SUNRPC: Introduce rpc_prepare_reply_pages()
prepare_reply_buffer() and its NFSv4 equivalents expose the details
of the RPC header and the auth slack values to upper layer
consumers, creating a layering violation, and duplicating code.
Remedy these issues by adding a new RPC client API that hides those
details from upper layers in a common helper function.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index 803e931..f780605 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -1164,6 +1164,25 @@ struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req)
}
#endif /* CONFIG_SUNRPC_BACKCHANNEL */
+/**
+ * rpc_prepare_reply_pages - Prepare to receive a reply data payload into pages
+ * @req: RPC request to prepare
+ * @pages: vector of struct page pointers
+ * @base: offset in first page where receive should start, in bytes
+ * @len: expected size of the upper layer data payload, in bytes
+ * @hdrsize: expected size of upper layer reply header, in XDR words
+ *
+ */
+void rpc_prepare_reply_pages(struct rpc_rqst *req, struct page **pages,
+ unsigned int base, unsigned int len,
+ unsigned int hdrsize)
+{
+ hdrsize += RPC_REPHDRSIZE + req->rq_cred->cr_auth->au_rslack;
+ xdr_inline_pages(&req->rq_rcv_buf, hdrsize << 2, pages, base, len);
+ trace_rpc_reply_pages(req);
+}
+EXPORT_SYMBOL_GPL(rpc_prepare_reply_pages);
+
void
rpc_call_start(struct rpc_task *task)
{
diff --git a/net/sunrpc/xdr.c b/net/sunrpc/xdr.c
index 4bce619..7cca515 100644
--- a/net/sunrpc/xdr.c
+++ b/net/sunrpc/xdr.c
@@ -163,6 +163,15 @@ xdr_free_bvec(struct xdr_buf *buf)
buf->bvec = NULL;
}
+/**
+ * xdr_inline_pages - Prepare receive buffer for a large reply
+ * @xdr: xdr_buf into which reply will be placed
+ * @offset: expected offset where data payload will start, in bytes
+ * @pages: vector of struct page pointers
+ * @base: offset in first page where receive should start, in bytes
+ * @len: expected size of the upper layer data payload, in bytes
+ *
+ */
void
xdr_inline_pages(struct xdr_buf *xdr, unsigned int offset,
struct page **pages, unsigned int base, unsigned int len)
