nvme-fc: avoid calling _nvme_fc_abort_outstanding_ios from interrupt context

Recent patches changed calling sequences. nvme_fc_abort_outstanding_ios
used to be called from a timeout or work context. Now it is being called
in an io completion context, which can be an interrupt handler.
Unfortunately, the abort outstanding ios routine attempts to stop nvme
queues and nested routines that may try to sleep, which is in conflict
with the interrupt handler.

Correct replacing the direct call with a work element scheduling, and the
abort outstanding ios routine will be called in the work element.

Fixes: 95ced8a ("nvme-fc: eliminate terminate_io use by nvme_fc_error_recovery")
Signed-off-by: James Smart <james.smart@broadcom.com>
Reported-by: Daniel Wagner <dwagner@suse.de>
Tested-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>

Author: James Smart

drivers/nvme/host/fc.c

@@ -166,6 +166,7 @@ struct nvme_fc_ctrl {
 	struct blk_mq_tag_set	admin_tag_set;
 	struct blk_mq_tag_set	tag_set;
 
+	struct work_struct	ioerr_work;
 	struct delayed_work	connect_work;
 
 	struct kref		ref;
@@ -1888,6 +1889,15 @@ __nvme_fc_fcpop_chk_teardowns(struct nvme_fc_ctrl *ctrl,
 	}
 }
 
+static void
+nvme_fc_ctrl_ioerr_work(struct work_struct *work)
+{
+	struct nvme_fc_ctrl *ctrl =
+			container_of(work, struct nvme_fc_ctrl, ioerr_work);
+
+	nvme_fc_error_recovery(ctrl, "transport detected io error");
+}
+
 static void
 nvme_fc_fcpio_done(struct nvmefc_fcp_req *req)
 {
@@ -2046,7 +2056,7 @@ nvme_fc_fcpio_done(struct nvmefc_fcp_req *req)
 
 check_error:
 	if (terminate_assoc)
-		nvme_fc_error_recovery(ctrl, "transport detected io error");
+		queue_work(nvme_reset_wq, &ctrl->ioerr_work);
 }
 
 static int
@@ -3233,6 +3243,7 @@ nvme_fc_delete_ctrl(struct nvme_ctrl *nctrl)
 {
 	struct nvme_fc_ctrl *ctrl = to_fc_ctrl(nctrl);
 
+	cancel_work_sync(&ctrl->ioerr_work);
 	cancel_delayed_work_sync(&ctrl->connect_work);
 	/*
 	 * kill the association on the link side.  this will block
@@ -3449,6 +3460,7 @@ nvme_fc_init_ctrl(struct device *dev, struct nvmf_ctrl_options *opts,
 
 	INIT_WORK(&ctrl->ctrl.reset_work, nvme_fc_reset_ctrl_work);
 	INIT_DELAYED_WORK(&ctrl->connect_work, nvme_fc_connect_ctrl_work);
+	INIT_WORK(&ctrl->ioerr_work, nvme_fc_ctrl_ioerr_work);
 	spin_lock_init(&ctrl->lock);
 
 	/* io queue count */
@@ -3540,6 +3552,7 @@ nvme_fc_init_ctrl(struct device *dev, struct nvmf_ctrl_options *opts,
 
 fail_ctrl:
 	nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_DELETING);
+	cancel_work_sync(&ctrl->ioerr_work);
 	cancel_work_sync(&ctrl->ctrl.reset_work);
 	cancel_delayed_work_sync(&ctrl->connect_work);