Messages in this thread | | | Date | Mon, 03 Mar 2008 13:09:13 +0900 | From | Tejun Heo <> | Subject | Re: [PATCH] block: fix residual byte count handling |
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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. Apply your patch and try to do sg IO on IDE cdrom w/ various transfer lengths.
-- tejun
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