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=-3.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS 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 3DEE2C4724C for ; Fri, 1 May 2020 16:51:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1CE5824955 for ; Fri, 1 May 2020 16:51:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588351911; bh=++sDVtfRPslmaRC40X9+zsZ1c0TFAxBbEziiGGuGPdw=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=VZmt++GH3nzTpHYMAIHXpcCGjmJlIk4xyGvQ54FglaE2egGhaiMZrOd5TlcEyRsQ/ FXvVDkJGnuTS4xtBaWc9VUZOiBOEWPB0k48mybfV0LKokCsPvFZQRRaHaCH9jkt3Zx CAKVzZsD8gt/ZLrFxNJ7wv1EX1elk2uiAr5qQdM4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729312AbgEAQvs (ORCPT ); Fri, 1 May 2020 12:51:48 -0400 Received: from mail.kernel.org ([198.145.29.99]:45166 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728919AbgEAQvr (ORCPT ); Fri, 1 May 2020 12:51:47 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (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 1FEA32173E; Fri, 1 May 2020 16:51:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588351907; bh=++sDVtfRPslmaRC40X9+zsZ1c0TFAxBbEziiGGuGPdw=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=WngqC7Pp4qUBPz23YQI6VXXQbL775RJYV1qHAbUnahMAU7i97p+hdeoTrHVZJmTc6 7eInjZEqMYXE9+rjz9GElVbALjjynHJg27bEE+WfpjG2pCDIB0KUOK498PLlFL+ilo ZykZT9G0ACcVZ5kT76jLEejG1Jky7AZu9EVDwWGI= Date: Fri, 1 May 2020 18:51:45 +0200 From: Greg KH To: Luis Chamberlain 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: <20200501165145.GA2085362@kroah.com> References: <20200429074627.5955-1-mcgrof@kernel.org> <20200429074627.5955-6-mcgrof@kernel.org> <20200429094937.GB2081185@kroah.com> <20200501150626.GM11244@42.do-not-panic.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200501150626.GM11244@42.do-not-panic.com> Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Fri, May 01, 2020 at 03:06:26PM +0000, Luis Chamberlain wrote: > 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. That's fine, give us a chance to know what went wrong, your line as is does not do that :( thanks, greg k-h