libceph: assign cookies in linger_submit()

Register lingers directly in linger_submit().  This avoids allocating
memory for notify pagelist while holding osdc->lock and simplifies both
callers of linger_submit().
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

net/ceph/osd_client.c

@@ -2998,11 +2998,21 @@ static void linger_submit(struct ceph_osd_linger_request *lreq)
 	struct ceph_osd_client *osdc = lreq->osdc;
 	struct ceph_osd *osd;
 
+	down_write(&osdc->lock);
+	linger_register(lreq);
+	if (lreq->is_watch) {
+		lreq->reg_req->r_ops[0].watch.cookie = lreq->linger_id;
+		lreq->ping_req->r_ops[0].watch.cookie = lreq->linger_id;
+	} else {
+		lreq->reg_req->r_ops[0].notify.cookie = lreq->linger_id;
+	}
+
 	calc_target(osdc, &lreq->t, NULL, false);
 	osd = lookup_create_osd(osdc, lreq->t.osd, true);
 	link_linger(osd, lreq);
 
 	send_linger(lreq);
+	up_write(&osdc->lock);
 }
 
 static void cancel_linger_map_check(struct ceph_osd_linger_request *lreq)
@@ -4523,15 +4533,14 @@ ceph_osdc_watch(struct ceph_osd_client *osdc,
 		goto err_put_lreq;
 	}
 
-	down_write(&osdc->lock);
-	linger_register(lreq); /* before osd_req_op_* */
-	osd_req_op_watch_init(lreq->reg_req, 0, lreq->linger_id,
-			      CEPH_OSD_WATCH_OP_WATCH);
-	osd_req_op_watch_init(lreq->ping_req, 0, lreq->linger_id,
-			      CEPH_OSD_WATCH_OP_PING);
-	linger_submit(lreq);
-	up_write(&osdc->lock);
+	/*
+	 * Pass 0 for cookie because we don't know it yet, it will be
+	 * filled in by linger_submit().
+	 */
+	osd_req_op_watch_init(lreq->reg_req, 0, 0, CEPH_OSD_WATCH_OP_WATCH);
+	osd_req_op_watch_init(lreq->ping_req, 0, 0, CEPH_OSD_WATCH_OP_PING);
 
+	linger_submit(lreq);
 	ret = linger_reg_commit_wait(lreq);
 	if (ret) {
 		linger_cancel(lreq);
@@ -4728,29 +4737,26 @@ int ceph_osdc_notify(struct ceph_osd_client *osdc,
 		goto out_put_lreq;
 	}
 
+	/*
+	 * Pass 0 for cookie because we don't know it yet, it will be
+	 * filled in by linger_submit().
+	 */
+	ret = osd_req_op_notify_init(lreq->reg_req, 0, 0, 1, timeout,
+				     payload, payload_len);
+	if (ret)
+		goto out_put_lreq;
+
 	/* for notify_id */
 	pages = ceph_alloc_page_vector(1, GFP_NOIO);
 	if (IS_ERR(pages)) {
 		ret = PTR_ERR(pages);
 		goto out_put_lreq;
 	}
-
-	down_write(&osdc->lock);
-	linger_register(lreq); /* before osd_req_op_* */
-	ret = osd_req_op_notify_init(lreq->reg_req, 0, lreq->linger_id, 1,
-				     timeout, payload, payload_len);
-	if (ret) {
-		linger_unregister(lreq);
-		up_write(&osdc->lock);
-		ceph_release_page_vector(pages, 1);
-		goto out_put_lreq;
-	}
 	ceph_osd_data_pages_init(osd_req_op_data(lreq->reg_req, 0, notify,
 						 response_data),
 				 pages, PAGE_SIZE, 0, false, true);
-	linger_submit(lreq);
-	up_write(&osdc->lock);
 
+	linger_submit(lreq);
 	ret = linger_reg_commit_wait(lreq);
 	if (!ret)
 		ret = linger_notify_finish_wait(lreq);