[SCSI] iscsi class: add async scan helper
In qla4xxx's probe it will call the iscsi session setup functions
for session that got setup on the initial start. This then makes
it easy for the iscsi class to export a helper which indicates
when those scans are done.
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
diff --git a/drivers/scsi/scsi_transport_iscsi.c b/drivers/scsi/scsi_transport_iscsi.c
index af88955..af17997 100644
--- a/drivers/scsi/scsi_transport_iscsi.c
+++ b/drivers/scsi/scsi_transport_iscsi.c
@@ -127,6 +127,7 @@
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 @@
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 @@
{
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 @@
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 @@
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);