Re: [Qemu-devel] [PATCH] Error on O_DIRECT for physical CDROM/DVD drives

[Markus Armbruster]

Jes Sorensen <address@hidden> writes:

> On 07/20/10 18:35, David S. Ahern wrote:
>> On 07/20/10 10:09, address@hidden wrote:
>>> diff --git a/block/raw-posix.c b/block/raw-posix.c
>>> index 291699f..1b840c4 100644
>>> --- a/block/raw-posix.c
>>> +++ b/block/raw-posix.c
>>> @@ -1139,6 +1139,11 @@ static int cdrom_open(BlockDriverState *bs, const 
>>> char *filename, int flags)
>>>      BDRVRawState *s = bs->opaque;
>>>  
>>>      s->type = FTYPE_CD;
>>> +    if (flags & BDRV_O_NOCACHE) {
>>> +        fprintf(stderr, "O_DIRECT (cache=none) for CDROM/DVD device (%s) "
>>> +                "is unsupported\n", filename);
>>> +        exit(1);
>>> +    }
>> 
>> If a cdrom is added via the monitor this would abruptly terminate the VM
>> - which is not good.
>
> True, but this would only happen if the user explicitly marks it
> cache=none which is not the default value for a new drive, so it would
> be a corner case.

Why not return -ENOTSUP?