[SCSI] libiscsi: use bh locking instead of irq with session lock

The session lock is taken in threads, timers, and bottom halves
like softirqs and tasklets. All the code but
iscsi_conn/session_failure take the session lock with the spin_lock_bh
call. This was done because I thought some offload drivers
would be calling these functions from a irq. They never did,
so this patch has iscsi_conn/session_failure use the bh
locking.

Signed-off-by: Mike Christie <[e-mail]>
Signed-off-by: James Bottomley <[e-mail]>

drivers/scsi/libiscsi.c

···
 {
 	struct iscsi_conn *conn;
 	struct device *dev;
-	unsigned long flags;
 
-	spin_lock_irqsave(&session->lock, flags);
+	spin_lock_bh(&session->lock);
 	conn = session->leadconn;
 	if (session->state == ISCSI_STATE_TERMINATE || !conn) {
-		spin_unlock_irqrestore(&session->lock, flags);
+		spin_unlock_bh(&session->lock);
 		return;
 	}
 
 	dev = get_device(&conn->cls_conn->dev);
-	spin_unlock_irqrestore(&session->lock, flags);
+	spin_unlock_bh(&session->lock);
 	if (!dev)
 	        return;
 	/*
···
 void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err)
 {
 	struct iscsi_session *session = conn->session;
-	unsigned long flags;
 
-	spin_lock_irqsave(&session->lock, flags);
+	spin_lock_bh(&session->lock);
 	if (session->state == ISCSI_STATE_FAILED) {
-		spin_unlock_irqrestore(&session->lock, flags);
+		spin_unlock_bh(&session->lock);
 		return;
 	}
 
 	if (conn->stop_stage == 0)
 		session->state = ISCSI_STATE_FAILED;
-	spin_unlock_irqrestore(&session->lock, flags);
+	spin_unlock_bh(&session->lock);
 
 	set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
 	set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);