| Date | Sat, 21 Jan 2023 05:10:18 -0800 | From | Christoph Hellwig <> | Subject | Re: [PATCH v7 2/8] iov_iter: Add a function to extract a page list from an iterator |
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On Fri, Jan 20, 2023 at 05:55:50PM +0000, David Howells wrote: > (3) Any other sort of iterator. > > No refs or pins are obtained on the page, the assumption is made that > the caller will manage page retention. ITER_ALLOW_P2PDMA is not > permitted.
The ITER_ALLOW_P2PDMA check here is fundamentally wrong and will break things like io_uring to fixed buffers on NVMe. ITER_ALLOW_P2PDMA should strictly increase the group of acceptable iters, it does must not restrict anything.
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