Messages in this thread | | | Date | Fri, 23 Nov 2018 18:50:26 +0800 | From | Ming Lei <> | Subject | Re: [PATCH V11 15/19] block: enable multipage bvecs |
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On Wed, Nov 21, 2018 at 05:12:06PM +0100, Christoph Hellwig wrote: > On Wed, Nov 21, 2018 at 11:48:13PM +0800, Ming Lei wrote: > > I guess the correct check should be: > > > > end_addr = vec_addr + bv->bv_offset + bv->bv_len; > > if (same_page && > > (end_addr & PAGE_MASK) != (page_addr & PAGE_MASK)) > > return false; > > Indeed.
The above is still not totally correct, and it should have been:
end_addr = vec_addr + bv->bv_offset + bv->bv_len - 1; if (same_page && (end_addr & PAGE_MASK) != page_addr) return false;
Also bv->bv_len should be guaranteed as being bigger than zero.
It also shows that it is quite easy to figure out the last page as wrong, :-(
Thanks, Ming
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