From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-fsdevel-owner@vger.kernel.org>
Received: from mga06.intel.com ([134.134.136.31]:44391 "EHLO mga06.intel.com"
        rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP
        id S1752141AbdECRPx (ORCPT <rfc822;linux-fsdevel@vger.kernel.org>);
        Wed, 3 May 2017 13:15:53 -0400
Message-ID: <1493831747.30052.10.camel@linux.intel.com>
Subject: Re: [RFC][PATCH] linux/uuid.h: hoist uuid_is_null() helper from
 libnvdimm
From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
To: Amir Goldstein <amir73il@gmail.com>, Christoph Hellwig <hch@lst.de>
Cc: Miklos Szeredi <miklos@szeredi.hu>,
        Mimi Zohar <zohar@linux.vnet.ibm.com>,
        Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
        Richard Weinberger <richard@nod.at>,
        "Darrick J . Wong" <darrick.wong@oracle.com>,
        Mark Fasheh <mfasheh@versity.com>,
        Al Viro <viro@zeniv.linux.org.uk>,
        linux-xfs <linux-xfs@vger.kernel.org>,
        linux-unionfs@vger.kernel.org,
        linux-fsdevel <linux-fsdevel@vger.kernel.org>,
        Dan Williams <dan.j.williams@intel.com>,
        David Howells <dhowells@redhat.com>,
        Theodore Tso <tytso@mit.edu>
Date: Wed, 03 May 2017 20:15:47 +0300
In-Reply-To: <1493829352.30052.6.camel@linux.intel.com>
References: <1493756363-5113-1-git-send-email-amir73il@gmail.com>
         <1493802823.4154.3.camel@linux.intel.com>
         <CAOQ4uxh4Ysg9Q_K2sK9zefvid3hvzswDKxSa-QTN9_D0fAWvyQ@mail.gmail.com>
         <1493809233.30052.1.camel@linux.intel.com>
         <CAOQ4uxj3ppxm4LC6xr54n6GUF1T=yhQ4-5YJfbjXcBJugVENZQ@mail.gmail.com>
         <1493829352.30052.6.camel@linux.intel.com>
Content-Type: text/plain; charset="UTF-8"
Mime-Version: 1.0
Content-Transfer-Encoding: 8bit
Sender: linux-fsdevel-owner@vger.kernel.org
List-ID: <linux-fsdevel.vger.kernel.org>

On Wed, 2017-05-03 at 19:35 +0300, Andy Shevchenko wrote:
> On Wed, 2017-05-03 at 15:42 +0300, Amir Goldstein wrote:
> > On Wed, May 3, 2017 at 2:00 PM, Andy Shevchenko
> > <andriy.shevchenko@linux.intel.com> wrote:
> > > On Wed, 2017-05-03 at 13:05 +0300, Amir Goldstein wrote:
> > > > On Wed, May 3, 2017 at 12:13 PM, Andy Shevchenko

> > I can hear the voices of
> > > > those saying that there should be a 'natural' helper
> > > > uuid_is_null(u8
> > > > *) for the
> > > > users that represent uuid as u8[16] (i.e. filesystems and sb-
> > > > > s_uuid).
> > > 
> > > u8 * doesn't represent UUID as a type.
> > > Perhaps we need to reflect this in the name of the function
> > > somehow.
> > > 
> > 
> > OK, since you have no time nor the intention to convert filesystem
> > code
> > to use uuid_le 
> 
> uuid_be I suppose. I noticed core developers doesn't support endianess
> feature of UUID: https://lkml.org/lkml/2016/5/25/724
> 
> That's also why I don't want to touch filesystem stuff.
> 
> > (not should you), I see 2 options for filesystems/VFS:
> > 
> > 1. Use the simple u8* libnvdimm helper proposed by this patch
> > 2. Hoist uuid_t + helpers from fs/xfs/uuid.* to linux/uuid.h
> > lib/uuid.c
> > 
> > If option #2 is preferred, I think we should conform to libuuid's
> > helper
> > name uuid_is_null() (instead of freebsd's uuid_is_nil()) 

I renamed as proposed and updated my branch.

By the way, notice that uuid_v1 type (which had been moved to uuid.h
already) is the same what xfs uses as uuid_t.

So, helpers against it we can prefix with uuid_v1_[foo_bar()].

-- 
Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Intel Finland Oy