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=-8.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 72FB9C433B4 for ; Wed, 31 Mar 2021 16:05:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5409A61040 for ; Wed, 31 Mar 2021 16:05:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233575AbhCaQFE (ORCPT ); Wed, 31 Mar 2021 12:05:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38192 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232319AbhCaQEo (ORCPT ); Wed, 31 Mar 2021 12:04:44 -0400 Received: from mail-ej1-x630.google.com (mail-ej1-x630.google.com [IPv6:2a00:1450:4864:20::630]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8303AC061574 for ; Wed, 31 Mar 2021 09:04:43 -0700 (PDT) Received: by mail-ej1-x630.google.com with SMTP id w3so30896219ejc.4 for ; Wed, 31 Mar 2021 09:04:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=intel-com.20150623.gappssmtp.com; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=/K8jhwDcWdtQO8TgpjZZoFEiAtw8FI9cBvy1a1rTDN8=; b=n98YQxI+8gd6h3kZzKYrEF739lerNLf9t8oyCoS2TJyNMaNFL6UJhBu/UuusrT4qiF 4IiTkSg4USBePHxB+IYW/b9H74TqaoiTSLaPyMsY58DnwNmx1m2p2nInVBop5vaFoFqF 1gTDhuJ2bUKv3YWP0erWmiFTAGXG7WuKr01VIR8J6Mn3aR9e3BW4qHcpjTLr/2rJ1hOy /SaZ0obFL7QqVEpsM0+l+1cNkCBrcElevYRJokNDUp0KeLWBDXbm2uBLsx7+M6U6K9Ar IJMgFpN0v9+iBI3vNt5IqaYv+CspHhLfbmjIrqkJzx+nLicb0UeJ3uECqj3eL39YZV+a 2PNg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=/K8jhwDcWdtQO8TgpjZZoFEiAtw8FI9cBvy1a1rTDN8=; b=gVim0m+1QoINELpLjZ9aj0UNWF5yYRRUP+caZcvVGVeRq8KvKoO/Ti9ImpTm7VYkZF FFLGAVuaGTEK15b5hhiLTFyBi+DUJvCxsJh+0cPEabPugeHFOpNOhNkjb9WYyAqeqdAX SAUKjRczjEYwd4spNW+cXqLfu2KN8IXB/dU1kI521zNv/bMxoVTt+PTCDhy0RMNeTnuy LXLXi0GHw+UVtZ1RNaZpVIR6IIus3HQHwKF1yucmPIYF3CbzZKS1MWzuIdUFDR6IU9Q8 +SjhetLU+5ZGfevldi54wVs+ZrqO6VA3fIejqGC4BXmyHbTlSodM3MRqlAGz9TTQEHKc ukLA== X-Gm-Message-State: AOAM5321JY/14YsbUt47zacaLhDW6gcMV5DafJlW5VOu8o+3h9M9TwgS gbfkrF0RWon3CdHhmAFbcQBSoI0v3DvNC9MdqYfVKA== X-Google-Smtp-Source: ABdhPJx2vS46/Y5jbwBa9EENsyxfekhK0CyN/G/O6mqN+sRR/ycmUklyCtiEkx+kxNfBjLDHmIy1v6PK0IqgLLQq6+4= X-Received: by 2002:a17:906:ae88:: with SMTP id md8mr4161716ejb.264.1617206681177; Wed, 31 Mar 2021 09:04:41 -0700 (PDT) MIME-Version: 1.0 References: <161714738634.2168142.10860201861152789544.stgit@dwillia2-desk3.amr.corp.intel.com> <161714740233.2168142.11116065966198937093.stgit@dwillia2-desk3.amr.corp.intel.com> <20210331130953.GG1463678@nvidia.com> In-Reply-To: <20210331130953.GG1463678@nvidia.com> From: Dan Williams Date: Wed, 31 Mar 2021 09:04:32 -0700 Message-ID: Subject: Re: [PATCH v3 3/4] cxl/mem: Do not rely on device_add() side effects for dev_set_name() failures To: Jason Gunthorpe Cc: linux-cxl@vger.kernel.org, Linux Kernel Mailing List , Vishal L Verma , "Weiny, Ira" , "Schofield, Alison" Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Mar 31, 2021 at 6:10 AM Jason Gunthorpe wrote: > > On Tue, Mar 30, 2021 at 04:36:42PM -0700, Dan Williams wrote: > > +static int cxl_mem_add_memdev(struct cxl_mem *cxlm) > > +{ > > + struct cxl_memdev *cxlmd; > > + struct device *dev; > > + struct cdev *cdev; > > + int rc; > > + > > + cxlmd = cxl_memdev_alloc(cxlm); > > + if (IS_ERR(cxlmd)) > > + return PTR_ERR(cxlmd); > > + > > + dev = &cxlmd->dev; > > + rc = dev_set_name(dev, "mem%d", cxlmd->id); > > + if (rc) > > + goto err; > > > > + cdev = &cxlmd->cdev; > > cxl_memdev_activate(cxlmd, cxlm); > > rc = cdev_device_add(cdev, dev); > > if (rc) > > - goto err_add; > > + goto err; > > It might read nicer to have the error unwind here just call cxl_memdev_unregister() Perhaps, but I don't think cdev_del() and device_del() are prepared to deal with an object that was not successfully added. > > > - return devm_add_action_or_reset(&pdev->dev, cxl_memdev_unregister, > > + return devm_add_action_or_reset(dev->parent, cxl_memdev_unregister, > > cxlmd); > > Since that is what the error unwind does at this point. Right, but at this point the code knows that cdev_del() and device_del() will receive an object in the appropriate state. > > > > > -err_add: > > +err: > > /* > > * The cdev was briefly live, shutdown any ioctl operations that > > * saw that state. > > */ > > cxl_memdev_shutdown(cxlmd); > > Then this doesn't need to be a function > > But it is OK as is Unless I'm missing something I think it's required to use only put_device() to cleanup after cdev_device_add() failure, but yes I don't like that cxl_memdev_shutdown() needs to be open coded like this. > > Reviewed-by: Jason Gunthorpe Appreciate it.