2 files changed, 37 insertions, 4 deletions

diff --git a/drivers/scsi/scsi_transport_iscsi.c b/drivers/scsi/scsi_transport_iscsi.c
index af88955d0ec1..af1799723e7b 100644
--- a/drivers/scsi/scsi_transport_iscsi.c
+++ b/drivers/scsi/scsi_transport_iscsi.c
@@ -127,6 +127,7 @@ static int iscsi_setup_host(struct transport_container *tc, struct device *dev,
         memset(ihost, 0, sizeof(*ihost));
         INIT_LIST_HEAD(&ihost->sessions);
         mutex_init(&ihost->mutex);
+        atomic_set(&ihost->nr_scans, 0);
 
         snprintf(ihost->scan_workq_name, KOBJ_NAME_LEN, "iscsi_scan_%d",
                 shost->host_no);
@@ -284,6 +285,25 @@ static int iscsi_is_session_dev(const struct device *dev)
         return dev->release == iscsi_session_release;
 }
 
+/**
+ * iscsi_scan_finished - helper to report when running scans are done
+ * @shost: scsi host
+ * @time: scan run time
+ *
+ * This function can be used by drives like qla4xxx to report to the scsi
+ * layer when the scans it kicked off at module load time are done.
+ */
+int iscsi_scan_finished(struct Scsi_Host *shost, unsigned long time)
+{
+        struct iscsi_host *ihost = shost->shost_data;
+        /*
+         * qla4xxx will have kicked off some session unblocks before calling
+         * scsi_scan_host, so just wait for them to complete.
+         */
+        return !atomic_read(&ihost->nr_scans);
+}
+EXPORT_SYMBOL_GPL(iscsi_scan_finished);
+
 static int iscsi_user_scan(struct Scsi_Host *shost, uint channel,
                            uint id, uint lun)
 {
@@ -306,17 +326,21 @@ static void iscsi_scan_session(struct work_struct *work)
 {
         struct iscsi_cls_session *session =
                         container_of(work, struct iscsi_cls_session, scan_work);
+        struct Scsi_Host *shost = iscsi_session_to_shost(session);
+        struct iscsi_host *ihost = shost->shost_data;
         unsigned long flags;
 
         spin_lock_irqsave(&session->lock, flags);
         if (session->state != ISCSI_SESSION_LOGGED_IN) {
                 spin_unlock_irqrestore(&session->lock, flags);
-                return;
+                goto done;
         }
         spin_unlock_irqrestore(&session->lock, flags);
 
         scsi_scan_target(&session->dev, 0, session->target_id,
                          SCAN_WILD_CARD, 1);
+done:
+        atomic_dec(&ihost->nr_scans);
 }
 
 static void session_recovery_timedout(struct work_struct *work)
@@ -366,7 +390,15 @@ void iscsi_unblock_session(struct iscsi_cls_session *session)
         spin_unlock_irqrestore(&session->lock, flags);
 
         __iscsi_unblock_session(session);
-        queue_work(ihost->scan_workq, &session->scan_work);
+        /*
+         * Only do kernel scanning if the driver is properly hooked into
+         * the async scanning code (drivers like iscsi_tcp do login and
+         * scanning from userspace).
+         */
+        if (shost->hostt->scan_finished) {
+                if (queue_work(ihost->scan_workq, &session->scan_work))
+                        atomic_inc(&ihost->nr_scans);
+        }
 }
 EXPORT_SYMBOL_GPL(iscsi_unblock_session);
 
@@ -550,7 +582,7 @@ void iscsi_remove_session(struct iscsi_cls_session *session)
         session->state = ISCSI_SESSION_FREE;
         spin_unlock_irqrestore(&session->lock, flags);
         __iscsi_unblock_session(session);
-        iscsi_unbind_session(session);
+        __iscsi_unbind_session(&session->unbind_work);
 
         /* flush running scans */
         flush_workqueue(ihost->scan_workq);
diff --git a/include/scsi/scsi_transport_iscsi.h b/include/scsi/scsi_transport_iscsi.h
index 1f0ec46b4f87..83693ba09c29 100644
--- a/include/scsi/scsi_transport_iscsi.h
+++ b/include/scsi/scsi_transport_iscsi.h
@@ -203,6 +203,7 @@ struct iscsi_cls_session {
 
 struct iscsi_host {
         struct list_head sessions;
+        atomic_t nr_scans;
         struct mutex mutex;
         struct workqueue_struct *scan_workq;
         char scan_workq_name[KOBJ_NAME_LEN];
@@ -229,6 +230,6 @@ extern struct iscsi_cls_conn *iscsi_create_conn(struct iscsi_cls_session *sess,
 extern int iscsi_destroy_conn(struct iscsi_cls_conn *conn);
 extern void iscsi_unblock_session(struct iscsi_cls_session *session);
 extern void iscsi_block_session(struct iscsi_cls_session *session);
-
+extern int iscsi_scan_finished(struct Scsi_Host *shost, unsigned long time);
 
 #endif