[Qemu-devel] Re: [PATCH 01/14] Introduce qemu_write_full()

[Anthony Liguori <anthony@codemonkey.ws>]

On 01/19/2010 06:04 PM, Juan Quintela wrote:
> Anthony Liguori<anthony@codemonkey.ws>  wrote:
>    
>> On 01/19/2010 06:17 AM, Kirill A. Shutemov wrote:
>>      
>>> On Tue, Jan 19, 2010 at 2:11 PM, Juan Quintela<quintela@redhat.com>   wrote:
>>>
>>>        
>>>> "Kirill A. Shutemov"<kirill@shutemov.name>   wrote:
>>>>
>>>>          
>>>>> A variant of write(2) which handles partial write.
>>>>>
>>>>> Signed-off-by: Kirill A. Shutemov<kirill@shutemov.name>
>>>>>
>>>>>            
>>>> Hi
>>>>
>>>> Have you updated this series?  Is there any reason that you know when
>>>> they haven't been picked?
>>>>
>>>>          
>>> I don't  know any reason, but I'm going to review it once again.
>>>
>>> I also have plan to get rid of -fno-strict-aliasing where it's possible.
>>>
>>>        
>> I haven't reviewed the series in detail, but generally speaking I
>> don't feel that good about these sort of series.
>>
>> You're essentially adding dummy error handling to quiet the compiler.
>> That's worse than just disabling -Werror because at least you aren't
>> losing the information in the code.
>>
>> If you're going to update error handling, it should be part of an
>> effort to make code paths resilient to error.  IOW, actually audit the
>> full error path of the function and make it deal with errors
>> gracefully.
>>      
> I reviewed his series, and I reviewed callers.  Please take a look at my
> improved series.  Appart for the comments added there, I don't know what
> to do here:
>
> @@ -501,8 +501,11 @@ static void aio_signal_handler(int signum)
>   {
>       if (posix_aio_state) {
>           char byte = 0;
> +        ssize_t ret;
>
> -        write(posix_aio_state->wfd,&byte, sizeof(byte));
> +        ret = write(posix_aio_state->wfd,&byte, sizeof(byte));
> +        if (ret<  0&&  errno != EAGAIN)
> +            die("write()");
>       }
>
> if write() fails in a pipe in the signal handler, I am at a lost about
> what to do here.
>    

That's nothing we can do.  I guess exiting is reasonable.

Regards,

Anthony Liguori