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From:   Ilya Dryomov <idryomov@gmail.com>
Date:   Mon, 30 Jan 2023 19:35:17 +0100
Message-ID: <CAOi1vP_aU58YpiOkYgQy4a=VVnm64WeWH5pwYf+bc_C=COYY3g@mail.gmail.com>
Subject: Re: [PATCH 01/23] block: factor out a bvec_set_page helper
To:     Christoph Hellwig <hch@lst.de>
Cc:     David Howells <dhowells@redhat.com>, Jens Axboe <axboe@kernel.dk>,
        "Michael S. Tsirkin" <mst@redhat.com>,
        Jason Wang <jasowang@redhat.com>,
        Minchan Kim <minchan@kernel.org>,
        Sergey Senozhatsky <senozhatsky@chromium.org>,
        Keith Busch <kbusch@kernel.org>,
        Sagi Grimberg <sagi@grimberg.me>,
        Chaitanya Kulkarni <kch@nvidia.com>,
        "Martin K. Petersen" <martin.petersen@oracle.com>,
        Marc Dionne <marc.dionne@auristor.com>,
        Xiubo Li <xiubli@redhat.com>, Steve French <sfrench@samba.org>,
        Trond Myklebust <trond.myklebust@hammerspace.com>,
        Anna Schumaker <anna@kernel.org>,
        Mike Marshall <hubcap@omnibond.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        Chuck Lever <chuck.lever@oracle.com>,
        linux-block@vger.kernel.org, ceph-devel@vger.kernel.org,
        virtualization@lists.linux-foundation.org,
        linux-nvme@lists.infradead.org, linux-scsi@vger.kernel.org,
        target-devel@vger.kernel.org, kvm@vger.kernel.org,
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        linux-cifs@vger.kernel.org, samba-technical@lists.samba.org,
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        linux-mm@kvack.org
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On Mon, Jan 30, 2023 at 11:36 AM Christoph Hellwig <hch@lst.de> wrote:
>
> On Mon, Jan 30, 2023 at 10:33:36AM +0000, David Howells wrote:
> > Christoph Hellwig <hch@lst.de> wrote:
> >
> > > +static inline void bvec_set_page(struct bio_vec *bv, struct page *page,
> > > +           unsigned int len, unsigned int offset)
> >
> > Could you swap len and offset around?  It reads better offset first.  You move
> > offset into the page and then do something with len bytes.
>
> This matches bio_add_page and the order inside bio_vec itself.  willy
> wanted to switch it around for bio_add_folio but Jens didn't like it,
> so I'll stick to the current convention in this area as well.

This also matches sg_set_page() so sticking to the current convention
is definitely a good idea!

Thanks,

                Ilya