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2020-08-26scsi: zfcp: Fix use-after-free in request timeout handlersSteffen Maier
commit 2d9a2c5f581be3991ba67fa9e7497c711220ea8e upstream. Before v4.15 commit 75492a51568b ("s390/scsi: Convert timers to use timer_setup()"), we intentionally only passed zfcp_adapter as context argument to zfcp_fsf_request_timeout_handler(). Since we only trigger adapter recovery, it was unnecessary to sync against races between timeout and (late) completion. Likewise, we only passed zfcp_erp_action as context argument to zfcp_erp_timeout_handler(). Since we only wakeup an ERP action, it was unnecessary to sync against races between timeout and (late) completion. Meanwhile the timeout handlers get timer_list as context argument and do a timer-specific container-of to zfcp_fsf_req which can have been freed. Fix it by making sure that any request timeout handlers, that might just have started before del_timer(), are completed by using del_timer_sync() instead. This ensures the request free happens afterwards. Space time diagram of potential use-after-free: Basic idea is to have 2 or more pending requests whose timeouts run out at almost the same time. req 1 timeout ERP thread req 2 timeout ---------------- ---------------- --------------------------------------- zfcp_fsf_request_timeout_handler fsf_req = from_timer(fsf_req, t, timer) adapter = fsf_req->adapter zfcp_qdio_siosl(adapter) zfcp_erp_adapter_reopen(adapter,...) zfcp_erp_strategy ... zfcp_fsf_req_dismiss_all list_for_each_entry_safe zfcp_fsf_req_complete 1 del_timer 1 zfcp_fsf_req_free 1 zfcp_fsf_req_complete 2 zfcp_fsf_request_timeout_handler del_timer 2 fsf_req = from_timer(fsf_req, t, timer) zfcp_fsf_req_free 2 adapter = fsf_req->adapter ^^^^^^^ already freed Link: https://lore.kernel.org/r/20200813152856.50088-1-maier@linux.ibm.com Fixes: 75492a51568b ("s390/scsi: Convert timers to use timer_setup()") Cc: <stable@vger.kernel.org> #4.15+ Suggested-by: Julian Wiedmann <jwi@linux.ibm.com> Reviewed-by: Julian Wiedmann <jwi@linux.ibm.com> Signed-off-by: Steffen Maier <maier@linux.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-30scsi: zfcp: Fix panic on ERP timeout for previously dismissed ERP actionSteffen Maier
commit 936e6b85da0476dd2edac7c51c68072da9fb4ba2 upstream. Suppose that, for unrelated reasons, FSF requests on behalf of recovery are very slow and can run into the ERP timeout. In the case at hand, we did adapter recovery to a large degree. However due to the slowness a LUN open is pending so the corresponding fc_rport remains blocked. After fast_io_fail_tmo we trigger close physical port recovery for the port under which the LUN should have been opened. The new higher order port recovery dismisses the pending LUN open ERP action and dismisses the pending LUN open FSF request. Such dismissal decouples the ERP action from the pending corresponding FSF request by setting zfcp_fsf_req->erp_action to NULL (among other things) [zfcp_erp_strategy_check_fsfreq()]. If now the ERP timeout for the pending open LUN request runs out, we must not use zfcp_fsf_req->erp_action in the ERP timeout handler. This is a problem since v4.15 commit 75492a51568b ("s390/scsi: Convert timers to use timer_setup()"). Before that we intentionally only passed zfcp_erp_action as context argument to zfcp_erp_timeout_handler(). Note: The lifetime of the corresponding zfcp_fsf_req object continues until a (late) response or an (unrelated) adapter recovery. Just like the regular response path ignores dismissed requests [zfcp_fsf_req_complete() => zfcp_fsf_protstatus_eval() => return early] the ERP timeout handler now needs to ignore dismissed requests. So simply return early in the ERP timeout handler if the FSF request is marked as dismissed in its status flags. To protect against the race where zfcp_erp_strategy_check_fsfreq() dismisses and sets zfcp_fsf_req->erp_action to NULL after our previous status flag check, return early if zfcp_fsf_req->erp_action is NULL. After all, the former ERP action does not need to be woken up as that was already done as part of the dismissal above [zfcp_erp_action_dismiss()]. This fixes the following panic due to kernel page fault in IRQ context: Unable to handle kernel pointer dereference in virtual kernel address space Failing address: 0000000000000000 TEID: 0000000000000483 Fault in home space mode while using kernel ASCE. AS:000009859238c00b R2:00000e3e7ffd000b R3:00000e3e7ffcc007 S:00000e3e7ffd7000 P:000000000000013d Oops: 0004 ilc:2 [#1] SMP Modules linked in: ... CPU: 82 PID: 311273 Comm: stress Kdump: loaded Tainted: G E X ... Hardware name: IBM 8561 T01 701 (LPAR) Krnl PSW : 0404c00180000000 001fffff80549be0 (zfcp_erp_notify+0x40/0xc0 [zfcp]) R:0 T:1 IO:0 EX:0 Key:0 M:1 W:0 P:0 AS:3 CC:0 PM:0 RI:0 EA:3 Krnl GPRS: 0000000000000080 00000e3d00000000 00000000000000f0 0000000000030000 000000010028e700 000000000400a39c 000000010028e700 00000e3e7cf87e02 0000000010000000 0700098591cb67f0 0000000000000000 0000000000000000 0000033840e9a000 0000000000000000 001fffe008d6bc18 001fffe008d6bbc8 Krnl Code: 001fffff80549bd4: a7180000 lhi %r1,0 001fffff80549bd8: 4120a0f0 la %r2,240(%r10) #001fffff80549bdc: a53e0003 llilh %r3,3 >001fffff80549be0: ba132000 cs %r1,%r3,0(%r2) 001fffff80549be4: a7740037 brc 7,1fffff80549c52 001fffff80549be8: e320b0180004 lg %r2,24(%r11) 001fffff80549bee: e31020e00004 lg %r1,224(%r2) 001fffff80549bf4: 412020e0 la %r2,224(%r2) Call Trace: [<001fffff80549be0>] zfcp_erp_notify+0x40/0xc0 [zfcp] [<00000985915e26f0>] call_timer_fn+0x38/0x190 [<00000985915e2944>] expire_timers+0xfc/0x190 [<00000985915e2ac4>] run_timer_softirq+0xec/0x218 [<0000098591ca7c4c>] __do_softirq+0x144/0x398 [<00000985915110aa>] do_softirq_own_stack+0x72/0x88 [<0000098591551b58>] irq_exit+0xb0/0xb8 [<0000098591510c6a>] do_IRQ+0x82/0xb0 [<0000098591ca7140>] ext_int_handler+0x128/0x12c [<0000098591722d98>] clear_subpage.constprop.13+0x38/0x60 ([<000009859172ae4c>] clear_huge_page+0xec/0x250) [<000009859177e7a2>] do_huge_pmd_anonymous_page+0x32a/0x768 [<000009859172a712>] __handle_mm_fault+0x88a/0x900 [<000009859172a860>] handle_mm_fault+0xd8/0x1b0 [<0000098591529ef6>] do_dat_exception+0x136/0x3e8 [<0000098591ca6d34>] pgm_check_handler+0x1c8/0x220 Last Breaking-Event-Address: [<001fffff80549c88>] zfcp_erp_timeout_handler+0x10/0x18 [zfcp] Kernel panic - not syncing: Fatal exception in interrupt Link: https://lore.kernel.org/r/20200623140242.98864-1-maier@linux.ibm.com Fixes: 75492a51568b ("s390/scsi: Convert timers to use timer_setup()") Cc: <stable@vger.kernel.org> #4.15+ Reviewed-by: Julian Wiedmann <jwi@linux.ibm.com> Signed-off-by: Steffen Maier <maier@linux.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-17scsi: zfcp: fix missing erp_lock in port recovery trigger for point-to-pointSteffen Maier
commit 819732be9fea728623e1ed84eba28def7384ad1f upstream. v2.6.27 commit cc8c282963bd ("[SCSI] zfcp: Automatically attach remote ports") introduced zfcp automatic port scan. Before that, the user had to use the sysfs attribute "port_add" of an FCP device (adapter) to add and open remote (target) ports, even for the remote peer port in point-to-point topology. That code path did a proper port open recovery trigger taking the erp_lock. Since above commit, a new helper function zfcp_erp_open_ptp_port() performed an UNlocked port open recovery trigger. This can race with other parallel recovery triggers. In zfcp_erp_action_enqueue() this could corrupt e.g. adapter->erp_total_count or adapter->erp_ready_head. As already found for fabric topology in v4.17 commit fa89adba1941 ("scsi: zfcp: fix infinite iteration on ERP ready list"), there was an endless loop during tracing of rport (un)block. A subsequent v4.18 commit 9e156c54ace3 ("scsi: zfcp: assert that the ERP lock is held when tracing a recovery trigger") introduced a lockdep assertion for that case. As a side effect, that lockdep assertion now uncovered the unlocked code path for PtP. It is from within an adapter ERP action: zfcp_erp_strategy[1479] intentionally DROPs erp lock around zfcp_erp_strategy_do_action() zfcp_erp_strategy_do_action[1441] NO erp lock zfcp_erp_adapter_strategy[876] NO erp lock zfcp_erp_adapter_strategy_open[855] NO erp lock zfcp_erp_adapter_strategy_open_fsf[806]NO erp lock zfcp_erp_adapter_strat_fsf_xconf[772] erp lock only around zfcp_erp_action_to_running(), BUT *_not_* around zfcp_erp_enqueue_ptp_port() zfcp_erp_enqueue_ptp_port[728] BUG: *_not_* taking erp lock _zfcp_erp_port_reopen[432] assumes to be called with erp lock zfcp_erp_action_enqueue[314] assumes to be called with erp lock zfcp_dbf_rec_trig[288] _checks_ to be called with erp lock: lockdep_assert_held(&adapter->erp_lock); It causes the following lockdep warning: WARNING: CPU: 2 PID: 775 at drivers/s390/scsi/zfcp_dbf.c:288 zfcp_dbf_rec_trig+0x16a/0x188 no locks held by zfcperp0.0.17c0/775. Fix this by using the proper locked recovery trigger helper function. Link: https://lore.kernel.org/r/20200312174505.51294-2-maier@linux.ibm.com Fixes: cc8c282963bd ("[SCSI] zfcp: Automatically attach remote ports") Cc: <stable@vger.kernel.org> #v2.6.27+ Reviewed-by: Jens Remus <jremus@linux.ibm.com> Reviewed-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Steffen Maier <maier@linux.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-12-17scsi: zfcp: trace channel log even for FCP command responsesSteffen Maier
[ Upstream commit 100843f176109af94600e500da0428e21030ca7f ] While v2.6.26 commit b75db73159cc ("[SCSI] zfcp: Add qtcb dump to hba debug trace") is right that we don't want to flood the (payload) trace ring buffer, we don't trace successful FCP command responses by default. So we can include the channel log for problem determination with failed responses of any FSF request type. Fixes: b75db73159cc ("[SCSI] zfcp: Add qtcb dump to hba debug trace") Fixes: a54ca0f62f95 ("[SCSI] zfcp: Redesign of the debug tracing for HBA records.") Cc: <stable@vger.kernel.org> #2.6.38+ Link: https://lore.kernel.org/r/e37597b5c4ae123aaa85fd86c23a9f71e994e4a9.1572018132.git.bblock@linux.ibm.com Reviewed-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Steffen Maier <maier@linux.ibm.com> Signed-off-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-13scsi: zfcp: drop default switch case which might paper over missing caseSteffen Maier
[ Upstream commit 0c902936e55cff9335b27ed632fc45e7115ced75 ] This was introduced with v4.18 commit 8c3d20aada70 ("scsi: zfcp: fix missing REC trigger trace for all objects in ERP_FAILED") but would now suppress helpful -Wswitch compiler warnings when building with W=1 such as the following forced example: drivers/s390/scsi/zfcp_erp.c: In function 'zfcp_erp_handle_failed': drivers/s390/scsi/zfcp_erp.c:126:2: warning: enumeration value 'ZFCP_ERP_ACTION_REOPEN_PORT_FORCED' not handled in switch [-Wswitch] switch (want) { ^~~~~~ But then again, only with W=1 we would notice unhandled enum cases. Without the default cases and a missed unhandled enum case, the code might perform unforeseen things we might not want... As of today, we never run through the removed default case, so removing it is no functional change. In the future, we never should run through a default case but introduce the necessary specific case(s) to handle new functionality. Signed-off-by: Steffen Maier <maier@linux.ibm.com> Reviewed-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-13scsi: zfcp: update kernel message for invalid FCP_CMND length, it's not the CDBSteffen Maier
[ Upstream commit 724e144387f4d7e7668d3da913d0efc44a9b4664 ] The CDB is just a part inside of FCP_CMND, see zfcp_fc_scsi_to_fcp(). While at it, fix the device driver reaction: adapter not LUN shutdown. Signed-off-by: Steffen Maier <maier@linux.ibm.com> Reviewed-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-10-29scsi: zfcp: fix reaction on bit error threshold notificationSteffen Maier
commit 2190168aaea42c31bff7b9a967e7b045f07df095 upstream. On excessive bit errors for the FCP channel ingress fibre path, the channel notifies us. Previously, we only emitted a kernel message and a trace record. Since performance can become suboptimal with I/O timeouts due to bit errors, we now stop using an FCP device by default on channel notification so multipath on top can timely failover to other paths. A new module parameter zfcp.ber_stop can be used to get zfcp old behavior. User explanation of new kernel message: * Description: * The FCP channel reported that its bit error threshold has been exceeded. * These errors might result from a problem with the physical components * of the local fibre link into the FCP channel. * The problem might be damage or malfunction of the cable or * cable connection between the FCP channel and * the adjacent fabric switch port or the point-to-point peer. * Find details about the errors in the HBA trace for the FCP device. * The zfcp device driver closed down the FCP device * to limit the performance impact from possible I/O command timeouts. * User action: * Check for problems on the local fibre link, ensure that fibre optics are * clean and functional, and all cables are properly plugged. * After the repair action, you can manually recover the FCP device by * writing "0" into its "failed" sysfs attribute. * If recovery through sysfs is not possible, set the CHPID of the device * offline and back online on the service element. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: <stable@vger.kernel.org> #2.6.30+ Link: https://lore.kernel.org/r/20191001104949.42810-1-maier@linux.ibm.com Reviewed-by: Jens Remus <jremus@linux.ibm.com> Reviewed-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Steffen Maier <maier@linux.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-09-16scsi: zfcp: fix request object use-after-free in send path causing wrong tracesBenjamin Block
[ Upstream commit 106d45f350c7cac876844dc685845cba4ffdb70b ] When tracing instances where we open and close WKA ports, we also pass the request-ID of the respective FSF command. But after successfully sending the FSF command we must not use the request-object anymore, as this might result in an use-after-free (see "zfcp: fix request object use-after-free in send path causing seqno errors" ). To fix this add a new variable that caches the request-ID before sending the request. This won't change during the hand-off to the FCP channel, and so it's safe to trace this cached request-ID later, instead of using the request object. Signed-off-by: Benjamin Block <bblock@linux.ibm.com> Fixes: d27a7cb91960 ("zfcp: trace on request for open and close of WKA port") Cc: <stable@vger.kernel.org> #2.6.38+ Reviewed-by: Steffen Maier <maier@linux.ibm.com> Reviewed-by: Jens Remus <jremus@linux.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-08-06scsi: zfcp: fix GCC compiler warning emitted with -Wmaybe-uninitializedBenjamin Block
[ Upstream commit 484647088826f2f651acbda6bcf9536b8a466703 ] GCC v9 emits this warning: CC drivers/s390/scsi/zfcp_erp.o drivers/s390/scsi/zfcp_erp.c: In function 'zfcp_erp_action_enqueue': drivers/s390/scsi/zfcp_erp.c:217:26: warning: 'erp_action' may be used uninitialized in this function [-Wmaybe-uninitialized] 217 | struct zfcp_erp_action *erp_action; | ^~~~~~~~~~ This is a possible false positive case, as also documented in the GCC documentations: https://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html#index-Wmaybe-uninitialized The actual code-sequence is like this: Various callers can invoke the function below with the argument "want" being one of: ZFCP_ERP_ACTION_REOPEN_ADAPTER, ZFCP_ERP_ACTION_REOPEN_PORT_FORCED, ZFCP_ERP_ACTION_REOPEN_PORT, or ZFCP_ERP_ACTION_REOPEN_LUN. zfcp_erp_action_enqueue(want, ...) ... need = zfcp_erp_required_act(want, ...) need = want ... maybe: need = ZFCP_ERP_ACTION_REOPEN_PORT maybe: need = ZFCP_ERP_ACTION_REOPEN_ADAPTER ... return need ... zfcp_erp_setup_act(need, ...) struct zfcp_erp_action *erp_action; // <== line 217 ... switch(need) { case ZFCP_ERP_ACTION_REOPEN_LUN: ... erp_action = &zfcp_sdev->erp_action; WARN_ON_ONCE(erp_action->port != port); // <== access ... break; case ZFCP_ERP_ACTION_REOPEN_PORT: case ZFCP_ERP_ACTION_REOPEN_PORT_FORCED: ... erp_action = &port->erp_action; WARN_ON_ONCE(erp_action->port != port); // <== access ... break; case ZFCP_ERP_ACTION_REOPEN_ADAPTER: ... erp_action = &adapter->erp_action; WARN_ON_ONCE(erp_action->port != NULL); // <== access ... break; } ... WARN_ON_ONCE(erp_action->adapter != adapter); // <== access When zfcp_erp_setup_act() is called, 'need' will never be anything else than one of the 4 possible enumeration-names that are used in the switch-case, and 'erp_action' is initialized for every one of them, before it is used. Thus the warning is a false positive, as documented. We introduce the extra if{} in the beginning to create an extra code-flow, so the compiler can be convinced that the switch-case will never see any other value. BUG_ON()/BUG() is intentionally not used to not crash anything, should this ever happen anyway - right now it's impossible, as argued above; and it doesn't introduce a 'default:' switch-case to retain warnings should 'enum zfcp_erp_act_type' ever be extended and no explicit case be introduced. See also v5.0 commit 399b6c8bc9f7 ("scsi: zfcp: drop old default switch case which might paper over missing case"). Signed-off-by: Benjamin Block <bblock@linux.ibm.com> Reviewed-by: Jens Remus <jremus@linux.ibm.com> Reviewed-by: Steffen Maier <maier@linux.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-06-09scsi: zfcp: fix to prevent port_remove with pure auto scan LUNs (only sdevs)Steffen Maier
commit ef4021fe5fd77ced0323cede27979d80a56211ca upstream. When the user tries to remove a zfcp port via sysfs, we only rejected it if there are zfcp unit children under the port. With purely automatically scanned LUNs there are no zfcp units but only SCSI devices. In such cases, the port_remove erroneously continued. We close the port and this implicitly closes all LUNs under the port. The SCSI devices survive with their private zfcp_scsi_dev still holding a reference to the "removed" zfcp_port (still allocated but invisible in sysfs) [zfcp_get_port_by_wwpn in zfcp_scsi_slave_alloc]. This is not a problem as long as the fc_rport stays blocked. Once (auto) port scan brings back the removed port, we unblock its fc_rport again by design. However, there is no mechanism that would recover (open) the LUNs under the port (no "ersfs_3" without zfcp_unit [zfcp_erp_strategy_followup_success]). Any pending or new I/O to such LUN leads to repeated: Done: NEEDS_RETRY Result: hostbyte=DID_IMM_RETRY driverbyte=DRIVER_OK See also v4.10 commit 6f2ce1c6af37 ("scsi: zfcp: fix rport unblock race with LUN recovery"). Even a manual LUN recovery (echo 0 > /sys/bus/scsi/devices/H:C:T:L/zfcp_failed) does not help, as the LUN links to the old "removed" port which remains to lack ZFCP_STATUS_COMMON_RUNNING [zfcp_erp_required_act]. The only workaround is to first ensure that the fc_rport is blocked (e.g. port_remove again in case it was re-discovered by (auto) port scan), then delete the SCSI devices, and finally re-discover by (auto) port scan. The port scan includes an fc_rport unblock, which in turn triggers a new scan on the scsi target to freshly get new pure auto scan LUNs. Fix this by rejecting port_remove also if there are SCSI devices (even without any zfcp_unit) under this port. Re-use mechanics from v3.7 commit d99b601b6338 ("[SCSI] zfcp: restore refcount check on port_remove"). However, we have to give up zfcp_sysfs_port_units_mutex earlier in unit_add to prevent a deadlock with scsi_host scan taking shost->scan_mutex first and then zfcp_sysfs_port_units_mutex now in our zfcp_scsi_slave_alloc(). Signed-off-by: Steffen Maier <maier@linux.ibm.com> Fixes: b62a8d9b45b9 ("[SCSI] zfcp: Use SCSI device data zfcp scsi dev instead of zfcp unit") Fixes: f8210e34887e ("[SCSI] zfcp: Allow midlayer to scan for LUNs when running in NPIV mode") Cc: <stable@vger.kernel.org> #2.6.37+ Reviewed-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-09scsi: zfcp: fix missing zfcp_port reference put on -EBUSY from port_removeSteffen Maier
commit d27e5e07f9c49bf2a6a4ef254ce531c1b4fb5a38 upstream. With this early return due to zfcp_unit child(ren), we don't use the zfcp_port reference from the earlier zfcp_get_port_by_wwpn() anymore and need to put it. Signed-off-by: Steffen Maier <maier@linux.ibm.com> Fixes: d99b601b6338 ("[SCSI] zfcp: restore refcount check on port_remove") Cc: <stable@vger.kernel.org> #3.7+ Reviewed-by: Jens Remus <jremus@linux.ibm.com> Reviewed-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-04scsi: zfcp: reduce flood of fcrscn1 trace records on multi-element RSCNSteffen Maier
[ Upstream commit c8206579175c34a2546de8a74262456278a7795a ] If an incoming ELS of type RSCN contains more than one element, zfcp suboptimally causes repeated erp trigger NOP trace records for each previously failed port. These could be ports that went away. It loops over each RSCN element, and for each of those in an inner loop over all zfcp_ports. The trigger to recover failed ports should be just the reception of some RSCN, no matter how many elements it has. So we can loop over failed ports separately, and only then loop over each RSCN element to handle the non-failed ports. The call chain was: zfcp_fc_incoming_rscn for (i = 1; i < no_entries; i++) _zfcp_fc_incoming_rscn list_for_each_entry(port, &adapter->port_list, list) if (masked port->d_id match) zfcp_fc_test_link if (!port->d_id) zfcp_erp_port_reopen "fcrscn1" <=== In order the reduce the "flooding" of the REC trace area in such cases, we factor out handling the failed ports to be outside of the entries loop: zfcp_fc_incoming_rscn if (no_entries > 1) <=== list_for_each_entry(port, &adapter->port_list, list) <=== if (!port->d_id) zfcp_erp_port_reopen "fcrscn1" <=== for (i = 1; i < no_entries; i++) _zfcp_fc_incoming_rscn list_for_each_entry(port, &adapter->port_list, list) if (masked port->d_id match) zfcp_fc_test_link Abbreviated example trace records before this code change: Tag : fcrscn1 WWPN : 0x500507630310d327 ERP want : 0x02 ERP need : 0x02 Tag : fcrscn1 WWPN : 0x500507630310d327 ERP want : 0x02 ERP need : 0x00 NOP => superfluous trace record The last trace entry repeats if there are more than 2 RSCN elements. Signed-off-by: Steffen Maier <maier@linux.ibm.com> Reviewed-by: Benjamin Block <bblock@linux.ibm.com> Reviewed-by: Jens Remus <jremus@linux.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Sasha Levin (Microsoft) <sashal@kernel.org>
2019-04-03scsi: zfcp: fix scsi_eh host reset with port_forced ERP for non-NPIV FCP devicesSteffen Maier
commit 242ec1455151267fe35a0834aa9038e4c4670884 upstream. Suppose more than one non-NPIV FCP device is active on the same channel. Send I/O to storage and have some of the pending I/O run into a SCSI command timeout, e.g. due to bit errors on the fibre. Now the error situation stops. However, we saw FCP requests continue to timeout in the channel. The abort will be successful, but the subsequent TUR fails. Scsi_eh starts. The LUN reset fails. The target reset fails. The host reset only did an FCP device recovery. However, for non-NPIV FCP devices, this does not close and reopen ports on the SAN-side if other non-NPIV FCP device(s) share the same open ports. In order to resolve the continuing FCP request timeouts, we need to explicitly close and reopen ports on the SAN-side. This was missing since the beginning of zfcp in v2.6.0 history commit ea127f975424 ("[PATCH] s390 (7/7): zfcp host adapter."). Note: The FSF requests for forced port reopen could run into FSF request timeouts due to other reasons. This would trigger an internal FCP device recovery. Pending forced port reopen recoveries would get dismissed. So some ports might not get fully reopened during this host reset handler. However, subsequent I/O would trigger the above described escalation and eventually all ports would be forced reopen to resolve any continuing FCP request timeouts due to earlier bit errors. Signed-off-by: Steffen Maier <maier@linux.ibm.com> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: <stable@vger.kernel.org> #3.0+ Reviewed-by: Jens Remus <jremus@linux.ibm.com> Reviewed-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-03scsi: zfcp: fix rport unblock if deleted SCSI devices on Scsi_HostSteffen Maier
commit fe67888fc007a76b81e37da23ce5bd8fb95890b0 upstream. An already deleted SCSI device can exist on the Scsi_Host and remain there because something still holds a reference. A new SCSI device with the same H:C:T:L and FCP device, target port WWPN, and FCP LUN can be created. When we try to unblock an rport, we still find the deleted SCSI device and return early because the zfcp_scsi_dev of that SCSI device is not ZFCP_STATUS_COMMON_UNBLOCKED. Hence we miss to unblock the rport, even if the new proper SCSI device would be in good state. Therefore, skip deleted SCSI devices when iterating the sdevs of the shost. [cf. __scsi_device_lookup{_by_target}() or scsi_device_get()] The following abbreviated trace sequence can indicate such problem: Area : REC Tag : ersfs_3 LUN : 0x4045400300000000 WWPN : 0x50050763031bd327 LUN status : 0x40000000 not ZFCP_STATUS_COMMON_UNBLOCKED Ready count : n not incremented yet Running count : 0x00000000 ERP want : 0x01 ERP need : 0xc1 ZFCP_ERP_ACTION_NONE Area : REC Tag : ersfs_3 LUN : 0x4045400300000000 WWPN : 0x50050763031bd327 LUN status : 0x41000000 Ready count : n+1 Running count : 0x00000000 ERP want : 0x01 ERP need : 0x01 ... Area : REC Level : 4 only with increased trace level Tag : ertru_l LUN : 0x4045400300000000 WWPN : 0x50050763031bd327 LUN status : 0x40000000 Request ID : 0x0000000000000000 ERP status : 0x01800000 ERP step : 0x1000 ERP action : 0x01 ERP count : 0x00 NOT followed by a trace record with tag "scpaddy" for WWPN 0x50050763031bd327. Signed-off-by: Steffen Maier <maier@linux.ibm.com> Fixes: 6f2ce1c6af37 ("scsi: zfcp: fix rport unblock race with LUN recovery") Cc: <stable@vger.kernel.org> #2.6.32+ Reviewed-by: Jens Remus <jremus@linux.ibm.com> Reviewed-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-13scsi: zfcp: fix posting too many status read buffers leading to adapter shutdownSteffen Maier
commit 60a161b7e5b2a252ff0d4c622266a7d8da1120ce upstream. Suppose adapter (open) recovery is between opened QDIO queues and before (the end of) initial posting of status read buffers (SRBs). This time window can be seconds long due to FSF_PROT_HOST_CONNECTION_INITIALIZING causing by design looping with exponential increase sleeps in the function performing exchange config data during recovery [zfcp_erp_adapter_strat_fsf_xconf()]. Recovery triggered by local link up. Suppose an event occurs for which the FCP channel would send an unsolicited notification to zfcp by means of a previously posted SRB. We saw it with local cable pull (link down) in multi-initiator zoning with multiple NPIV-enabled subchannels of the same shared FCP channel. As soon as zfcp_erp_adapter_strategy_open_fsf() starts posting the initial status read buffers from within the adapter's ERP thread, the channel does send an unsolicited notification. Since v2.6.27 commit d26ab06ede83 ("[SCSI] zfcp: receiving an unsolicted status can lead to I/O stall"), zfcp_fsf_status_read_handler() schedules adapter->stat_work to re-fill the just consumed SRB from a work item. Now the ERP thread and the work item post SRBs in parallel. Both contexts call the helper function zfcp_status_read_refill(). The tracking of missing (to be posted / re-filled) SRBs is not thread-safe due to separate atomic_read() and atomic_dec(), in order to depend on posting success. Hence, both contexts can see atomic_read(&adapter->stat_miss) == 1. One of the two contexts posts one too many SRB. Zfcp gets QDIO_ERROR_SLSB_STATE on the output queue (trace tag "qdireq1") leading to zfcp_erp_adapter_shutdown() in zfcp_qdio_handler_error(). An obvious and seemingly clean fix would be to schedule stat_work from the ERP thread and wait for it to finish. This would serialize all SRB re-fills. However, we already have another work item wait on the ERP thread: adapter->scan_work runs zfcp_fc_scan_ports() which calls zfcp_fc_eval_gpn_ft(). The latter calls zfcp_erp_wait() to wait for all the open port recoveries during zfcp auto port scan, but in fact it waits for any pending recovery including an adapter recovery. This approach leads to a deadlock. [see also v3.19 commit 18f87a67e6d6 ("zfcp: auto port scan resiliency"); v2.6.37 commit d3e1088d6873 ("[SCSI] zfcp: No ERP escalation on gpn_ft eval"); v2.6.28 commit fca55b6fb587 ("[SCSI] zfcp: fix deadlock between wq triggered port scan and ERP") fixing v2.6.27 commit c57a39a45a76 ("[SCSI] zfcp: wait until adapter is finished with ERP during auto-port"); v2.6.27 commit cc8c282963bd ("[SCSI] zfcp: Automatically attach remote ports")] Instead make the accounting of missing SRBs atomic for parallel execution in both the ERP thread and adapter->stat_work. Signed-off-by: Steffen Maier <maier@linux.ibm.com> Fixes: d26ab06ede83 ("[SCSI] zfcp: receiving an unsolicted status can lead to I/O stall") Cc: <stable@vger.kernel.org> #2.6.27+ Reviewed-by: Jens Remus <jremus@linux.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-02s390/dasd,zfcp: fix gcc 8 stringop-truncation warningsVasily Gorbik
ccw "busid" should always be NUL-terminated, as evident from e.g. get_ccwdev_by_busid doing "return (strcmp(bus_id, dev_name(dev)) == 0)". Replace all strncpy initializing busid with strlcpy. This fixes the following gcc 8 warnings: drivers/s390/scsi/zfcp_aux.c:104:2: warning: 'strncpy' specified bound 20 equals destination size [-Wstringop-truncation] strncpy(busid, token, ZFCP_BUS_ID_SIZE); drivers/s390/block/dasd_eer.c:316:2: warning: 'strncpy' specified bound 10 equals destination size [-Wstringop-truncation] strncpy(header.busid, dev_name(&device->cdev->dev), DASD_EER_BUSID_SIZE); drivers/s390/block/dasd_eer.c:359:2: warning: 'strncpy' specified bound 10 equals destination size [-Wstringop-truncation] strncpy(header.busid, dev_name(&device->cdev->dev), DASD_EER_BUSID_SIZE); drivers/s390/block/dasd_devmap.c:429:3: warning: 'strncpy' specified bound 20 equals destination size [-Wstringop-truncation] strncpy(new->bus_id, bus_id, DASD_BUS_ID_SIZE); Acked-by: Stefan Haberland <sth@linux.ibm.com> Acked-by: Steffen Maier <maier@linux.ibm.com> Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-06-10Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsiLinus Torvalds
Pull SCSI updates from James Bottomley: "This is mostly updates to the usual drivers: ufs, qedf, mpt3sas, lpfc, xfcp, hisi_sas, cxlflash, qla2xxx. In the absence of Nic, we're also taking target updates which are mostly minor except for the tcmu refactor. The only real core change to worry about is the removal of high page bouncing (in sas, storvsc and iscsi). This has been well tested and no problems have shown up so far" * tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (268 commits) scsi: lpfc: update driver version to 12.0.0.4 scsi: lpfc: Fix port initialization failure. scsi: lpfc: Fix 16gb hbas failing cq create. scsi: lpfc: Fix crash in blk_mq layer when executing modprobe -r lpfc scsi: lpfc: correct oversubscription of nvme io requests for an adapter scsi: lpfc: Fix MDS diagnostics failure (Rx < Tx) scsi: hisi_sas: Mark PHY as in reset for nexus reset scsi: hisi_sas: Fix return value when get_free_slot() failed scsi: hisi_sas: Terminate STP reject quickly for v2 hw scsi: hisi_sas: Add v2 hw force PHY function for internal ATA command scsi: hisi_sas: Include TMF elements in struct hisi_sas_slot scsi: hisi_sas: Try wait commands before before controller reset scsi: hisi_sas: Init disks after controller reset scsi: hisi_sas: Create a scsi_host_template per HW module scsi: hisi_sas: Reset disks when discovered scsi: hisi_sas: Add LED feature for v3 hw scsi: hisi_sas: Change common allocation mode of device id scsi: hisi_sas: change slot index allocation mode scsi: hisi_sas: Introduce hisi_sas_phy_set_linkrate() scsi: hisi_sas: fix a typo in hisi_sas_task_prep() ...
2018-05-18scsi: zfcp: enhance comments on fc_link_speed and supported_speedJens Remus
The comment on fsf_qtcb_bottom_port.supported_speed did read as if the field can only assume one of two possible values (i.e. 0x1 for 1 GBit/s or 0x2 for 2 GBit/s). This is not true for two reasons: first it is a flag field and can thus assume any combination and second there are meanwhile more speeds. Clarify comment on fsf_qtcb_bottom_port.supported_speed and add a comment to fsf_qtcb_bottom_config.fc_link_speed. Signed-off-by: Jens Remus <jremus@linux.ibm.com> Reviewed-by: Steffen Maier <maier@linux.ibm.com> Reviewed-by: Fedor Loshakov <loshakov@linux.ibm.com> Acked-by: Benjamin Block <bblock@linux.ibm.com> Acked-by: Hendrik Brueckner <brueckner@linux.ibm.com> Signed-off-by: Steffen Maier <maier@linux.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-05-18scsi: zfcp: add port speed capabilitiesJens Remus
Add port speed capabilities as defined in FC-LS RPSC ELS that have a counterpart FC_PORTSPEED_* defined in scsi/scsi_transport_fc.h. Suggested-by: Steffen Maier <maier@linux.ibm.com> Signed-off-by: Jens Remus <jremus@linux.ibm.com> Reviewed-by: Steffen Maier <maier@linux.ibm.com> Reviewed-by: Fedor Loshakov <loshakov@linux.ibm.com> Acked-by: Hendrik Brueckner <brueckner@linux.ibm.com> Acked-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Steffen Maier <maier@linux.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-05-18scsi: zfcp: assert that the ERP lock is held when tracing a recovery triggerJens Remus
Otherwise iterating with list_for_each() over the adapter->erp_ready_head and adapter->erp_running_head lists can lead to an infinite loop. See commit "zfcp: fix infinite iteration on erp_ready_head list". The run-time check is only performed for debug kernels which have the kernel lock validator enabled. Following is an example of the warning that is reported, if the ERP lock is not held when calling zfcp_dbf_rec_trig(): WARNING: CPU: 0 PID: 604 at drivers/s390/scsi/zfcp_dbf.c:288 zfcp_dbf_rec_trig+0x172/0x188 Modules linked in: ... CPU: 0 PID: 604 Comm: kworker/u128:3 Not tainted 4.16.0-... #1 Hardware name: IBM 2964 N96 702 (z/VM 6.4.0) Workqueue: zfcp_q_0.0.1906 zfcp_scsi_rport_work Krnl PSW : 00000000330fdbf9 00000000367e9728 (zfcp_dbf_rec_trig+0x172/0x188) R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:3 PM:0 RI:0 EA:3 Krnl GPRS: 00000000c57a5d99 3288200000000000 0000000000000000 000000006cc82740 00000000009d09d6 0000000000000000 00000000000000ff 0000000000000000 0000000000000000 0000000000e1b5fe 000000006de01d38 0000000076130958 000000006cc82548 000000006de01a98 00000000009d09d6 000000006a6d3c80 Krnl Code: 00000000009d0ad2: eb7ff0b80004 lmg %r7,%r15,184(%r15) 00000000009d0ad8: c0f4000d7dd0 brcl 15,b80678 #00000000009d0ade: a7f40001 brc 15,9d0ae0 >00000000009d0ae2: a7f4ff7d brc 15,9d09dc 00000000009d0ae6: e340f0f00004 lg %r4,240(%r15) 00000000009d0aec: eb7ff0b80004 lmg %r7,%r15,184(%r15) 00000000009d0af2: 07f4 bcr 15,%r4 00000000009d0af4: 0707 bcr 0,%r7 Call Trace: ([<00000000009d09d6>] zfcp_dbf_rec_trig+0x66/0x188) [<00000000009dd740>] zfcp_scsi_rport_work+0x98/0x190 [<0000000000169b34>] process_one_work+0x3d4/0x6f8 [<000000000016a08a>] worker_thread+0x232/0x418 [<000000000017219e>] kthread+0x166/0x178 [<0000000000b815ea>] kernel_thread_starter+0x6/0xc [<0000000000b815e4>] kernel_thread_starter+0x0/0xc 2 locks held by kworker/u128:3/604: #0: ((wq_completion)name){+.+.}, at: [<0000000082af1024>] process_one_work+0x1dc/0x6f8 #1: ((work_completion)(&port->rport_work)){+.+.}, at: [<0000000082af1024>] process_one_work+0x1dc/0x6f8 Last Breaking-Event-Address: [<00000000009d0ade>] zfcp_dbf_rec_trig+0x16e/0x188 ---[ end trace b2f4020572e2c124 ]--- Suggested-by: Steffen Maier <maier@linux.ibm.com> Signed-off-by: Jens Remus <jremus@linux.ibm.com> Reviewed-by: Benjamin Block <bblock@linux.ibm.com> Reviewed-by: Steffen Maier <maier@linux.ibm.com> Signed-off-by: Steffen Maier <maier@linux.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-05-18scsi: zfcp: cleanup indentation for posting FC eventsSteffen Maier
I just happened to see the function header indentation of zfcp_fc_enqueue_event() and I picked some more from checkpatch: $ checkpatch.pl --strict -f drivers/s390/scsi/zfcp_fc.c ... CHECK: Alignment should match open parenthesis #113: FILE: drivers/s390/scsi/zfcp_fc.c:113: + fc_host_post_event(adapter->scsi_host, fc_get_event_number(), + event->code, event->data); CHECK: Blank lines aren't necessary before a close brace '}' #118: FILE: drivers/s390/scsi/zfcp_fc.c:118: + +} ... The change complements v2.6.36 commit 2d1e547f7523 ("[SCSI] zfcp: Post events through FC transport class"). Signed-off-by: Steffen Maier <maier@linux.ibm.com> Reviewed-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-05-18scsi: zfcp: support SCSI_ADAPTER_RESET via scsi_host sysfs attribute host_resetSteffen Maier
Make use of feature introduced with v3.2 commit 294436914454 ("[SCSI] scsi: Added support for adapter and firmware reset"). The common code interface was introduced for commit 95d31262b3c1 ("[SCSI] qla4xxx: Added support for adapter and firmware reset"). $ echo adapter > /sys/class/scsi_host/host<N>/host_reset Example trace record formatted with zfcpdbf from s390-tools: Timestamp : ... Area : REC Subarea : 00 Level : 1 Exception : - CPU ID : .. Caller : 0x... Record ID : 1 ZFCP_DBF_REC_TRIG Tag : scshr_y SCSI sysfs host_reset yes LUN : 0xffffffffffffffff none (invalid) WWPN : 0x0000000000000000 none (invalid) D_ID : 0x00000000 none (invalid) Adapter status : 0x4500050b Port status : 0x00000000 none (invalid) LUN status : 0x00000000 none (invalid) Ready count : 0x00000001 Running count : 0x00000000 ERP want : 0x04 ZFCP_ERP_ACTION_REOPEN_ADAPTER ERP need : 0x04 ZFCP_ERP_ACTION_REOPEN_ADAPTER This is the common code equivalent to the zfcp-specific &dev_attr_adapter_failed.attr in zfcp_sysfs_adapter_attrs.attrs[]: $ echo 0 > /sys/bus/ccw/drivers/zfcp/<devbusid>/failed The unsupported case returns EOPNOTSUPP: $ echo firmware > /sys/class/scsi_host/host<N>/host_reset -bash: echo: write error: Operation not supported Example trace record formatted with zfcpdbf from s390-tools: Timestamp : ... Area : SCSI Subarea : 00 Level : 1 Exception : - CPU ID : .. Caller : 0x... Record ID : 1 Tag : scshr_n SCSI sysfs host_reset no Request ID : 0x0000000000000000 none (invalid) SCSI ID : 0xffffffff none (invalid) SCSI LUN : 0xffffffff none (invalid) SCSI LUN high : 0xffffffff none (invalid) SCSI result : 0xffffffa1 -EOPNOTSUPP==-95 SCSI retries : 0xff none (invalid) SCSI allowed : 0xff none (invalid) SCSI scribble : 0xffffffffffffffff none (invalid) SCSI opcode : ffffffff ffffffff ffffffff ffffffff none (invalid) FCP rsp inf cod: 0xff none (invalid) FCP rsp IU : 00000000 00000000 00000000 00000000 none (invalid) 00000000 00000000 For any other invalid value, common code returns EINVAL without invoking our callback: $ echo foo > /sys/class/scsi_host/host<N>/host_reset -bash: echo: write error: Invalid argument Signed-off-by: Steffen Maier <maier@linux.ibm.com> Reviewed-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-05-18scsi: zfcp: explicitly support initiator in scsi_host_templateSteffen Maier
While the default did already correctly print "Initiator" let's make it explicit and convert zfcp to the feature. $ cat /sys/class/scsi_host/host0/supported_mode Initiator $ cat /sys/class/scsi_host/host0/active_mode Initiator The default worked, because not setting the field has it initialized to zero == MODE_UNKNOWN. scsi_host_alloc() sets shost->active_mode = MODE_INITIATOR in this case. The sysfs accessor function show_shost_supported_mode() assumes MODE_INITIATOR in this case. This default behavior was introduced with v2.6.24 commit 7a39ac3f25be ("[SCSI] make supported_mode default to initiator."). The feature flag was introduced with v2.6.24 commit 5dc2b89e1242 ("[SCSI] add supported_mode and active_mode attributes to the host"). So there was no release where zfcp would have shown "unknown". Signed-off-by: Steffen Maier <maier@linux.ibm.com> Reviewed-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-05-18scsi: zfcp: remove unused return values of ERP trigger functionsSteffen Maier
Since v2.6.27 commit 553448f6c483 ("[SCSI] zfcp: Message cleanup"), none of the callers has been interested any more. Values were not returned consistently in all ERP trigger functions. Signed-off-by: Steffen Maier <maier@linux.ibm.com> Reviewed-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-05-18scsi: zfcp: zfcp_erp_action_exists() does only check for runningSteffen Maier
Simplify its signature to return boolean and rename it to zfcp_erp_action_is_running() to indicate its actual unmodified semantics. It has always been used like this since v2.6.0 history commit ea127f975424 ("[PATCH] s390 (7/7): zfcp host adapter."). Signed-off-by: Steffen Maier <maier@linux.ibm.com> Reviewed-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-05-18scsi: zfcp: remove unused ERP enum valuesSteffen Maier
All constant defines were introduced with v2.6.0 history commit ea127f975424 ("[PATCH] s390 (7/7): zfcp host adapter.") and refactored into enums with commit 287ac01acf22 ("[SCSI] zfcp: Cleanup code in zfcp_erp.c"). ZFCP_STATUS_ERP_DISMISSING and ZFCP_ERP_STEP_FSF_XCONFIG were never used. v2.6.27 commit 287ac01acf22 ("[SCSI] zfcp: Cleanup code in zfcp_erp.c") removed the use of ZFCP_ERP_ACTION_READY on refactoring zfcp_erp_action_exists() to now only check adapter->erp_running_head but no longer adapter->erp_ready_head. The same commit could have changed the function return type from int to "enum zfcp_erp_act_state". ZFCP_ERP_ACTION_READY was never used outside of zfcp_erp_action_exists(). Signed-off-by: Steffen Maier <maier@linux.ibm.com> Reviewed-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-05-18scsi: zfcp: consistently use function name space prefixSteffen Maier
I've been mixing up zfcp_task_mgmt_function() [SCSI] and zfcp_fsf_fcp_task_mgmt() [FSF] so often lately that I wanted to fix this. SCSI changes complement v2.6.27 commit f76af7d7e363 ("[SCSI] zfcp: Cleanup of code in zfcp_scsi.c"). While at it, also fixup the other inconsistencies elsewhere. ERP changes complement v2.6.27 commit 287ac01acf22 ("[SCSI] zfcp: Cleanup code in zfcp_erp.c") which introduced status_change_set(). FC changes complement v2.6.32 commit 6f53a2d2ecae ("[SCSI] zfcp: Apply common naming conventions to zfcp_fc"). by renaming a leftover introduced with v2.6.27 commit cc8c282963bd ("[SCSI] zfcp: Automatically attach remote ports"). FSF changes fixup v2.6.32 commit a4623c467ff7 ("[SCSI] zfcp: Improve request allocation through mempools"). which replaced zfcp_fsf_alloc_qtcb() introduced with v2.6.27 commit c41f8cbddd4e ("[SCSI] zfcp: zfcp_fsf cleanup."). SCSI fc_host statistics were introduced with v2.6.16 commit f6cd94b126aa ("[SCSI] zfcp: transport class adaptations"). SCSI fc_host port_state was introduced with v2.6.27 commit 85a82392fe6f ("[SCSI] zfcp: Add port_state attribute to sysfs"). SCSI rport setter for dev_loss_tmo was introduced with v2.6.18 commit 338151e06608 ("[SCSI] zfcp: make use of fc_remote_port_delete when target port is unavailable"). Signed-off-by: Steffen Maier <maier@linux.ibm.com> Reviewed-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-05-18scsi: zfcp: workqueue: set description for port work items with their WWPN ↵Steffen Maier
as context As a prerequisite, complement commit 3d1cb2059d93 ("workqueue: include workqueue info when printing debug dump of a worker task") to be usable with kernel modules by exporting the symbol set_worker_desc(). Current built-in user was introduced with commit ef3b101925f2 ("writeback: set worker desc to identify writeback workers in task dumps"). Can help distinguishing work items which do not have adapter scope. Description is printed out with task dump for debugging on WARN, BUG, panic, or magic-sysrq [show-task-states(t)]. Example: $ echo 0 >| /sys/bus/ccw/drivers/zfcp/0.0.1880/0x50050763031bd327/failed & $ echo 't' >| /proc/sysrq-trigger $ dmesg sysrq: SysRq : Show State task PC stack pid father ... zfcp_q_0.0.1880 S14640 2165 2 0x02000000 Call Trace: ([<00000000009df464>] __schedule+0xbf4/0xc78) [<00000000009df57c>] schedule+0x94/0xc0 [<0000000000168654>] rescuer_thread+0x33c/0x3a0 [<000000000016f8be>] kthread+0x166/0x178 [<00000000009e71f2>] kernel_thread_starter+0x6/0xc [<00000000009e71ec>] kernel_thread_starter+0x0/0xc no locks held by zfcp_q_0.0.1880/2165. ... kworker/u512:2 D11280 2193 2 0x02000000 Workqueue: zfcp_q_0.0.1880 zfcp_scsi_rport_work [zfcp] (zrpd-50050763031bd327) ^^^^^^^^^^^^^^^^^^^^^ Call Trace: ([<00000000009df464>] __schedule+0xbf4/0xc78) [<00000000009df57c>] schedule+0x94/0xc0 [<00000000009e50c0>] schedule_timeout+0x488/0x4d0 [<00000000001e425c>] msleep+0x5c/0x78 >>test code only<< [<000003ff8008a21e>] zfcp_scsi_rport_work+0xbe/0x100 [zfcp] [<0000000000167154>] process_one_work+0x3b4/0x718 [<000000000016771c>] worker_thread+0x264/0x408 [<000000000016f8be>] kthread+0x166/0x178 [<00000000009e71f2>] kernel_thread_starter+0x6/0xc [<00000000009e71ec>] kernel_thread_starter+0x0/0xc 2 locks held by kworker/u512:2/2193: #0: (name){++++.+}, at: [<0000000000166f4e>] process_one_work+0x1ae/0x718 #1: ((&(&port->rport_work)->work)){+.+.+.}, at: [<0000000000166f4e>] process_one_work+0x1ae/0x718 ... ============================================= Showing busy workqueues and worker pools: workqueue zfcp_q_0.0.1880: flags=0x2000a pwq 512: cpus=0-255 flags=0x4 nice=0 active=1/1 in-flight: 2193:zfcp_scsi_rport_work [zfcp] pool 512: cpus=0-255 flags=0x4 nice=0 hung=0s workers=4 idle: 5 2354 2311 Work items with adapter scope are already identified by the workqueue name "zfcp_q_<devbusid>" and the work item function name. Signed-off-by: Steffen Maier <maier@linux.ibm.com> Cc: Tejun Heo <tj@kernel.org> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Reviewed-by: Benjamin Block <bblock@linux.ibm.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-05-18scsi: zfcp: decouple our scsi_eh callbacks from scsi_cmndSteffen Maier
Note: zfcp_scsi_eh_host_reset_handler() will be converted in a later patch. zfcp_scsi_eh_device_reset_handler() now only depends on scsi_device. zfcp_scsi_eh_target_reset_handler() now only depends on scsi_target. All derive other objects from these intended callback arguments. zfcp_scsi_eh_target_reset_handler() is special: The FCP channel requires a valid LUN handle so we try to find ourselves a stand-in scsi_device as suggested by Hannes Reinecke. If it cannot find a stand-in scsi device, trace a record like the following (formatted with zfcpdbf from s390-tools): Timestamp : ... Area : SCSI Subarea : 00 Level : 1 Exception : - CPU ID : .. Caller : 0x... Record ID : 1 Tag : tr_nosd target reset, no SCSI device Request ID : 0x0000000000000000 none (invalid) SCSI ID : 0x00000000 SCSI ID/target denoting scope SCSI LUN : 0xffffffff none (invalid) SCSI LUN high : 0xffffffff none (invalid) SCSI result : 0x00002003 field re-used for midlayer value: FAILED SCSI retries : 0xff none (invalid) SCSI allowed : 0xff none (invalid) SCSI scribble : 0xffffffffffffffff none (invalid) SCSI opcode : ffffffff ffffffff ffffffff ffffffff none (invalid) FCP rsp inf cod: 0xff none (invalid) FCP rsp IU : 00000000 00000000 00000000 00000000 none (invalid) 00000000 00000000 Actually change the signature of zfcp_task_mgmt_function() used by zfcp_scsi_eh_device_reset_handler() & zfcp_scsi_eh_target_reset_handler(). Since it was prepared in a previous patch, we only need to delete a local auto variable which is now the intended argument. Suggested-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Steffen Maier <maier@linux.ibm.com> Reviewed-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-05-18scsi: zfcp: decouple TMFs from scsi_cmnd by using fc_block_rportSteffen Maier
Intentionally retrieve the rport by walking SCSI common code objects rather than zfcp_sdev->port->rport. The latter is used for pairing the calls to fc_remote_port_add() and fc_remote_port_delete(). [see v2.6.31 commit 379d6bf6573e ("[SCSI] zfcp: Add port only once to FC transport class")] zfcp_scsi_rport_register() sets zfcp_port.rport to what fc_remote_port_add() returned. zfcp_scsi_rport_block() sets zfcp_port.rport = NULL after having called fc_remote_port_delete(). Hence, while an rport is blocked (or in any subsequent state due to scsi_transport_fc timeouts such as fast_io_fail_tmo or dev_loss_tmo), zfcp_port.rport is NULL and cannot serve as argument to fc_block_rport(). During zfcp recovery, a just recovered zfcp_port can have the UNBLOCKED status flag, but an async rport unblocking has only started via zfcp_scsi_schedule_rport_register() in zfcp_erp_try_rport_unblock() [see v4.10 commit 6f2ce1c6af37 ("scsi: zfcp: fix rport unblock race with LUN recovery")] in zfcp_erp_action_cleanup(). Now zfcp_erp_wait() can return. This would be sufficient to successfully send a TMF. But the rport can still be blocked and zfcp_port.rport can still be NULL until zfcp_port.rport_work was scheduled and has actually called fc_remote_port_add() and assigned its return value to zfcp_port.rport. We need an unblocked rport for a successful scsi_eh TUR. Similarly, for a zfcp_port which has just lost its UNBLOCKED status flag, the return of zfcp_erp_wait() can race with zfcp_port.rport_work queued by zfcp_scsi_schedule_rport_block(). Therefore we cannot reliably access zfcp_port.rport. However, we'd like to get fc_rport_block()'s opinion on when fast_io_fail_tmo triggered. While we might use flush_work(&port->rport_work) to sync with the work item, we can simply use the other way to get an rport pointer. Signed-off-by: Steffen Maier <maier@linux.ibm.com> Reviewed-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-05-18scsi: zfcp: decouple SCSI setup of TMF from scsi_cmndSteffen Maier
Actually change the signature of zfcp_fsf_fcp_task_mgmt(). Since it was prepared in the previous patch, we only need to delete a local auto variable which is now the intended argument. Prepare zfcp_fsf_fcp_task_mgmt's caller zfcp_task_mgmt_function() to have its function body only depend on a scsi_device and derived objects. Signed-off-by: Steffen Maier <maier@linux.ibm.com> Reviewed-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-05-18scsi: zfcp: decouple FSF request setup of TMF from scsi_cmndSteffen Maier
In zfcp_fsf_fcp_task_mgmt() resolve the still old argument scsi_cmnd into scsi_device very early and only depend on scsi_device and derived objects in the function body. This prepares to later change the function signature replacing the scsi_cmnd argument with scsi_device. Signed-off-by: Steffen Maier <maier@linux.ibm.com> Reviewed-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-05-18scsi: zfcp: split FCP_CMND IU setup between SCSI I/O and TMF againSteffen Maier
This reverts commit 2443c8b23aea ("[SCSI] zfcp: Merge FCP task management setup with regular FCP command setup"), because this introduced a dependency on the unsuitable SCSI command for scsi_eh / TMF. Signed-off-by: Steffen Maier <maier@linux.ibm.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Reviewed-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-05-18scsi: zfcp: decouple TMF response handler from scsi_cmndSteffen Maier
Originally, I planned for TMF handling to have different context data in fsf_req->data depending on the TMF scope in fcp_cmnd->fc_tm_flags: * scsi_device if FCP_TMF_LUN_RESET, * zfcp_port if FCP_TMF_TGT_RESET. However, the FCP channel requires a valid LUN handle so we now use scsi_device as context data with any TMF for the time being. Regular SCSI I/O FCP requests continue using scsi_cmnd as req->data. Hence, the callers of zfcp_fsf_fcp_handler_common() must resolve req->data and pass scsi_device as common context. While at it, remove the detour zfcp_sdev->port->adapter and use the more direct req->adapter as elsewhere in this function already. Signed-off-by: Steffen Maier <maier@linux.ibm.com> Reviewed-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-05-18scsi: zfcp: decouple SCSI traces for scsi_eh / TMF from scsi_cmndSteffen Maier
The SCSI command pointer passed to scsi_eh callbacks is just one arbitrary command of potentially many that are in the eh queue to be processed. The command is only used to indirectly pass the TMF scope in terms of SCSI ID/target and SCSI LUN for LUN reset. Hence, zfcp had filled in SCSI trace record fields which do not really belong to the TMF. This was confusing. Therefore, refactor the TMF tracing to work without SCSI command. Since the FCP channel always requires a valid LUN handle, we use SCSI device as common context for any TMF (even target reset). To make it even clearer, we set all bits to 1 for the fields, which do not belong to the TMF, to indicate that these fields are invalid. The old zfcp_dbf_scsi() became zfcp_dbf_scsi_common() to now handle both SCSI commands and TMFs. The old argument scsi_cmnd is now optional and can be NULL with TMFs. The new argument scsi_device is mandatory to carry context, as well as SCSI ID/target and SCSI LUN in case of TMFs. New example trace record formatted with zfcpdbf from s390-tools: Timestamp : ... Area : SCSI Subarea : 00 Level : 1 Exception : - CPU ID : .. Caller : 0x... Record ID : 1 Tag : [lt]r_.... Request ID : 0x<reqid> ID of FSF FCP request with TM flag For cases without FSF request: 0x0 for none (invalid) SCSI ID : 0x<scsi_id> SCSI ID/target denoting scope SCSI LUN : 0x<scsi_lun> SCSI LUN denoting scope SCSI LUN high : 0x<scsi_lun_high> SCSI LUN denoting scope SCSI result : 0xffffffff none (invalid) SCSI retries : 0xff none (invalid) SCSI allowed : 0xff none (invalid) SCSI scribble : 0xffffffffffffffff none (invalid) SCSI opcode : ffffffff ffffffff ffffffff ffffffff none (invalid) FCP rsp inf cod: 0x00 FCP_RSP info code of TMF FCP rsp IU : 00000000 00000000 00000100 00000000 ext FCP_RSP IU 00000000 00000008 ext FCP_RSP IU FCP rsp IU len : 32 FCP_RSP IU length Payload time : ... FCP rsp IU all : 00000000 00000000 00000100 00000000 full FCP_RSP IU 00000000 00000008 00000000 00000000 full FCP_RSP IU Signed-off-by: Steffen Maier <maier@linux.ibm.com> Reviewed-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-05-18scsi: zfcp: fix missing REC trigger trace on enqueue without ERP threadSteffen Maier
Example trace record formatted with zfcpdbf from s390-tools: Timestamp : ... Area : REC Subarea : 00 Level : 1 Exception : - CPU ID : .. Caller : 0x... Record ID : 1 ZFCP_DBF_REC_TRIG Tag : ....... LUN : 0x... WWPN : 0x... D_ID : 0x... Adapter status : 0x... Port status : 0x... LUN status : 0x... Ready count : 0x... Running count : 0x... ERP want : 0x0. ZFCP_ERP_ACTION_REOPEN_... ERP need : 0xc0 ZFCP_ERP_ACTION_NONE Signed-off-by: Steffen Maier <maier@linux.ibm.com> Cc: <stable@vger.kernel.org> #2.6.38+ Reviewed-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-05-18scsi: zfcp: fix missing REC trigger trace for all objects in ERP_FAILEDSteffen Maier
That other commit introduced an inconsistency because it would trace on ERP_FAILED for all callers of port forced reopen triggers (not just terminate_rport_io), but it would not trace on ERP_FAILED for all callers of other ERP triggers such as adapter, port regular, LUN. Therefore, generalize that other commit. zfcp_erp_action_enqueue() already had two early outs which re-used the one zfcp_dbf_rec_trig() call. All ERP trigger functions finally run through zfcp_erp_action_enqueue(). So move the special handling for ZFCP_STATUS_COMMON_ERP_FAILED into zfcp_erp_action_enqueue() and add another early out with new trace marker for pseudo ERP need in this case. This removes all early returns from all ERP trigger functions so we always end up at zfcp_dbf_rec_trig(). Example trace record formatted with zfcpdbf from s390-tools: Timestamp : ... Area : REC Subarea : 00 Level : 1 Exception : - CPU ID : .. Caller : 0x... Record ID : 1 ZFCP_DBF_REC_TRIG Tag : ....... LUN : 0x... WWPN : 0x... D_ID : 0x... Adapter status : 0x... Port status : 0x... LUN status : 0x... Ready count : 0x... Running count : 0x... ERP want : 0x0. ZFCP_ERP_ACTION_REOPEN_... ERP need : 0xe0 ZFCP_ERP_ACTION_FAILED Signed-off-by: Steffen Maier <maier@linux.ibm.com> Cc: <stable@vger.kernel.org> #2.6.38+ Reviewed-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-05-18scsi: zfcp: fix missing REC trigger trace on terminate_rport_io for ERP_FAILEDSteffen Maier
For problem determination we always want to see when we were invoked on the terminate_rport_io callback whether we perform something or not. Temporal event sequence of interest with a long fast_io_fail_tmo of 27 sec: loose remote port t workqueue [s] zfcp_q_<dev> IRQ zfcperp<dev> === ================== =================== ============================ 0 recv RSCN q p.test_link_work block rport start fast_io_fail_tmo send ADISC ELS 4 recv ADISC fail block zfcp_port port forced reopen send open port 12 recv open port fail q p.gid_pn_work zfcp_erp_wakeup (zfcp_erp_wait would return) GID_PN fail Before this point, we got a SCSI trace with tag "sctrpi1" on fast_io_fail, e.g. with the typical 5 sec setting. port.status |= ERP_FAILED If fast_io_fail_tmo triggers after this point, we missed a SCSI trace. workqueue fc_dl_<host> ================== 27 fc_timeout_fail_rport_io fc_terminate_rport_io zfcp_scsi_terminate_rport_io zfcp_erp_port_forced_reopen _zfcp_erp_port_forced_reopen if (port.status & ERP_FAILED) return; Therefore, write a trace before above early return. Example trace record formatted with zfcpdbf from s390-tools: Timestamp : ... Area : REC Subarea : 00 Level : 1 Exception : - CPU ID : .. Caller : 0x... Record ID : 1 ZFCP_DBF_REC_TRIG Tag : sctrpi1 SCSI terminate rport I/O LUN : 0xffffffffffffffff none (invalid) WWPN : 0x<wwpn> D_ID : 0x<n_port_id> Adapter status : 0x... Port status : 0x... LUN status : 0x00000000 none (invalid) Ready count : 0x... Running count : 0x... ERP want : 0x03 ZFCP_ERP_ACTION_REOPEN_PORT_FORCED ERP need : 0xe0 ZFCP_ERP_ACTION_FAILED Signed-off-by: Steffen Maier <maier@linux.ibm.com> Cc: <stable@vger.kernel.org> #2.6.38+ Reviewed-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-05-18scsi: zfcp: fix missing REC trigger trace on terminate_rport_io early returnSteffen Maier
get_device() and its internally used kobject_get() only return NULL if they get passed NULL as argument. zfcp_get_port_by_wwpn() loops over adapter->port_list so the iteration variable port is always non-NULL. Struct device is embedded in struct zfcp_port so &port->dev is always non-NULL. This is the argument to get_device(). However, if we get an fc_rport in terminate_rport_io() for which we cannot find a match within zfcp_get_port_by_wwpn(), the latter can return NULL. v2.6.30 commit 70932935b61e ("[SCSI] zfcp: Fix oops when port disappears") introduced an early return without adding a trace record for this case. Even if we don't need recovery in this case, for debugging we should still see that our callback was invoked originally by scsi_transport_fc. Example trace record formatted with zfcpdbf from s390-tools: Timestamp : ... Area : REC Subarea : 00 Level : 1 Exception : - CPU ID : .. Caller : 0x... Record ID : 1 Tag : sctrpin SCSI terminate rport I/O, no zfcp port LUN : 0xffffffffffffffff none (invalid) WWPN : 0x<wwpn> WWPN D_ID : 0x<n_port_id> N_Port-ID Adapter status : 0x... Port status : 0xffffffff unknown (-1) LUN status : 0x00000000 none (invalid) Ready count : 0x... Running count : 0x... ERP want : 0x03 ZFCP_ERP_ACTION_REOPEN_PORT_FORCED ERP need : 0xc0 ZFCP_ERP_ACTION_NONE Signed-off-by: Steffen Maier <maier@linux.ibm.com> Fixes: 70932935b61e ("[SCSI] zfcp: Fix oops when port disappears") Cc: <stable@vger.kernel.org> #2.6.38+ Reviewed-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-05-18scsi: zfcp: fix misleading REC trigger trace where erp_action setup failedSteffen Maier
If a SCSI device is deleted during scsi_eh host reset, we cannot get a reference to the SCSI device anymore since scsi_device_get returns !=0 by design. Assuming the recovery of adapter and port(s) was successful, zfcp_erp_strategy_followup_success() attempts to trigger a LUN reset for the half-gone SCSI device. Unfortunately, it causes the following confusing trace record which states that zfcp will do a LUN recovery as "ERP need" is ZFCP_ERP_ACTION_REOPEN_LUN == 1 and equals "ERP want". Old example trace record formatted with zfcpdbf from s390-tools: Tag: : ersfs_3 ERP, trigger, unit reopen, port reopen succeeded LUN : 0x<FCP_LUN> WWPN : 0x<WWPN> D_ID : 0x<N_Port-ID> Adapter status : 0x5400050b Port status : 0x54000001 LUN status : 0x40000000 ZFCP_STATUS_COMMON_RUNNING but not ZFCP_STATUS_COMMON_UNBLOCKED as it was closed on close part of adapter reopen ERP want : 0x01 ERP need : 0x01 misleading However, zfcp_erp_setup_act() returns NULL as it cannot get the reference. Hence, zfcp_erp_action_enqueue() takes an early goto out and _NO_ recovery actually happens. We always do want the recovery trigger trace record even if no erp_action could be enqueued as in this case. For other cases where we did not enqueue an erp_action, 'need' has always been zero to indicate this. In order to indicate above goto out, introduce an eyecatcher "flag" to mark the "ERP need" as 'not needed' but still keep the information which erp_action type, that zfcp_erp_required_act() had decided upon, is needed. 0xc_ is chosen to be visibly different from 0x0_ in "ERP want". New example trace record formatted with zfcpdbf from s390-tools: Tag: : ersfs_3 ERP, trigger, unit reopen, port reopen succeeded LUN : 0x<FCP_LUN> WWPN : 0x<WWPN> D_ID : 0x<N_Port-ID> Adapter status : 0x5400050b Port status : 0x54000001 LUN status : 0x40000000 ERP want : 0x01 ERP need : 0xc1 would need LUN ERP, but no action set up ^ Before v2.6.38 commit ae0904f60fab ("[SCSI] zfcp: Redesign of the debug tracing for recovery actions.") we could detect this case because the "erp_action" field in the trace was NULL. The rework removed erp_action as argument and field from the trace. This patch here is for tracing. A fix to allow LUN recovery in the case at hand is a topic for a separate patch. See also commit fdbd1c5e27da ("[SCSI] zfcp: Allow running unit/LUN shutdown without acquiring reference") for a similar case and background info. Signed-off-by: Steffen Maier <maier@linux.ibm.com> Fixes: ae0904f60fab ("[SCSI] zfcp: Redesign of the debug tracing for recovery actions.") Cc: <stable@vger.kernel.org> #2.6.38+ Reviewed-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-05-18scsi: zfcp: fix missing SCSI trace for retry of abort / scsi_eh TMFSteffen Maier
We already have a SCSI trace for the end of abort and scsi_eh TMF. Due to zfcp_erp_wait() and fc_block_scsi_eh() time can pass between the start of our eh callback and an actual send/recv of an abort / TMF request. In order to see the temporal sequence including any abort / TMF send retries, add a trace before the above two blocking functions. This supports problem determination with scsi_eh and parallel zfcp ERP. No need to explicitly trace the beginning of our eh callback, since we typically can send an abort / TMF and see its HBA response (in the worst case, it's a pseudo response on dismiss all of adapter recovery, e.g. due to an FSF request timeout [fsrth_1] of the abort / TMF). If we cannot send, we now get a trace record for the first "abrt_wt" or "[lt]r_wait" which denotes almost the beginning of the callback. No need to explicitly trace the wakeup after the above two blocking functions because the next retry loop causes another trace in any case and that is sufficient. Example trace records formatted with zfcpdbf from s390-tools: Timestamp : ... Area : SCSI Subarea : 00 Level : 1 Exception : - CPU ID : .. Caller : 0x... Record ID : 1 Tag : abrt_wt abort, before zfcp_erp_wait() Request ID : 0x0000000000000000 none (invalid) SCSI ID : 0x<scsi_id> SCSI LUN : 0x<scsi_lun> SCSI LUN high : 0x<scsi_lun_high> SCSI result : 0x<scsi_result_of_cmd_to_be_aborted> SCSI retries : 0x<retries_of_cmd_to_be_aborted> SCSI allowed : 0x<allowed_retries_of_cmd_to_be_aborted> SCSI scribble : 0x<req_id_of_cmd_to_be_aborted> SCSI opcode : <CDB_of_cmd_to_be_aborted> FCP rsp inf cod: 0x.. none (invalid) FCP rsp IU : ... none (invalid) Timestamp : ... Area : SCSI Subarea : 00 Level : 1 Exception : - CPU ID : .. Caller : 0x... Record ID : 1 Tag : lr_wait LUN reset, before zfcp_erp_wait() Request ID : 0x0000000000000000 none (invalid) SCSI ID : 0x<scsi_id> SCSI LUN : 0x<scsi_lun> SCSI LUN high : 0x<scsi_lun_high> SCSI result : 0x... unrelated SCSI retries : 0x.. unrelated SCSI allowed : 0x.. unrelated SCSI scribble : 0x... unrelated SCSI opcode : ... unrelated FCP rsp inf cod: 0x.. none (invalid) FCP rsp IU : ... none (invalid) Signed-off-by: Steffen Maier <maier@linux.ibm.com> Fixes: 63caf367e1c9 ("[SCSI] zfcp: Improve reliability of SCSI eh handlers in zfcp") Fixes: af4de36d911a ("[SCSI] zfcp: Block scsi_eh thread for rport state BLOCKED") Cc: <stable@vger.kernel.org> #2.6.38+ Reviewed-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-05-18scsi: zfcp: fix missing SCSI trace for result of eh_host_reset_handlerSteffen Maier
For problem determination we need to see whether and why we were successful or not. This allows deduction of scsi_eh escalation. Example trace record formatted with zfcpdbf from s390-tools: Timestamp : ... Area : SCSI Subarea : 00 Level : 1 Exception : - CPU ID : .. Caller : 0x... Record ID : 1 Tag : schrh_r SCSI host reset handler result Request ID : 0x0000000000000000 none (invalid) SCSI ID : 0xffffffff none (invalid) SCSI LUN : 0xffffffff none (invalid) SCSI LUN high : 0xffffffff none (invalid) SCSI result : 0x00002002 field re-used for midlayer value: SUCCESS or in other cases: 0x2009 == FAST_IO_FAIL SCSI retries : 0xff none (invalid) SCSI allowed : 0xff none (invalid) SCSI scribble : 0xffffffffffffffff none (invalid) SCSI opcode : ffffffff ffffffff ffffffff ffffffff none (invalid) FCP rsp inf cod: 0xff none (invalid) FCP rsp IU : 00000000 00000000 00000000 00000000 none (invalid) 00000000 00000000 v2.6.35 commit a1dbfddd02d2 ("[SCSI] zfcp: Pass return code from fc_block_scsi_eh to scsi eh") introduced the first return with something other than the previously hardcoded single SUCCESS return path. Signed-off-by: Steffen Maier <maier@linux.ibm.com> Fixes: a1dbfddd02d2 ("[SCSI] zfcp: Pass return code from fc_block_scsi_eh to scsi eh") Cc: <stable@vger.kernel.org> #2.6.38+ Reviewed-by: Jens Remus <jremus@linux.ibm.com> Reviewed-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-05-08scsi: zfcp: fix infinite iteration on ERP ready listJens Remus
zfcp_erp_adapter_reopen() schedules blocking of all of the adapter's rports via zfcp_scsi_schedule_rports_block() and enqueues a reopen adapter ERP action via zfcp_erp_action_enqueue(). Both are separately processed asynchronously and concurrently. Blocking of rports is done in a kworker by zfcp_scsi_rport_work(). It calls zfcp_scsi_rport_block(), which then traces a DBF REC "scpdely" via zfcp_dbf_rec_trig(). zfcp_dbf_rec_trig() acquires the DBF REC spin lock and then iterates with list_for_each() over the adapter's ERP ready list without holding the ERP lock. This opens a race window in which the current list entry can be moved to another list, causing list_for_each() to iterate forever on the wrong list, as the erp_ready_head is never encountered as terminal condition. Meanwhile the ERP action can be processed in the ERP thread by zfcp_erp_thread(). It calls zfcp_erp_strategy(), which acquires the ERP lock and then calls zfcp_erp_action_to_running() to move the ERP action from the ready to the running list. zfcp_erp_action_to_running() can move the ERP action using list_move() just during the aforementioned race window. It then traces a REC RUN "erator1" via zfcp_dbf_rec_run(). zfcp_dbf_rec_run() tries to acquire the DBF REC spin lock. If this is held by the infinitely looping kworker, it effectively spins forever. Example Sequence Diagram: Process ERP Thread rport_work ------------------- ------------------- ------------------- zfcp_erp_adapter_reopen() zfcp_erp_adapter_block() zfcp_scsi_schedule_rports_block() lock ERP zfcp_scsi_rport_work() zfcp_erp_action_enqueue(ZFCP_ERP_ACTION_REOPEN_ADAPTER) list_add_tail() on ready !(rport_task==RPORT_ADD) wake_up() ERP thread zfcp_scsi_rport_block() zfcp_dbf_rec_trig() zfcp_erp_strategy() zfcp_dbf_rec_trig() unlock ERP lock DBF REC zfcp_erp_wait() lock ERP | zfcp_erp_action_to_running() | list_for_each() ready | list_move() current entry | ready to running | zfcp_dbf_rec_run() endless loop over running | zfcp_dbf_rec_run_lvl() | lock DBF REC spins forever Any adapter recovery can trigger this, such as setting the device offline or reboot. V4.9 commit 4eeaa4f3f1d6 ("zfcp: close window with unblocked rport during rport gone") introduced additional tracing of (un)blocking of rports. It missed that the adapter->erp_lock must be held when calling zfcp_dbf_rec_trig(). This fix uses the approach formerly introduced by commit aa0fec62391c ("[SCSI] zfcp: Fix sparse warning by providing new entry in dbf") that got later removed by commit ae0904f60fab ("[SCSI] zfcp: Redesign of the debug tracing for recovery actions."). Introduce zfcp_dbf_rec_trig_lock(), a wrapper for zfcp_dbf_rec_trig() that acquires and releases the adapter->erp_lock for read. Reported-by: Sebastian Ott <sebott@linux.ibm.com> Signed-off-by: Jens Remus <jremus@linux.ibm.com> Fixes: 4eeaa4f3f1d6 ("zfcp: close window with unblocked rport during rport gone") Cc: <stable@vger.kernel.org> # 2.6.32+ Reviewed-by: Benjamin Block <bblock@linux.vnet.ibm.com> Signed-off-by: Steffen Maier <maier@linux.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-03-13bsg-lib: introduce a timeout field in struct bsg_jobChristoph Hellwig
The zfcp driver wants to know the timeout for a bsg job, so add a field to struct bsg_job for it in preparation of not exposing the request to the bsg-lib users. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Benjamin Block <bblock@linux.vnet.ibm.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-12-05s390: add a few more SPDX identifiersMartin Schwidefsky
Add the correct SPDX license to a few more files under arch/s390 and drivers/s390 which have been missed to far. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-11-30Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 fixes from Martin Schwidefsky: - SPDX identifiers are added to more of the s390 specific files. - The ELF_ET_DYN_BASE base patch from Kees is reverted, with the change some old 31-bit programs crash. - Bug fixes and cleanups. * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (29 commits) s390/gs: add compat regset for the guarded storage broadcast control block s390: revert ELF_ET_DYN_BASE base changes s390: Remove redundant license text s390: crypto: Remove redundant license text s390: include: Remove redundant license text s390: kernel: Remove redundant license text s390: add SPDX identifiers to the remaining files s390: appldata: add SPDX identifiers to the remaining files s390: pci: add SPDX identifiers to the remaining files s390: mm: add SPDX identifiers to the remaining files s390: crypto: add SPDX identifiers to the remaining files s390: kernel: add SPDX identifiers to the remaining files s390: sthyi: add SPDX identifiers to the remaining files s390: drivers: Remove redundant license text s390: crypto: Remove redundant license text s390: virtio: add SPDX identifiers to the remaining files s390: scsi: zfcp_aux: add SPDX identifier s390: net: add SPDX identifiers to the remaining files s390: char: add SPDX identifiers to the remaining files s390: cio: add SPDX identifiers to the remaining files ...
2017-11-24s390: scsi: zfcp_aux: add SPDX identifierGreg Kroah-Hartman
It's good to have SPDX identifiers in all files to make it easier to audit the kernel tree for correct licenses. Update the drivers/s390/scsi/zfcp_aux.c file with the correct SPDX license identifier based on the license text in the file itself. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This work is based on a script and data from Thomas Gleixner, Philippe Ombredanne, and Kate Stewart. Cc: Steffen Maier <maier@linux.vnet.ibm.com> Cc: Benjamin Block <bblock@linux.vnet.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Kate Stewart <kstewart@linuxfoundation.org> Cc: Philippe Ombredanne <pombredanne@nexb.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-11-21treewide: Remove TIMER_FUNC_TYPE and TIMER_DATA_TYPE castsKees Cook
With all callbacks converted, and the timer callback prototype switched over, the TIMER_FUNC_TYPE cast is no longer needed, so remove it. Conversion was done with the following scripts: perl -pi -e 's|\(TIMER_FUNC_TYPE\)||g' \ $(git grep TIMER_FUNC_TYPE | cut -d: -f1 | sort -u) perl -pi -e 's|\(TIMER_DATA_TYPE\)||g' \ $(git grep TIMER_DATA_TYPE | cut -d: -f1 | sort -u) The now unused macros are also dropped from include/linux/timer.h. Signed-off-by: Kees Cook <keescook@chromium.org>
2017-11-16zfcp: purely mechanical update using timer API, plus blank linesSteffen Maier
erp_memwait only occurs in seldom memory pressure situations. The typical case never uses the associated timer and thus also does not need to initialize the timer. Also, we don't want to re-initialize the timer each time we re-use an erp_action in zfcp_erp_setup_act() [see also v4.14-rc7 commit ab31fd0ce65e ("scsi: zfcp: fix erp_action use-before-initialize in REC action trace") for erp_action life cycle]. Hence, retain the lazy inintialization of zfcp_erp_action.timer in zfcp_erp_strategy_memwait(). Add an empty line after declarations in zfcp_erp_timeout_handler() and zfcp_fsf_request_timeout_handler() even though it was also missing before the timer conversion. Fix checkpatch warning: WARNING: function definition argument 'struct timer_list *' should also have an identifier name +extern void zfcp_erp_timeout_handler(struct timer_list *); Depends-on: v4.14-rc3 commit 686fef928bba ("timer: Prepare to change timer callback argument type") Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com> Reviewed-by: Jens Remus <jremus@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-11-16s390/scsi: Convert timers to use timer_setup()Kees Cook
In preparation for unconditionally passing the struct timer_list pointer to all timer callbacks, switch to using the new timer_setup() and from_timer() to pass the timer pointer explicitly. Cc: Steffen Maier <maier@linux.vnet.ibm.com> Cc: Benjamin Block <bblock@linux.vnet.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: linux-s390@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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