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 AE52114EC79; Wed, 17 Apr 2024 16:10:23 +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=1713370226; cv=none; b=c7Ll6oRj7NjruDlNb54Z+6qQOe1wdzpQr4bE+fSH+o6P/f7CsbOSMldH2xizsl5xCdmvXGBFboLdpvQgBY8kL7IsrhQaeykYT42VjXOQb6eWC58p6aABaCCjkRaqwSx+ej+DhsU+gGtxmkelbrW2/4HK/n2x+mU0UYr7yy6F8aU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713370226; c=relaxed/simple; bh=gSfe2mh9bkp+vU+sT4Snqq3+U6upnEe1SHDBCsuBkkk=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=e15exCaT8DqaXmuNjmJyZzyPFW7tWlfPnP2WiBhA15aNX5R+hSN2EtE1tOvuTk3f2JfsrDfMnNxtf/5oDb+RPmeuXVB8cRBvgtDmfj+uhlbQn4Br/+k7FqDJ5zf+QZ8hP+YmHWliKxWy9/wTNdfz1KiRkP+gFsVRQ9UU/tFerhU= 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 8987CE803C0; Wed, 17 Apr 2024 18:10:21 +0200 (CEST) Received: by gardel-login.0pointer.net (Postfix, from userid 1000) id 430131602F7; Wed, 17 Apr 2024 18:10:21 +0200 (CEST) Date: Wed, 17 Apr 2024 18:10:21 +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> Precedence: bulk X-Mailing-List: linux-block@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: <20240417155913.GA6447@lst.de> On Mi, 17.04.24 17:59, Christoph Hellwig (hch@lst.de) wrote: > On Wed, Apr 17, 2024 at 05:48:16PM +0200, Lennart Poettering wrote: > > Block devices with part scanning off are quite common after all, > > i.e. "losetup" creates them by default like that, and partition block > > devices themselves have no part scanning on and so on, hence we have > > to be ablet to operate sanely with them. > > Maybe and ioctl to turn on partition scanning if it is currently disabled > or return an error otherwise would be the better thing? It would > do the right thing for the most common loop case, and with a bit more > work could do the right thing for those that more or less disable it > graciously (ubiblock, drbd, zram) and would just fail for those who are > so grotty old code and slow devices that we never want to do a partition > scan (basically old floppy drivers and the Nintendo N64 cartridge driver) 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. Lennart -- Lennart Poettering, Berlin