[RFC 2/3] vhost: fix vhost-user socket cleanup order

[Maxime Coquelin]

This patch leverages the new FD entry cleanup callback
to properly cleanup the vhost-user socket on disconnection
from the frontend.

Fixes: 0e38b42bf61c ("vhost: manage FD with epoll")
Cc: sta...@dpdk.org

Signed-off-by: Maxime Coquelin <maxime.coque...@redhat.com>
---
 lib/vhost/socket.c | 44 +++++++++++++++++++++++++-------------------
 1 file changed, 25 insertions(+), 19 deletions(-)

diff --git a/lib/vhost/socket.c b/lib/vhost/socket.c
index e301efb367..898570606c 100644
--- a/lib/vhost/socket.c
+++ b/lib/vhost/socket.c
@@ -86,6 +86,7 @@ struct vhost_user {
 
 static void vhost_user_server_new_connection(int fd, void *data, int *remove);
 static void vhost_user_read_cb(int fd, void *dat, int *remove);
+static void vhost_user_cleanup_cb(int fd, void *dat);
 static int create_unix_socket(struct vhost_user_socket *vsocket);
 static int vhost_user_start_client(struct vhost_user_socket *vsocket);
 
@@ -263,7 +264,7 @@ vhost_user_add_connection(int fd, struct vhost_user_socket 
*vsocket)
        conn->vsocket = vsocket;
        conn->vid = vid;
        ret = fdset_add(vhost_user.fdset, fd, vhost_user_read_cb,
-                       NULL, NULL, conn);
+                       NULL, vhost_user_cleanup_cb, conn);
        if (ret < 0) {
                VHOST_CONFIG_LOG(vsocket->path, ERR,
                        "failed to add fd %d into vhost server fdset",
@@ -306,35 +307,40 @@ static void
 vhost_user_read_cb(int connfd, void *dat, int *remove)
 {
        struct vhost_user_connection *conn = dat;
-       struct vhost_user_socket *vsocket = conn->vsocket;
        int ret;
 
        ret = vhost_user_msg_handler(conn->vid, connfd);
-       if (ret < 0) {
-               struct virtio_net *dev = get_device(conn->vid);
-
-               close(connfd);
+       if (ret < 0)
                *remove = 1;
+}
 
-               if (dev)
-                       vhost_destroy_device_notify(dev);
+static void
+vhost_user_cleanup_cb(int connfd, void *dat)
+{
+       struct vhost_user_connection *conn = dat;
+       struct vhost_user_socket *vsocket = conn->vsocket;
+       struct virtio_net *dev = get_device(conn->vid);
 
-               if (vsocket->notify_ops->destroy_connection)
-                       vsocket->notify_ops->destroy_connection(conn->vid);
+       close(connfd);
 
-               vhost_destroy_device(conn->vid);
+       if (dev)
+               vhost_destroy_device_notify(dev);
 
-               if (vsocket->reconnect) {
-                       create_unix_socket(vsocket);
-                       vhost_user_start_client(vsocket);
-               }
+       if (vsocket->notify_ops->destroy_connection)
+               vsocket->notify_ops->destroy_connection(conn->vid);
 
-               pthread_mutex_lock(&vsocket->conn_mutex);
-               TAILQ_REMOVE(&vsocket->conn_list, conn, next);
-               pthread_mutex_unlock(&vsocket->conn_mutex);
+       vhost_destroy_device(conn->vid);
 
-               free(conn);
+       if (vsocket->reconnect) {
+               create_unix_socket(vsocket);
+               vhost_user_start_client(vsocket);
        }
+
+       pthread_mutex_lock(&vsocket->conn_mutex);
+       TAILQ_REMOVE(&vsocket->conn_list, conn, next);
+       pthread_mutex_unlock(&vsocket->conn_mutex);
+
+       free(conn);
 }
 
 static int
-- 
2.47.1