[PATCH 12/35] libfc: vport link handling and fc_vport state managment

[Robert Love <robert.w.love@intel.com>]

From: Chris Leech <christopher.leech@intel.com>

NPIV vports are managed in libfc by changing their virtual link state
when the parent N_Ports internal state changes.  The vport link is only
online when the N_Port is in a ready state (logged into the fabric).

vport_state is updated as needed in this patch as well, currently the states
LINKDOWN, INITIALIZING, ACTIVE, DSIABLED, and NO_FABRIC_SUPP are used.

This also changes the fc_host port_state handling to differentiate between
LINKDOWN and OFFLINE.

Signed-off-by: Chris Leech <christopher.leech@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
---

 drivers/scsi/libfc/fc_lport.c |   72 +++++++++++++++++++++++++++++++--------
 drivers/scsi/libfc/fc_npiv.c  |   75 +++++++++++++++++++++++++++++++++++++++++
 include/scsi/libfc.h          |    8 ++++
 3 files changed, 140 insertions(+), 15 deletions(-)

diff --git a/drivers/scsi/libfc/fc_lport.c b/drivers/scsi/libfc/fc_lport.c
index c5f50e2..2729e60 100644
--- a/drivers/scsi/libfc/fc_lport.c
+++ b/drivers/scsi/libfc/fc_lport.c
@@ -224,10 +224,18 @@ void fc_get_host_port_state(struct Scsi_Host *shost)
 {
 	struct fc_lport *lp = shost_priv(shost);
 
-	if (lp->link_up)
-		fc_host_port_state(shost) = FC_PORTSTATE_ONLINE;
+	mutex_lock(&lp->lp_mutex);
+	if (!lp->link_up)
+		fc_host_port_state(shost) = FC_PORTSTATE_LINKDOWN;
 	else
-		fc_host_port_state(shost) = FC_PORTSTATE_OFFLINE;
+		switch (lp->state) {
+		case LPORT_ST_READY:
+			fc_host_port_state(shost) = FC_PORTSTATE_ONLINE;
+			break;
+		default:
+			fc_host_port_state(shost) = FC_PORTSTATE_OFFLINE;
+		}
+	mutex_unlock(&lp->lp_mutex);
 }
 EXPORT_SYMBOL(fc_get_host_port_state);
 
@@ -493,40 +501,62 @@ int fc_fabric_login(struct fc_lport *lport)
 EXPORT_SYMBOL(fc_fabric_login);
 
 /**
- * fc_linkup() - Handler for transport linkup events
+ * __fc_linkup() - Handler for transport linkup events
  * @lport: The lport whose link is up
+ *
+ * Locking: must be called with the lp_mutex held
  */
-void fc_linkup(struct fc_lport *lport)
+void __fc_linkup(struct fc_lport *lport)
 {
-	printk(KERN_INFO "libfc: Link up on port (%6x)\n",
-	       fc_host_port_id(lport->host));
-
-	mutex_lock(&lport->lp_mutex);
 	if (!lport->link_up) {
 		lport->link_up = 1;
 
 		if (lport->state == LPORT_ST_RESET)
 			fc_lport_enter_flogi(lport);
 	}
+}
+
+/**
+ * fc_linkup() - Handler for transport linkup events
+ * @lport: The lport whose link is up
+ */
+void fc_linkup(struct fc_lport *lport)
+{
+	printk(KERN_INFO "libfc: Link up on port (%6x)\n",
+	       fc_host_port_id(lport->host));
+
+	mutex_lock(&lport->lp_mutex);
+	__fc_linkup(lport);
 	mutex_unlock(&lport->lp_mutex);
 }
 EXPORT_SYMBOL(fc_linkup);
 
 /**
- * fc_linkdown() - Handler for transport linkdown events
+ * __fc_linkdown() - Handler for transport linkdown events
  * @lport: The lport whose link is down
+ *
+ * Locking: must be called with the lp_mutex held
  */
-void fc_linkdown(struct fc_lport *lport)
+void __fc_linkdown(struct fc_lport *lport)
 {
-	mutex_lock(&lport->lp_mutex);
-	printk(KERN_INFO "libfc: Link down on port (%6x)\n",
-	       fc_host_port_id(lport->host));
-
 	if (lport->link_up) {
 		lport->link_up = 0;
 		fc_lport_enter_reset(lport);
 		lport->tt.fcp_cleanup(lport);
 	}
+}
+
+/**
+ * fc_linkdown() - Handler for transport linkdown events
+ * @lport: The lport whose link is down
+ */
+void fc_linkdown(struct fc_lport *lport)
+{
+	printk(KERN_INFO "libfc: Link down on port (%6x)\n",
+	       fc_host_port_id(lport->host));
+
+	mutex_lock(&lport->lp_mutex);
+	__fc_linkdown(lport);
 	mutex_unlock(&lport->lp_mutex);
 }
 EXPORT_SYMBOL(fc_linkdown);
@@ -654,6 +684,9 @@ static void fc_lport_enter_ready(struct fc_lport *lport)
 		     fc_lport_state(lport));
 
 	fc_lport_state_enter(lport, LPORT_ST_READY);
+	if (lport->vport)
+		fc_vport_set_state(lport->vport, FC_VPORT_ACTIVE);
+	fc_vports_linkchange(lport);
 
 	if (!lport->ptp_rp)
 		lport->tt.disc_start(fc_lport_disc_callback, lport);
@@ -868,7 +901,14 @@ static void fc_lport_enter_reset(struct fc_lport *lport)
 	FC_LPORT_DBG(lport, "Entered RESET state from %s state\n",
 		     fc_lport_state(lport));
 
+	if (lport->vport) {
+		if (lport->link_up)
+			fc_vport_set_state(lport->vport, FC_VPORT_INITIALIZING);
+		else
+			fc_vport_set_state(lport->vport, FC_VPORT_LINKDOWN);
+	}
 	fc_lport_state_enter(lport, LPORT_ST_RESET);
+	fc_vports_linkchange(lport);
 	fc_lport_reset_locked(lport);
 	if (lport->link_up)
 		fc_lport_enter_flogi(lport);
@@ -887,6 +927,7 @@ static void fc_lport_enter_disabled(struct fc_lport *lport)
 		     fc_lport_state(lport));
 
 	fc_lport_state_enter(lport, LPORT_ST_DISABLED);
+	fc_vports_linkchange(lport);
 	fc_lport_reset_locked(lport);
 }
 
@@ -1330,6 +1371,7 @@ static void fc_lport_enter_logo(struct fc_lport *lport)
 		     fc_lport_state(lport));
 
 	fc_lport_state_enter(lport, LPORT_ST_LOGO);
+	fc_vports_linkchange(lport);
 
 	fp = fc_frame_alloc(lport, sizeof(*logo));
 	if (!fp) {
diff --git a/drivers/scsi/libfc/fc_npiv.c b/drivers/scsi/libfc/fc_npiv.c
index 39f02c0..c68f6c7 100644
--- a/drivers/scsi/libfc/fc_npiv.c
+++ b/drivers/scsi/libfc/fc_npiv.c
@@ -84,3 +84,78 @@ struct fc_lport *fc_vport_id_lookup(struct fc_lport *n_port, u32 port_id)
 	return lport;
 }
 
+/*
+ * When setting the link state of vports during an lport state change, it's
+ * necessary to hold the lp_mutex of both the N_Port and the VN_Port.
+ * This tells the lockdep engine to treat the nested locking of the VN_Port
+ * as a different lock class.
+ */
+enum libfc_lport_mutex_class {
+	LPORT_MUTEX_NORMAL = 0,
+	LPORT_MUTEX_VN_PORT = 1,
+};
+
+/**
+ * __fc_vport_setlink() - update link and status on a VN_Port
+ * @n_port: parent N_Port
+ * @vn_port: VN_Port to update
+ *
+ * Locking: must be called with both the N_Port and VN_Port lp_mutex held
+ */
+static void __fc_vport_setlink(struct fc_lport *n_port,
+			       struct fc_lport *vn_port)
+{
+	struct fc_vport *vport = vn_port->vport;
+
+	if (vn_port->state == LPORT_ST_DISABLED)
+		return;
+
+	if (n_port->state == LPORT_ST_READY) {
+		if (n_port->npiv_enabled) {
+			fc_vport_set_state(vport, FC_VPORT_INITIALIZING);
+			__fc_linkup(vn_port);
+		} else {
+			fc_vport_set_state(vport, FC_VPORT_NO_FABRIC_SUPP);
+			__fc_linkdown(vn_port);
+		}
+	} else {
+		fc_vport_set_state(vport, FC_VPORT_LINKDOWN);
+		__fc_linkdown(vn_port);
+	}
+}
+
+/**
+ * fc_vport_setlink() - update link and status on a VN_Port
+ * @vn_port: virtual port to update
+ */
+void fc_vport_setlink(struct fc_lport *vn_port)
+{
+	struct fc_vport *vport = vn_port->vport;
+	struct Scsi_Host *shost = vport_to_shost(vport);
+	struct fc_lport *n_port = shost_priv(shost);
+
+	mutex_lock(&n_port->lp_mutex);
+	mutex_lock_nested(&vn_port->lp_mutex, LPORT_MUTEX_VN_PORT);
+	__fc_vport_setlink(n_port, vn_port);
+	mutex_unlock(&vn_port->lp_mutex);
+	mutex_unlock(&n_port->lp_mutex);
+}
+EXPORT_SYMBOL(fc_vport_setlink);
+
+/**
+ * fc_vports_linkchange() - change the link state of all vports
+ * @n_port: Parent N_Port that has changed state
+ *
+ * Locking: called with the n_port lp_mutex held
+ */
+void fc_vports_linkchange(struct fc_lport *n_port)
+{
+	struct fc_lport *vn_port;
+
+	list_for_each_entry(vn_port, &n_port->vports, list) {
+		mutex_lock_nested(&vn_port->lp_mutex, LPORT_MUTEX_VN_PORT);
+		__fc_vport_setlink(n_port, vn_port);
+		mutex_unlock(&vn_port->lp_mutex);
+	}
+}
+
diff --git a/include/scsi/libfc.h b/include/scsi/libfc.h
index e5078a0..015e520 100644
--- a/include/scsi/libfc.h
+++ b/include/scsi/libfc.h
@@ -788,11 +788,13 @@ int fc_fabric_login(struct fc_lport *lp);
 /*
  * The link is up for the given local port.
  */
+void __fc_linkup(struct fc_lport *);
 void fc_linkup(struct fc_lport *);
 
 /*
  * Link is down for the given local port.
  */
+void __fc_linkdown(struct fc_lport *);
 void fc_linkdown(struct fc_lport *);
 
 /*
@@ -821,6 +823,12 @@ struct fc_lport *libfc_vport_create(struct fc_vport *vport, int privsize);
 struct fc_lport *fc_vport_id_lookup(struct fc_lport *n_port, u32 port_id);
 
 /*
+ * NPIV VN_Port link state management
+ */
+void fc_vport_setlink(struct fc_lport *vn_port);
+void fc_vports_linkchange(struct fc_lport *n_port);
+
+/*
  * REMOTE PORT LAYER
  *****************************/
 int fc_rport_init(struct fc_lport *lp);