/tmp on tmpfs (was: Re: Summary/Minutes for today's FESCo meeting (2012-04-02))
selinux at davequigley.com
Mon Apr 2 20:04:23 UTC 2012
On 04/02/2012 15:58, Richard W.M. Jones wrote:
> On Mon, Apr 02, 2012 at 08:32:56PM +0200, Miloslav Trmač wrote:
>> * #834 F18 Feature: /tmp on tmpfs -
>> http://fedoraproject.org/wiki/Features/tmp-on-tmpfs (mitr,
>> * AGREED: tmp-on-tmpfs is accepted (+5 -3) (mitr, 18:12:52)
> Actually I think this is a good feature, but ...
> The feature page is wrong about "The user experience should barely
> change. This is mostly a low-level change that has little visibility
> to the user."
> tmpfs is different in a number of important ways:
> - it's very limited in space compared to a real disk
> - it doesn't support O_DIRECT
> - it doesn't support user extended attrs; and not very old kernels
> didn't support any xattrs at all, meaning things like SELinux
> labels don't work
> All this means it's going to need a bit more testing, since
> potentially any package that stores a file on /tmp should be tested
> and may need to be fixed.
> Richard Jones, Virtualization Group, Red Hat
> New in Fedora 11: Fedora Windows cross-compiler. Compile Windows
> programs, test, and build Windows installers. Over 70 libraries
I really need to remember to send with the right user identity for this
<resend of my message since its going to bounce>
That third part is not correct. tmpfs supports SELinux labels. If you
mount a tmpfs filesystem you'll see it reports seclabel as one of the
mount options. You can also just use chcon -t to set the type on any
file you like. SELinux labels are stored in the security namespace which
is separate from user extended attributes.
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