Re: [git pull] vfs pile 1.5

From: Linus Torvalds
Date: Tue Jul 26 2011 - 12:38:08 EST


On Tue, Jul 26, 2011 at 9:18 AM, Christoph Hellwig <hch@xxxxxxxxxxxxx> wrote:
>
> Even getting to check_acl() requires MS_POSIXACL to be set on the
> superblock, which it won't be if CONFIG_XFS_ACL isn't set.

Ahh, ok. That thing is well-hidden behind that IS_POSIXACL() thing..
And it turns out that now that I see it, I shudder. That's another of
those potentially expensive inode indirect pointer accesses - but I
haven't seen it because my normal test-workload is as the owner of the
tree I'm traversing.

> These days we can probably kill CONFIG_FOOFS_ACL given that everyone
> now uses the generic code, and due to the deeper VFS interaction is
> more or less forced to anyway.  Historically that wasn't the case.

Yeah. And these days pretty much every single distribution uses ACL's,
which also didn't use to be the case (or even if they used them, it
wasn't a requirement: now it tends to be).

> While I agree with you that we should life it into the common code,
> the common caching is not related at all to this particular issue.

Yeah, I had missed the hidden MS_POSIX_ACL test.

So I agree, the plain NULL return for "no ACL" works fine.

Do we have a signed-off version with a changelog etc?

Linus
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