Re: Bugreport on Ubuntu LTS: not ok - 2 Objects creation does not break ACLs with restrictive umask

> [+cc ecryptfs@vger, as I think this is an ecryptfs bug]
>
> On Tue, Jun 05, 2012 at 10:28:13AM -0400, Jeff King wrote:
>
>> OK, here's the _real_ issue. Git creates with mode 0444, which should
>> still allow read in the mask. But it's the restrictive umask at the top
>> of the test script that causes the problem. Try this:
>> 
>>   setfacl -m m:rwx .
>>   perl -MFcntl -e 'sysopen(X, "a", O_WRONLY|O_CREAT, 0444)'
>>   umask 077
>>   perl -MFcntl -e 'sysopen(X, "b", O_WRONLY|O_CREAT, 0444)'
>>   getfacl a b
>> 
>> On ext4, both files will have the read bit set in the mask. On ecryptfs,
>> "b" will have an empty mask. I think the wrong thing is that we should
>> not be respecting umask at all when default ACLs are in play, and
>> ecryptfs is getting that wrong. But I'm having trouble digging up an
>> authoritative source.
>
> Reading the withdrawn posix 1003.1e and "man 5 acl", it seems pretty
> clear that if a default ACL is present, it should be used, and umask
> consulted only if it is not (so the umask should not be making a
> difference in this case).
>
> The reproduction recipe above shows the minimum required to trigger it;
> adding a more realistic default ACL (with actual entries for users) does
> not seem to make a difference.