From: Nilay Shroff nilay@linux.ibm.com
[ Upstream commit c199fac88fe7c749f88a0653e9f621b9f5a71cf1 ]
While shutting down loop controller, we first quiesce the admin/IO queue, delete the admin/IO tag-set and then at last destroy the admin/IO queue. However it's quite possible that during the window between quiescing and destroying of the admin/IO queue, some admin/IO request might sneak in and if that happens then we could potentially encounter a hung task because shutdown operation can't forward progress until any pending I/O is flushed off.
This commit helps ensure that before destroying the admin/IO queue, we unquiesce the admin/IO queue so that any outstanding requests, which are added after the admin/IO queue is quiesced, are now flushed to its completion.
Reviewed-by: Christoph Hellwig hch@lst.de Signed-off-by: Nilay Shroff nilay@linux.ibm.com Signed-off-by: Keith Busch kbusch@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/nvme/target/loop.c | 13 +++++++++++++ 1 file changed, 13 insertions(+)
diff --git a/drivers/nvme/target/loop.c b/drivers/nvme/target/loop.c index 48d5df054cd02..bd61a1b82c4cd 100644 --- a/drivers/nvme/target/loop.c +++ b/drivers/nvme/target/loop.c @@ -265,6 +265,13 @@ static void nvme_loop_destroy_admin_queue(struct nvme_loop_ctrl *ctrl) { if (!test_and_clear_bit(NVME_LOOP_Q_LIVE, &ctrl->queues[0].flags)) return; + /* + * It's possible that some requests might have been added + * after admin queue is stopped/quiesced. So now start the + * queue to flush these requests to the completion. + */ + nvme_unquiesce_admin_queue(&ctrl->ctrl); + nvmet_sq_destroy(&ctrl->queues[0].nvme_sq); nvme_remove_admin_tag_set(&ctrl->ctrl); } @@ -297,6 +304,12 @@ static void nvme_loop_destroy_io_queues(struct nvme_loop_ctrl *ctrl) nvmet_sq_destroy(&ctrl->queues[i].nvme_sq); } ctrl->ctrl.queue_count = 1; + /* + * It's possible that some requests might have been added + * after io queue is stopped/quiesced. So now start the + * queue to flush these requests to the completion. + */ + nvme_unquiesce_io_queues(&ctrl->ctrl); }
static int nvme_loop_init_io_queues(struct nvme_loop_ctrl *ctrl)