Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753813AbcDVXOh (ORCPT ); Fri, 22 Apr 2016 19:14:37 -0400 Received: from ipmail07.adl2.internode.on.net ([150.101.137.131]:1385 "EHLO ipmail07.adl2.internode.on.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751995AbcDVXOf (ORCPT ); Fri, 22 Apr 2016 19:14:35 -0400 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: A2DVCQC6rxpX/7GFLHlegziBUKV0BowUhWqEEoYIAgIBAQKBI00BAQEBAQFmJ0ESAYNuAQEEOhwjEAgDGAklDwUlAyETiCm/UQEBAQEGAgEdGYVAhROHaoIrBZgPjgqPGo8vYoN9KjCBPIc/AQEB Date: Sat, 23 Apr 2016 09:14:19 +1000 From: Dave Chinner To: Florian Margaine Cc: Eric Sandeen , Alexander Viro , Jeff Layton , "J. Bruce Fields" , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] fs: add the FIGETFROZEN ioctl call Message-ID: <20160422231419.GE18517@dastard> References: <20160415021737.GZ567@dastard> <5714FB36.6020704@sandeen.net> <20160418230601.GA18496@dastard> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1094 Lines: 29 On Fri, Apr 22, 2016 at 11:53:48PM +0200, Florian Margaine wrote: > On Tue, Apr 19, 2016 at 1:06 AM, Dave Chinner wrote: > >> A way to query freeze state might be nice, I think, but yeah, it's > >> racy, so you can't depend on it - but it might be useful in the "huh, > >> IO is failing, what's going on? Oh, it's frozen, ok" scenario... > > > > So maybe we should just add the frozen state to /proc/self/mountinfo > > or something similar, then people who think it matters can shoot > > themselves in the foot all they want without us needing to care > > about it. > > Sorry if it's a basic question, but what is the difference between > /proc/self/mountinfo and providing an ioctl call? Simply this: $ grep xfs /proc/self/mountinfo 22 0 9:0 / / rw,relatime - xfs /dev/block/9:0 rw,attr2,inode64,sunit=1024,swidth=2048,noquota i.e. no need for a custom binary to query state in diagnostic situations where it might matter. And it shows up in things like SOS reports that distro's gather when users report issues. Cheers, Dave. -- Dave Chinner david@fromorbit.com