[SCSI] fcoe: fcoe_interface create, destroy and refcounting

Up to this point the fcoe_instance structure was simply kzalloc/kfreed.  This
patch introduces create and destroy functions as well as kref based reference
counting.  The create function will grow as the initialization code is moved
there.

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>

1 files changed, 78 insertions, 19 deletions

diff --git a/drivers/scsi/fcoe/fcoe.c b/drivers/scsi/fcoe/fcoe.c
index 7f14c633da6f..d1d6b3b8bf5b 100644
--- a/drivers/scsi/fcoe/fcoe.c
+++ b/drivers/scsi/fcoe/fcoe.c
@@ -139,6 +139,58 @@ static struct scsi_host_template fcoe_shost_template = {
 };
 
 /**
+ * fcoe_interface_create()
+ * @netdev: network interface
+ *
+ * Returns: pointer to a struct fcoe_interface or NULL on error
+ */
+static struct fcoe_interface *fcoe_interface_create(struct net_device *netdev)
+{
+        struct fcoe_interface *fcoe;
+
+        fcoe = kzalloc(sizeof(*fcoe), GFP_KERNEL);
+        if (!fcoe) {
+                FCOE_NETDEV_DBG(netdev, "Could not allocate fcoe structure\n");
+                return NULL;
+        }
+
+        kref_init(&fcoe->kref);
+        fcoe->netdev = netdev;
+
+        return fcoe;
+}
+
+/**
+ * fcoe_interface_release() - fcoe_port kref release function
+ * @kref: embedded reference count in an fcoe_interface struct
+ */
+static void fcoe_interface_release(struct kref *kref)
+{
+        struct fcoe_interface *fcoe;
+
+        fcoe = container_of(kref, struct fcoe_interface, kref);
+        kfree(fcoe);
+}
+
+/**
+ * fcoe_interface_get()
+ * @fcoe:
+ */
+static inline void fcoe_interface_get(struct fcoe_interface *fcoe)
+{
+        kref_get(&fcoe->kref);
+}
+
+/**
+ * fcoe_interface_put()
+ * @fcoe:
+ */
+static inline void fcoe_interface_put(struct fcoe_interface *fcoe)
+{
+        kref_put(&fcoe->kref, fcoe_interface_release);
+}
+
+/**
  * fcoe_fip_recv - handle a received FIP frame.
  * @skb: the receive skb
  * @dev: associated &net_device
@@ -558,7 +610,7 @@ static void fcoe_if_destroy(struct fc_lport *lport)
         /* Release the net_device and Scsi_Host */
         dev_put(netdev);
         scsi_host_put(lport->host);
-        kfree(fcoe);            /* TODO, should be refcounted */
+        fcoe_interface_put(fcoe);
 }
 
 /*
@@ -604,8 +656,8 @@ static struct libfc_function_template fcoe_libfc_fcn_templ = {
 };
 
 /**
- * fcoe_if_create() - this function creates the fcoe interface
- * @netdev: pointer the associated netdevice
+ * fcoe_if_create() - this function creates the fcoe port
+ * @fcoe: fcoe_interface structure to create an fc_lport instance on
  * @parent: device pointer to be the parent in sysfs for the SCSI host
  *
  * Creates fc_lport struct and scsi_host for lport, configures lport
@@ -613,30 +665,23 @@ static struct libfc_function_template fcoe_libfc_fcn_templ = {
  *
  * Returns : The allocated fc_lport or an error pointer
  */
-static struct fc_lport *fcoe_if_create(struct net_device *netdev,
+static struct fc_lport *fcoe_if_create(struct fcoe_interface *fcoe,
                                        struct device *parent)
 {
         int rc;
         struct fc_lport *lport = NULL;
         struct fcoe_port *port;
-        struct fcoe_interface *fcoe;
         struct Scsi_Host *shost;
+        struct net_device *netdev = fcoe->netdev;
 
         FCOE_NETDEV_DBG(netdev, "Create Interface\n");
 
-        fcoe = kzalloc(sizeof(*fcoe), GFP_KERNEL);
-        if (!fcoe) {
-                FCOE_NETDEV_DBG(netdev, "Could not allocate fcoe structure\n");
-                rc = -ENOMEM;
-                goto out;
-        }
-
         shost = libfc_host_alloc(&fcoe_shost_template,
                                  sizeof(struct fcoe_port));
         if (!shost) {
                 FCOE_NETDEV_DBG(netdev, "Could not allocate host structure\n");
                 rc = -ENOMEM;
-                goto out_kfree_port;
+                goto out;
         }
         lport = shost_priv(shost);
         port = lport_priv(lport);
@@ -708,7 +753,7 @@ static struct fc_lport *fcoe_if_create(struct net_device *netdev,
                 fcoe_ctlr_link_up(&fcoe->ctlr);
 
         dev_hold(netdev);
-
+        fcoe_interface_get(fcoe);
         return lport;
 
 out_lp_destroy:
@@ -717,8 +762,6 @@ out_netdev_cleanup:
         fcoe_netdev_cleanup(port);
 out_host_put:
         scsi_host_put(lport->host);
-out_kfree_port:
-        kfree(fcoe);
 out:
         return ERR_PTR(rc);
 }
@@ -1620,6 +1663,8 @@ static int fcoe_ethdrv_put(const struct net_device *netdev)
 static int fcoe_destroy(const char *buffer, struct kernel_param *kp)
 {
         struct net_device *netdev;
+        struct fcoe_interface *fcoe;
+        struct fcoe_port *port;
         struct fc_lport *lport;
         int rc;
 
@@ -1634,6 +1679,8 @@ static int fcoe_destroy(const char *buffer, struct kernel_param *kp)
                 rc = -ENODEV;
                 goto out_putdev;
         }
+        port = lport_priv(lport);
+        fcoe = port->fcoe;
         fcoe_if_destroy(lport);
         fcoe_ethdrv_put(netdev);
         rc = 0;
@@ -1653,6 +1700,7 @@ out_nodev:
 static int fcoe_create(const char *buffer, struct kernel_param *kp)
 {
         int rc;
+        struct fcoe_interface *fcoe;
         struct fc_lport *lport;
         struct net_device *netdev;
 
@@ -1668,15 +1716,26 @@ static int fcoe_create(const char *buffer, struct kernel_param *kp)
         }
         fcoe_ethdrv_get(netdev);
 
-        lport = fcoe_if_create(netdev, &netdev->dev);
+        fcoe = fcoe_interface_create(netdev);
+        if (!fcoe) {
+                rc = -ENOMEM;
+                goto out_putdev;
+        }
+
+        lport = fcoe_if_create(fcoe, &netdev->dev);
         if (IS_ERR(lport)) {
                 printk(KERN_ERR "fcoe: Failed to create interface (%s)\n",
                        netdev->name);
                 fcoe_ethdrv_put(netdev);
                 rc = -EIO;
-                goto out_putdev;
+                goto out_free;
         }
-        rc = 0;
+
+        dev_put(netdev);
+        return 0;
+
+out_free:
+        fcoe_interface_put(fcoe);
 out_putdev:
         dev_put(netdev);
 out_nodev: