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Date: Tue, 20 Jul 2010 18:18:34 +0200
From: Jes Sorensen <Jes.Sorensen@redhat.com>
MIME-Version: 1.0
Subject: Re: [Qemu-devel] [PATCH] Disable O_DIRECT for physical CDROM/DVD
	drives
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To: Kevin Wolf <kwolf@redhat.com>
Cc: qemu-devel@nongnu.org

On 07/20/10 18:12, Kevin Wolf wrote:
> Am 20.07.2010 18:04, schrieb Jes Sorensen:
>> On 07/20/10 17:40, Kevin Wolf wrote:
>> Thats effectively what my patch does. cdrom_open() calls
>> raw_open_common() which has this part:
>>
>>     /* Use O_DSYNC for write-through caching, no flags for write-back
>> caching,
>>      * and O_DIRECT for no caching. */
>>     if ((bdrv_flags & BDRV_O_NOCACHE))
>>         s->open_flags |= O_DIRECT;
> 
> s and bs both have a field open_flags (and I think they share some more
> field names, which has caused confusion more than once). I meant the bs
> one here.
> 
> Kevin
Hi,

It shows up even that case is handled as one of the first things
bdrv_open_common() does is to set bs->open_flags = flags. Anyway
throwing an error as Anthony suggested seems safer.

Cheers,
Jes