Re: [PATCH 2/9] block: add scatterlist-less DMA mapping helpers

[Daniel Gomez <da.gomez@xxxxxxxxxx>]

On 16/06/2025 14.42, Christoph Hellwig wrote:
> On Mon, Jun 16, 2025 at 02:37:43PM +0200, Daniel Gomez wrote:
>> 	
>> 2. In the if/switch case default case (line 181-183):
>> 	It sets the status to invalid and *iter_start() returns false:
>> 	
>> 		default:
>> 			iter->status = BLK_STS_INVAL;
>> 			return false;
>>
>>
>> Removing the invalid assignment "makes it" valid (because of the
>> initialization)
> 
> Huhhh?  How do you make a field access valid by dropping an assignment?
> 

It should be valid already. But if the initialized value at line 160 can be
changed through the previous code then, this should suffice:

diff --git a/block/blk-mq-dma.c b/block/blk-mq-dma.c
index 37f8fba077e6..7d5ebe1a3f49 100644
--- a/block/blk-mq-dma.c
+++ b/block/blk-mq-dma.c
@@ -179,7 +179,7 @@ bool blk_rq_dma_map_iter_start(struct request *req, struct device *dma_dev,
                        req->cmd_flags &= ~REQ_P2PDMA;
                        break;
                default:
-                       iter->status = BLK_STS_INVAL;
+                       iter->status = BLK_STS_OK;
                        return false;
                }
        }