From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from eggs.gnu.org ([2001:4830:134:3::10]:48157)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <bharata@linux.vnet.ibm.com>) id 1VuDsb-0005gl-Rw
	for qemu-devel@nongnu.org; Fri, 20 Dec 2013 23:09:42 -0500
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <bharata@linux.vnet.ibm.com>) id 1VuDsS-0007yO-VR
	for qemu-devel@nongnu.org; Fri, 20 Dec 2013 23:09:33 -0500
Received: from e28smtp07.in.ibm.com ([122.248.162.7]:59852)
	by eggs.gnu.org with esmtp (Exim 4.71)
	(envelope-from <bharata@linux.vnet.ibm.com>) id 1VuDsS-0007y9-BY
	for qemu-devel@nongnu.org; Fri, 20 Dec 2013 23:09:24 -0500
Received: from /spool/local
	by e28smtp07.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use
	Only! Violators will be prosecuted
	for <qemu-devel@nongnu.org> from <bharata@linux.vnet.ibm.com>;
	Sat, 21 Dec 2013 09:39:20 +0530
Received: from d28relay05.in.ibm.com (d28relay05.in.ibm.com [9.184.220.62])
	by d28dlp03.in.ibm.com (Postfix) with ESMTP id 729731258054
	for <qemu-devel@nongnu.org>; Sat, 21 Dec 2013 09:40:34 +0530 (IST)
Received: from d28av05.in.ibm.com (d28av05.in.ibm.com [9.184.220.67])
	by d28relay05.in.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id
	rBL49FBq63897802
	for <qemu-devel@nongnu.org>; Sat, 21 Dec 2013 09:39:15 +0530
Received: from d28av05.in.ibm.com (localhost [127.0.0.1])
	by d28av05.in.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id
	rBL49H6H023715
	for <qemu-devel@nongnu.org>; Sat, 21 Dec 2013 09:39:17 +0530
Date: Sat, 21 Dec 2013 09:40:56 +0530
From: Bharata B Rao <bharata@linux.vnet.ibm.com>
Message-ID: <20131221041056.GA2780@in.ibm.com>
References: <1387551488-6824-1-git-send-email-pbonzini@redhat.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <1387551488-6824-1-git-send-email-pbonzini@redhat.com>
Subject: Re: [Qemu-devel] [PATCH] scsi-disk: add non-zero MAX UNMAP LBA
 COUNT to block limits VPD page
Reply-To: bharata@linux.vnet.ibm.com
List-Id: <qemu-devel.nongnu.org>
List-Unsubscribe: <https://lists.nongnu.org/mailman/options/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>
List-Archive: <http://lists.nongnu.org/archive/html/qemu-devel>
List-Post: <mailto:qemu-devel@nongnu.org>
List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help>
List-Subscribe: <https://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: qemu-devel@nongnu.org

On Fri, Dec 20, 2013 at 03:58:08PM +0100, Paolo Bonzini wrote:
> Linux prefers WRITE SAME to UNMAP if the count is zero, and WRITE
> SAME does not discard anything unless the device can guarantee that
> the resulting block is zero.
> 
> This fixes thin provisioning on glusterfs.

I don't see discard requests reaching GlusterFS even after this patch.
bdrv_co_discard or bdrv_aio_discard isn't getting called for the gluster
drive.

Regards,
Bharata.