From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,UNPARSEABLE_RELAY, URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 81F97C43381 for ; Wed, 27 Mar 2019 03:46:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5D6562146F for ; Wed, 27 Mar 2019 03:46:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733023AbfC0DqE (ORCPT ); Tue, 26 Mar 2019 23:46:04 -0400 Received: from mail-il-dmz.mellanox.com ([193.47.165.129]:40541 "EHLO mellanox.co.il" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1733039AbfC0DqA (ORCPT ); Tue, 26 Mar 2019 23:46:00 -0400 Received: from Internal Mail-Server by MTLPINE1 (envelope-from parav@mellanox.com) with ESMTPS (AES256-SHA encrypted); 27 Mar 2019 05:45:58 +0200 Received: from sw-mtx-036.mtx.labs.mlnx (sw-mtx-036.mtx.labs.mlnx [10.12.150.149]) by labmailer.mlnx (8.13.8/8.13.8) with ESMTP id x2R3jlGA031531; Wed, 27 Mar 2019 05:45:57 +0200 From: Parav Pandit To: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, kwankhede@nvidia.com, alex.williamson@redhat.com Cc: cjia@nvidia.com, parav@mellanox.com Subject: [PATCHv1 6/7] vfio/mdev: Fix aborting mdev child device removal if one fails Date: Tue, 26 Mar 2019 22:45:44 -0500 Message-Id: <1553658345-43995-7-git-send-email-parav@mellanox.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1553658345-43995-1-git-send-email-parav@mellanox.com> References: <1553658345-43995-1-git-send-email-parav@mellanox.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org device_for_each_child() stops executing callback function for remaining child devices, if callback hits an error. Each child mdev device is independent of each other. While unregistering parent device, mdev core must remove all child mdev devices. Therefore, mdev_device_remove_cb() always returns success so that device_for_each_child doesn't abort if one child removal hits error. While at it, improve remove and unregister functions for below simplicity. There isn't need to pass forced flag pointer during mdev parent removal which invokes mdev_device_remove(). So simplify the flow. mdev_device_remove() is called from two paths. 1. mdev_unregister_driver() mdev_device_remove_cb() mdev_device_remove() 2. remove_store() mdev_device_remove() When device is removed by user using remote_store(), device under removal is mdev device. When device is removed during parent device removal using generic child iterator, mdev check is already done using dev_is_mdev(). Hence, remove the unnecessary loop in mdev_device_remove(). Fixes: 7b96953bc640 ("vfio: Mediated device Core driver") Reviewed-by: Maxim Levitsky Signed-off-by: Parav Pandit --- drivers/vfio/mdev/mdev_core.c | 23 +++++------------------ 1 file changed, 5 insertions(+), 18 deletions(-) diff --git a/drivers/vfio/mdev/mdev_core.c b/drivers/vfio/mdev/mdev_core.c index 836d319..aefcf34 100644 --- a/drivers/vfio/mdev/mdev_core.c +++ b/drivers/vfio/mdev/mdev_core.c @@ -149,10 +149,10 @@ static int mdev_device_remove_ops(struct mdev_device *mdev, bool force_remove) static int mdev_device_remove_cb(struct device *dev, void *data) { - if (!dev_is_mdev(dev)) - return 0; + if (dev_is_mdev(dev)) + mdev_device_remove(dev, true); - return mdev_device_remove(dev, data ? *(bool *)data : true); + return 0; } /* @@ -240,7 +240,6 @@ int mdev_register_device(struct device *dev, const struct mdev_parent_ops *ops) void mdev_unregister_device(struct device *dev) { struct mdev_parent *parent; - bool force_remove = true; mutex_lock(&parent_list_lock); parent = __find_parent_device(dev); @@ -254,8 +253,7 @@ void mdev_unregister_device(struct device *dev) list_del(&parent->next); class_compat_remove_link(mdev_bus_compat_class, dev, NULL); - device_for_each_child(dev, (void *)&force_remove, - mdev_device_remove_cb); + device_for_each_child(dev, NULL, mdev_device_remove_cb); parent_remove_sysfs_files(parent); @@ -348,24 +346,13 @@ int mdev_device_create(struct kobject *kobj, int mdev_device_remove(struct device *dev, bool force_remove) { - struct mdev_device *mdev, *tmp; + struct mdev_device *mdev; struct mdev_parent *parent; struct mdev_type *type; int ret; mdev = to_mdev_device(dev); - mutex_lock(&mdev_list_lock); - list_for_each_entry(tmp, &mdev_list, next) { - if (tmp == mdev) - break; - } - - if (tmp != mdev) { - mutex_unlock(&mdev_list_lock); - return -ENODEV; - } - if (!mdev->active) { mutex_unlock(&mdev_list_lock); return -EAGAIN; -- 1.8.3.1