kernel/linux.git/drivers/s390, branch linux-4.16.y

s390/qeth: fix request-side race during cmd IO timeout

2018-06-20T19:01:22+00:00

[ Upstream commit db71bbbd11a4d314f0fa3fbf3369b71cf33ce33c ] Submitting a cmd IO request (usually on the WRITE device, but for IDX also on the READ device) is currently done with ccw_device_start() and a manual timeout in the caller. On timeout, the caller cleans up the related resources (eg. IO buffer). But 1) the IO might still be active and utilize those resources, and 2) when the IO completes, qeth_irq() will attempt to clean up the same resources again. Instead of introducing additional resource locking, switch to ccw_device_start_timeout() to ensure IO termination after timeout, and let the IRQ handler alone deal with cleaning up after a request. This also removes a stray write->irq_pending reset from clear_ipacmd_list(). The routine doesn't terminate any pending IO on the WRITE device, so this should be handled properly via IO timeout in the IRQ handler. Signed-off-by: Julian Wiedmann Signed-off-by: David S. Miller Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

s390/smsgiucv: disable SMSG on module unload

2018-06-20T19:01:15+00:00

[ Upstream commit 760dd0eeaec1689430243ead14e5a429613d8c52 ] The module exit function of the smsgiucv module uses the incorrect CP command to disable SMSG messages. The correct command is "SET SMSG OFF". Use it. Signed-off-by: Martin Schwidefsky Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

vfio-ccw: fence off transport mode

2018-05-30T06:17:39+00:00

[ Upstream commit 9851bc77e62499957567e7c39a5beba7d6de6296 ] vfio-ccw only supports command mode for channel programs, not transport mode. User space is supposed to already take care of that and pass us command-mode ORBs only, but better make sure and return an error to the caller instead of trying to process tcws as ccws. Reviewed-by: Dong Jia Shi Acked-by: Halil Pasic Signed-off-by: Cornelia Huck Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

scsi: zfcp: fix infinite iteration on ERP ready list

2018-05-25T14:46:08+00:00

commit fa89adba1941e4f3b213399b81732a5c12fd9131 upstream. 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 Signed-off-by: Jens Remus Fixes: 4eeaa4f3f1d6 ("zfcp: close window with unblocked rport during rport gone") Cc: # 2.6.32+ Reviewed-by: Benjamin Block Signed-off-by: Steffen Maier Signed-off-by: Martin K. Petersen Signed-off-by: Greg Kroah-Hartman

s390/qdio: don't release memory in qdio_setup_irq()

2018-05-22T16:56:23+00:00

commit 2e68adcd2fb21b7188ba449f0fab3bee2910e500 upstream. Calling qdio_release_memory() on error is just plain wrong. It frees the main qdio_irq struct, when following code still uses it. Also, no other error path in qdio_establish() does this. So trust callers to clean up via qdio_free() if some step of the QDIO initialization fails. Fixes: 779e6e1c724d ("[S390] qdio: new qdio driver.") Cc: #v2.6.27+ Signed-off-by: Julian Wiedmann Signed-off-by: Martin Schwidefsky Signed-off-by: Greg Kroah-Hartman

s390/qdio: fix access to uninitialized qdio_q fields

2018-05-22T16:56:23+00:00

commit e521813468f786271a87e78e8644243bead48fad upstream. Ever since CQ/QAOB support was added, calling qdio_free() straight after qdio_alloc() results in qdio_release_memory() accessing uninitialized memory (ie. q->u.out.use_cq and q->u.out.aobs). Followed by a kmem_cache_free() on the random AOB addresses. For older kernels that don't have 6e30c549f6ca, the same applies if qdio_establish() fails in the DEV_STATE_ONLINE check. While initializing q->u.out.use_cq would be enough to fix this particular bug, the more future-proof change is to just zero-alloc the whole struct. Fixes: 104ea556ee7f ("qdio: support asynchronous delivery of storage blocks") Cc: #v3.2+ Signed-off-by: Julian Wiedmann Signed-off-by: Martin Schwidefsky Signed-off-by: Greg Kroah-Hartman

vfio: ccw: fix cleanup if cp_prefetch fails

2018-05-22T16:56:21+00:00

commit d66a7355717ec903d455277a550d930ba13df4a8 upstream. If the translation of a channel program fails, we may end up attempting to clean up (free, unpin) stuff that never got translated (and allocated, pinned) in the first place. By adjusting the lengths of the chains accordingly (so the element that failed, and all subsequent elements are excluded) cleanup activities based on false assumptions can be avoided. Let's make sure cp_free works properly after cp_prefetch returns with an error by setting ch_len of a ccw chain to the number of the translated CCWs on that chain. Cc: stable@vger.kernel.org #v4.12+ Acked-by: Pierre Morel Reviewed-by: Dong Jia Shi Signed-off-by: Halil Pasic Signed-off-by: Dong Jia Shi Message-Id: <20180423110113.59385-2-bjsdjshi@linux.vnet.ibm.com> [CH: fixed typos] Signed-off-by: Cornelia Huck Signed-off-by: Martin Schwidefsky Signed-off-by: Greg Kroah-Hartman

vfio: ccw: process ssch with interrupts disabled

2018-05-01T19:47:25+00:00

commit 3368e547c52b96586f0edf9657ca12b94d8e61a7 upstream. When we call ssch, an interrupt might already be pending once we return from the START SUBCHANNEL instruction. Therefore we need to make sure interrupts are disabled while holding the subchannel lock until after we're done with our processing. Cc: stable@vger.kernel.org #v4.12+ Reviewed-by: Dong Jia Shi Acked-by: Halil Pasic Acked-by: Pierre Morel Signed-off-by: Cornelia Huck Signed-off-by: Martin Schwidefsky Signed-off-by: Greg Kroah-Hartman

s390/dasd: fix IO error for newly defined devices

2018-04-29T09:35:52+00:00

commit 5d27a2bf6e14f5c7d1033ad1e993fcd0eba43e83 upstream. When a new CKD storage volume is defined at the storage server, Linux may be relying on outdated information about that volume, which leads to the following errors: 1. Command Reject Errors for minidisk on z/VM: dasd-eckd.b3193d: 0.0.XXXX: An error occurred in the DASD device driver, reason=09 dasd(eckd): I/O status report for device 0.0.XXXX: dasd(eckd): in req: 00000000XXXXXXXX CC:00 FC:04 AC:00 SC:17 DS:02 CS:00 RC:0 dasd(eckd): device 0.0.2046: Failing CCW: 00000000XXXXXXXX dasd(eckd): Sense(hex) 0- 7: 80 00 00 00 00 00 00 00 dasd(eckd): Sense(hex) 8-15: 00 00 00 00 00 00 00 00 dasd(eckd): Sense(hex) 16-23: 00 00 00 00 e1 00 0f 00 dasd(eckd): Sense(hex) 24-31: 00 00 40 e2 00 00 00 00 dasd(eckd): 24 Byte: 0 MSG 0, no MSGb to SYSOP 2. Equipment Check errors on LPAR or for dedicated devices on z/VM: dasd(eckd): I/O status report for device 0.0.XXXX: dasd(eckd): in req: 00000000XXXXXXXX CC:00 FC:04 AC:00 SC:17 DS:0E CS:40 fcxs:01 schxs:00 RC:0 dasd(eckd): device 0.0.9713: Failing TCW: 00000000XXXXXXXX dasd(eckd): Sense(hex) 0- 7: 10 00 00 00 13 58 4d 0f dasd(eckd): Sense(hex) 8-15: 67 00 00 00 00 00 00 04 dasd(eckd): Sense(hex) 16-23: e5 18 05 33 97 01 0f 0f dasd(eckd): Sense(hex) 24-31: 00 00 40 e2 00 04 58 0d dasd(eckd): 24 Byte: 0 MSG f, no MSGb to SYSOP Fix this problem by using the up-to-date information provided during online processing via the device specific SNEQ to detect the case of outdated LCU data. If there is a difference, perform a re-read of that data. Cc: stable@vger.kernel.org Reviewed-by: Jan Hoeppner Signed-off-by: Stefan Haberland Signed-off-by: Martin Schwidefsky Signed-off-by: Greg Kroah-Hartman

s390/cio: update chpid descriptor after resource accessibility event

2018-04-29T09:35:52+00:00

commit af2e460ade0b0180d0f3812ca4f4f59cc9597f3e upstream. Channel path descriptors have been seen as something stable (as long as the chpid is configured). Recent tests have shown that the descriptor can also be altered when the link state of a channel path changes. Thus it is necessary to update the descriptor during handling of resource accessibility events. Cc: Signed-off-by: Sebastian Ott Reviewed-by: Peter Oberparleiter Signed-off-by: Martin Schwidefsky Signed-off-by: Greg Kroah-Hartman