On 4/11/17 1:49 PM, Brian Foster wrote:
> On Tue, Apr 11, 2017 at 01:39:55PM -0500, Eric Sandeen wrote:
>> On 4/11/17 1:33 PM, Brian Foster wrote:
...
>>> BTW, this is going to warn on every xfs_mdrestore of an image with a
>>> dirty log, right? That is slightly unfortunate, if so. Do we have any
>>> method to track or determine whether an image is obfuscated (I'm
>>> guessing not easily...)?
>>
>> Nope! There is an unused slot in the header, maybe we could add flags?
>>
>> Hm, or we could do a trick like setting the fs label to "OBFUSCATED"
>> instead of "label" like we currently do. That might be reasonable...
>>
>> /* Replace any filesystem label with "L's" */
>> if (obfuscate) {
>> struct xfs_sb *sb = iocur_top->data;
>> memset(sb->sb_fname, 'L',
>> min(strlen(sb->sb_fname), sizeof(sb->sb_fname)));
>> iocur_top->need_crc = 1;
>> }
>>
>> (today we keep the same label length, but that's probably not
>> necessary?)
>
> That's an interesting idea. It looks like we currently set the fname to
> L's when obfuscated. Could we just key off that in mdrestore?
Right, like the code above. :)
I guess the problem is that if a filesystem had no label, then we replaced
it with "no" L's, i.e. it stays empty.
So we may want to:
1) Start replacing it with 12 L's going forward, no matter what, and
2) Look for L's in mdrestore as a clue, which may sometimes fail ...
3) Any non-NULL label != "LLL..." probably isn't obfuscated, and can skip warning
-Eric
> Brian
>
>> -Eric
>>
>>> Brian
>>>
>>>> + case 0:
>>>> + /* Everything is ok. */
>>>> + break;
>>>> + }
>>>> +
>>>> +}
>>>> +
>>>> +
>>>> static void
>>>> usage(void)
>>>> {
>>>> @@ -271,5 +353,7 @@ main(
>>>> if (src_f != stdin)
>>>> fclose(src_f);
>>>>
>>>> + test_dirty_log(is_target_file, argv[optind]);
>>>> +
>>>> return 0;
>>>> }
>>>> --
>>>> 2.1.4
>>>>
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