[Qemu-devel] Re: [PATCH v5 3/6] char: Let writers know how much data was written in case of errors

[Gerd Hoffmann <kraxel@redhat.com>]

On 05/04/10 13:31, Amit Shah wrote:
> On (Tue) May 04 2010 [13:24:58], Gerd Hoffmann wrote:
>>> @@ -531,8 +534,12 @@ static int unix_write(int fd, const uint8_t *buf, int len1)
>>>        while (len>   0) {
>>>            ret = write(fd, buf, len);
>>>            if (ret<   0) {
>>> -            if (errno != EINTR&&   errno != EAGAIN)
>>> +            if (len1 - len) {
>>> +                return len1 - len;
>>> +            }
>>> +            if (errno != EINTR&&   errno != EAGAIN) {
>>>                    return -1;
>>> +            }
>>
>> This makes unix_write pass -EINTR up to the caller which it didn't before.
>
> Only on partial writes. Should be OK, no?

No.  Callers which never saw partial writes due to write() syscall being 
interrupted by some signal start seeing them now.

cheers,
   Gerd