scsi: smartpqi: Update device scan operations

Change return type from EINPROGRESS to EBUSY to signal applications to
retry a REGNEWD if the driver cannot process the REGNEWD. Events such as
OFA, suspend, and shutdown return EINPROGRESS if a scan is currently
running. This prevents applications from immediately retrying REGNEWD.

Schedule a new REGNEWD if system low on memory.

Link: https://lore.kernel.org/r/161549382157.25025.16054784597622125373.stgit@brunhilda
Reviewed-by: Scott Benesh <scott.benesh@microchip.com>
Reviewed-by: Mike McGowen <mike.mcgowen@microchip.com>
Reviewed-by: Scott Teel <scott.teel@microchip.com>
Signed-off-by: Kevin Barnett <kevin.barnett@microchip.com>
Signed-off-by: Don Brace <don.brace@microchip.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/smartpqi/smartpqi_init.c b/drivers/scsi/smartpqi/smartpqi_init.c
index 89b6972a21f6a56a156c699d5f22192a286d4b61..9f6ab2f4144f17154e6584d2f3454979a7644047 100644 (file)
--- a/drivers/scsi/smartpqi/smartpqi_init.c
+++ b/drivers/scsi/smartpqi/smartpqi_init.c
@@ -2312,21 +2312,27 @@ out:
 
 static int pqi_scan_scsi_devices(struct pqi_ctrl_info *ctrl_info)
 {
-       int rc = 0;
+       int rc;
+       int mutex_acquired;
 
        if (pqi_ctrl_offline(ctrl_info))
                return -ENXIO;
 
-       if (!mutex_trylock(&ctrl_info->scan_mutex)) {
+       mutex_acquired = mutex_trylock(&ctrl_info->scan_mutex);
+
+       if (!mutex_acquired) {
+               if (pqi_ctrl_scan_blocked(ctrl_info))
+                       return -EBUSY;
                pqi_schedule_rescan_worker_delayed(ctrl_info);
-               rc = -EINPROGRESS;
-       } else {
-               rc = pqi_update_scsi_devices(ctrl_info);
-               if (rc)
-                       pqi_schedule_rescan_worker_delayed(ctrl_info);
-               mutex_unlock(&ctrl_info->scan_mutex);
+               return -EINPROGRESS;
        }
 
+       rc = pqi_update_scsi_devices(ctrl_info);
+       if (rc && !pqi_ctrl_scan_blocked(ctrl_info))
+               pqi_schedule_rescan_worker_delayed(ctrl_info);
+
+       mutex_unlock(&ctrl_info->scan_mutex);
+
        return rc;
 }