lib/vhost: rename device stop function calls

Existing `vhost_user_session_send_event` is only used to
stop vhost user device's session now, so we rename it to
`vhost_user_wait_for_session_stop` and also rename the
whole function calls when stopping the device with
more apposite names.

Change-Id: Ib8ea48273e85f7856ca2dfca57b5fd933ac4cf7a
Signed-off-by: Changpeng Liu <changpeng.liu@intel.com>
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/15296
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Shuhei Matsumoto <smatsumoto@nvidia.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>

lib/vhost/rte_vhost_user.c

@@ -53,6 +53,9 @@ struct vhost_session_fn_ctx {
 	void *user_ctx;
 };
 
+static int vhost_user_wait_for_session_stop(struct spdk_vhost_session *vsession,
+		unsigned timeout_sec, const char *errmsg);
+
 static void
 __attribute__((constructor))
 _vhost_user_sem_init(void)
@@ -857,13 +860,11 @@ vhost_register_memtable_if_required(struct spdk_vhost_session *vsession, int vid
 static int
 _stop_session(struct spdk_vhost_session *vsession)
 {
-	struct spdk_vhost_dev *vdev = vsession->vdev;
-	struct spdk_vhost_user_dev *user_vdev = to_user_dev(vdev);
 	struct spdk_vhost_virtqueue *q;
 	int rc;
 	uint16_t i;
 
-	rc = user_vdev->user_backend->stop_session(vsession);
+	rc = vhost_user_wait_for_session_stop(vsession, 3, "stop session");
 	if (rc != 0) {
 		SPDK_ERRLOG("Couldn't stop device with vid %d.\n", vsession->vid);
 		return rc;
@@ -1273,13 +1274,6 @@ wait_for_semaphore(int timeout_sec, const char *errmsg)
 	}
 }
 
-static void
-vhost_session_cb_done(int rc)
-{
-	g_dpdk_response = rc;
-	sem_post(&g_dpdk_sem);
-}
-
 void
 vhost_user_session_stop_done(struct spdk_vhost_session *vsession, int response)
 {
@@ -1287,11 +1281,12 @@ vhost_user_session_stop_done(struct spdk_vhost_session *vsession, int response)
 		vsession->started = false;
 	}
 
-	vhost_session_cb_done(response);
+	g_dpdk_response = response;
+	sem_post(&g_dpdk_sem);
 }
 
 static void
-vhost_event_cb(void *arg1)
+vhost_user_session_stop_event(void *arg1)
 {
 	struct vhost_session_fn_ctx *ctx = arg1;
 	struct spdk_vhost_dev *vdev = ctx->vdev;
@@ -1299,19 +1294,18 @@ vhost_event_cb(void *arg1)
 	struct spdk_vhost_session *vsession;
 
 	if (pthread_mutex_trylock(&user_dev->lock) != 0) {
-		spdk_thread_send_msg(spdk_get_thread(), vhost_event_cb, arg1);
+		spdk_thread_send_msg(spdk_get_thread(), vhost_user_session_stop_event, arg1);
 		return;
 	}
 
 	vsession = vhost_session_find_by_id(vdev, ctx->vsession_id);
-	ctx->cb_fn(vdev, vsession, NULL);
+	user_dev->user_backend->stop_session(vdev, vsession, NULL);
 	pthread_mutex_unlock(&user_dev->lock);
 }
 
-int
+static int
-vhost_user_session_send_event(struct spdk_vhost_session *vsession,
+vhost_user_wait_for_session_stop(struct spdk_vhost_session *vsession,
-			      spdk_vhost_session_fn cb_fn, unsigned timeout_sec,
+				 unsigned timeout_sec, const char *errmsg)
-			      const char *errmsg)
 {
 	struct vhost_session_fn_ctx ev_ctx = {0};
 	struct spdk_vhost_dev *vdev = vsession->vdev;
@@ -1319,9 +1313,8 @@ vhost_user_session_send_event(struct spdk_vhost_session *vsession,
 
 	ev_ctx.vdev = vdev;
 	ev_ctx.vsession_id = vsession->id;
-	ev_ctx.cb_fn = cb_fn;
 
-	spdk_thread_send_msg(vdev->thread, vhost_event_cb, &ev_ctx);
+	spdk_thread_send_msg(vdev->thread, vhost_user_session_stop_event, &ev_ctx);
 
 	pthread_mutex_unlock(&user_dev->lock);
 	wait_for_semaphore(timeout_sec, errmsg);

lib/vhost/vhost_blk.c

@@ -1397,7 +1397,7 @@ destroy_session_poller_cb(void *arg)
 }
 
 static int
-vhost_blk_stop_cb(struct spdk_vhost_dev *vdev,
+vhost_blk_stop(struct spdk_vhost_dev *vdev,
 	       struct spdk_vhost_session *vsession, void *unused)
 {
 	struct spdk_vhost_blk_session *bvsession = to_blk_session(vsession);
@@ -1420,13 +1420,6 @@ vhost_blk_stop_cb(struct spdk_vhost_dev *vdev,
 	return 0;
 }
 
-static int
-vhost_blk_stop(struct spdk_vhost_session *vsession)
-{
-	return vhost_user_session_send_event(vsession, vhost_blk_stop_cb,
-					     3, "stop session");
-}
-
 static void
 vhost_blk_dump_info_json(struct spdk_vhost_dev *vdev, struct spdk_json_write_ctx *w)
 {

lib/vhost/vhost_internal.h

@@ -222,7 +222,7 @@ struct spdk_vhost_user_dev_backend {
 	size_t session_ctx_size;
 
 	spdk_vhost_session_fn start_session;
-	int (*stop_session)(struct spdk_vhost_session *vsession);
+	spdk_vhost_session_fn stop_session;
 	int (*alloc_vq_tasks)(struct spdk_vhost_session *vsession, uint16_t qid);
 };
 
@@ -435,49 +435,13 @@ void vhost_user_dev_foreach_session(struct spdk_vhost_dev *dev,
 				    void *arg);
 
 /**
- * Call a function on the provided lcore and block until either
+ * Finish a blocking vhost_user_wait_for_session_stop() call and finally
- * vhost_user_session_start_done() or vhost_user_session_stop_done()
- * is called.
- *
- * This must be called under the global vhost mutex, which this function
- * will unlock for the time it's waiting. It's meant to be called only
- * from start/stop session callbacks.
- *
- * \param vsession vhost session
- * \param cb_fn the function to call. The void *arg parameter in cb_fn
- * is always NULL.
- * \param timeout_sec timeout in seconds. This function will still
- * block after the timeout expires, but will print the provided errmsg.
- * \param errmsg error message to print once the timeout expires
- * \return return the code passed to spdk_vhost_session_event_done().
- */
-int vhost_user_session_send_event(struct spdk_vhost_session *vsession,
-				  spdk_vhost_session_fn cb_fn, unsigned timeout_sec,
-				  const char *errmsg);
-
-/**
- * Finish a blocking spdk_vhost_user_session_send_event() call and finally
- * start the session. This must be called on the target lcore, which
- * will now receive all session-related messages (e.g. from
- * vhost_user_dev_foreach_session()).
- *
- * Must be called under the global vhost lock.
- *
- * \param vsession vhost session
- * \param response return code
- */
-void vhost_user_session_start_done(struct spdk_vhost_session *vsession, int response);
-
-/**
- * Finish a blocking spdk_vhost_user_session_send_event() call and finally
  * stop the session. This must be called on the session's lcore which
  * used to receive all session-related messages (e.g. from
  * vhost_user_dev_foreach_session()). After this call, the session-
  * related messages will be once again processed by any arbitrary thread.
  *
- * Must be called under the global vhost lock.
+ * Must be called under the vhost user device's session access lock.
- *
- * Must be called under the global vhost mutex.
  *
  * \param vsession vhost session
  * \param response return code

lib/vhost/vhost_scsi.c

@@ -114,7 +114,8 @@ struct spdk_vhost_scsi_task {
 
 static int vhost_scsi_start(struct spdk_vhost_dev *vdev,
 			    struct spdk_vhost_session *vsession, void *unused);
-static int vhost_scsi_stop(struct spdk_vhost_session *vsession);
+static int vhost_scsi_stop(struct spdk_vhost_dev *vdev,
+			   struct spdk_vhost_session *vsession, void *unused);
 static void vhost_scsi_dump_info_json(struct spdk_vhost_dev *vdev,
 				      struct spdk_json_write_ctx *w);
 static void vhost_scsi_write_config_json(struct spdk_vhost_dev *vdev,
@@ -1473,7 +1474,7 @@ destroy_session_poller_cb(void *arg)
 }
 
 static int
-vhost_scsi_stop_cb(struct spdk_vhost_dev *vdev,
+vhost_scsi_stop(struct spdk_vhost_dev *vdev,
 		struct spdk_vhost_session *vsession, void *unused)
 {
 	struct spdk_vhost_scsi_session *svsession = to_scsi_session(vsession);
@@ -1504,13 +1505,6 @@ vhost_scsi_stop_cb(struct spdk_vhost_dev *vdev,
 	return 0;
 }
 
-static int
-vhost_scsi_stop(struct spdk_vhost_session *vsession)
-{
-	return vhost_user_session_send_event(vsession, vhost_scsi_stop_cb,
-					     3, "stop session");
-}
-
 static void
 vhost_scsi_dump_info_json(struct spdk_vhost_dev *vdev, struct spdk_json_write_ctx *w)
 {