Date:   Tue, 24 Jan 2023 09:43:27 -0400
From:   Jason Gunthorpe <jgg@nvidia.com>
To:     Christoph Hellwig <hch@infradead.org>
Cc:     John Hubbard <jhubbard@nvidia.com>,
        David Howells <dhowells@redhat.com>,
        Al Viro <viro@zeniv.linux.org.uk>,
        Matthew Wilcox <willy@infradead.org>,
        Jens Axboe <axboe@kernel.dk>, Jan Kara <jack@suse.cz>,
        Jeff Layton <jlayton@kernel.org>,
        Logan Gunthorpe <logang@deltatee.com>,
        linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org,
        linux-kernel@vger.kernel.org, Christoph Hellwig <hch@lst.de>,
        linux-mm@kvack.org
Subject: Re: [PATCH v8 10/10] mm: Renumber FOLL_PIN and FOLL_GET down
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On Tue, Jan 24, 2023 at 05:18:07AM -0800, Christoph Hellwig wrote:
> On Tue, Jan 24, 2023 at 09:13:30AM -0400, Jason Gunthorpe wrote:
> > Yeah, I already wrote a similar patch, using the 1<< notation, 
> > splitting the internal/external, and rebasing on the move to
> > mm_types.. I can certainly drop that patch if we'd rather do this.
> 
> Given that you are doing more work in that area it might be best
> to drop this patch from this series.
> 
> > Though, I'm not so keen on using FOLL_ internal flags inside the block
> > layer.. Can you stick with the BIO versions of these?
> 
> The block layer doesn't really use it - the new helper in iov_iter.c
> returns it, and the block layer instantly turns it into an internal
> flag.  But maybe it should just return a bool pinned (by reference)
> now?

Yes, a bool flag to the new mm helper instead of a FOLL_* seems good
to me

Thanks,
Jason