[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [PATCH 2/2] tests: add file-write-read test
From: |
Eric Blake |
Subject: |
Re: [Qemu-devel] [PATCH 2/2] tests: add file-write-read test |
Date: |
Tue, 24 Nov 2015 11:44:20 -0700 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.3.0 |
On 11/24/2015 10:58 AM, Marc-André Lureau wrote:
>>> + cmd = g_strdup_printf("{'execute': 'guest-file-seek',"
>>> + " 'arguments': { 'handle': %" PRId64 ", "
>>> + " 'offset': %d, 'whence': %d } }",
>>> + id, 0, SEEK_SET);
>>
>> EWWWW. We seriously released this interface as taking an integer for
>> whence? SEEK_SET is not required to be the same value on every
>> platform. Which is a severe problem if the guest and the host are on
>> different OS with different choices of values for the constants (if
>> SEEK_CUR on my host is 1, but 1 maps to SEEK_END on my guest OS, what
>> behavior am I going to get?).
>>
>> It would be worth a patch to qga to document the actual integer values
>> that we have hard-coded (0 for set, 1 for cur, 2 for end; even if that
>> differs from the guest's local definition of the SEEK_ constants),
>> and/or to fix the interface to take symbolic names rather than integers
>> for the whence argument.
>>
>> Our whole guest-file-* API is lousy.
>
> Are you going to send a patch for this?
Sure, now that you've asked. For 2.5, it will just be documentation and
mapping integers to the correct constants (any magic of using a qapi
alternate type to support symbolic names would be 2.6 territory).
--
Eric Blake eblake redhat com +1-919-301-3266
Libvirt virtualization library http://libvirt.org
signature.asc
Description: OpenPGP digital signature