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Date: Mon, 19 Jul 2010 22:55:17 +0200
From: Stefan Weil <weil@mail.berlios.de>
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Subject: [Qemu-devel] Re: [PATCH] block: Use error codes from lower levels
	for error message
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To: Kevin Wolf <kwolf@redhat.com>
Cc: QEMU Developers <qemu-devel@nongnu.org>

Am 19.07.2010 14:26, schrieb Kevin Wolf:
> Am 18.07.2010 21:42, schrieb Stefan Weil:
>    
>> "No such file or directory" is a misleading error message
>> when a user tries to open a file with wrong permissions.
>>
>> Cc: Kevin Wolf<kwolf@redhat.com>
>> Signed-off-by: Stefan Weil<weil@mail.berlios.de>
>> ---
>>   block.c |   12 ++++++++----
>>   1 files changed, 8 insertions(+), 4 deletions(-)
>>
>> diff --git a/block.c b/block.c
>> index f837876..2f80540 100644
>> --- a/block.c
>> +++ b/block.c
>> @@ -330,16 +330,20 @@ BlockDriver *bdrv_find_protocol(const char *filename)
>>       return NULL;
>>   }
>>
>> -static BlockDriver *find_image_format(const char *filename)
>> +static BlockDriver *find_image_format(const char *filename, int *error)
>>      
> Wouldn't it be a more natural interface to return an 0/-errno int and
> pass the BlockDriver* by reference? I think we already have some
> function that work this way in the block code, but I can't remember any
> that get an int *error.
>    

... nor did I find a function which takes a BlockDriver**.
But if you prefer it like that, I can send a new version of the patch.

>    
>>   {
>>       int ret, score, score_max;
>>       BlockDriver *drv1, *drv;
>>       uint8_t buf[2048];
>>       BlockDriverState *bs;
>>
>> +    *error = -ENOENT;
>>      
> Why -ENOENT is the default would be clearer if you moved it down next to
> the drv = NULL before the loop that searches for the driver.
>
>    

What about the "return bdrv_find_format" lines?
They need a default value, too.

And I did not want to change too much because I cannot
run a complete test for all cases.

So setting *error at the beginning should be the safest
modification.

> Apart from these minor nitpicks it looks good.
>
> Kevin
>
>    
Thanks.

Stefan