Messages in this thread | | | Date | Tue, 23 Dec 2014 02:22:21 -0800 | From | Christoph Hellwig <> | Subject | Re: [RFC PATCH 02/17] block: simplify bio_add_page() |
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On Mon, Dec 22, 2014 at 12:48:29PM +0100, Dongsu Park wrote: > From: Kent Overstreet <kmo@daterainc.com> > > Since generic_make_request() can now handle arbitrary size bios, all we > have to do is make sure the bvec array doesn't overflow. > __bio_add_page() doesn't need to call ->merge_bvec_fn(), where > we can get rid of unnecessary code paths.
This needs an explanation of why removign the call to ->merge_bvec_fn is fine for bio_add_pc_page. I guess it's because neither the target pscsi pass through mode, nor the osd code ever use anything but a simple scsi devices that doesn't even have one, but it needs to be clearly spelled out.
> + * Attempt to add a page to the bio_vec maplist. This will only fail if > + * bio->bi_vcnt == bio->bi_max_vecs.
It also fails on a cloned bio, although that might better be turned into a BUG_ON().
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