Michael J. Ruhl 6edd85a787 IB/hfi1: Fix destroy_qp hang after a link down ... commit b4a4957d3d upstream. rvt_destroy_qp() cannot complete until all in process packets have been released from the underlying hardware. If a link down event occurs, an application can hang with a kernel stack similar to: cat /proc/<app PID>/stack quiesce_qp+0x178/0x250 [hfi1] rvt_reset_qp+0x23d/0x400 [rdmavt] rvt_destroy_qp+0x69/0x210 [rdmavt] ib_destroy_qp+0xba/0x1c0 [ib_core] nvme_rdma_destroy_queue_ib+0x46/0x80 [nvme_rdma] nvme_rdma_free_queue+0x3c/0xd0 [nvme_rdma] nvme_rdma_destroy_io_queues+0x88/0xd0 [nvme_rdma] nvme_rdma_error_recovery_work+0x52/0xf0 [nvme_rdma] process_one_work+0x17a/0x440 worker_thread+0x126/0x3c0 kthread+0xcf/0xe0 ret_from_fork+0x58/0x90 0xffffffffffffffff quiesce_qp() waits until all outstanding packets have been freed. This wait should be momentary. During a link down event, the cleanup handling does not ensure that all packets caught by the link down are flushed properly. This is caused by the fact that the freeze path and the link down event is handled the same. This is not correct. The freeze path waits until the HFI is unfrozen and then restarts PIO. A link down is not a freeze event. The link down path cannot restart the PIO until link is restored. If the PIO path is restarted before the link comes up, the application (QP) using the PIO path will hang (until link is restored). Fix by separating the linkdown path from the freeze path and use the link down path for link down events. Close a race condition sc_disable() by acquiring both the progress and release locks. Close a race condition in sc_stop() by moving the setting of the flag bits under the alloc lock. Cc: <stable@vger.kernel.org> # 4.9.x+ Fixes: 7724105686 ("IB/hfi1: add driver files") Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com> Signed-off-by: Michael J. Ruhl <michael.j.ruhl@intel.com> Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2018-10-20 09:48:54 +02:00
..
core	ucma: fix a use-after-free in ucma_resolve_ip()	2018-10-13 09:27:29 +02:00
hw	IB/hfi1: Fix destroy_qp hang after a link down	2018-10-20 09:48:54 +02:00
sw	IB/rxe: Drop QP0 silently	2018-09-26 08:38:00 +02:00
ulp	IB/srp: Avoid that sg_reset -d ${srp_device} triggers an infinite loop	2018-10-03 17:00:56 -07:00
Kconfig	RDMA/ucm: Mark UCM interface as BROKEN	2018-07-17 11:39:33 +02:00
Makefile	IB/rdmavt: Create module framework and handle driver registration	2016-03-10 20:37:04 -05:00