Messages in this thread | | | From | Dmitry Monakhov <> | Subject | Re: [PATCH 1/2] blkdev: fix merge_bvec_fn return value checks | Date | Wed, 03 Mar 2010 22:42:17 +0300 |
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Mike Snitzer <snitzer@redhat.com> writes:
> Linux has all sorts of internal interfaces that are "odd"... the current > 'q->merge_bvec_fn' interface included. But odd is not a problem (nor is > it "broken") unless you make changes that don't consider how the current > interface is defined. Ok. then cant you please explain more historical questions 1) Why bio_add_page() can not add less data than requested? Seems that it doesn't make caller's code much complicate Off course barrier bio is special case. I don't consider it here.
2) What statement "bio_add_page() must accept at least one page" exactly means? IMHO this means that bio_add_page() must accept at least one page with len (PAGE_SIZE - offset). Or more restricted statemnt that first bio_add_page() must be always successfull.
But currently in some places this rule treated as what all bio which has size less whan PAGE_SIZE are accepted. And in x86 such bio may has up to 8 pages/bvecs. > > But I digress... > > Mike
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