Re: [PATCH 0/6] File Sealing & memfd_create()

From: Andy Lutomirski
Date: Thu Apr 10 2014 - 15:16:18 EST


On 04/10/2014 07:45 AM, Colin Walters wrote:
> On Thu, Mar 20, 2014 at 11:32 AM, tytso@xxxxxxx wrote:
>>
>> Looking at your patches, and what files you are modifying, you are
>> enforcing this in the low-level file system.
>
> I would love for this to be implemented in the filesystem level as
> well. Something like the ext4 immutable bit, but with the ability to
> still make hardlinks would be *very* useful for OSTree. And anyone else
> that uses hardlinks as a data source. The vserver people do something
> similiar:
> http://linux-vserver.org/util-vserver:Vhashify
>
> At the moment I have a read-only bind mount over /usr, but what I really
> want is to make the individual objects in the object store in
> /ostree/repo/objects be immutable, so even if a user or app navigates
> out to /sysroot they still can't mutate them (or the link targets in the
> visible /usr).

COW links can do this already, I think. Of course, you'll have to use a
filesystem that supports them.

--Andy
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