[SCSI] scsi_dh: fix reference counting in scsi_dh_activate error path

Commit db422318cbca55168cf965f655471dbf8be82433 ([SCSI] scsi_dh:
propagate SCSI device deletion) introduced a regression where the device
reference is not dropped prior to scsi_dh_activate's early return from
the error path.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@kernel.org # 2.6.38
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

1 files changed, 6 insertions, 3 deletions

diff --git a/drivers/scsi/device_handler/scsi_dh.c b/drivers/scsi/device_handler/scsi_dh.c
index 564e6ecd17c2..0119b8147797 100644
--- a/drivers/scsi/device_handler/scsi_dh.c
+++ b/drivers/scsi/device_handler/scsi_dh.c
@@ -394,12 +394,14 @@ int scsi_dh_activate(struct request_queue *q, activate_complete fn, void *data)
         unsigned long flags;
         struct scsi_device *sdev;
         struct scsi_device_handler *scsi_dh = NULL;
+        struct device *dev = NULL;
 
         spin_lock_irqsave(q->queue_lock, flags);
         sdev = q->queuedata;
         if (sdev && sdev->scsi_dh_data)
                 scsi_dh = sdev->scsi_dh_data->scsi_dh;
-        if (!scsi_dh || !get_device(&sdev->sdev_gendev) ||
+        dev = get_device(&sdev->sdev_gendev);
+        if (!scsi_dh || !dev ||
             sdev->sdev_state == SDEV_CANCEL ||
             sdev->sdev_state == SDEV_DEL)
                 err = SCSI_DH_NOSYS;
@@ -410,12 +412,13 @@ int scsi_dh_activate(struct request_queue *q, activate_complete fn, void *data)
         if (err) {
                 if (fn)
                         fn(data, err);
-                return err;
+                goto out;
         }
 
         if (scsi_dh->activate)
                 err = scsi_dh->activate(sdev, fn, data);
-        put_device(&sdev->sdev_gendev);
+out:
+        put_device(dev);
         return err;
 }
 EXPORT_SYMBOL_GPL(scsi_dh_activate);