Re: [Qemu-devel] [PATCH 01/23] block: Split bdrv_new_named() off bdrv_new()

[Eric Blake]

On 09/10/2014 05:03 AM, Benoît Canet wrote:
> The Wednesday 10 Sep 2014 à 10:13:30 (+0200), Markus Armbruster wrote :
>> Creating an anonymous BDS can't fail.  Make that obvious.
>>
>> Signed-off-by: Markus Armbruster <address@hidden>
>> ---

>>  /* create a new block device (by default it is empty) */
>> -BlockDriverState *bdrv_new(const char *device_name, Error **errp)
>> +BlockDriverState *bdrv_new_named(const char *device_name, Error **errp)
>>  {
>>      BlockDriverState *bs;
>> -    int i;
>> +
>> +    assert(*device_name);
> 
> This assert that device_name is not a null pointer.

No, it assumes that device_name is non-NULL and blindly dereferences it;
it is asserting that the first byte of the dereferenced pointer is not NUL.

> But here we are pretty sure that the BDS should be named given the name of 
> the function.
> Should we bake an assert on device_name[0] != '\0' to avoid bdrv_new_named 
> being called
> with "" as device_name ?

That's already what the code does.  About the only thing it could do
differently is:

assert(device_name && *device_name);

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org

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