Re: [PATCH 01/11] IMA: use rbtree instead of radix tree for inodeinformation cache

From: John Stoffel
Date: Tue Oct 26 2010 - 10:08:44 EST


>>>>> "Linus" == Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> writes:

Linus> On Mon, Oct 25, 2010 at 12:38 PM, J.H. <warthog9@xxxxxxxxxx> wrote:
>>
>> I'll second both points.  If IMA is disabled, but compiled in, it *HAS*
>> to consume 0 resources.

Linus> I disagree. First off, this isn't actually true. Look at things
Linus> like quota support: it eats more memory in the inode than IMA
Linus> does after this patch-series (two pointers), and most people
Linus> don't use that either. So the "it must use zero extra memory"
Linus> is bogus - it's a balance between simplicity of the code and
Linus> memory use.

Quotas are useful in a much more general sense for managing a limited
resource (disk space) and for a larger audience as well. And hey,
let's target quotas next! *grin*

Linus> Secondly, right now we're in the situation that IMA just
Linus> sucks. Sucks with all capital letters, in fact. This
Linus> patch-series may not be perfect, but it's _so_ much better than
Linus> the current situation that I don't really see why people are so
Linus> adamantly negative about it.

I'm negative about it because I forsee very limited applicability to
normal day to day use of Linux in my work. Quotas I use every day.

Linus> Please do feel free to be constructive about it, and I'm sure
Linus> there are ways to improve even more, but right now
Linus> "constructive" is not what the objections seem to be.

Sorry, will certainly try to be more positive about my objections to
this system.

Mostly I'd really like to just see:

- documentation
- Kconfig updated to default to N.

John
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