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scsi_dh: fix reference counting in scsi_dh_activate error path

PATCH RESEND In review Mike Snitzer 2 participants 2 messages Apr 8, 2011 SCSI

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Mike Snitzer

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#0 lore raw

PATCH RESEND 1/1 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 <[email protected]>
Cc [email protected] # 2.6.38
---
 drivers/scsi/device_handler/scsi_dh.c |    9 ++++++---
 1 files changed, 6 insertions(+), 3 deletions(-)

(I embedded this fix in another scsi_dh_emc thread on 3/21 so figured I'd resend to get it back on the radar)

drivers/scsi/device_handler/scsi_dh.c +6 -3
index 564e6ec..0119b81 100644
@@ -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);
Reviewed-by on v1 1/1
#1 lore raw
Quoted 27 lines · Mike Snitzer
drivers/scsi/device_handler/scsi_dh.c +4 -2
index 564e6ec..0119b81 100644
@@ -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;

drivers/scsi/device_handler/scsi_dh.c int scsi_dh_activate(struct request_queue *q, activate_complete fn, void *data) · line 424

Quoted 10 lines
drivers/scsi/device_handler/scsi_dh.c +2 -1
  	}
 
  	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);

Looks correct to me.

Reviewed-by Mike Christie <[email protected]>