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From:   David Howells <dhowells@redhat.com>
In-Reply-To: <Y8/hhvfDtVcsgQd6@nvidia.com>
References: <Y8/hhvfDtVcsgQd6@nvidia.com> <Y8/ZekMEAfi8VeFl@nvidia.com> <20230123173007.325544-1-dhowells@redhat.com> <20230123173007.325544-11-dhowells@redhat.com> <31f7d71d-0eb9-2250-78c0-2e8f31023c66@nvidia.com> <84721e8d-d40e-617c-b75e-ead51c3e1edf@nvidia.com> <852117.1674567983@warthog.procyon.org.uk>
To:     Jason Gunthorpe <jgg@nvidia.com>
Cc:     dhowells@redhat.com, John Hubbard <jhubbard@nvidia.com>,
        Al Viro <viro@zeniv.linux.org.uk>,
        Christoph Hellwig <hch@infradead.org>,
        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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Content-ID: <852913.1674568628.1@warthog.procyon.org.uk>
Date:   Tue, 24 Jan 2023 13:57:08 +0000
Message-ID: <852914.1674568628@warthog.procyon.org.uk>
Precedence: bulk

Jason Gunthorpe <jgg@nvidia.com> wrote:

> I moved FOLL_PIN to internal.h because it is not supposed to be used
> outside mm/*
> 
> I would prefer to keep it that way.

I'll need to do something else, then, such as creating a new pair of 'cleanup'
flags:

	[include/linux/mm_types.h]
	#define PAGE_CLEANUP_UNPIN	(1U << 0)
	#define PAGE_CLEANUP_PUT	(1U << 0)

	[mm/gup.h]
	void folio_put_unpin(struct folio *folio, unsigned int cleanup_flags)
	{
		unsigned int gup_flags = 0;

		cleanup_flags &= PAGE_CLEANUP_UNPIN | PAGE_CLEANUP_PUT;
		if (!cleanup_flags)
			return;
		gup_flags |= cleanup_flags & PAGE_CLEANUP_UNPIN ? FOLL_PIN : 0;
		gup_flags |= cleanup_flags & PAGE_CLEANUP_PUT ? FOLL_GET : 0;
		gup_put_folio(folio, 1, flags);
	}
	EXPORT_SYMBOL_GPL(folio_put_unpin);

David