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>

2 files changed, 7 insertions, 1 deletions

diff --git a/include/linux/sunrpc/xprt.h b/include/linux/sunrpc/xprt.h
index 068e1fb0868b..3b8b6e823c70 100644
--- a/include/linux/sunrpc/xprt.h
+++ b/include/linux/sunrpc/xprt.h
@@ -73,7 +73,10 @@ struct rpc_rqst {
         int                     rq_cong;        /* has incremented xprt->cong */
         int                     rq_received;    /* receive completed */
         u32                     rq_seqno;       /* gss seq no. used on req. */
-
+        int                     rq_enc_pages_num;
+        struct page             **rq_enc_pages; /* scratch pages for use by
+                                                   gss privacy code */
+        void (*rq_release_snd_buf)(struct rpc_rqst *); /* release rq_enc_pages */
         struct list_head        rq_list;
 
         struct xdr_buf          rq_private_buf;         /* The receive buffer
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);