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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 714E1E9270D for ; Thu, 5 Oct 2023 15:42:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229552AbjJEPmN (ORCPT ); Thu, 5 Oct 2023 11:42:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43604 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233787AbjJEPlf (ORCPT ); Thu, 5 Oct 2023 11:41:35 -0400 Received: from verein.lst.de (verein.lst.de [213.95.11.211]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5992B9EEB for ; Thu, 5 Oct 2023 06:56:35 -0700 (PDT) Received: by verein.lst.de (Postfix, from userid 2407) id 47FA96732D; Thu, 5 Oct 2023 08:48:19 +0200 (CEST) Date: Thu, 5 Oct 2023 08:48:18 +0200 From: Christoph Hellwig To: Jan Kara Cc: "Darrick J. Wong" , Christian Brauner , Christoph Hellwig , linux-fsdevel@vger.kernel.org Subject: Re: [PATCH 7/7] porting: document block device freeze and thaw changes Message-ID: <20231005064818.GA5728@lst.de> References: <20230927-vfs-super-freeze-v1-0-ecc36d9ab4d9@kernel.org> <20230927-vfs-super-freeze-v1-7-ecc36d9ab4d9@kernel.org> <20230927151911.GG11414@frogsfrogsfrogs> <20231002164524.lh6ljbdxdqln33jk@quack3> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20231002164524.lh6ljbdxdqln33jk@quack3> User-Agent: Mutt/1.5.17 (2007-11-01) Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Mon, Oct 02, 2023 at 06:45:24PM +0200, Jan Kara wrote: > > "Filesystems opening a block device must pass the super_block object > > and fs_holder_ops as the @holder and @hops parameters." > > > > Though TBH I see a surprising amount of fs code that doesn't do this, so > > perhaps it's not so mandatory? > > This is actually a good point. For the main device, fs/super.c takes care > of this (perhaps except for btrfs). So this patch set should not regress > anything. But for other devices such as the journal device or similar, > passing proper holder and holder_ops from the filesystem is necessary. It is is necessary to gain functionality where we call into the fs based on the block device. In the old get_super based world these never worked either as get_super was based on sb->s_dev only.