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Date: Mon, 24 Feb 2014 11:39:40 +0100
From: Paolo Bonzini <pbonzini@redhat.com>
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Subject: Re: [Qemu-devel] [RFC PATCH] block: optimize zero writes with
	bdrv_write_zeroes
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To: Fam Zheng <famz@redhat.com>, Peter Lieven <pl@kamp.de>
Cc: kwolf@redhat.com, qemu-devel@nongnu.org, stefanha@redhat.com

Il 24/02/2014 02:01, Fam Zheng ha scritto:
>
> I would do this in qcow2:
>
>  1. In qcow2_co_writev, allocate cluster regardless of if data is zero or not.
>  2. If data is zero, set QCOW2_OFLAG_ZERO in L2.

This is (or should be) bdrv_co_write_zeroes without BDRV_REQ_MAY_UNMAP.

Paolo