On Mon, 03 Mar 2008 22:38:55 +0900 Tejun Heo <htejun@xxxxxxxxx> wrote: > FUJITA Tomonori wrote: > > On Mon, 03 Mar 2008 18:21:13 +0900 > > Tejun Heo <htejun@xxxxxxxxx> wrote: > > > >> FUJITA Tomonori wrote: > >>>>> 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. > >> Yeah, that's what I was saying. You end up breaking one of the two > >> assumptions. As sglist is getting modified for any driver if it has DMA > >> alignment set, whether rq->data_len is adjusted together or not, sglist > >> and data_len usages have to be audited. > > > > My patch (well, James' original approach) doesn't affect drivers that > > don't use drain buffer. rq->data_len still means the true data length > > and rq->data_len is equal to sum(sg) for them. So right now we need to > > audit only libata. > > Your patch does change sglist for any driver which sets DMA alignment. I overlook it. Where does it changes sglist? -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
