scsi: libsas: use flush_workqueue to process disco events synchronously

Now we are processing sas event and discover event in different
workqueues.  It's safe to wait the discover event done in the sas event
work. Use flush_workqueue() to insure the disco and revalidate events
processed synchronously so that the whole discover and revalidate
process will not be interrupted by other events.

Signed-off-by: Jason Yan <yanaijie@huawei.com>
CC: John Garry <john.garry@huawei.com>
CC: Johannes Thumshirn <jthumshirn@suse.de>
CC: Ewan Milne <emilne@redhat.com>
CC: Christoph Hellwig <hch@lst.de>
CC: Tomas Henzl <thenzl@redhat.com>
CC: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/libsas/sas_port.c b/drivers/scsi/libsas/sas_port.c
index 93266283f51ff0c606b4e5d7210aa0f5d63d48ab..64722f42b2564f8cacca93d97fdb89f396242122 100644 (file)
--- a/drivers/scsi/libsas/sas_port.c
+++ b/drivers/scsi/libsas/sas_port.c
@@ -192,6 +192,7 @@ static void sas_form_port(struct asd_sas_phy *phy)
                si->dft->lldd_port_formed(phy);
 
        sas_discover_event(phy->port, DISCE_DISCOVER_DOMAIN);
+       flush_workqueue(sas_ha->disco_q);
 }
 
 /**
@@ -277,6 +278,9 @@ void sas_porte_broadcast_rcvd(struct work_struct *work)
 
        SAS_DPRINTK("broadcast received: %d\n", prim);
        sas_discover_event(phy->port, DISCE_REVALIDATE_DOMAIN);
+
+       if (phy->port)
+               flush_workqueue(phy->port->ha->disco_q);
 }
 
 void sas_porte_link_reset_err(struct work_struct *work)