Re: [PATCH] NFSD: Fix bad checking of space for padding in splice read

["J. Bruce Fields" <bfields@fieldses.org>]

On Wed, Jul 09, 2014 at 09:51:27PM +0800, Kinglong Mee wrote:
> Fix commit dc97618ddd (nfsd4: separate splice and readv cases).
> xdr->end and xdr->p are type of __be32 *, so padding needs one here.

I agree with the patch, but not the changelog.

The problem here is that xdr->p isn't that those are __be32 *'s, but
that xdr->p has already advanced past the eof and the count, right?

Applying with an updated changelog.

--b.

> 
> Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
> ---
>  fs/nfsd/nfs4xdr.c | 7 ++-----
>  1 file changed, 2 insertions(+), 5 deletions(-)
> 
> diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
> index 523c666..8a2fbb2 100644
> --- a/fs/nfsd/nfs4xdr.c
> +++ b/fs/nfsd/nfs4xdr.c
> @@ -3067,11 +3067,8 @@ static __be32 nfsd4_encode_splice_read(
>  	__be32 nfserr;
>  	__be32 *p = xdr->p - 2;
>  
> -	/*
> -	 * Don't inline pages unless we know there's room for eof,
> -	 * count, and possible padding:
> -	 */
> -	if (xdr->end - xdr->p < 3)
> +	/* Make sure there will be room for padding if needed */
> +	if (xdr->end - xdr->p < 1)
>  		return nfserr_resource;
>  
>  	nfserr = nfsd_splice_read(read->rd_rqstp, file,
> -- 
> 1.9.3
>