[patch 03/38] [SCSI] scsi_dh: fix reference counting in scsi_dh_activate error path

From: Greg KH
Date: Thu May 05 2011 - 20:21:14 EST


2.6.38-stable review patch. If anyone has any objections, please let us know.

------------------

From: Mike Snitzer <snitzer@xxxxxxxxxx>

commit 0b8393578c70bc1f09790eeae7d918f38da2e010 upstream.

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@xxxxxxxxxx>
Reviewed-by: Mike Christie <michaelc@xxxxxxxxxxx>
Signed-off-by: James Bottomley <James.Bottomley@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
drivers/scsi/device_handler/scsi_dh.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)

--- a/drivers/scsi/device_handler/scsi_dh.c
+++ b/drivers/scsi/device_handler/scsi_dh.c
@@ -437,12 +437,14 @@ int scsi_dh_activate(struct request_queu
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;
@@ -453,12 +455,13 @@ int scsi_dh_activate(struct request_queu
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);


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