Re: [GIT PULL] Btrfs updates for 2.6.29-rc

[Kay Sievers <kay.sievers@vrfy.org>]

On Sat, Feb 7, 2009 at 17:37, Linus Torvalds
<torvalds@linux-foundation.org> wrote:
> On Fri, 6 Feb 2009, Chris Mason wrote:
>>
>> Crud, the confusion would be me.  I missed the cleanups and bug fixes
>> between 2.6.29-rc1 and rc3.   The correct diffstat and short log are
>> below, and the only non-btrfs change is to the MAINTAINERS file.
>
> Ok.
>
> I notice that it now asks about ACL's, and says
>
>        If you don't know what Access Control Lists are, say N
>
> which is all fine, but last I saw some (most?) distributions use POSIX
> ACL's for things like desktop access permissions to /dev/audio etc.
>
> I don't particularly have to like it, but it does mean that if you don't
> do POSIX ACL's, and have btrfs as your root filesystem, you'll quite
> likely not get sound when logging in.
>
> I dunno. I haven't actually yet tried to convert my laptop, so I just
> reacted to this thanks to the new question..

Systems using ACLs to grant device permissions to logged-in users have
/dev on a tmpfs mount, where the content will not survive a reboot.
This should not be a problem for btrfs, or the rootfs fs type, but
TMPFS_POSIX_ACL. Maybe we want to have a comment there?

Thanks,
Kay