06.11.2018 18:30, Alberto Garcia wrote:
> On Tue 06 Nov 2018 04:13:58 PM CET, Vladimir Sementsov-Ogievskiy wrote:
>> 06.11.2018 18:06, Alberto Garcia wrote:
>>> On Thu 01 Nov 2018 07:27:37 PM CET, Vladimir Sementsov-Ogievskiy wrote:
>>>
>>>> + buf = g_try_malloc(csize);
>>>> + if (!buf) {
>>>> + return -ENOMEM;
>>>> + }
>>>> + iov.iov_base = buf;
>>>> + iov.iov_len = csize;
>>>> + qemu_iovec_init_external(&local_qiov, &iov, 1);
>>>>
>>>> - iov.iov_base = s->cluster_data;
>>>> - iov.iov_len = csize;
>>>> - qemu_iovec_init_external(&local_qiov, &iov, 1);
>>>> + out_buf = qemu_blockalign(bs, s->cluster_size);
>>> You should also check whether out_buf is NULL, shouldn't you?
>> No, it will abort on fail. qemu_try_blockalign result should be
>> checked.
> Is there any reason why some parts of the QEMU code use qemu_blockalign
> and others qemu_try_blockalign() ? From what I can see it seems to be up
> to whoever wrote it...
>
> Berto
As I understand, the good reason to use _try_ versions, is when we are
allocating some size, taken from user input, so it may be unpredictable
large (hm, or just any really large allocation), so, I use try_malloc
for compressed size, which may be very large in somehow corrupted image.
And it looks a common practice to use not-failing (aborting) allocation
functions for cluster_size allocations in qcow2.c
--
Best regards,
Vladimir
