SUNRPC: Add rpc_auth::au_ralign field
Currently rpc_inline_rcv_pages() uses au_rslack to estimate the
size of the upper layer reply header. This is fine for auth flavors
where au_verfsize == au_rslack.
However, some auth flavors have more going on. krb5i for example has
two more words after the verifier, and another blob following the
RPC message. The calculation involving au_rslack pushes the upper
layer reply header too far into the rcv_buf.
au_rslack is still valuable: it's the amount of buffer space needed
for the reply, and is used when allocating the reply buffer. We'll
keep that.
But, add a new field that can be used to properly estimate the
location of the upper layer header in each RPC reply, based on the
auth flavor in use.
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 4ea38b0..99bfeb1 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -1180,7 +1180,7 @@ void rpc_prepare_reply_pages(struct rpc_rqst *req, struct page **pages,
/* Subtract one to force an extra word of buffer space for the
* payload's XDR pad to fall into the rcv_buf's tail iovec.
*/
- hdrsize += RPC_REPHDRSIZE + req->rq_cred->cr_auth->au_rslack - 1;
+ hdrsize += RPC_REPHDRSIZE + req->rq_cred->cr_auth->au_ralign - 1;
xdr_inline_pages(&req->rq_rcv_buf, hdrsize << 2, pages, base, len);
trace_rpc_reply_pages(req);