[PATCH 8/8] scsi: scsi-multipath: Add stubbed scsi_multipath_dev_rescan()

[John Garry]

Add an empty function scsi_multipath_dev_rescan() to handle sdev rescans.

It should handle ALUA reconfiguration, and that will be possible when the
core ALUA driver can handle that.

Signed-off-by: John Garry <john.g.garry@xxxxxxxxxx>
---
 drivers/scsi/scsi_multipath.c | 6 ++++++
 drivers/scsi/scsi_scan.c      | 2 ++
 include/scsi/scsi_multipath.h | 4 ++++
 3 files changed, 12 insertions(+)

diff --git a/drivers/scsi/scsi_multipath.c b/drivers/scsi/scsi_multipath.c
index 2b916c7af4bd7..97d835f1b6aaf 100644
--- a/drivers/scsi/scsi_multipath.c
+++ b/drivers/scsi/scsi_multipath.c
@@ -539,6 +539,12 @@ static int scsi_mpath_ua_thread(void *data)
 	return 0;
 }
 
+void scsi_multipath_dev_rescan(struct scsi_device *sdev)
+{
+	/* Handle ALUA reconfig */
+	dev_warn_once(&sdev->sdev_gendev, "mulitpath rescan not handled\n");
+}
+
 static struct scsi_mpath_head *scsi_mpath_alloc_head(void)
 {
 	struct scsi_mpath_head *scsi_mpath_head;
diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c
index e22d3245d4b65..bf602daeac1db 100644
--- a/drivers/scsi/scsi_scan.c
+++ b/drivers/scsi/scsi_scan.c
@@ -1743,6 +1743,8 @@ int scsi_rescan_device(struct scsi_device *sdev)
 
 	if (sdev->handler && sdev->handler->rescan)
 		sdev->handler->rescan(sdev);
+	else if (sdev->scsi_mpath_dev)
+		scsi_multipath_dev_rescan(sdev);
 
 	if (dev->driver && try_module_get(dev->driver->owner)) {
 		struct scsi_driver *drv = to_scsi_driver(dev->driver);
diff --git a/include/scsi/scsi_multipath.h b/include/scsi/scsi_multipath.h
index d30f2c41e17de..9dc02a56e6342 100644
--- a/include/scsi/scsi_multipath.h
+++ b/include/scsi/scsi_multipath.h
@@ -78,6 +78,7 @@ void scsi_mpath_add_sysfs_link(struct scsi_device *sdev);
 void scsi_mpath_remove_sysfs_link(struct scsi_device *sdev);
 int scsi_mpath_get_head(struct scsi_mpath_head *);
 void scsi_mpath_put_head(struct scsi_mpath_head *);
+void scsi_multipath_dev_rescan(struct scsi_device *sdev);
 
 static inline void scsi_mpath_start_request(struct request *req)
 {
@@ -156,5 +157,8 @@ static inline void scsi_mpath_add_sysfs_link(struct scsi_device *sdev)
 static inline void scsi_mpath_remove_sysfs_link(struct scsi_device *sdev)
 {
 }
+static inline void scsi_multipath_dev_rescan(struct scsi_device *sdev)
+{
+}
 #endif /* CONFIG_SCSI_MULTIPATH */
 #endif /* _SCSI_SCSI_MULTIPATH_H */
-- 
2.43.5