lustre/ptlrpc: fix 'data race condition' issues

Fix 'data race condition' defects found by Coverity version
6.5.0:
Data race condition (MISSING_LOCK)
Accessing variable without holding lock. Elsewhere,
this variable is accessed with lock held.
Signed-off-by: Sebastien Buisson <sebastien.buisson@bull.net>
Reviewed-on: http://review.whamcloud.com/6575
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-2744Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Signed-off-by: Oeg Drokin <oleg.drokin@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/lustre/lustre/ptlrpc/client.c

@@ -1190,7 +1190,9 @@ static int after_reply(struct ptlrpc_request *req)
 		 * will roundup it */
 		req->rq_replen       = req->rq_nob_received;
 		req->rq_nob_received = 0;
+		spin_lock(&req->rq_lock);
 		req->rq_resend       = 1;
+		spin_unlock(&req->rq_lock);
 		return 0;
 	}
 
@@ -1408,7 +1410,9 @@ static int ptlrpc_send_new_req(struct ptlrpc_request *req)
 			req->rq_status = rc;
 			return 1;
 		} else {
+			spin_lock(&req->rq_lock);
 			req->rq_wait_ctx = 1;
+			spin_unlock(&req->rq_lock);
 			return 0;
 		}
 	}
@@ -1423,7 +1427,9 @@ static int ptlrpc_send_new_req(struct ptlrpc_request *req)
 	rc = ptl_send_rpc(req, 0);
 	if (rc) {
 		DEBUG_REQ(D_HA, req, "send failed (%d); expect timeout", rc);
+		spin_lock(&req->rq_lock);
 		req->rq_net_err = 1;
+		spin_unlock(&req->rq_lock);
 		return rc;
 	}
 	return 0;

drivers/staging/lustre/lustre/ptlrpc/niobuf.c

@@ -511,7 +511,9 @@ int ptl_send_rpc(struct ptlrpc_request *request, int noreply)
 		CDEBUG(D_HA, "muting rpc for failed imp obd %s\n",
 		       request->rq_import->imp_obd->obd_name);
 		/* this prevents us from waiting in ptlrpc_queue_wait */
+		spin_lock(&request->rq_lock);
 		request->rq_err = 1;
+		spin_unlock(&request->rq_lock);
 		request->rq_status = -ENODEV;
 		return -ENODEV;
 	}
@@ -553,7 +555,9 @@ int ptl_send_rpc(struct ptlrpc_request *request, int noreply)
 			if (rc) {
 				/* this prevents us from looping in
 				 * ptlrpc_queue_wait */
+				spin_lock(&request->rq_lock);
 				request->rq_err = 1;
+				spin_unlock(&request->rq_lock);
 				request->rq_status = rc;
 				GOTO(cleanup_bulk, rc);
 			}