From: Daniel Wagner Date: Wed, 1 Sep 2021 09:25:24 +0000 (+0200) Subject: nvme: only call synchronize_srcu when clearing current path X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=041bd1a1fc737cd73b0b8a9f74909191a8acc9fe;p=linux.git nvme: only call synchronize_srcu when clearing current path The function nmve_mpath_clear_current_path returns true if the current path has changed. In this case we have to wait for all concurrent submissions to finish. But if we didn't change the current path, there is no point in waiting for another RCU period to finish. Signed-off-by: Daniel Wagner Signed-off-by: Christoph Hellwig --- diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c index 1c98a2f590ea8..4a3a33f5f11c9 100644 --- a/drivers/nvme/host/core.c +++ b/drivers/nvme/host/core.c @@ -3838,9 +3838,12 @@ static void nvme_ns_remove(struct nvme_ns *ns) list_del_rcu(&ns->siblings); mutex_unlock(&ns->ctrl->subsys->lock); - synchronize_rcu(); /* guarantee not available in head->list */ - nvme_mpath_clear_current_path(ns); - synchronize_srcu(&ns->head->srcu); /* wait for concurrent submissions */ + /* guarantee not available in head->list */ + synchronize_rcu(); + + /* wait for concurrent submissions */ + if (nvme_mpath_clear_current_path(ns)) + synchronize_srcu(&ns->head->srcu); if (!nvme_ns_head_multipath(ns->head)) nvme_cdev_del(&ns->cdev, &ns->cdev_device);