SUNRPC: Provide a callback to allow free pages allocated during xdr encoding

 For privacy, we need to allocate pages to store the encrypted data (passed
 in pages can't be used without the risk of corrupting data in the page cache).
 So we need a way to free that memory after the request has been transmitted.

 Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
 Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c
index 1ba55dc38b7a..6dda3860351f 100644
--- a/net/sunrpc/xprt.c
+++ b/net/sunrpc/xprt.c
@@ -839,6 +839,7 @@ static void xprt_request_init(struct rpc_task *task, struct rpc_xprt *xprt)
         req->rq_task    = task;
         req->rq_xprt    = xprt;
         req->rq_xid     = xprt_alloc_xid(xprt);
+        req->rq_release_snd_buf = NULL;
         dprintk("RPC: %4d reserved req %p xid %08x\n", task->tk_pid,
                         req, ntohl(req->rq_xid));
 }
@@ -867,6 +868,8 @@ void xprt_release(struct rpc_task *task)
                                 xprt->last_used + xprt->idle_timeout);
         spin_unlock_bh(&xprt->transport_lock);
         task->tk_rqstp = NULL;
+        if (req->rq_release_snd_buf)
+                req->rq_release_snd_buf(req);
         memset(req, 0, sizeof(*req));   /* mark unused */
 
         dprintk("RPC: %4d release request %p\n", task->tk_pid, req);