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Date: Thu, 22 Mar 2012 15:30:12 +0000
Message-ID: <CAJSP0QVZLmi5=o5WyQSy_2jbtRGR5stzCBUrdcSZLJCviaPUNg@mail.gmail.com>
From: Stefan Hajnoczi <stefanha@gmail.com>
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Subject: Re: [Qemu-devel] [PATCH V2 4/7] qed: add bdrv_invalidate_cache to
 be called after incoming live migration
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To: Paolo Bonzini <pbonzini@redhat.com>
Cc: kwolf@redhat.com, Anthony Liguori <aliguori@us.ibm.com>, =?ISO-8859-1?Q?Beno=EEt_Canet?= <benoit.canet@gmail.com>, qemu-devel@nongnu.org, stefanha@linux.vnet.ibm.com

On Thu, Mar 22, 2012 at 2:17 PM, Paolo Bonzini <pbonzini@redhat.com> wrote:
> Il 22/03/2012 15:15, Beno=EEt Canet ha scritto:
>>
>> I added this flag after seeing the following code in in bdrv_open_common=
.
>>
>> =A0 =A0 /*
>> =A0 =A0 =A0* Clear flags that are internal to the block layer before ope=
ning the
>> =A0 =A0 =A0* image.
>> =A0 =A0 =A0*/
>> =A0 =A0 open_flags =3D flags & ~(BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING);
>>
>> This lead me to believe that =A0bs->open_flags !=3D open_flags.
>
> Correct, see the first two patches in the series at
> http://lists.gnu.org/archive/html/qemu-devel/2012-01/msg03467.html

We mangle the flags but I guess what I'm asking is, does it even
matter?  Those two bits don't affect qed or qcow2 .bdrv_open().  If
possible, I think we should use bs->open_flags.

Stefan