Re: [PATCH v11 21/48] ext4: Add richacl feature flag

Andreas Gruenbacher
2015-10-19T15:35:03Z

On Mon, Oct 19, 2015 at 3:16 PM, Austin S Hemmelgarn
<ahferroin7@gmail.com> wrote:
> On 2015-10-16 13:41, Andreas Gruenbacher wrote:
>>
>> On Fri, Oct 16, 2015 at 7:31 PM, Austin S Hemmelgarn
>> <ahferroin7@gmail.com> wrote:
>>>
>>> I would like to re-iterate, on both XFS and ext4, I _really_ think this
>>> should be a ro_compat flag, and not an incompat one. If a person has the
>>> ability to mount the FS (even if it's a read-only mount), then they by
>>> definition have read access to the file or partition that the filesystem
>>> is contained in, which means that any ACL's stored on the filesystem are
>>> functionally irrelevant,
>>
>> It is unfortunately not safe to make such a file system accessible to
>> other users, so the feature is not strictly read-only compatible.
>>
> OK, seeing as I wasn't particularly clear as to why I object to this in my
> other e-mail, let's try this again.
>
> Can you please explain exactly why it isn't safe to make such a filesystem
> accessible to other users?

See here: http://www.spinics.net/lists/linux-ext4/msg49541.html

Andreas