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Date:   Tue, 6 Sep 2022 10:52:37 -0600
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To:     John Hubbard <jhubbard@nvidia.com>, linux-kernel@vger.kernel.org,
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Cc:     Christoph Hellwig <hch@lst.de>,
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        Dan Williams <dan.j.williams@intel.com>,
        Jason Gunthorpe <jgg@ziepe.ca>,
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        Don Dutile <ddutile@redhat.com>,
        Matthew Wilcox <willy@infradead.org>,
        Daniel Vetter <daniel.vetter@ffwll.ch>,
        Minturn Dave B <dave.b.minturn@intel.com>,
        Jason Ekstrand <jason@jlekstrand.net>,
        Dave Hansen <dave.hansen@linux.intel.com>,
        Xiong Jianxin <jianxin.xiong@intel.com>,
        Bjorn Helgaas <helgaas@kernel.org>,
        Ira Weiny <ira.weiny@intel.com>,
        Robin Murphy <robin.murphy@arm.com>,
        Martin Oliveira <martin.oliveira@eideticom.com>,
        Chaitanya Kulkarni <ckulkarnilinux@gmail.com>,
        Ralph Campbell <rcampbell@nvidia.com>,
        Stephen Bates <sbates@raithlin.com>
References: <20220825152425.6296-1-logang@deltatee.com>
 <20220825152425.6296-3-logang@deltatee.com>
 <24ee706f-b70c-28d0-15a7-13d0dc9254bb@nvidia.com>
From:   Logan Gunthorpe <logang@deltatee.com>
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Subject: Re: [PATCH v9 2/8] iov_iter: introduce
 iov_iter_get_pages_[alloc_]flags()
Precedence: bulk


On 2022-09-05 17:21, John Hubbard wrote:
> Looking ahead, interestingly enough, it turns out that this approach to
> the wrappers is really pretty close to what I posted in patch 4/7 of my
> "convert most filesystems to pin_user_pages_fast()" series [1]. Instead
> of passing gup_flags through, I tried to avoid that (because FOLL_PIN
> is, as a mild design preference, supposed to remain internal to gup.c),
> but given that you need to do it, I think I can just build on top of
> your approach, and pass in FOLL_PIN via your new gup_flags arg.

Seems to me like we could just provide the one exported function with a
flag then use an static inline helper for the pin version. That would
help keep the FOLL_PIN flag contained as you like.

> Along those lines, I've copied you in on "New topic branch for block + 
> gup work?", let's see what happens over there.
> 
> [1] https://lore.kernel.org/r/20220831041843.973026-1-jhubbard@nvidia.com

Thanks for the review. All the feedback makes sense. I'll apply all the
changes from you and Christoph for the next version.

I'm happy to base the next version off of any other changes to the iov
functions. I suspect my patches can hold off a cycle or two more while
we do it. Let me know if you'd like some help making the conversions,
I'm also fine to do some work to aid with the effort.

Thanks,

Logan