From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from gardel.0pointer.net (gardel.0pointer.net [85.214.157.71]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id ED29C1411E5; Wed, 17 Apr 2024 16:26:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=85.214.157.71 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713371222; cv=none; b=aFDKshMZouvXJa7aMbdG1y8dwyyYu7IVEpJYcbz8zFIEflWkaOZxCYs0HZjpFeRk7Bjy/pp9EfGWXqh0bU9iElUxkiJ97YckAINjGcQmcz7XJuOu2hTB/tMxpJXzIC7MsYOixQ0Hyg0Lc1yMbresGiqHQdnw9KkA0m1IyyJkq4o= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713371222; c=relaxed/simple; bh=Kfk/+PMXTSlj8X88Ks9ci1e34mQJ52fS/4pU0B16Qjo=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=BN0r4foFkYFD44lTu0vhWyA4brhMUXjjXABxJTPQDGCYIbefSPcOkNsTMvqYvoXhetoV0nSpWWT6x8Z1KqqL1eSH1qtSUi9/9uYzKka5iLXLb25uBtvjvpKCLY7MDwgdmKRslfKp9k68e6dn00RmRfBII3hxYmWLOY9215TkYdU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=0pointer.de; spf=pass smtp.mailfrom=0pointer.de; arc=none smtp.client-ip=85.214.157.71 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=0pointer.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=0pointer.de Received: from gardel-login.0pointer.net (gardel-mail [85.214.157.71]) by gardel.0pointer.net (Postfix) with ESMTP id CB2E6E803A9; Wed, 17 Apr 2024 18:26:57 +0200 (CEST) Received: by gardel-login.0pointer.net (Postfix, from userid 1000) id 51EDF1602F7; Wed, 17 Apr 2024 18:26:57 +0200 (CEST) Date: Wed, 17 Apr 2024 18:26:57 +0200 From: Lennart Poettering To: Christoph Hellwig Cc: Keith Busch , Linux regressions mailing list , linux-block@vger.kernel.org, LKML , Jens Axboe Subject: Re: API break, sysfs "capability" file Message-ID: References: <20240409141531.GB21514@lst.de> <20240417151350.GB2167@lst.de> <20240417155913.GA6447@lst.de> <20240417162257.GA8098@lst.de> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240417162257.GA8098@lst.de> eOn Mi, 17.04.24 18:22, Christoph Hellwig (hch@lst.de) wrote: > On Wed, Apr 17, 2024 at 06:10:21PM +0200, Lennart Poettering wrote: > > Well, there are plenty of other block devices with part scanning off, > > such as DM, including dm-crypt, dm-integrity and so on. And that's > > certainly stuff we want to cover for this. > > But there is no good reason to prohibit scanning for them. We can't > scan by default as that would probably break a few expectations in > userspace, but we can trivially allow manual scanning. Hmm, so you want to generically allow toggling the flag from userspace? I mean that'd be fine with me, but it would feel a bit weird if you let's say have a partition block device, where you'd toggle this, and then you have two levels of part scanning, and then you toggle it on one of the part block devices there and so on, and so on. Could that work at all with the major/minor allocation stuff? But let's say you add such a user-controlled thing, if you'd add that I figure you really also need a way to query the current state, right? which is basically what I originally was looking for... i.e. it would be really weird if we could set the flag, but not query it in the first place. Lennart -- Lennart Poettering, Berlin