1 files changed, 13 insertions, 12 deletions

diff --git a/drivers/scsi/device_handler/scsi_dh.c b/drivers/scsi/device_handler/scsi_dh.c
index 1a8dbf33f2ac..d8a8aac2c3db 100644
--- a/drivers/scsi/device_handler/scsi_dh.c
+++ b/drivers/scsi/device_handler/scsi_dh.c
@@ -108,19 +108,17 @@ static int scsi_dh_handler_attach(struct scsi_device *sdev,
                 return 0;
         }
 
-        if (scsi_dh->attach) {
-                if (!try_module_get(scsi_dh->module))
-                        return -EINVAL;
-
-                err = scsi_dh->attach(sdev);
-                if (err) {
-                        module_put(scsi_dh->module);
-                        return err;
-                }
+        if (!try_module_get(scsi_dh->module))
+                return -EINVAL;
 
-                kref_init(&sdev->scsi_dh_data->kref);
-                sdev->scsi_dh_data->sdev = sdev;
+        err = scsi_dh->attach(sdev);
+        if (err) {
+                module_put(scsi_dh->module);
+                return err;
         }
+
+        kref_init(&sdev->scsi_dh_data->kref);
+        sdev->scsi_dh_data->sdev = sdev;
         return err;
 }
 
@@ -154,7 +152,7 @@ static void scsi_dh_handler_detach(struct scsi_device *sdev,
         if (!scsi_dh)
                 scsi_dh = sdev->scsi_dh_data->scsi_dh;
 
-        if (scsi_dh && scsi_dh->detach)
+        if (scsi_dh)
                 kref_put(&sdev->scsi_dh_data->kref, __detach_handler);
 }
 
@@ -343,6 +341,9 @@ int scsi_register_device_handler(struct scsi_device_handler *scsi_dh)
         if (get_device_handler(scsi_dh->name))
                 return -EBUSY;
 
+        if (!scsi_dh->attach || !scsi_dh->detach)
+                return -EINVAL;
+
         spin_lock(&list_lock);
         list_add(&scsi_dh->list, &scsi_dh_list);
         spin_unlock(&list_lock);