[PATCH] RPC: Ensure XDR iovec length is initialized correctly in call_header

 Fix up call_header() so that it calls xdr_adjust_iovec().
 Fix calculation of the scratch buffer length in xdr_init_encode().

 Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

3 files changed, 19 insertions, 4 deletions

diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index 02bc029d46fe..209aaf595695 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -957,7 +957,9 @@ call_header(struct rpc_task *task)
         *p++ = htonl(clnt->cl_prog);    /* program number */
         *p++ = htonl(clnt->cl_vers);    /* program version */
         *p++ = htonl(task->tk_msg.rpc_proc->p_proc);    /* procedure */
-        return rpcauth_marshcred(task, p);
+        p = rpcauth_marshcred(task, p);
+        req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
+        return p;
 }
 
 /*
diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c
index bb2d99f33315..a02d424a7409 100644
--- a/net/sunrpc/svc.c
+++ b/net/sunrpc/svc.c
@@ -281,6 +281,7 @@ svc_process(struct svc_serv *serv, struct svc_rqst *rqstp)
         rqstp->rq_res.len = 0;
         rqstp->rq_res.page_base = 0;
         rqstp->rq_res.page_len = 0;
+        rqstp->rq_res.buflen = PAGE_SIZE;
         rqstp->rq_res.tail[0].iov_len = 0;
         /* tcp needs a space for the record length... */
         if (rqstp->rq_prot == IPPROTO_TCP)
diff --git a/net/sunrpc/xdr.c b/net/sunrpc/xdr.c
index 67b9f035ba86..f86d1baa6302 100644
--- a/net/sunrpc/xdr.c
+++ b/net/sunrpc/xdr.c
@@ -616,12 +616,24 @@ xdr_shift_buf(struct xdr_buf *buf, size_t len)
 void xdr_init_encode(struct xdr_stream *xdr, struct xdr_buf *buf, uint32_t *p)
 {
         struct kvec *iov = buf->head;
+        int scratch_len = buf->buflen - buf->page_len - buf->tail[0].iov_len;
 
+        BUG_ON(scratch_len < 0);
         xdr->buf = buf;
         xdr->iov = iov;
-        xdr->end = (uint32_t *)((char *)iov->iov_base + iov->iov_len);
-        buf->len = iov->iov_len = (char *)p - (char *)iov->iov_base;
-        xdr->p = p;
+        xdr->p = (uint32_t *)((char *)iov->iov_base + iov->iov_len);
+        xdr->end = (uint32_t *)((char *)iov->iov_base + scratch_len);
+        BUG_ON(iov->iov_len > scratch_len);
+
+        if (p != xdr->p && p != NULL) {
+                size_t len;
+
+                BUG_ON(p < xdr->p || p > xdr->end);
+                len = (char *)p - (char *)xdr->p;
+                xdr->p = p;
+                buf->len += len;
+                iov->iov_len += len;
+        }
 }
 EXPORT_SYMBOL(xdr_init_encode);