Received-SPF: pass (google.com: domain of linux-nfs-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Content-Type: text/plain;
        charset=us-ascii
Mime-Version: 1.0 (Mac OS X Mail 13.4 \(3608.120.23.2.4\))
Subject: Re: [PATCH 5/8] SUNRPC: Don't truncate tail in xdr_inline_pages()
From:   Chuck Lever <chuck.lever@oracle.com>
In-Reply-To: <20201122205229.3826-6-trondmy@kernel.org>
Date:   Sun, 22 Nov 2020 20:24:03 -0500
Cc:     Linux NFS Mailing List <linux-nfs@vger.kernel.org>
Content-Transfer-Encoding: quoted-printable
Message-Id: <0CB9471F-ACC6-42A1-8DCD-8A9E74BAF8F1@oracle.com>
References: <20201122205229.3826-1-trondmy@kernel.org>
 <20201122205229.3826-2-trondmy@kernel.org>
 <20201122205229.3826-3-trondmy@kernel.org>
 <20201122205229.3826-4-trondmy@kernel.org>
 <20201122205229.3826-5-trondmy@kernel.org>
 <20201122205229.3826-6-trondmy@kernel.org>
To:     trondmy@kernel.org
Precedence: bulk


> On Nov 22, 2020, at 3:52 PM, trondmy@kernel.org wrote:
>=20
> From: Trond Myklebust <trond.myklebust@hammerspace.com>
>=20
> True that if the length of the pages[] array is not 4-byte aligned, =
then
> we will need to store the padding in the tail, but there is no need to
> truncate the total buffer length here.

This description confuses me. The existing code reduces the length of
the tail, not the "total buffer length." And what the removed logic is
doing is taking out the length of the XDR pad for the pages array when
it is not expected to be used.


> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
> ---
> net/sunrpc/xdr.c | 3 ---
> 1 file changed, 3 deletions(-)
>=20
> diff --git a/net/sunrpc/xdr.c b/net/sunrpc/xdr.c
> index 3ce0a5daa9eb..5a450055469f 100644
> --- a/net/sunrpc/xdr.c
> +++ b/net/sunrpc/xdr.c
> @@ -193,9 +193,6 @@ xdr_inline_pages(struct xdr_buf *xdr, unsigned int =
offset,
>=20
> 	tail->iov_base =3D buf + offset;
> 	tail->iov_len =3D buflen - offset;
> -	if ((xdr->page_len & 3) =3D=3D 0)
> -		tail->iov_len -=3D sizeof(__be32);
> -
> 	xdr->buflen +=3D len;
> }
> EXPORT_SYMBOL_GPL(xdr_inline_pages);
> --=20
> 2.28.0
>=20

--
Chuck Lever