[SCSI] libfc: vport link handling and fc_vport state managment

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>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

2 files changed, 132 insertions, 15 deletions

diff --git a/drivers/scsi/libfc/fc_lport.c b/drivers/scsi/libfc/fc_lport.c
index 41650d336289..46897cf23ea6 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);
 }
 
@@ -1333,6 +1374,7 @@ 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 39f02c09a8d9..c68f6c7341c2 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);
+        }
+}
+