block: allow queue dma_alignment of zero
Let queue_dma_alignment return 0 if it was specifically set to 0.
This permits devices with no particular alignment restrictions to
use arbitrary user space buffers without copying.
Signed-off-by: Pete Wyckoff <pw@osc.edu>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 49b7a4c..c7a3ab5 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -836,12 +836,7 @@
static inline int queue_dma_alignment(struct request_queue *q)
{
- int retval = 511;
-
- if (q && q->dma_alignment)
- retval = q->dma_alignment;
-
- return retval;
+ return q ? q->dma_alignment : 511;
}
/* assumes size > 256 */