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Date:   Fri, 19 May 2023 20:56:56 -0700
From:   Christoph Hellwig <hch@infradead.org>
To:     Kent Overstreet <kent.overstreet@linux.dev>
Cc:     David Howells <dhowells@redhat.com>, Jens Axboe <axboe@kernel.dk>,
        Al Viro <viro@zeniv.linux.org.uk>,
        Christoph Hellwig <hch@infradead.org>,
        Matthew Wilcox <willy@infradead.org>, Jan Kara <jack@suse.cz>,
        Jeff Layton <jlayton@kernel.org>,
        David Hildenbrand <david@redhat.com>,
        Jason Gunthorpe <jgg@nvidia.com>,
        Logan Gunthorpe <logang@deltatee.com>,
        Hillf Danton <hdanton@sina.com>,
        Christian Brauner <brauner@kernel.org>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-mm@kvack.org,
        Christoph Hellwig <hch@lst.de>,
        John Hubbard <jhubbard@nvidia.com>
Subject: Re: [PATCH v20 29/32] block: Replace BIO_NO_PAGE_REF with
 BIO_PAGE_REFFED with inverted logic
Message-ID: <ZGhFCCBdlSWWcG1G@infradead.org>
References: <20230519074047.1739879-1-dhowells@redhat.com>
 <20230519074047.1739879-30-dhowells@redhat.com>
 <ZGghr0/lFRKmaoAX@moria.home.lan>
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On Fri, May 19, 2023 at 09:26:07PM -0400, Kent Overstreet wrote:
> On Fri, May 19, 2023 at 08:40:44AM +0100, David Howells wrote:
> > From: Christoph Hellwig <hch@lst.de>
> > 
> > Replace BIO_NO_PAGE_REF with a BIO_PAGE_REFFED flag that has the inverted
> > meaning is only set when a page reference has been acquired that needs to
> > be released by bio_release_pages().
> 
> What was the motivation for this patch?

So that is only is set when we need to release a page, instead telling
code to not release it when it otherwise would, where otherwise would
is implicit and undocumented and changes in this series.