Received: by 2002:a25:6193:0:0:0:0:0 with SMTP id v141csp3236817ybb; Tue, 31 Mar 2020 00:50:16 -0700 (PDT) X-Google-Smtp-Source: ADFU+vuzcu1zH8WuWi8NfCiO7PhY1274ljtjn1nCPbCKCPSzM9IuTvV5BMQZFdskh/5X11lNKJAR X-Received: by 2002:a4a:2c55:: with SMTP id o82mr12594226ooo.33.1585641016047; Tue, 31 Mar 2020 00:50:16 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1585641016; cv=none; d=google.com; s=arc-20160816; b=jFeMUXTcNGPLbBgRli+t7AEC7MPiLb98ieFZxbdcyvghDe/UcTdes9jZVPiEqYXVhL ln3kAQWWYiSIhvCHFpNNzOY7ChPnAGS7ctZG3lPcJTgK/jYXPP3udUUPxBu3Yiaj2yi7 FC4mh8dKv7Z91D8C68Mf1KtE5/tbDf/eRGSDlQ4WV8XcsYyGQxwYGRFzps1rDHSwiavP jA/8+u8BbifdjtdqUCxxEUxorQgowyNgZ8bXV+iEdDVAK0VBZ1XComMZ/0Hjvjg9Sfb5 j00Nut3pFanK0y2Yjvpl7w1b7dRSFyNaRKXV9/tyJkkKilFo0hADyiCksQ1/ipRYhviB iQKw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:user-agent:in-reply-to :content-disposition:mime-version:references:message-id:subject:cc :to:from:date; bh=c7c5bOm5QSFreAAY66zM9ZXAoVqX8kiRtA6j/PIjrQU=; b=kI7RRMGGlZ7K51Ont4+ej3s0sIZhyP97UKM07SxvEQSXhbimWCw8MROcjGbPPTztaP RvGTWQTK0I7IzbPcevytUTw86KJU2dmPp30FpcJzZ+xBiqbqwl3QMSZKQDyXddDgr92h esbUw4QLFfrASPEDuhAwB1pkz7Fv8HS4aIOYMtPEfDLsRxKps1Z5V9ay4UHgRBq4rjz2 gRHfiv5MN7uMy9+DAo5d7KAzxNyiUKx4U2IvEb5Gj7d0BAgKPnPtwfwe+jmS84+m4+iF oIpYVXKC6YjhpGcPGuoufKBnVNNkXVb96LoufURAnitMbH98dfpugNmnJg0hCifyQFW8 mbtA== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id d4si7495462ood.77.2020.03.31.00.50.04; Tue, 31 Mar 2020 00:50:16 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730105AbgCaHsc (ORCPT + 99 others); Tue, 31 Mar 2020 03:48:32 -0400 Received: from verein.lst.de ([213.95.11.211]:37197 "EHLO verein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726636AbgCaHsc (ORCPT ); Tue, 31 Mar 2020 03:48:32 -0400 Received: by verein.lst.de (Postfix, from userid 2407) id ABC3168C4E; Tue, 31 Mar 2020 09:48:28 +0200 (CEST) Date: Tue, 31 Mar 2020 09:48:28 +0200 From: Christoph Hellwig To: Martijn Coenen Cc: Ming Lei , Jens Axboe , Christoph Hellwig , Bart Van Assche , Chaitanya Kulkarni , linux-block , LKML , kernel-team@android.com Subject: Re: [PATCH] loop: Add LOOP_SET_FD_WITH_OFFSET ioctl. Message-ID: <20200331074828.GA24372@lst.de> References: <20200329140459.18155-1-maco@android.com> <20200330010024.GA23640@ming.t460p> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Mar 30, 2020 at 10:06:41AM +0200, Martijn Coenen wrote: > Hi Ming, > > On Mon, Mar 30, 2020 at 3:00 AM Ming Lei wrote: > > The new ioctl LOOP_SET_FD_WITH_OFFSET looks not generic enough, could > > you consider to add one ioctl LOOP_SET_FD_AND_STATUS to cover both > > SET_FD and SET_STATUS so that using two ioctl() to setup loop can become > > deprecated finally? > > I originally started out doing that. However, it is a significantly > larger refactoring of the loop driver, and it makes things like error > handling more complex. I thought configuring loop with an offset is > the most common case. But if there's a preference to do an ioctl that > takes the full status, I can work on that. I think the full blown set fd an status would seem a lot more useful, or even better a LOOP_CTL_ADD variant that sets up everything important on the character device so that we avoid the half set up block devices entirely.