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=-9.0 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 B5DD5C433EF for ; Sun, 5 Sep 2021 18:11:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 955F560232 for ; Sun, 5 Sep 2021 18:11:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238139AbhIESMp (ORCPT ); Sun, 5 Sep 2021 14:12:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42512 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238124AbhIESMo (ORCPT ); Sun, 5 Sep 2021 14:12:44 -0400 Received: from bombadil.infradead.org (unknown [IPv6:2607:7c80:54:e::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 217C4C061575 for ; Sun, 5 Sep 2021 11:11:41 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=Sender:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=p8aku6deYsnC1Rl2Pv2bYisBKiEg/qHT0F2g7t0ztIE=; b=IxALWL/lWGme5SHk7Br8S8fEQF AAJgnKQuiIZhHMzwTU7RNAVfnGocinY5yyJQaFLRGCrr2EY1Ey271csVrD3qHhFeGUH6a9zD6Md4a Gi61tUrz5o53q2ITXpN8/y1cmCq4i57rLkWMcrwoq76RHuOODfHyy9E4BQid2d3HotdaRUscghj/5 NfjFxSDPG1FR/Zcxh67xgKp7RE58tt342EsOFlGOSsa3MdBWcK1y4oGbgC84A12corar/w4cM2k8N F5l5C/0jtQBJVR6syoXyyKUaGDZ7mTKTUhCZEKPYVqFfgqQkakuaAx4Lxh7LQ6rIortianwei3QlA oSp/SwuA==; Received: from mcgrof by bombadil.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1mMwcB-00GDQ7-VP; Sun, 05 Sep 2021 18:11:35 +0000 Date: Sun, 5 Sep 2021 11:11:35 -0700 From: Luis Chamberlain To: Tetsuo Handa Cc: axboe@kernel.dk, hch@lst.de, linux-block@vger.kernel.org Subject: Re: [PATCH 1/2] block: make __register_blkdev() return an error Message-ID: References: <20210904013932.3182778-1-mcgrof@kernel.org> <20210904013932.3182778-2-mcgrof@kernel.org> <9b9e8bfd-a2a6-4b78-413b-7c6c7eb83e05@I-love.SAKURA.ne.jp> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <9b9e8bfd-a2a6-4b78-413b-7c6c7eb83e05@I-love.SAKURA.ne.jp> Sender: Luis Chamberlain Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Sat, Sep 04, 2021 at 11:49:06AM +0900, Tetsuo Handa wrote: > On 2021/09/04 10:39, Luis Chamberlain wrote: > > diff --git a/fs/block_dev.c b/fs/block_dev.c > > index 45df6cbccf12..81a4738910a8 100644 > > --- a/fs/block_dev.c > > +++ b/fs/block_dev.c > > @@ -1144,10 +1144,13 @@ struct block_device *blkdev_get_no_open(dev_t dev) > > { > > struct block_device *bdev; > > struct inode *inode; > > + int ret; > > > > inode = ilookup(blockdev_superblock, dev); > > if (!inode) { > > - blk_request_module(dev); > > + ret = blk_request_module(dev); > > + if (ret) > > + return NULL; > > Since e.g. loop_add() from loop_probe() returns -EEXIST when /dev/loop$num already > exists (e.g. raced with ioctl(LOOP_CTL_ADD)), isn't unconditionally failing an over-failing? It's not clear to me how. What do we loose by capturing the failure on blk_request_module()? Luis