediately, since termination means early DMB unregistering. For SMCD the global smc_server_lgr_pending lock is given up early. A linkgroup to be given up with smc_lgr_cleanup_early() may already contain more than one connection. Using __smc_lgr_terminate() in smc_lgr_cleanup_early() covers this. And consolidate smc_ism_put_vlan() and smc_put_device() into smc_lgr_free() only. Signed-off-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-10net/smc: common routine for CLC accept and confirmUrsula Braun
smc_clc_send_accept() and smc_clc_send_confirm() are quite similar. Move common code into a separate function smc_clc_send_confirm_accept(). And introduce separate SMCD and SMCR struct definitions for CLC accept resp. confirm. No functional change. Signed-off-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-10net/smc: introduce better field namesUrsula Braun
Field names "srv_first_contact" and "cln_first_contact" are misleading, since they apply to both, server and client. Rename them to "first_contact_peer" and "first_contact_local". Rename "ism_gid" by the more precise name "ism_peer_gid". Rename version constant "SMC_CLC_V1" into "SMC_V1". No functional change. Signed-off-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-03net/smc: reset sndbuf_desc if freedUrsula Braun
When an SMC connection is created, and there is a problem to create an RMB or DMB, the previously created send buffer is thrown away as well including buffer descriptor freeing. Make sure the connection no longer references the freed buffer descriptor, otherwise bugs like this are possible: [71556.835148] ============================================================================= [71556.835168] BUG kmalloc-128 (Tainted: G B OE ): Poison overwritten [71556.835172] ----------------------------------------------------------------------------- [71556.835179] INFO: 0x00000000d20894be-0x00000000aaef63e9 @offset=2724. First byte 0x0 instead of 0x6b [71556.835215] INFO: Allocated in __smc_buf_create+0x184/0x578 [smc] age=0 cpu=5 pid=46726 [71556.835234] ___slab_alloc+0x5a4/0x690 [71556.835239] __slab_alloc.constprop.0+0x70/0xb0 [71556.835243] kmem_cache_alloc_trace+0x38e/0x3f8 [71556.835250] __smc_buf_create+0x184/0x578 [smc] [71556.835257] smc_buf_create+0x2e/0xe8 [smc] [71556.835264] smc_listen_work+0x516/0x6a0 [smc] [71556.835275] process_one_work+0x280/0x478 [71556.835280] worker_thread+0x66/0x368 [71556.835287] kthread+0x17a/0x1a0 [71556.835294] ret_from_fork+0x28/0x2c [71556.835301] INFO: Freed in smc_buf_create+0xd8/0xe8 [smc] age=0 cpu=5 pid=46726 [71556.835307] __slab_free+0x246/0x560 [71556.835311] kfree+0x398/0x3f8 [71556.835318] smc_buf_create+0xd8/0xe8 [smc] [71556.835324] smc_listen_work+0x516/0x6a0 [smc] [71556.835328] process_one_work+0x280/0x478 [71556.835332] worker_thread+0x66/0x368 [71556.835337] kthread+0x17a/0x1a0 [71556.835344] ret_from_fork+0x28/0x2c [71556.835348] INFO: Slab 0x00000000a0744551 objects=51 used=51 fp=0x0000000000000000 flags=0x1ffff00000010200 [71556.835352] INFO: Object 0x00000000563480a1 @offset=2688 fp=0x00000000289567b2 [71556.835359] Redzone 000000006783cde2: bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb ................ [71556.835363] Redzone 00000000e35b876e: bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb ................ [71556.835367] Redzone 0000000023074562: bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb ................ [71556.835372] Redzone 00000000b9564b8c: bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb ................ [71556.835376] Redzone 00000000810c6362: bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb ................ [71556.835380] Redzone 0000000065ef52c3: bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb ................ [71556.835384] Redzone 00000000c5dd6984: bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb ................ [71556.835388] Redzone 000000004c480f8f: bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb ................ [71556.835392] Object 00000000563480a1: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk [71556.835397] Object 000000009c479d06: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk [71556.835401] Object 000000006e1dce92: 6b 6b 6b 6b 00 00 00 00 6b 6b 6b 6b 6b 6b 6b 6b kkkk....kkkkkkkk [71556.835405] Object 00000000227f7cf8: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk [71556.835410] Object 000000009a701215: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk [71556.835414] Object 000000003731ce76: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk [71556.835418] Object 00000000f7085967: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk [71556.835422] Object 0000000007f99927: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b a5 kkkkkkkkkkkkkkk. [71556.835427] Redzone 00000000579c4913: bb bb bb bb bb bb bb bb ........ [71556.835431] Padding 00000000305aef82: 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a ZZZZZZZZZZZZZZZZ [71556.835435] Padding 00000000b1cdd722: 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a ZZZZZZZZZZZZZZZZ [71556.835438] Padding 00000000c7568199: 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a ZZZZZZZZZZZZZZZZ [71556.835442] Padding 00000000fad4c4d4: 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a ZZZZZZZZZZZZZZZZ [71556.835451] CPU: 0 PID: 47939 Comm: kworker/0:15 Tainted: G B OE 5.9.0-rc1uschi+ #54 [71556.835456] Hardware name: IBM 3906 M03 703 (LPAR) [71556.835464] Workqueue: events smc_listen_work [smc] [71556.835470] Call Trace: [71556.835478] [<00000000d5eaeb10>] show_stack+0x90/0xf8 [71556.835493] [<00000000d66fc0f8>] dump_stack+0xa8/0xe8 [71556.835499] [<00000000d61a511c>] check_bytes_and_report+0x104/0x130 [71556.835504] [<00000000d61a57b2>] check_object+0x26a/0x2e0 [71556.835509] [<00000000d61a59bc>] alloc_debug_processing+0x194/0x238 [71556.835514] [<00000000d61a8c14>] ___slab_alloc+0x5a4/0x690 [71556.835519] [<00000000d61a9170>] __slab_alloc.constprop.0+0x70/0xb0 [71556.835524] [<00000000d61aaf66>] kmem_cache_alloc_trace+0x38e/0x3f8 [71556.835530] [<000003ff80549bbc>] __smc_buf_create+0x184/0x578 [smc] [71556.835538] [<000003ff8054a396>] smc_buf_create+0x2e/0xe8 [smc] [71556.835545] [<000003ff80540c16>] smc_listen_work+0x516/0x6a0 [smc] [71556.835549] [<00000000d5f0f448>] process_one_work+0x280/0x478 [71556.835554] [<00000000d5f0f6a6>] worker_thread+0x66/0x368 [71556.835559] [<00000000d5f18692>] kthread+0x17a/0x1a0 [71556.835563] [<00000000d6abf3b8>] ret_from_fork+0x28/0x2c [71556.835569] INFO: lockdep is turned off. [71556.835573] FIX kmalloc-128: Restoring 0x00000000d20894be-0x00000000aaef63e9=0x6b [71556.835577] FIX kmalloc-128: Marking all objects used Fixes: fd7f3a746582 ("net/smc: remove freed buffer from list") Reviewed-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-03net/smc: set rx_off for SMCR explicitlyUrsula Braun
SMC tries to make use of SMCD first. If a problem shows up, it tries to switch to SMCR. If the SMCD initializing problem shows up after the SMCD connection has already been initialized, field rx_off keeps the wrong SMCD value for SMCR, which results in corrupted data at the receiver. This patch adds an explicit (re-)setting of field rx_off to zero if the connection uses SMCR. Fixes: be244f28d22f ("net/smc: add SMC-D support in data transfer") Reviewed-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-27net/smc: unique reason code for exceeded max dmb countKarsten Graul
When the maximum dmb buffer limit for an ism device is reached no more dmb buffers can be registered. When this happens the reason code is set to SMC_CLC_DECL_MEM indicating out-of-memory. This is the same reason code that is used when no memory could be allocated for the new dmb buffer. This is confusing for users when they see this error but there is more memory available. To solve this set a separate new reason code when the maximum dmb limit exceeded. Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-20net/smc: fix dmb buffer shortageKarsten Graul
There is a current limit of 1920 registered dmb buffers per ISM device for smc-d. One link group can contain 255 connections, each connection is using one dmb buffer. When the connection is closed then the registered buffer is held in a queue and is reused by the next connection. When a link group is 'full' then another link group is created and uses an own buffer pool. The link groups are added to a list using list_add() which puts a new link group to the first position in the list. In the situation that many connections are opened (>1920) and a few of them stay open while others are closed quickly we end up with at least 8 link groups. For a new connection a matching link group is looked up, iterating over the list of link groups. The trailing 7 link groups all have registered dmb buffers which could be reused, while the first link group has only a few dmb buffers and then hit the 1920 limit. Because the first link group is not full (255 connection limit not reached) it is chosen and finally the connection falls back to TCP because there is no dmb buffer available in this link group. There are multiple ways to fix that: using list_add_tail() allows to scan older link groups first for free buffers which ensures that buffers are reused first. This fixes the problem for smc-r link groups as well. For smc-d there is an even better way to address this problem because smc-d does not have the 255 connections per link group limit. So fix the problem for smc-d by allowing large link groups. Fixes: c6ba7c9ba43d ("net/smc: add base infrastructure for SMC-D and ISM") Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-19net/smc: remove freed buffer from listKarsten Graul
Two buffers are allocated for each SMC connection. Each buffer is added to a buffer list after creation. When the second buffer allocation fails, the first buffer is freed but not deleted from the list. This might result in crashes when another connection picks up the freed buffer later and starts to work with it. Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Fixes: 6511aad3f039 ("net/smc: change smc_buf_free function parameters") Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-19net/smc: do not call dma sync for unmapped memoryKarsten Graul
The dma related ...sync_sg... functions check the link state before the dma function is actually called. But the check in smc_link_usable() allows links in ACTIVATING state which are not yet mapped to dma memory. Under high load it may happen that the sync_sg functions are called for such a link which results in an debug output like DMA-API: mlx5_core 0002:00:00.0: device driver tries to sync DMA memory it has not allocated [device address=0x0000000103370000] [size=65536 bytes] To fix that introduce a helper to check for the link state ACTIVE and use it where appropriate. And move the link state update to ACTIVATING to the end of smcr_link_init() when most initial setup is done. Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Fixes: d854fcbfaeda ("net/smc: add new link state and related helpers") Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-19net/smc: move add link processing for new device into llc layerKarsten Graul
When a new ib device is up smc will send an add link invitation to the peer if needed. This is currently done with rudimentary flow control. Under high workload these add link invitations can disturb other llc flows because they arrive unexpected. Fix this by integrating the invitations into the normal llc event flow and handle them as a flow. While at it, check for already assigned requests in the flow before the new add link request is assigned. Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Fixes: 1f90a05d9ff9 ("net/smc: add smcr_port_add() and smcr_link_up() processing") Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-19net/smc: clear link during SMC client link down processingKarsten Graul
In a link-down condition we notify the SMC server and expect that the server will finally trigger the link clear processing on the client side. This could fail when anything along this notification path goes wrong. Clear the link as part of SMC client link-down processing to prevent dangling links. Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Fixes: 541afa10c126 ("net/smc: add smcr_port_err() and smcr_link_down() processing") Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-08net/smc: switch smcd_dev_list spinlock to mutexUrsula Braun
The similar smc_ib_devices spinlock has been converted to a mutex. Protecting the smcd_dev_list by a mutex is possible as well. This patch converts the smcd_dev_list spinlock to a mutex. Fixes: c6ba7c9ba43d ("net/smc: add base infrastructure for SMC-D and ISM") Signed-off-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-08net/smc: fix sleep bug in smc_pnet_find_roce_resource()Ursula Braun
Tests showed this BUG: [572555.252867] BUG: sleeping function called from invalid context at kernel/locking/mutex.c:935 [572555.252876] in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 131031, name: smcapp [572555.252879] INFO: lockdep is turned off. [572555.252883] CPU: 1 PID: 131031 Comm: smcapp Tainted: G O 5.7.0-rc3uschi+ #356 [572555.252885] Hardware name: IBM 3906 M03 703 (LPAR) [572555.252887] Call Trace: [572555.252896] [<00000000ac364554>] show_stack+0x94/0xe8 [572555.252901] [<00000000aca1f400>] dump_stack+0xa0/0xe0 [572555.252906] [<00000000ac3c8c10>] ___might_sleep+0x260/0x280 [572555.252910] [<00000000acdc0c98>] __mutex_lock+0x48/0x940 [572555.252912] [<00000000acdc15c2>] mutex_lock_nested+0x32/0x40 [572555.252975] [<000003ff801762d0>] mlx5_lag_get_roce_netdev+0x30/0xc0 [mlx5_core] [572555.252996] [<000003ff801fb3aa>] mlx5_ib_get_netdev+0x3a/0xe0 [mlx5_ib] [572555.253007] [<000003ff80063848>] smc_pnet_find_roce_resource+0x1d8/0x310 [smc] [572555.253011] [<000003ff800602f0>] __smc_connect+0x1f0/0x3e0 [smc] [572555.253015] [<000003ff80060634>] smc_connect+0x154/0x190 [smc] [572555.253022] [<00000000acbed8d4>] __sys_connect+0x94/0xd0 [572555.253025] [<00000000acbef620>] __s390x_sys_socketcall+0x170/0x360 [572555.253028] [<00000000acdc6800>] system_call+0x298/0x2b8 [572555.253030] INFO: lockdep is turned off. Function smc_pnet_find_rdma_dev() might be called from smc_pnet_find_roce_resource(). It holds the smc_ib_devices list spinlock while calling infiniband op get_netdev(). At least for mlx5 the get_netdev operation wants mutex serialization, which conflicts with the smc_ib_devices spinlock. This patch switches the smc_ib_devices spinlock into a mutex to allow sleeping when calling get_netdev(). Fixes: a4cf0443c414 ("smc: introduce SMC as an IB-client") Signed-off-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-08net/smc: separate LLC wait queues for flow and messagesKarsten Graul
There might be races in scenarios where both SMC link groups are on the same system. Prevent that by creating separate wait queues for LLC flows and messages. Switch to non-interruptable versions of wait_event() and wake_up() for the llc flow waiter to make sure the waiters get control sequentially. Fine tune the llc_flow_lock to include the assignment of the message. Write to system log when an unexpected message was dropped. And remove an extra indirection and use the existing local variable lgr in smc_llc_enqueue(). Fixes: 555da9af827d ("net/smc: add event-based llc_flow framework") Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-30net/smc: pre-fetch send buffer outside of send_lockKarsten Graul
Pre-fetch send buffer for the CDC validation message before entering the send_lock. Without that the send call might fail with -EBUSY because there are no free buffers and waiting for buffers is not possible under send_lock. Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-05net/smc: log important pnetid and state change eventsKarsten Graul
Print to system log when SMC links are available or go down, link group state changes or pnetids are applied to and removed from devices. The log entries are triggered by either user configuration actions or adapter activation/deactivation events and are not expected to happen often. The entries help SMC users to keep track of the SMC link group status and to detect when actions are needed (like to add replacements for failed adapters). Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-04net/smc: create improved SMC-R link_uidKarsten Graul
The link_uid of an SMC-R link is exchanged between SMC peers and its value can be used for debugging purposes. Create a unique link_uid during link initialization and use it in communication with SMC-R peers. Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-04net/smc: improve termination processingKarsten Graul
Add helper smcr_lgr_link_deactivate_all() and eliminate duplicate code. In smc_lgr_free(), clear the smc-r links before smc_lgr_free_bufs() is called so buffers are already prepared for free. The usage of the soft parameter in __smc_lgr_terminate() is no longer needed, smc_lgr_free() can be called directly. smc_lgr_terminate_sched() and smc_smcd_terminate() set lgr->freeing to indicate that the link group will be freed soon to avoid unnecessary schedules of the free worker. Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-04net/smc: add termination reason and handle LLC protocol violationKarsten Graul
Allow to set the reason code for the link group termination, and set meaningful values before termination processing is triggered. This reason code is sent to the peer in the final delete link message. When the LLC request or response layer receives a message type that was not handled, drop a warning and terminate the link group. Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-04net/smc: asymmetric link taggingKarsten Graul
New connections must not be assigned to asymmetric links. Add asymmetric link tagging using new link variable link_is_asym. The new helpers smcr_lgr_set_type() and smcr_lgr_set_type_asym() are called to set the state of the link group, and tag all links accordingly. smcr_lgr_conn_assign_link() respects the link tagging and will not assign new connections to links tagged as asymmetric link. Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-04net/smc: assign link to a new connectionKarsten Graul
For new connections, assign a link from the link group, using some simple load balancing. Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-04net/smc: send DELETE_LINK, ALL message and wait for send to completeKarsten Graul
Add smc_llc_send_message_wait() which uses smc_wr_tx_send_wait() to send an LLC message and waits for the message send to complete. smc_llc_send_link_delete_all() calls the new function to send an DELETE_LINK,ALL LLC message. The RFC states that the sender of this type of message needs to wait for the completion event of the message transmission and can terminate the link afterwards. Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-04net/smc: handle incoming CDC validation messageKarsten Graul
Call smc_cdc_msg_validate() when a CDC message with the failover validation bit enabled was received. Validate that the sequence number sent with the message is one we already have received. If not, messages were lost and the connection is terminated using a new abort_work. Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-04net/smc: send failover validation messageKarsten Graul
When a connection is switched to a new link then a link validation message must be sent to the peer over the new link, containing the sequence number of the last CDC message that was sent over the old link. The peer will validate if this sequence number is the same or lower then the number he received, and abort the connection if messages were lost. Add smcr_cdc_msg_send_validation() to send the message validation message and call it when a connection was switched in smc_switch_cursor(). Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-04net/smc: switch connections to alternate linkKarsten Graul
Add smc_switch_conns() to switch all connections from a link that is going down. Find an other link to switch the connections to, and switch each connection to the new link. smc_switch_cursor() updates the cursors of a connection to the state of the last successfully sent CDC message. When there is no link to switch to, terminate the link group. Call smc_switch_conns() when a link is going down. And with the possibility that links of connections can switch adapt CDC and TX functions to detect and handle link switches. Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>