[PATCH v6 13/14] nvmet-fc: take tgtport refs for portentry

[Daniel Wagner <wagi@kernel.org>]

Ensure that the tgtport is not going away as long portentry has a
pointer on it.

Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Daniel Wagner <wagi@kernel.org>
---
 drivers/nvme/target/fc.c | 44 +++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 39 insertions(+), 5 deletions(-)

diff --git a/drivers/nvme/target/fc.c b/drivers/nvme/target/fc.c
index 75ddb7425605dd6623db38a133b63e201592354c..2835772677f9486324ef77d9021b49f8d153e916 100644
--- a/drivers/nvme/target/fc.c
+++ b/drivers/nvme/target/fc.c
@@ -1254,6 +1254,7 @@ nvmet_fc_portentry_bind(struct nvmet_fc_tgtport *tgtport,
 {
 	lockdep_assert_held(&nvmet_fc_tgtlock);
 
+	nvmet_fc_tgtport_get(tgtport);
 	pe->tgtport = tgtport;
 	tgtport->pe = pe;
 
@@ -1273,8 +1274,10 @@ nvmet_fc_portentry_unbind(struct nvmet_fc_port_entry *pe)
 	unsigned long flags;
 
 	spin_lock_irqsave(&nvmet_fc_tgtlock, flags);
-	if (pe->tgtport)
+	if (pe->tgtport) {
+		nvmet_fc_tgtport_put(pe->tgtport);
 		pe->tgtport->pe = NULL;
+	}
 	list_del(&pe->pe_list);
 	spin_unlock_irqrestore(&nvmet_fc_tgtlock, flags);
 }
@@ -1292,8 +1295,10 @@ nvmet_fc_portentry_unbind_tgt(struct nvmet_fc_tgtport *tgtport)
 
 	spin_lock_irqsave(&nvmet_fc_tgtlock, flags);
 	pe = tgtport->pe;
-	if (pe)
+	if (pe) {
+		nvmet_fc_tgtport_put(pe->tgtport);
 		pe->tgtport = NULL;
+	}
 	tgtport->pe = NULL;
 	spin_unlock_irqrestore(&nvmet_fc_tgtlock, flags);
 }
@@ -1316,6 +1321,9 @@ nvmet_fc_portentry_rebind_tgt(struct nvmet_fc_tgtport *tgtport)
 	list_for_each_entry(pe, &nvmet_fc_portentry_list, pe_list) {
 		if (tgtport->fc_target_port.node_name == pe->node_name &&
 		    tgtport->fc_target_port.port_name == pe->port_name) {
+			if (!nvmet_fc_tgtport_get(tgtport))
+				continue;
+
 			WARN_ON(pe->tgtport);
 			tgtport->pe = pe;
 			pe->tgtport = tgtport;
@@ -2887,12 +2895,17 @@ nvmet_fc_add_port(struct nvmet_port *port)
 	list_for_each_entry(tgtport, &nvmet_fc_target_list, tgt_list) {
 		if ((tgtport->fc_target_port.node_name == traddr.nn) &&
 		    (tgtport->fc_target_port.port_name == traddr.pn)) {
+			if (!nvmet_fc_tgtport_get(tgtport))
+				continue;
+
 			/* a FC port can only be 1 nvmet port id */
 			if (!tgtport->pe) {
 				nvmet_fc_portentry_bind(tgtport, pe, port);
 				ret = 0;
 			} else
 				ret = -EALREADY;
+
+			nvmet_fc_tgtport_put(tgtport);
 			break;
 		}
 	}
@@ -2908,11 +2921,21 @@ static void
 nvmet_fc_remove_port(struct nvmet_port *port)
 {
 	struct nvmet_fc_port_entry *pe = port->priv;
+	struct nvmet_fc_tgtport *tgtport = NULL;
+	unsigned long flags;
+
+	spin_lock_irqsave(&nvmet_fc_tgtlock, flags);
+	if (pe->tgtport && nvmet_fc_tgtport_get(pe->tgtport))
+		tgtport = pe->tgtport;
+	spin_unlock_irqrestore(&nvmet_fc_tgtlock, flags);
 
 	nvmet_fc_portentry_unbind(pe);
 
-	/* terminate any outstanding associations */
-	__nvmet_fc_free_assocs(pe->tgtport);
+	if (tgtport) {
+		/* terminate any outstanding associations */
+		__nvmet_fc_free_assocs(tgtport);
+		nvmet_fc_tgtport_put(tgtport);
+	}
 
 	kfree(pe);
 }
@@ -2921,10 +2944,21 @@ static void
 nvmet_fc_discovery_chg(struct nvmet_port *port)
 {
 	struct nvmet_fc_port_entry *pe = port->priv;
-	struct nvmet_fc_tgtport *tgtport = pe->tgtport;
+	struct nvmet_fc_tgtport *tgtport = NULL;
+	unsigned long flags;
+
+	spin_lock_irqsave(&nvmet_fc_tgtlock, flags);
+	if (pe->tgtport && nvmet_fc_tgtport_get(pe->tgtport))
+		tgtport = pe->tgtport;
+	spin_unlock_irqrestore(&nvmet_fc_tgtlock, flags);
+
+	if (!tgtport)
+		return;
 
 	if (tgtport && tgtport->ops->discovery_event)
 		tgtport->ops->discovery_event(&tgtport->fc_target_port);
+
+	nvmet_fc_tgtport_put(tgtport);
 }
 
 static ssize_t

-- 
2.49.0