On Mon, 03 Mar 2008 13:09:13 +0900 Tejun Heo <htejun@xxxxxxxxx> wrote: > FUJITA Tomonori wrote: > >> - I think bugs caused by using raw_data_len instead of data_len are more > >> subtle than the other way around. Using data_len instead of > >> raw_data_len usually affects the application layer while using > >> raw_data_len instead of data_len affects the DMA engine and transport layer. > > > > If we add extra_len, we can get what raw_data_len and data_len > > provide. > > > > I can't see what changing the meaning of rq->data_len (and > > investigating all the block drivers) gives us. > > No matter which way you go, you change the meaning of rq->data_len and > you MUST inspect rq->data_len usage whichever way you go. The patch doens't change that rq->data_len means the true data length. But yeah, it breaks rq->data_len == sum(sg). So it might break some drivers. > Apply your patch and try to do sg IO on IDE cdrom w/ various > transfer lengths. I've just tried the patch with both ata and libata and it seems to work. For anyone hitting this problem, please try the following patch: http://lkml.org/lkml/2008/3/2/218 Thanks, -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
