[SCSI] fc_transport: fix sysfs deadlock on vport delete

When the vport attribute "delete" is used to delete the vport, sysfs
deadlocks waiting for the write to complete, which is waiting for the
sysfs teardown to complete. Moved this effort to a work_q element.

Took the opportunity to make some other cosmetic changes:
 - removed tabs in Doc file - replaced with expanded spaces
 - minor copyright text and author text updates
 - removed a bunch of trailing whitespace
Signed-off-by: James Smart <James.Smart@emulex.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

drivers/scsi/scsi_transport_fc.c

@@ -22,6 +22,7 @@
  *  Copyright (C) 2004-2007   James Smart, Emulex Corporation
  *    Rewrite for host, target, device, and remote port attributes,
  *    statistics, and service functions...
+ *    Add vports, etc
  *
  */
 #include <linux/module.h>
@@ -37,6 +38,7 @@
 #include "scsi_priv.h"
 
 static int fc_queue_work(struct Scsi_Host *, struct work_struct *);
+static void fc_vport_sched_delete(struct work_struct *work);
 
 /*
  * This is a temporary carrier for creating a vport. It will eventually
@@ -1198,12 +1200,9 @@ store_fc_vport_delete(struct class_device *cdev, const char *buf,
 			   size_t count)
 {
 	struct fc_vport *vport = transport_class_to_vport(cdev);
-	int stat;
-
-	stat = fc_vport_terminate(vport);
-	if (stat)
-		return stat;
+	struct Scsi_Host *shost = vport_to_shost(vport);
 
+	fc_queue_work(shost, &vport->vport_delete_work);
 	return count;
 }
 static FC_CLASS_DEVICE_ATTR(vport, vport_delete, S_IWUSR,
@@ -2215,23 +2214,12 @@ fc_remove_host(struct Scsi_Host *shost)
 	struct workqueue_struct *work_q;
 	struct fc_host_attrs *fc_host = shost_to_fc_host(shost);
 	unsigned long flags;
-	int stat;
 
 	spin_lock_irqsave(shost->host_lock, flags);
 
 	/* Remove any vports */
-	list_for_each_entry_safe(vport, next_vport, &fc_host->vports, peers) {
-		spin_unlock_irqrestore(shost->host_lock, flags);
-		/* this must be called synchronously */
-		stat = fc_vport_terminate(vport);
-		spin_lock_irqsave(shost->host_lock, flags);
-		if (stat)
-			dev_printk(KERN_ERR, vport->dev.parent,
-				"%s: %s could not be deleted created via "
-				"shost%d channel %d\n", __FUNCTION__,
-				vport->dev.bus_id, vport->shost->host_no,
-				vport->channel);
-	}
+	list_for_each_entry_safe(vport, next_vport, &fc_host->vports, peers)
+		fc_queue_work(shost, &vport->vport_delete_work);
 
 	/* Remove any remote ports */
 	list_for_each_entry_safe(rport, next_rport,
@@ -3061,6 +3049,7 @@ fc_vport_create(struct Scsi_Host *shost, int channel, struct device *pdev,
 	vport->shost = shost;
 	vport->channel = channel;
 	vport->flags = FC_VPORT_CREATING;
+	INIT_WORK(&vport->vport_delete_work, fc_vport_sched_delete);
 
 	spin_lock_irqsave(shost->host_lock, flags);
 
@@ -3207,8 +3196,30 @@ fc_vport_terminate(struct fc_vport *vport)
 }
 EXPORT_SYMBOL(fc_vport_terminate);
 
+/**
+ * fc_vport_sched_delete - workq-based delete request for a vport
+ *
+ * @work:	vport to be deleted.
+ **/
+static void
+fc_vport_sched_delete(struct work_struct *work)
+{
+	struct fc_vport *vport =
+		container_of(work, struct fc_vport, vport_delete_work);
+	int stat;
+
+	stat = fc_vport_terminate(vport);
+	if (stat)
+		dev_printk(KERN_ERR, vport->dev.parent,
+			"%s: %s could not be deleted created via "
+			"shost%d channel %d - error %d\n", __FUNCTION__,
+			vport->dev.bus_id, vport->shost->host_no,
+			vport->channel, stat);
+}
+
 
-MODULE_AUTHOR("Martin Hicks");
+/* Original Author:  Martin Hicks */
+MODULE_AUTHOR("James Smart");
 MODULE_DESCRIPTION("FC Transport Attributes");
 MODULE_LICENSE("GPL");
 

include/scsi/scsi_transport_fc.h

@@ -223,6 +223,7 @@ struct fc_vport {
 	u8 flags;
 	struct list_head peers;
 	struct device dev;
+	struct work_struct vport_delete_work;
 } __attribute__((aligned(sizeof(unsigned long))));
 
 /* bit field values for struct fc_vport "flags" field: */