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=-8.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FAKE_REPLY_C,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable 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 551D4C2D0E9 for ; Wed, 25 Mar 2020 22:10:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2510520719 for ; Wed, 25 Mar 2020 22:10:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1585174238; bh=wloj/EPW+OkyZtwQxndjXMPki61/NdW12lp51YiYTEc=; h=Date:From:To:Cc:Subject:In-Reply-To:List-ID:From; b=xEjhnt6iYQwN9bH14D7dm/TB8hr+4yWnBfPbtlhNc/99z3pOoP6asfUmZUYeqBN60 oNmybld5D2eqh0RiJtI4i5KkqfN+GkJbQ5h/YzvIXBjqE0PbqqWV+iR32RIQyveE4T TW+cwOufI9uLDty6aizvLQTjM6OhwVen0fiAsE8c= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727536AbgCYWKh (ORCPT ); Wed, 25 Mar 2020 18:10:37 -0400 Received: from mail.kernel.org ([198.145.29.99]:48744 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727358AbgCYWKg (ORCPT ); Wed, 25 Mar 2020 18:10:36 -0400 Received: from localhost (mobile-166-175-186-165.mycingular.net [166.175.186.165]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id F0F9620719; Wed, 25 Mar 2020 22:10:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1585174235; bh=wloj/EPW+OkyZtwQxndjXMPki61/NdW12lp51YiYTEc=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=FltFgdlKsLUIr06TgjYDl3xuTRpmeUvHTz9DBzAOP0fcHWjtGO2OAqUAgsmhfCTK9 SO/Jn7FWP/Lbgnjd1M5kl9cS43HivJClsd1JipENC9IyU/ha2yT8xElvQXZWT03EtB UHw+RwlbloTcmJQU79d0wgbveu8CzrA9KTUurhPk= Date: Wed, 25 Mar 2020 17:10:33 -0500 From: Bjorn Helgaas To: Kelsey Skunberg Cc: linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, Kelsey Skunberg , rbilovol@cisco.com, stable , ddutile@redhat.com, ruslan.bilovol@gmail.com, linux-kernel-mentees@lists.linuxfoundation.org, bodong@mellanox.com Subject: Re: [Linux-kernel-mentees] [PATCH v2] PCI: sysfs: Change bus_rescan and dev_rescan to rescan Message-ID: <20200325221033.GA88141@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200325151708.32612-1-skunberg.kelsey@gmail.com> User-Agent: Mutt/1.12.2 (2019-09-21) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Kelsey, On Wed, Mar 25, 2020 at 09:17:08AM -0600, Kelsey Skunberg wrote: > From: Kelsey Skunberg > > rename device attribute name arguments 'bus_rescan' and 'dev_rescan' to 'rescan' > to avoid breaking userspace applications. > > The attribute argument names were changed in the following commits: > 8bdfa145f582 ("PCI: sysfs: Define device attributes with DEVICE_ATTR*()") > 4e2b79436e4f ("PCI: sysfs: Change DEVICE_ATTR() to DEVICE_ATTR_WO()") > > Revert the names used for attributes back to the names used before the above > patches were applied. This also requires to change DEVICE_ATTR_WO() to > DEVICE_ATTR() and __ATTR(). > > Note when using DEVICE_ATTR() the attribute is automatically named > dev_attr_.attr. To avoid duplicated names between attributes, use > __ATTR() instead of DEVICE_ATTR() to a assign a custom attribute name for > dev_rescan. > > change bus_rescan_store() to dev_bus_rescan_store() to complete matching the > names used before the mentioned patches were applied. > > Fixes: 8bdfa145f582 ("PCI: sysfs: Define device attributes with DEVICE_ATTR*()") > Fixes: 4e2b79436e4f ("PCI: sysfs: Change DEVICE_ATTR() to DEVICE_ATTR_WO()") > > Cc: stable > Signed-off-by: Kelsey Skunberg > Reviewed-by: Greg Kroah-Hartman > --- > > v2 updates: > commit log updated to include 'Fixes: *' and Cc: stable to aid commit > being backported properly. > > drivers/pci/pci-sysfs.c | 17 ++++++++++------- > 1 file changed, 10 insertions(+), 7 deletions(-) > > diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c > index 13f766db0684..667e13d597ff 100644 > --- a/drivers/pci/pci-sysfs.c > +++ b/drivers/pci/pci-sysfs.c > @@ -464,7 +464,10 @@ static ssize_t dev_rescan_store(struct device *dev, > } > return count; > } > -static DEVICE_ATTR_WO(dev_rescan); > +static struct device_attribute dev_rescan_attr = __ATTR(rescan, > + 0220, NULL, > + dev_rescan_store); > + > > static ssize_t remove_store(struct device *dev, struct device_attribute *attr, > const char *buf, size_t count) > @@ -481,9 +484,9 @@ static ssize_t remove_store(struct device *dev, struct device_attribute *attr, > static DEVICE_ATTR_IGNORE_LOCKDEP(remove, 0220, NULL, > remove_store); > > -static ssize_t bus_rescan_store(struct device *dev, > - struct device_attribute *attr, > - const char *buf, size_t count) > +static ssize_t dev_bus_rescan_store(struct device *dev, > + struct device_attribute *attr, > + const char *buf, size_t count) > { > unsigned long val; > struct pci_bus *bus = to_pci_bus(dev); > @@ -501,7 +504,7 @@ static ssize_t bus_rescan_store(struct device *dev, > } > return count; > } > -static DEVICE_ATTR_WO(bus_rescan); > +static DEVICE_ATTR(rescan, 0220, NULL, dev_bus_rescan_store); > > #if defined(CONFIG_PM) && defined(CONFIG_ACPI) > static ssize_t d3cold_allowed_store(struct device *dev, > @@ -641,7 +644,7 @@ static struct attribute *pcie_dev_attrs[] = { > }; > > static struct attribute *pcibus_attrs[] = { > - &dev_attr_bus_rescan.attr, > + &dev_attr_rescan.attr, > &dev_attr_cpuaffinity.attr, > &dev_attr_cpulistaffinity.attr, > NULL, > @@ -1487,7 +1490,7 @@ static umode_t pci_dev_attrs_are_visible(struct kobject *kobj, > > static struct attribute *pci_dev_hp_attrs[] = { > &dev_attr_remove.attr, > - &dev_attr_dev_rescan.attr, > + &dev_rescan_attr.attr, > NULL, > }; Thanks for taking care of this! Two questions: 1) You supplied permissions of 0220, but DEVICE_ATTR_WO() uses__ATTR_WO(), which uses 0200. Shouldn't we keep 0200? 2) I think the use of __ATTR() for the device side and DEVICE_ATTR() for the bus side is confusing. Couldn't we accomplish the same thing with a patch like the following (compiled but not tested)? Bjorn commit 06094b3fd9f1 ("PCI: sysfs: Revert "rescan" file renames") Author: Kelsey Skunberg Date: Wed Mar 25 09:17:08 2020 -0600 PCI: sysfs: Revert "rescan" file renames We changed these sysfs filenames: .../pci_bus//rescan -> .../pci_bus//bus_rescan ...//rescan -> ...//dev_rescan and Ruslan reported [1] that this broke a userspace application. Revert these name changes so both files are named "rescan" again. The argument to DEVICE_ATTR_WO() determines both the struct device_attribute name and the .store() function name. We have to use __ATTR() so we can specify different .store() functions for the two "rescan" files. [1] https://lore.kernel.org/r/CAB=otbSYozS-ZfxB0nCiNnxcbqxwrHOSYxJJtDKa63KzXbXgpw@mail.gmail.com [bhelgaas: commit log] Fixes: 8bdfa145f582 ("PCI: sysfs: Define device attributes with DEVICE_ATTR*()") Fixes: 4e2b79436e4f ("PCI: sysfs: Change DEVICE_ATTR() to DEVICE_ATTR_WO()") Link: https://lore.kernel.org/r/20200325151708.32612-1-skunberg.kelsey@gmail.com Signed-off-by: Kelsey Skunberg Cc: stable@vger.kernel.org # v5.4+ diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c index 13f766db0684..bf025a2c296d 100644 --- a/drivers/pci/pci-sysfs.c +++ b/drivers/pci/pci-sysfs.c @@ -464,7 +464,8 @@ static ssize_t dev_rescan_store(struct device *dev, } return count; } -static DEVICE_ATTR_WO(dev_rescan); +static struct device_attribute dev_attr_dev_rescan = __ATTR(rescan, 0200, NULL, + dev_rescan_store); static ssize_t remove_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) @@ -501,7 +502,8 @@ static ssize_t bus_rescan_store(struct device *dev, } return count; } -static DEVICE_ATTR_WO(bus_rescan); +static struct device_attribute dev_attr_bus_rescan = __ATTR(rescan, 0200, NULL, + bus_rescan_store); #if defined(CONFIG_PM) && defined(CONFIG_ACPI) static ssize_t d3cold_allowed_store(struct device *dev,