From owner-freebsd-fs@freebsd.org  Sat Jun 25 14:32:56 2016
Return-Path: <owner-freebsd-fs@freebsd.org>
Delivered-To: freebsd-fs@mailman.ysv.freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org
 [IPv6:2001:1900:2254:206a::19:1])
 by mailman.ysv.freebsd.org (Postfix) with ESMTP id C6592B801FB
 for <freebsd-fs@mailman.ysv.freebsd.org>; Sat, 25 Jun 2016 14:32:56 +0000 (UTC)
 (envelope-from mchangir@redhat.com)
Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28])
 (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits))
 (Client did not present a certificate)
 by mx1.freebsd.org (Postfix) with ESMTPS id AC52F1891
 for <freebsd-fs@freebsd.org>; Sat, 25 Jun 2016 14:32:56 +0000 (UTC)
 (envelope-from mchangir@redhat.com)
Received: from int-mx13.intmail.prod.int.phx2.redhat.com
 (int-mx13.intmail.prod.int.phx2.redhat.com [10.5.11.26])
 (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits))
 (No client certificate requested)
 by mx1.redhat.com (Postfix) with ESMTPS id 7F07E81F03
 for <freebsd-fs@freebsd.org>; Sat, 25 Jun 2016 14:32:55 +0000 (UTC)
Received: from [10.10.50.6] (unused [10.10.50.6] (may be forged))
 by int-mx13.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id
 u5PEWrhC026014
 for <freebsd-fs@freebsd.org>; Sat, 25 Jun 2016 10:32:54 -0400
To: freebsd-fs@freebsd.org
From: Milind Changire <mchangir@redhat.com>
Subject: Can NetBSD fdiscard() syscall support be added to FreeBSD?
Organization: Red Hat India Private Limited
Message-ID: <59b3ac11-6f2a-1f38-df8f-3f07859a9f9f@redhat.com>
Date: Sat, 25 Jun 2016 20:02:52 +0530
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101
 Thunderbird/45.1.1
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Transfer-Encoding: 7bit
X-Scanned-By: MIMEDefang 2.68 on 10.5.11.26
X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16
 (mx1.redhat.com [10.5.110.25]); Sat, 25 Jun 2016 14:32:55 +0000 (UTC)
X-BeenThere: freebsd-fs@freebsd.org
X-Mailman-Version: 2.1.22
Precedence: list
List-Id: Filesystems <freebsd-fs.freebsd.org>
List-Unsubscribe: <https://lists.freebsd.org/mailman/options/freebsd-fs>,
 <mailto:freebsd-fs-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-fs/>
List-Post: <mailto:freebsd-fs@freebsd.org>
List-Help: <mailto:freebsd-fs-request@freebsd.org?subject=help>
List-Subscribe: <https://lists.freebsd.org/mailman/listinfo/freebsd-fs>,
 <mailto:freebsd-fs-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Sat, 25 Jun 2016 14:32:56 -0000

I couldn't find any discussion in the mailing list archives regarding
this issue. Kindly point me to the appropriate discussion thread if
there's any.

-----

Here's my point of view ...

fdiscard() will help to support rsync --inplace and --sparse flags at
the same time which will help the Gluster geo-replication feature.

Punching holes in a file is possible on:
1. Linux
2. NetBSD

but not
3. FreeBSD

at the moment.

In-place hole punching will help Gluster geo-replicate virtual machine 
images efficiently.

Kindly comment.

--
Milind