diff options
| author | Trond Myklebust <Trond.Myklebust@netapp.com> | 2010-10-19 19:58:49 -0400 |
|---|---|---|
| committer | Trond Myklebust <Trond.Myklebust@netapp.com> | 2010-10-23 15:27:32 -0400 |
| commit | ba8e452a4fe64a51b74d43761e14d99f0666cc45 (patch) | |
| tree | 7237e9bf9f2415eda15fec5e517da3340342e9f1 | |
| parent | 0715dc632a271fc0fedf3ef4779fe28ac1e53ef4 (diff) | |
SUNRPC: Add a helper function xdr_inline_peek
We sometimes need to be able to read ahead in an xdr_stream without
incrementing the current pointer position.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
| -rw-r--r-- | include/linux/sunrpc/xdr.h | 1 | ||||
| -rw-r--r-- | net/sunrpc/xdr.c | 21 |
2 files changed, 22 insertions, 0 deletions
diff --git a/include/linux/sunrpc/xdr.h b/include/linux/sunrpc/xdr.h index 8c1dcbb54d89..ab91d86565fd 100644 --- a/include/linux/sunrpc/xdr.h +++ b/include/linux/sunrpc/xdr.h @@ -201,6 +201,7 @@ extern __be32 *xdr_reserve_space(struct xdr_stream *xdr, size_t nbytes); extern void xdr_write_pages(struct xdr_stream *xdr, struct page **pages, unsigned int base, unsigned int len); extern void xdr_init_decode(struct xdr_stream *xdr, struct xdr_buf *buf, __be32 *p); +extern __be32 *xdr_inline_peek(struct xdr_stream *xdr, size_t nbytes); extern __be32 *xdr_inline_decode(struct xdr_stream *xdr, size_t nbytes); extern void xdr_read_pages(struct xdr_stream *xdr, unsigned int len); extern void xdr_enter_page(struct xdr_stream *xdr, unsigned int len); diff --git a/net/sunrpc/xdr.c b/net/sunrpc/xdr.c index e0725d9d8107..cd9e841e7492 100644 --- a/net/sunrpc/xdr.c +++ b/net/sunrpc/xdr.c @@ -573,6 +573,27 @@ void xdr_init_decode(struct xdr_stream *xdr, struct xdr_buf *buf, __be32 *p) EXPORT_SYMBOL_GPL(xdr_init_decode); /** + * xdr_inline_peek - Allow read-ahead in the XDR data stream + * @xdr: pointer to xdr_stream struct + * @nbytes: number of bytes of data to decode + * + * Check if the input buffer is long enough to enable us to decode + * 'nbytes' more bytes of data starting at the current position. + * If so return the current pointer without updating the current + * pointer position. + */ +__be32 * xdr_inline_peek(struct xdr_stream *xdr, size_t nbytes) +{ + __be32 *p = xdr->p; + __be32 *q = p + XDR_QUADLEN(nbytes); + + if (unlikely(q > xdr->end || q < p)) + return NULL; + return p; +} +EXPORT_SYMBOL_GPL(xdr_inline_peek); + +/** * xdr_inline_decode - Retrieve non-page XDR data to decode * @xdr: pointer to xdr_stream struct * @nbytes: number of bytes of data to decode |