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=-5.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 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 44071C4724C for ; Fri, 1 May 2020 15:06:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 258672166E for ; Fri, 1 May 2020 15:06:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588345591; bh=4+d+6PqCRN/DZNNA1vhiK/ig8q/URx10ojjSbGFh0sk=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=1EKd2ufk55pmNHgPTq4NnZfUI5rNaonX3iqWl87LPT9S6sc2DYysh6ys6qLAac6S6 W9M9QrJeg870Xr3O+dM1eDI8pxJqzKgzFboqLCIEyKARINGnVPgjazdZjNMEXbN4Dd 1S3Qm9db5LUheJ71t8nMAqBcDxuoRVg+Bo040ylI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729017AbgEAPGa (ORCPT ); Fri, 1 May 2020 11:06:30 -0400 Received: from mail-pj1-f67.google.com ([209.85.216.67]:52962 "EHLO mail-pj1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728839AbgEAPGa (ORCPT ); Fri, 1 May 2020 11:06:30 -0400 Received: by mail-pj1-f67.google.com with SMTP id a5so7380pjh.2; Fri, 01 May 2020 08:06:29 -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=xZEuUIfKchT+EMbxhxCN46MIcCVcFm3FAvFpx36VX5s=; b=siMrVTnv76sHVgyryxeCag4mzdiPllfjhxdBsdoCPtD4YTwuArBXu/LIbbZv0Cew4M A1Jb/q1OhitBZ8qsdI0SJCfI/WxEBpe+bXtnFTfNbITtcj6/uQgskySb6tDBBPS3bhzh /pIimOiLbNCymlK6d3QNp01EG8je0btr+QXLw+09tHLkcYZH7qLsB/rbLlX3pzkgh3re ubljy6qDQ/uz7mcxhpHK6kVzIuCthNdHapVnXFNMjRNP/TPd++eMizPO1P/xwz581K5w T4aoW4gOtu1SAB4pFDt+rTE9n/JwsjLvc72sKeDznr9jIhnBGIVzN4MXgb+DsVZfv4Ci Pq+w== X-Gm-Message-State: AGi0PuYuZxqPm3EeKLR6WQrkmp9AaEKcL52JGupy8XxKq43DkmX/VyID aafRqbUXd7Tv1oXxpZ7XAuA= X-Google-Smtp-Source: APiQypLRVmetlTXe8oQnydpwRXsMDCGv8wGQxNnx9xTkyckOaqUJcm8Xfuuqc69dMqg8NZhPGGC9qQ== X-Received: by 2002:a17:90a:690b:: with SMTP id r11mr5175418pjj.119.1588345589022; Fri, 01 May 2020 08:06:29 -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 p16sm15627pjz.2.2020.05.01.08.06.27 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 01 May 2020 08:06:27 -0700 (PDT) Received: by 42.do-not-panic.com (Postfix, from userid 1000) id CABA44046C; Fri, 1 May 2020 15:06:26 +0000 (UTC) Date: Fri, 1 May 2020 15:06:26 +0000 From: Luis Chamberlain To: Greg KH Cc: axboe@kernel.dk, viro@zeniv.linux.org.uk, bvanassche@acm.org, rostedt@goodmis.org, mingo@redhat.com, jack@suse.cz, ming.lei@redhat.com, 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 Subject: Re: [PATCH v3 5/6] blktrace: break out of blktrace setup on concurrent calls Message-ID: <20200501150626.GM11244@42.do-not-panic.com> References: <20200429074627.5955-1-mcgrof@kernel.org> <20200429074627.5955-6-mcgrof@kernel.org> <20200429094937.GB2081185@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200429094937.GB2081185@kroah.com> 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 Wed, Apr 29, 2020 at 11:49:37AM +0200, Greg KH wrote: > On Wed, Apr 29, 2020 at 07:46:26AM +0000, Luis Chamberlain wrote: > > diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c > > index 5c52976bd762..383045f67cb8 100644 > > --- a/kernel/trace/blktrace.c > > +++ b/kernel/trace/blktrace.c > > @@ -516,6 +518,11 @@ static int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev, > > */ > > strreplace(buts->name, '/', '_'); > > > > + if (q->blk_trace) { > > + pr_warn("Concurrent blktraces are not allowed\n"); > > + return -EBUSY; > > You have access to a block device here, please use dev_warn() instead > here for that, that makes it obvious as to what device a "concurrent > blktrace" was attempted for. The block device may be empty, one example is for scsi-generic, but I'll use buts->name. Luis