On Wed, 2009-08-12 at 18:22 +0300, Benny Halevy wrote:
> Open code return pointer assignment and error checking using
> a read_buf helper (macro), yet keep the dprintk on failure using an
> internal __read_buf helper that gets the function name for printing.
>
> Signed-off-by: Benny Halevy <bhalevy@xxxxxxxxxxx>
> ---
> fs/nfs/nfs4xdr.c | 386 ++++++++++++++++++++++++++++++++++++++---------------
> 1 files changed, 277 insertions(+), 109 deletions(-)
>
> diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
> index ed9bbd2..fb10a77 100644
> --- a/fs/nfs/nfs4xdr.c
> +++ b/fs/nfs/nfs4xdr.c
> @@ -2438,26 +2438,17 @@ static int nfs4_xdr_enc_get_lease_time(struct rpc_rqst *req, uint32_t *p,
> }
> #endif /* CONFIG_NFS_V4_1 */
>
> -/*
> - * START OF "GENERIC" DECODE ROUTINES.
> - * These may look a little ugly since they are imported from a "generic"
> - * set of XDR encode/decode routines which are intended to be shared by
> - * all of our NFSv4 implementations (OpenBSD, MacOS X...).
> - *
> - * If the pain of reading these is too great, it should be a straightforward
> - * task to translate them into Linux-specific versions which are more
> - * consistent with the style used in NFSv2/v3...
> - */
> -#define READ_BUF(nbytes) do { \
> - p = xdr_inline_decode(xdr, nbytes); \
> - if (unlikely(!p)) { \
> - dprintk("nfs: %s: prematurely hit end of receive" \
> - " buffer\n", __func__); \
> - dprintk("nfs: %s: xdr->p=%p, bytes=%u, xdr->end=%p\n", \
> - __func__, xdr->p, nbytes, xdr->end); \
> - return -EIO; \
> - } \
> -} while (0)
> +static __be32 *__read_buf(struct xdr_stream *xdr, size_t nbytes, char *func)
> +{
> + __be32 *p = xdr_inline_decode(xdr, nbytes);
> + if (unlikely(!p))
> + dprintk("nfs: %s: prematurely hit end of receive buffer: "
> + "xdr->p=%p, bytes=%u, xdr->end=%p\n",
> + func, xdr->p, nbytes, xdr->end);
> + return p;
> +}
> +
> +#define read_buf(xdr, nbytes) __read_buf(xdr, nbytes, __func__)
>
> static __be32 *copymem(void *x, __be32 *p, u32 nbytes)
> {
> @@ -2469,9 +2460,13 @@ static int decode_opaque_inline(struct xdr_stream *xdr, unsigned int *len, char
> {
> __be32 *p;
>
> - READ_BUF(4);
> + p = read_buf(xdr, 4);
> + if (unlikely(!p))
> + return -EIO;
> p = xdr_decode_int(p, len);
> - READ_BUF(*len);
> + p = read_buf(xdr, *len);
> + if (unlikely(!p))
> + return -EIO;
> *string = (char *)p;
> return 0;
> }
I'd do this a little differently.
static void print_overflow_msg(const char *func, const struct xdr_stream *xdr)
{
dprintk("nfs: %s: prematurely hit end of receive buffer."
"Remaining buffer length is %tu words.\n",
func, xdr->end - xdr->p);
}
static int decode_opaque_inline(struct xdr_stream *xdr, unsigned int *len, char **string)
{
__be32 *p;
p = xdr_inline_decode(xdr, 4);
if (unlikely(!p))
goto out_overflow;
*len = be32_to_cpu(*p++);
p = xdr_inline_decode(xdr, *len);
if (unlikely(!p))
goto out_overflow;
*string = (char *)p;
return 0;
out_overflow:
print_overflow_msg(__func__, xdr);
return -EIO;
}
--
Trond Myklebust
Linux NFS client maintainer
NetApp
Trond.Myklebust@xxxxxxxxxx
www.netapp.com
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