scsi: use 'scsi_device_from_queue()' for scsi_dh
The device handler needs to check if a given queue belongs to a scsi
device; only then does it make sense to attach a device handler.
[mkp: dropped flags]
Cc: <stable@vger.kernel.org>
Signed-off-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 912fbc3..39b2d72 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -2231,6 +2231,29 @@
blk_mq_free_tag_set(&shost->tag_set);
}
+/**
+ * scsi_device_from_queue - return sdev associated with a request_queue
+ * @q: The request queue to return the sdev from
+ *
+ * Return the sdev associated with a request queue or NULL if the
+ * request_queue does not reference a SCSI device.
+ */
+struct scsi_device *scsi_device_from_queue(struct request_queue *q)
+{
+ struct scsi_device *sdev = NULL;
+
+ if (q->mq_ops) {
+ if (q->mq_ops == &scsi_mq_ops)
+ sdev = q->queuedata;
+ } else if (q->request_fn == scsi_request_fn)
+ sdev = q->queuedata;
+ if (!sdev || !get_device(&sdev->sdev_gendev))
+ sdev = NULL;
+
+ return sdev;
+}
+EXPORT_SYMBOL_GPL(scsi_device_from_queue);
+
/*
* Function: scsi_block_requests()
*