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From:   Chuck Lever III <chuck.lever@oracle.com>
To:     Neil Brown <neilb@suse.de>
CC:     Linux NFS Mailing List <linux-nfs@vger.kernel.org>
Subject: Re: [PATCH v1 3/5] SUNRPC: Clean up xdr_commit_encode()
Thread-Topic: [PATCH v1 3/5] SUNRPC: Clean up xdr_commit_encode()
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Date:   Tue, 7 Jun 2022 02:21:13 +0000
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> On Jun 6, 2022, at 9:05 PM, NeilBrown <neilb@suse.de> wrote:
>=20
> On Mon, 06 Jun 2022, Chuck Lever wrote:
>> Both the ::iov_len field and the third parameter of memcpy() and
>> memmove() are size_t. There's no reason for the implicit conversion
>> from size_t to int and back. Change the type of @shift to make the
>> code easier to read and understand.
>=20
> I wouldn't object to "shift" being renamed "frag1bytes" to make the
> connection with xdr_get_next_encode_buffer() more blatant..

I thought of that. Readers would wonder why frag1bytes in
xdr_commit_encode() was a size_t, but in xdr_get_next_encode_buffer()
it's a signed int. It started to become a longer string to pull.
Maybe it's worth it?


> Reviewed-by: NeilBrown <neilb@suse.de>
>=20
> Thanks,
> NeilBrown
>=20
>=20
>>=20
>> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
>> ---
>> net/sunrpc/xdr.c |    4 +++-
>> 1 file changed, 3 insertions(+), 1 deletion(-)
>>=20
>> diff --git a/net/sunrpc/xdr.c b/net/sunrpc/xdr.c
>> index 08a85375b311..de8f71468637 100644
>> --- a/net/sunrpc/xdr.c
>> +++ b/net/sunrpc/xdr.c
>> @@ -933,14 +933,16 @@ EXPORT_SYMBOL_GPL(xdr_init_encode);
>>  */
>> inline void xdr_commit_encode(struct xdr_stream *xdr)
>> {
>> -	int shift =3D xdr->scratch.iov_len;
>> +	size_t shift =3D xdr->scratch.iov_len;
>> 	void *page;
>>=20
>> 	if (shift =3D=3D 0)
>> 		return;
>> +
>> 	page =3D page_address(*xdr->page_ptr);
>> 	memcpy(xdr->scratch.iov_base, page, shift);
>> 	memmove(page, page + shift, (void *)xdr->p - page);
>> +
>> 	xdr_reset_scratch_buffer(xdr);
>> }
>> EXPORT_SYMBOL_GPL(xdr_commit_encode);
>>=20
>>=20
>>=20

--
Chuck Lever