From 909b96557b38ea4bf99f5ab7dc8d6d339a96ab60 Mon Sep 17 00:00:00 2001 From: Eli Cohen Date: Mon, 14 Nov 2022 15:17:55 +0200 Subject: [PATCH] vdpa/mlx5: Avoid using reslock in event_handler [ Upstream commit 0dbc1b4ae07d003b2e88ba9d4142846320f8e349 ] event_handler runs under atomic context and may not acquire reslock. We can still guarantee that the handler won't be called after suspend by clearing nb_registered, unregistering the handler and flushing the workqueue. Signed-off-by: Eli Cohen Message-Id: <20221114131759.57883-5-elic@nvidia.com> Signed-off-by: Michael S. Tsirkin Signed-off-by: Sasha Levin --- drivers/vdpa/mlx5/net/mlx5_vnet.c | 16 ++++------------ 1 file changed, 4 insertions(+), 12 deletions(-) diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c b/drivers/vdpa/mlx5/net/mlx5_vnet.c index b06260a..98dd8ce 100644 --- a/drivers/vdpa/mlx5/net/mlx5_vnet.c +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c @@ -2845,8 +2845,8 @@ static int mlx5_vdpa_suspend(struct vdpa_device *vdev) int i; down_write(&ndev->reslock); - mlx5_notifier_unregister(mvdev->mdev, &ndev->nb); ndev->nb_registered = false; + mlx5_notifier_unregister(mvdev->mdev, &ndev->nb); flush_workqueue(ndev->mvdev.wq); for (i = 0; i < ndev->cur_num_vqs; i++) { mvq = &ndev->vqs[i]; @@ -3024,7 +3024,7 @@ static void update_carrier(struct work_struct *work) else ndev->config.status &= cpu_to_mlx5vdpa16(mvdev, ~VIRTIO_NET_S_LINK_UP); - if (ndev->config_cb.callback) + if (ndev->nb_registered && ndev->config_cb.callback) ndev->config_cb.callback(ndev->config_cb.private); kfree(wqent); @@ -3041,21 +3041,13 @@ static int event_handler(struct notifier_block *nb, unsigned long event, void *p switch (eqe->sub_type) { case MLX5_PORT_CHANGE_SUBTYPE_DOWN: case MLX5_PORT_CHANGE_SUBTYPE_ACTIVE: - down_read(&ndev->reslock); - if (!ndev->nb_registered) { - up_read(&ndev->reslock); - return NOTIFY_DONE; - } wqent = kzalloc(sizeof(*wqent), GFP_ATOMIC); - if (!wqent) { - up_read(&ndev->reslock); + if (!wqent) return NOTIFY_DONE; - } wqent->mvdev = &ndev->mvdev; INIT_WORK(&wqent->work, update_carrier); queue_work(ndev->mvdev.wq, &wqent->work); - up_read(&ndev->reslock); ret = NOTIFY_OK; break; default: @@ -3242,8 +3234,8 @@ static void mlx5_vdpa_dev_del(struct vdpa_mgmt_dev *v_mdev, struct vdpa_device * struct workqueue_struct *wq; if (ndev->nb_registered) { - mlx5_notifier_unregister(mvdev->mdev, &ndev->nb); ndev->nb_registered = false; + mlx5_notifier_unregister(mvdev->mdev, &ndev->nb); } wq = mvdev->wq; mvdev->wq = NULL; -- 2.7.4