Date:   Mon, 30 Jan 2023 13:18:20 +0100
From:   Christoph Hellwig <hch@lst.de>
To:     David Howells <dhowells@redhat.com>
Cc:     Christoph Hellwig <hch@lst.de>, 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,
        netdev@vger.kernel.org, linux-afs@lists.infradead.org,
        linux-cifs@vger.kernel.org, samba-technical@lists.samba.org,
        linux-fsdevel@vger.kernel.org, linux-nfs@vger.kernel.org,
        devel@lists.orangefs.org, io-uring@vger.kernel.org,
        linux-mm@kvack.org
Subject: Re: [PATCH 20/23] rxrpc: use bvec_set_page to initialize a bvec
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On Mon, Jan 30, 2023 at 11:24:15AM +0000, David Howells wrote:
> Seems to be something people want to do quite a lot and don't know about.

Hmm.  Right now there is one case where it would be used, and there's
about three that are and should be using bio_add_page.

> I've seen places where someone allocates a buffer and clears it just to use as
> a source of zeros.  There's at least one place in cifs, for example.  I know
> about it from wrangling arch code, but most people working on Linux haven't
> done that.

But we don't really need a helper for every possible page use for that.
People just need to learn about ZERO_PAGE.