kernel/linux.git/drivers/s390, branch v4.4.235

s390/cio: add cond_resched() in the slow_eval_known_fn() loop

2020-09-03T09:19:25+00:00

[ Upstream commit 0b8eb2ee9da1e8c9b8082f404f3948aa82a057b2 ] The scanning through subchannels during the time of an event could take significant amount of time in case of platforms with lots of known subchannels. This might result in higher scheduling latencies for other tasks especially on systems with a single CPU. Add cond_resched() call, as the loop in slow_eval_known_fn() can be executed for a longer duration. Reviewed-by: Peter Oberparleiter Signed-off-by: Vineeth Vijayan Signed-off-by: Heiko Carstens Signed-off-by: Sasha Levin

s390/qeth: don't process empty bridge port events

2020-08-21T08:53:02+00:00

[ Upstream commit 02472e28b9a45471c6d8729ff2c7422baa9be46a ] Discard events that don't contain any entries. This shouldn't happen, but subsequent code relies on being able to use entry 0. So better be safe than accessing garbage. Fixes: b4d72c08b358 ("qeth: bridgeport support - basic control") Signed-off-by: Julian Wiedmann Reviewed-by: Alexandra Winter Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

s390/qdio: put thinint indicator after early error

2020-06-30T00:07:50+00:00

[ Upstream commit 75e82bec6b2622c6f455b7a543fb5476a5d0eed7 ] qdio_establish() calls qdio_setup_thinint() via qdio_setup_irq(). If the subsequent qdio_establish_thinint() fails, we miss to put the DSCI again. Thus the DSCI isn't available for re-use. Given enough of such errors, we could end up with having only the shared DSCI available. Merge qdio_setup_thinint() into qdio_establish_thinint(), and deal with such an error internally. Fixes: 779e6e1c724d ("[S390] qdio: new qdio driver.") Signed-off-by: Julian Wiedmann Reviewed-by: Benjamin Block Signed-off-by: Vasily Gorbik Signed-off-by: Sasha Levin

scsi: zfcp: fix request object use-after-free in send path causing wrong traces

2020-06-03T06:12:16+00:00

[ 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 Fixes: d27a7cb91960 ("zfcp: trace on request for open and close of WKA port") Cc: #2.6.38+ Reviewed-by: Steffen Maier Reviewed-by: Jens Remus Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin

s390/cio: avoid duplicated 'ADD' uevents

2020-05-02T15:20:31+00:00

[ Upstream commit 05ce3e53f375295c2940390b2b429e506e07655c ] The common I/O layer delays the ADD uevent for subchannels and delegates generating this uevent to the individual subchannel drivers. The io_subchannel driver will do so when the associated ccw_device has been registered -- but unconditionally, so more ADD uevents will be generated if a subchannel has been unbound from the io_subchannel driver and later rebound. To fix this, only generate the ADD event if uevents were still suppressed for the device. Fixes: fa1a8c23eb7d ("s390: cio: Delay uevents for subchannels") Message-Id: <20200327124503.9794-2-cohuck@redhat.com> Reported-by: Boris Fiuczynski Reviewed-by: Peter Oberparleiter Reviewed-by: Boris Fiuczynski Signed-off-by: Cornelia Huck Signed-off-by: Vasily Gorbik Signed-off-by: Sasha Levin

scsi: zfcp: fix missing erp_lock in port recovery trigger for point-to-point

2020-04-24T05:57:14+00:00

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: #v2.6.27+ Reviewed-by: Jens Remus Reviewed-by: Benjamin Block Signed-off-by: Steffen Maier Signed-off-by: Martin K. Petersen Signed-off-by: Greg Kroah-Hartman

s390/cio: cio_ignore_proc_seq_next should increase position index

2020-03-11T06:51:16+00:00

[ Upstream commit 8b101a5e14f2161869636ff9cb4907b7749dc0c2 ] if seq_file .next fuction does not change position index, read after some lseek can generate unexpected output. Link: https://bugzilla.kernel.org/show_bug.cgi?id=206283 Link: https://lore.kernel.org/r/d44c53a7-9bc1-15c7-6d4a-0c10cb9dffce@virtuozzo.com Reviewed-by: Cornelia Huck Signed-off-by: Christian Borntraeger Signed-off-by: Vasily Averin Signed-off-by: Vasily Gorbik Signed-off-by: Sasha Levin

scsi: zfcp: trace channel log even for FCP command responses

2019-12-21T09:35:30+00:00

[ 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: #2.6.38+ Link: https://lore.kernel.org/r/e37597b5c4ae123aaa85fd86c23a9f71e994e4a9.1572018132.git.bblock@linux.ibm.com Reviewed-by: Benjamin Block Signed-off-by: Steffen Maier Signed-off-by: Benjamin Block Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin

scsi: zfcp: drop default switch case which might paper over missing case

2019-12-21T09:34:29+00:00

[ 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 Reviewed-by: Benjamin Block Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin

s390/qeth: invoke softirqs after napi_schedule()

2019-11-25T14:53:59+00:00

[ Upstream commit 4d19db777a2f32c9b76f6fd517ed8960576cb43e ] Calling napi_schedule() from process context does not ensure that the NET_RX softirq is run in a timely fashion. So trigger it manually. This is no big issue with current code. A call to ndo_open() is usually followed by a ndo_set_rx_mode() call, and for qeth this contains a spin_unlock_bh(). Except for OSN, where qeth_l2_set_rx_mode() bails out early. Nevertheless it's best to not depend on this behaviour, and just fix the issue at its source like all other drivers do. For instance see commit 83a0c6e58901 ("i40e: Invoke softirqs after napi_reschedule"). Fixes: a1c3ed4c9ca0 ("qeth: NAPI support for l2 and l3 discipline") Signed-off-by: Julian Wiedmann Signed-off-by: David S. Miller Signed-off-by: Sasha Levin