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=-2.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no 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 57466C2D0EF for ; Thu, 16 Apr 2020 05:25:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3152720771 for ; Thu, 16 Apr 2020 05:25:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587014734; bh=mTV4yOfOt5MmZ8GQe00lVMWrQWROluQXaQPSmbvQm7g=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=eZohXyb4XGtcIN9SkIpqLZlZubcRnS3n9xfYot35R4652GtQPa9I68fR/du6sqTb6 Fr69GU1BVRrvNVepuxQWlAnMPnRHjongkt6ELuI7dsAxpyTMBZzkfCWRPBvc+HF5s0 MbOjcat7i9gpIhXWt+w6e10L64oNmz8tp2qx6Rl4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2406433AbgDPFZc (ORCPT ); Thu, 16 Apr 2020 01:25:32 -0400 Received: from mail-pg1-f193.google.com ([209.85.215.193]:43448 "EHLO mail-pg1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2406053AbgDPFZ1 (ORCPT ); Thu, 16 Apr 2020 01:25:27 -0400 Received: by mail-pg1-f193.google.com with SMTP id x26so1098904pgc.10; Wed, 15 Apr 2020 22:25:27 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=Kg7nI0Dukhm7hME7k56vQQPnaqgMUKpXaW8k038CnpY=; b=N6fkaAenH6mBP6CkcCtj9a4W+2OlFJTtDFNRthR3NlRm3SbO0B6hoC4WOAzlSveL4g prde5eX4LJNP6jgCrsJinl45EAjlNsA7gEFDNJAPwhtk5qYWUwVryVE4NFXwG2uGIfar J+Qg2h1PMtN5ulhw1auo/K1Aa9VdFq/2IibiW+7iYXXuYHpc4VVlW/Y26vk2Gx2+8VKA yoSruUgKxo2AOECVAvELY2nBGmjkA2z1jFcvdB+51rWeTrjWQCkJEM4YUr/DD5b6jXx0 PaRT3wo8AVcVR7stvsBv5M0ZsZl03U3/JD2am1nlFOTHboThwKY6eV+6q8kJkOAj6cKu WQMA== X-Gm-Message-State: AGi0PuamD27zH4Z1x6rDUhu29zrt9HmHh16hvpnmpejNIbs65dWtered WvZr+qW7pcFsjefp4LN7gEg= X-Google-Smtp-Source: APiQypIg+I4iUy63S0mBZ7fWRB3nVMRCNRDUKQvXsu0TEmZwpSFoQiVN/BIM0RYKLVeyKWhDUMDDWg== X-Received: by 2002:a62:2a8c:: with SMTP id q134mr32437286pfq.35.1587014726673; Wed, 15 Apr 2020 22:25:26 -0700 (PDT) Received: from 42.do-not-panic.com (42.do-not-panic.com. [157.230.128.187]) by smtp.gmail.com with ESMTPSA id b13sm6005334pfo.67.2020.04.15.22.25.25 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 15 Apr 2020 22:25:25 -0700 (PDT) Received: by 42.do-not-panic.com (Postfix, from userid 1000) id C8C0340277; Thu, 16 Apr 2020 05:25:24 +0000 (UTC) Date: Thu, 16 Apr 2020 05:25:24 +0000 From: Luis Chamberlain To: Ming Lei Cc: axboe@kernel.dk, viro@zeniv.linux.org.uk, bvanassche@acm.org, gregkh@linuxfoundation.org, rostedt@goodmis.org, mingo@redhat.com, jack@suse.cz, nstange@suse.de, akpm@linux-foundation.org, mhocko@suse.com, yukuai3@huawei.com, linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Omar Sandoval , Hannes Reinecke , Michal Hocko , syzbot+603294af2d01acfdd6da@syzkaller.appspotmail.com Subject: Re: [PATCH 2/5] blktrace: fix debugfs use after free Message-ID: <20200416052524.GH11244@42.do-not-panic.com> References: <20200414041902.16769-1-mcgrof@kernel.org> <20200414041902.16769-3-mcgrof@kernel.org> <20200416021036.GA2717677@T590> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200416021036.GA2717677@T590> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Thu, Apr 16, 2020 at 10:10:36AM +0800, Ming Lei wrote: > In theory, multiple partitions can be traced concurrently, but looks > it never works, so it won't cause trouble for multiple partition trace. > > One userspace visible change is that blktrace debugfs dir name is switched > to disk name from partition name in case of partition trace, will it > break some utilities? How is this possible, its not clear to me, we go from: - q->debugfs_dir = debugfs_create_dir(kobject_name(q->kobj.parent), - blk_debugfs_root); To this: + q->debugfs_dir = debugfs_create_dir(kobject_name(q->kobj.parent), + blk_debugfs_root); Maybe I am overlooking something. Luis