SUNRPC: Eliminate task->tk_xprt accesses that bypass rcu_dereference()

tk_xprt is just a shortcut for tk_client->cl_xprt, however cl_xprt is
defined as an __rcu variable. Replace dereferences of tk_xprt with
non-rcu dereferences where it is safe to do so.

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

7 files changed, 18 insertions, 16 deletions

diff --git a/net/sunrpc/auth_gss/auth_gss.c b/net/sunrpc/auth_gss/auth_gss.c
index 6e5c824b040b..e7243f9b405d 100644
--- a/net/sunrpc/auth_gss/auth_gss.c
+++ b/net/sunrpc/auth_gss/auth_gss.c
@@ -1154,7 +1154,7 @@ gss_marshal(struct rpc_task *task, __be32 *p)
 
         /* We compute the checksum for the verifier over the xdr-encoded bytes
          * starting with the xid and ending at the end of the credential: */
-        iov.iov_base = xprt_skip_transport_header(task->tk_xprt,
+        iov.iov_base = xprt_skip_transport_header(req->rq_xprt,
                                         req->rq_snd_buf.head[0].iov_base);
         iov.iov_len = (u8 *)p - (u8 *)iov.iov_base;
         xdr_buf_from_iov(&iov, &verf_buf);
diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index 507b5e84fbdb..6b3411ba23f1 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -1400,7 +1400,7 @@ call_allocate(struct rpc_task *task)
 {
         unsigned int slack = task->tk_rqstp->rq_cred->cr_auth->au_cslack;
         struct rpc_rqst *req = task->tk_rqstp;
-        struct rpc_xprt *xprt = task->tk_xprt;
+        struct rpc_xprt *xprt = req->rq_xprt;
         struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
 
         dprint_status(task);
@@ -1685,7 +1685,7 @@ call_transmit(struct rpc_task *task)
         if (rpc_reply_expected(task))
                 return;
         task->tk_action = rpc_exit_task;
-        rpc_wake_up_queued_task(&task->tk_xprt->pending, task);
+        rpc_wake_up_queued_task(&task->tk_rqstp->rq_xprt->pending, task);
 }
 
 /*
@@ -1784,7 +1784,7 @@ call_bc_transmit(struct rpc_task *task)
                  */
                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
                         "error: %d\n", task->tk_status);
-                xprt_conditional_disconnect(task->tk_xprt,
+                xprt_conditional_disconnect(req->rq_xprt,
                         req->rq_connect_cookie);
                 break;
         default:
@@ -1836,7 +1836,7 @@ call_status(struct rpc_task *task)
         case -ETIMEDOUT:
                 task->tk_action = call_timeout;
                 if (task->tk_client->cl_discrtry)
-                        xprt_conditional_disconnect(task->tk_xprt,
+                        xprt_conditional_disconnect(req->rq_xprt,
                                         req->rq_connect_cookie);
                 break;
         case -ECONNRESET:
@@ -1991,7 +1991,7 @@ out_retry:
         if (task->tk_rqstp == req) {
                 req->rq_reply_bytes_recvd = req->rq_rcv_buf.len = 0;
                 if (task->tk_client->cl_discrtry)
-                        xprt_conditional_disconnect(task->tk_xprt,
+                        xprt_conditional_disconnect(req->rq_xprt,
                                         req->rq_connect_cookie);
         }
 }
@@ -2005,7 +2005,7 @@ rpc_encode_header(struct rpc_task *task)
 
         /* FIXME: check buffer size? */
 
-        p = xprt_skip_transport_header(task->tk_xprt, p);
+        p = xprt_skip_transport_header(req->rq_xprt, p);
         *p++ = req->rq_xid;             /* XID */
         *p++ = htonl(RPC_CALL);         /* CALL */
         *p++ = htonl(RPC_VERSION);      /* RPC version */
diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c
index 33811db8788a..738ad59628cd 100644
--- a/net/sunrpc/xprt.c
+++ b/net/sunrpc/xprt.c
@@ -430,7 +430,9 @@ __xprt_put_cong(struct rpc_xprt *xprt, struct rpc_rqst *req)
  */
 void xprt_release_rqst_cong(struct rpc_task *task)
 {
-        __xprt_put_cong(task->tk_xprt, task->tk_rqstp);
+        struct rpc_rqst *req = task->tk_rqstp;
+
+        __xprt_put_cong(req->rq_xprt, req);
 }
 EXPORT_SYMBOL_GPL(xprt_release_rqst_cong);
 
diff --git a/net/sunrpc/xprtrdma/rpc_rdma.c b/net/sunrpc/xprtrdma/rpc_rdma.c
index 558fbab574f0..e03725bfe2b8 100644
--- a/net/sunrpc/xprtrdma/rpc_rdma.c
+++ b/net/sunrpc/xprtrdma/rpc_rdma.c
@@ -171,7 +171,7 @@ rpcrdma_create_chunks(struct rpc_rqst *rqst, struct xdr_buf *target,
                 struct rpcrdma_msg *headerp, enum rpcrdma_chunktype type)
 {
         struct rpcrdma_req *req = rpcr_to_rdmar(rqst);
-        struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(rqst->rq_task->tk_xprt);
+        struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(rqst->rq_xprt);
         int nsegs, nchunks = 0;
         unsigned int pos;
         struct rpcrdma_mr_seg *seg = req->rl_segments;
@@ -366,7 +366,7 @@ rpcrdma_inline_pullup(struct rpc_rqst *rqst, int pad)
 int
 rpcrdma_marshal_req(struct rpc_rqst *rqst)
 {
-        struct rpc_xprt *xprt = rqst->rq_task->tk_xprt;
+        struct rpc_xprt *xprt = rqst->rq_xprt;
         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
         struct rpcrdma_req *req = rpcr_to_rdmar(rqst);
         char *base;
diff --git a/net/sunrpc/xprtrdma/transport.c b/net/sunrpc/xprtrdma/transport.c
index c9aa7a35f3bf..b357c528d29c 100644
--- a/net/sunrpc/xprtrdma/transport.c
+++ b/net/sunrpc/xprtrdma/transport.c
@@ -475,7 +475,7 @@ xprt_rdma_reserve_xprt(struct rpc_xprt *xprt, struct rpc_task *task)
 static void *
 xprt_rdma_allocate(struct rpc_task *task, size_t size)
 {
-        struct rpc_xprt *xprt = task->tk_xprt;
+        struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
         struct rpcrdma_req *req, *nreq;
 
         req = rpcrdma_buffer_get(&rpcx_to_rdmax(xprt)->rx_buf);
@@ -627,7 +627,7 @@ static int
 xprt_rdma_send_request(struct rpc_task *task)
 {
         struct rpc_rqst *rqst = task->tk_rqstp;
-        struct rpc_xprt *xprt = task->tk_xprt;
+        struct rpc_xprt *xprt = rqst->rq_xprt;
         struct rpcrdma_req *req = rpcr_to_rdmar(rqst);
         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 
diff --git a/net/sunrpc/xprtrdma/xprt_rdma.h b/net/sunrpc/xprtrdma/xprt_rdma.h
index 9a66c95b5837..cc1445dc1d1a 100644
--- a/net/sunrpc/xprtrdma/xprt_rdma.h
+++ b/net/sunrpc/xprtrdma/xprt_rdma.h
@@ -235,13 +235,13 @@ struct rpcrdma_create_data_internal {
 };
 
 #define RPCRDMA_INLINE_READ_THRESHOLD(rq) \
-        (rpcx_to_rdmad(rq->rq_task->tk_xprt).inline_rsize)
+        (rpcx_to_rdmad(rq->rq_xprt).inline_rsize)
 
 #define RPCRDMA_INLINE_WRITE_THRESHOLD(rq)\
-        (rpcx_to_rdmad(rq->rq_task->tk_xprt).inline_wsize)
+        (rpcx_to_rdmad(rq->rq_xprt).inline_wsize)
 
 #define RPCRDMA_INLINE_PAD_VALUE(rq)\
-        rpcx_to_rdmad(rq->rq_task->tk_xprt).padding
+        rpcx_to_rdmad(rq->rq_xprt).padding
 
 /*
  * Statistics for RPCRDMA
diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c
index 68b0a81c31d5..25838901c97f 100644
--- a/net/sunrpc/xprtsock.c
+++ b/net/sunrpc/xprtsock.c
@@ -770,7 +770,7 @@ static void xs_tcp_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task)
                 goto out_release;
         if (req->rq_bytes_sent == req->rq_snd_buf.len)
                 goto out_release;
-        set_bit(XPRT_CLOSE_WAIT, &task->tk_xprt->state);
+        set_bit(XPRT_CLOSE_WAIT, &xprt->state);
 out_release:
         xprt_release_xprt(xprt, task);
 }