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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,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 3D479C3815B for ; Mon, 20 Apr 2020 11:38:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 11FFE2082E for ; Mon, 20 Apr 2020 11:38:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587382738; bh=veCGgKP+gaMaBxAIpl/jdA0mDZiqNm79OtKradPHlN8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=Y5MlRQn0Yk8EaCig6dIzzBH9Z8jVfU2wAymNmutxh7+V5gV/EztOYQAyZAO/IyLbX Qlg8ijH33Ua96QRcuXNbKMJeIqkJV9/po5lTqavYcQbjNRLu1JPIz+kVjmM1tIj133 ISbYHiGRcYmUsskZzxNcff6gZp5uyJn4d9s+R+iA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726209AbgDTLiy (ORCPT ); Mon, 20 Apr 2020 07:38:54 -0400 Received: from mail.kernel.org ([198.145.29.99]:40026 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725886AbgDTLix (ORCPT ); Mon, 20 Apr 2020 07:38:53 -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 03B3E206D4; Mon, 20 Apr 2020 11:38:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587382732; bh=veCGgKP+gaMaBxAIpl/jdA0mDZiqNm79OtKradPHlN8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=PSv9KlPALQJwITlfEXQWZBKfTFX3Lc197g3Q8P8hhWjMQdROLzHL4K9KMio/IONiC 5fodZe10QtCuAN7yHrgwgFtBahvsrbC6jYbm3WOBcv4YJEBjYg9GmRAm9CLUTGV3U2 HxwYBll9AtQn8IQGb+0B89WmylTNdKz49QFIMyqc= Date: Mon, 20 Apr 2020 13:38:50 +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 v2 09/10] block: panic if block debugfs dir is not created Message-ID: <20200420113850.GC3906674@kroah.com> References: <20200419194529.4872-1-mcgrof@kernel.org> <20200419194529.4872-10-mcgrof@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200419194529.4872-10-mcgrof@kernel.org> Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Sun, Apr 19, 2020 at 07:45:28PM +0000, Luis Chamberlain wrote: > If DEBUG_FS is disabled we have another inline > blk_debugfs_register() which just returns 0. > > If BLK_DEV_IO_TRACE is enabled we rely on the block debugfs > directory to have been created. If BLK_DEV_IO_TRACE is not enabled > though, but if debugfs is still enabled we will always create a > debugfs directory for a request_queue. Instead of special-casing > this just for BLK_DEV_IO_TRACE, ensure this block debugfs dir is > always created at boot if we have enabled debugfs. > > Signed-off-by: Luis Chamberlain > --- > block/blk-debugfs.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/block/blk-debugfs.c b/block/blk-debugfs.c > index 761318dcbf40..d6ec980e7531 100644 > --- a/block/blk-debugfs.c > +++ b/block/blk-debugfs.c > @@ -15,6 +15,8 @@ struct dentry *blk_debugfs_root; > void blk_debugfs_register(void) > { > blk_debugfs_root = debugfs_create_dir("block", NULL); > + if (!blk_debugfs_root) > + panic("Failed to create block debugfs directory\n"); How rude, never crash the kernel for something so trivial as that. Heck, never do ANYTHING different in the kernel if debugfs fails to do something you think it should do. This is debugging code, nothing should ever depend on it, so just save the value (if you need it) and move on. Never check the value, as it means nothing to you. greg k-h