From: James Smart <jsmart2021@gmail.com>
Date: Fri, 28 Jun 2019 17:26:08 -0700
Subject: [PATCH] nvme-fc: fix module unloads while lports still pending
Git-commit: 4c73cbdff1119d088ed16d63def59ad32b11b18f
Patch-Mainline: v5.3-rc1
References: bsc#1150033

Current code allows the module to be unloaded even if there are
pending data structures, such as localports and controllers on
the localports, that have yet to hit their reference counting
to remove them.

Fix by having exit entrypoint explicitly delete every controller,
which in turn will remove references on the remoteports and localports
causing them to be deleted as well. The exit entrypoint, after
initiating the deletes, will wait for the last localport to be deleted
before continuing.

Signed-off-by: James Smart <jsmart2021@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Hannes Reinecke <hare@suse.com>
---
 drivers/nvme/host/fc.c | 51 +++++++++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 48 insertions(+), 3 deletions(-)

diff --git a/drivers/nvme/host/fc.c b/drivers/nvme/host/fc.c
index a1063c08212d..6ff1c0a78ea7 100644
--- a/drivers/nvme/host/fc.c
+++ b/drivers/nvme/host/fc.c
@@ -211,6 +211,9 @@ static DEFINE_IDA(nvme_fc_ctrl_cnt);
 static DEFINE_IDA(nvme_fc_local_port_cnt);
 static DEFINE_IDA(nvme_fc_ctrl_cnt);
 
+static bool nvme_fc_waiting_to_unload;
+static DECLARE_COMPLETION(nvme_fc_unload_proceed);
+
 static struct workqueue_struct *nvme_fc_wq;
 
 /*
@@ -236,6 +239,8 @@ nvme_fc_free_lport(struct kref *ref)
 	/* remove from transport list */
 	spin_lock_irqsave(&nvme_fc_lock, flags);
 	list_del(&lport->port_list);
+	if (nvme_fc_waiting_to_unload && list_empty(&nvme_fc_lport_list))
+		complete(&nvme_fc_unload_proceed);
 	spin_unlock_irqrestore(&nvme_fc_lock, flags);
 
 	ida_simple_remove(&nvme_fc_local_port_cnt, lport->localport.port_num);
@@ -3462,11 +3467,51 @@ static int __init nvme_fc_init_module(void)
 	return ret;
 }
 
+static void
+nvme_fc_delete_controllers(struct nvme_fc_rport *rport)
+{
+	struct nvme_fc_ctrl *ctrl;
+
+	spin_lock(&rport->lock);
+	list_for_each_entry(ctrl, &rport->ctrl_list, ctrl_list) {
+		dev_warn(ctrl->ctrl.device,
+			"NVME-FC{%d}: transport unloading: deleting ctrl\n",
+			ctrl->cnum);
+		nvme_delete_ctrl(&ctrl->ctrl);
+	}
+	spin_unlock(&rport->lock);
+}
+
+static void
+nvme_fc_cleanup_for_unload(void)
+{
+	struct nvme_fc_lport *lport;
+	struct nvme_fc_rport *rport;
+
+	list_for_each_entry(lport, &nvme_fc_lport_list, port_list) {
+		list_for_each_entry(rport, &lport->endp_list, endp_list) {
+			nvme_fc_delete_controllers(rport);
+		}
+	}
+}
+
 static void __exit nvme_fc_exit_module(void)
 {
-	/* sanity check - all lports should be removed */
-	if (!list_empty(&nvme_fc_lport_list))
-		pr_warn("%s: localport list not empty\n", __func__);
+	unsigned long flags;
+	bool need_cleanup = false;
+
+	spin_lock_irqsave(&nvme_fc_lock, flags);
+	nvme_fc_waiting_to_unload = true;
+	if (!list_empty(&nvme_fc_lport_list)) {
+		need_cleanup = true;
+		nvme_fc_cleanup_for_unload();
+	}
+	spin_unlock_irqrestore(&nvme_fc_lock, flags);
+	if (need_cleanup) {
+		pr_info("%s: waiting for ctlr deletes\n", __func__);
+		wait_for_completion(&nvme_fc_unload_proceed);
+		pr_info("%s: ctrl deletes complete\n", __func__);
+	}
 
 	nvmf_unregister_transport(&nvme_fc_transport);
 
-- 
2.16.4