From: Theodore Ts'o <tytso@mit.edu>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-fsdevel <linux-fsdevel@vger.kernel.org>,
Sparse Mailing-list <linux-sparse@vger.kernel.org>
Subject: Re: What does this sparse warning mean in posix_acl.h?
Date: Sat, 17 Aug 2013 17:23:26 -0400 [thread overview]
Message-ID: <20130817212326.GI30769@thunk.org> (raw)
In-Reply-To: <CA+55aFyB9C9iT1vH+Gbhn+cVPCN7AA+r3wuQBc31NJBvt19d3w@mail.gmail.com>
On Sat, Aug 17, 2013 at 02:14:45PM -0700, Linus Torvalds wrote:
>
> So anybody using "get_cached_acl()" is safe. It gets either a locked
> ref-counted ACL pointer, or an unlocked optimistic NULL pointer.
Ah, I see. But as we start adding the RCU annotations and the calls
to rcu_derference(), then I imagine we'll start triggering warnings
from various other static analysis tools, even if it makes sparse happy.
> So the ACL accesses are this somewhat strange mix of RCU and non-RCU
> use. We probably could make *more* of them use the RCU model, but
> apart from the RCU pathname lookup nothing else has ever been critical
> enough to care.
Ugh. OK, I care mostly because it's adding noise to my make C=1 runs,
but I'm not sure I care enough to fix it up right away. I'll put it
on my todo list, and hope someone beats me to it. :-)
- Ted
next prev parent reply other threads:[~2013-08-17 21:23 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-08-17 14:28 What does this sparse warning mean in posix_acl.h? Theodore Ts'o
2013-08-17 16:16 ` Linus Torvalds
2013-08-17 20:55 ` Theodore Ts'o
2013-08-17 21:14 ` Linus Torvalds
2013-08-17 21:23 ` Theodore Ts'o [this message]
2013-08-17 21:31 ` Linus Torvalds
2013-08-17 21:23 ` Linus Torvalds
2013-08-17 16:17 ` Josh Triplett
2013-08-17 16:33 ` Linus Torvalds
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