kernel/linux.git/drivers/s390/block, branch v4.14.263

s390/dasd: fix hanging IO request during DASD driver unbind

2021-03-17T15:34:31+00:00

commit 66f669a272898feb1c69b770e1504aa2ec7723d1 upstream. Prevent that an IO request is build during device shutdown initiated by a driver unbind. This request will never be able to be processed or canceled and will hang forever. This will lead also to a hanging unbind. Fix by checking not only if the device is in READY state but also check that there is no device offline initiated before building a new IO request. Fixes: e443343e509a ("s390/dasd: blk-mq conversion") Cc: # v4.14+ Signed-off-by: Stefan Haberland Tested-by: Bjoern Walk Reviewed-by: Jan Hoeppner Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

s390/dasd: fix hanging DASD driver unbind

2021-03-17T15:34:31+00:00

commit 7d365bd0bff3c0310c39ebaffc9a8458e036d666 upstream. In case of an unbind of the DASD device driver the function dasd_generic_remove() is called which shuts down the device. Among others this functions removes the int_handler from the cdev. During shutdown the device cancels all outstanding IO requests and waits for completion of the clear request. Unfortunately the clear interrupt will never be received when there is no interrupt handler connected. Fix by moving the int_handler removal after the call to the state machine where no request or interrupt is outstanding. Cc: stable@vger.kernel.org Signed-off-by: Stefan Haberland Tested-by: Bjoern Walk Reviewed-by: Jan Hoeppner Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

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/dasd: fix memleak in path handling error case

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

[ Upstream commit 00b39f698a4f1ee897227cace2e3937fc4412270 ] If for whatever reason the dasd_eckd_check_characteristics() function exits after at least some paths have their configuration data allocated those data is never freed again. In the error case the device->private pointer is set to NULL and dasd_eckd_uncheck_device() will exit without freeing the path data because of this NULL pointer. Fix by calling dasd_eckd_clear_conf_data() for error cases. Also use dasd_eckd_clear_conf_data() in dasd_eckd_uncheck_device() to avoid code duplication. Reported-by: Qian Cai Reviewed-by: Jan Hoeppner Signed-off-by: Stefan Haberland Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

s390/dasd/cio: Interpret ccw_device_get_mdc return value correctly

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

[ Upstream commit dd4b3c83b9efac10d48a94c61372119fc555a077 ] The max data count (mdc) is an unsigned 16-bit integer value as per AR documentation and is received via ccw_device_get_mdc() for a specific path mask from the CIO layer. The function itself also always returns a positive mdc value or 0 in case mdc isn't supported or couldn't be determined. Though, the comment for this function describes a negative return value to indicate failures. As a result, the DASD device driver interprets the return value of ccw_device_get_mdc() incorrectly. The error case is essentially a dead code path. To fix this behaviour, check explicitly for a return value of 0 and change the comment for ccw_device_get_mdc() accordingly. This fix merely enables the error code path in the DASD functions get_fcx_max_data() and verify_fcx_max_data(). The actual functionality stays the same and is still correct. Reviewed-by: Cornelia Huck Signed-off-by: Jan Höppner Acked-by: Peter Oberparleiter Reviewed-by: Stefan Haberland Signed-off-by: Stefan Haberland Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin