kernel/linux.git/drivers/s390, branch v4.14.217

s390/dasd: fix hanging device offline processing

2021-01-09T12:37:37+00:00

[ Upstream commit 658a337a606f48b7ebe451591f7681d383fa115e ] For an LCU update a read unit address configuration IO is required. This is started using sleep_on(), which has early exit paths in case the device is not usable for IO. For example when it is in offline processing. In those cases the LCU update should fail and not be retried. Therefore lcu_update_work checks if EOPNOTSUPP is returned or not. Commit 41995342b40c ("s390/dasd: fix endless loop after read unit address configuration") accidentally removed the EOPNOTSUPP return code from read_unit_address_configuration(), which in turn might lead to an endless loop of the LCU update in offline processing. Fix by returning EOPNOTSUPP again if the device is not able to perform the request. Fixes: 41995342b40c ("s390/dasd: fix endless loop after read unit address configuration") Cc: stable@vger.kernel.org #5.3 Signed-off-by: Stefan Haberland Reviewed-by: Jan Hoeppner Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

s390/dasd: fix list corruption of lcu list

2020-12-29T12:47:06+00:00

commit 53a7f655834c7c335bf683f248208d4fbe4b47bc upstream. In dasd_alias_disconnect_device_from_lcu the device is removed from any list on the LCU. Afterwards the LCU is removed from the lcu list if it does not contain devices any longer. The lcu->lock protects the lcu from parallel updates. But to cancel all workers and wait for completion the lcu->lock has to be unlocked. If two devices are removed in parallel and both are removed from the LCU the first device that takes the lcu->lock again will delete the LCU because it is already empty but the second device also tries to free the LCU which leads to a list corruption of the lcu list. Fix by removing the device right before the lcu is checked without unlocking the lcu->lock in between. Fixes: 8e09f21574ea ("[S390] dasd: add hyper PAV support to DASD device driver, part 1") Cc: stable@vger.kernel.org Signed-off-by: Stefan Haberland Reviewed-by: Jan Hoeppner Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

s390/dasd: fix list corruption of pavgroup group list

2020-12-29T12:47:05+00:00

commit 0ede91f83aa335da1c3ec68eb0f9e228f269f6d8 upstream. dasd_alias_add_device() moves devices to the active_devices list in case of a scheduled LCU update regardless if they have previously been in a pavgroup or not. Example: device A and B are in the same pavgroup. Device A has already been in a pavgroup and the private->pavgroup pointer is set and points to a valid pavgroup. While going through dasd_add_device it is moved from the pavgroup to the active_devices list. In parallel device B might be removed from the same pavgroup in remove_device_from_lcu() which in turn checks if the group is empty and deletes it accordingly because device A has already been removed from there. When now device A enters remove_device_from_lcu() it is tried to remove it from the pavgroup again because the pavgroup pointer is still set and again the empty group will be cleaned up which leads to a list corruption. Fix by setting private->pavgroup to NULL in dasd_add_device. If the device has been the last device on the pavgroup an empty pavgroup remains but this will be cleaned up by the scheduled lcu_update which iterates over all existing pavgroups. Fixes: 8e09f21574ea ("[S390] dasd: add hyper PAV support to DASD device driver, part 1") Cc: stable@vger.kernel.org Signed-off-by: Stefan Haberland Reviewed-by: Jan Hoeppner Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

s390/dasd: prevent inconsistent LCU device data

2020-12-29T12:47:05+00:00

commit a29ea01653493b94ea12bb2b89d1564a265081b6 upstream. Prevent _lcu_update from adding a device to a pavgroup if the LCU still requires an update. The data is not reliable any longer and in parallel devices might have been moved on the lists already. This might lead to list corruptions or invalid PAV grouping. Only add devices to a pavgroup if the LCU is up to date. Additional steps are taken by the scheduled lcu update. Fixes: 8e09f21574ea ("[S390] dasd: add hyper PAV support to DASD device driver, part 1") Cc: stable@vger.kernel.org Signed-off-by: Stefan Haberland Reviewed-by: Jan Hoeppner Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

s390/dasd: fix null pointer dereference for ERP requests

2020-11-24T12:05:57+00:00

commit 6f117cb854a44a79898d844e6ae3fd23bd94e786 upstream. When requeueing all requests on the device request queue to the blocklayer we might get to an ERP (error recovery) request that is a copy of an original CQR. Those requests do not have blocklayer request information or a pointer to the dasd_queue set. When trying to access those data it will lead to a null pointer dereference in dasd_requeue_all_requests(). Fix by checking if the request is an ERP request that can simply be ignored. The blocklayer request will be requeued by the original CQR that is on the device queue right behind the ERP request. Fixes: 9487cfd3430d ("s390/dasd: fix handling of internal requests") Cc: #4.16 Signed-off-by: Stefan Haberland Reviewed-by: Jan Hoeppner Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

s390/dasd: Fix zero write for FBA devices

2020-10-01T11:12:51+00:00

commit 709192d531e5b0a91f20aa14abfe2fc27ddd47af upstream. A discard request that writes zeros using the global kernel internal ZERO_PAGE will fail for machines with more than 2GB of memory due to the location of the ZERO_PAGE. Fix this by using a driver owned global zero page allocated with GFP_DMA flag set. Fixes: 28b841b3a7cb ("s390/dasd: Add discard support for FBA devices") Signed-off-by: Jan Höppner Reviewed-by: Stefan Haberland Cc: # 4.14+ Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

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

2020-09-03T09:22:30+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

2020-08-21T07:48:11+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

2020-06-25T13:41:51+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

2020-06-03T06:18:13+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