Re: INFO: possible circular locking dependency detected3.1.0-rc2-00190-g3210d19

From: Al Viro
Date: Mon Aug 22 2011 - 09:16:33 EST


On Mon, Aug 22, 2011 at 09:09:14AM -0400, Josh Boyer wrote:

> We've had a report of this on 3.0.1 as well. Slightly different
> scenario and fs, but the locks in question are the same.
> https://bugzilla.redhat.com/show_bug.cgi?id=730998
>
> It seems that with CONFIG_PROVE_LOCKING on, might_fault will always
> attempt to grab mm->mmap_sem. The common flow here is that getdents
> calls filldir, which calls copy_to_user, which is what is calling
> might_fault.
>
> Beyond that, I'm a bit over my head at the moment because I don't know
> if the VFS is right and we just need some more lockdep annotations or
> if there really is a problem.

Don't grab ->i_mutex in ->evict_inode(). Why are you doing that, anyway?
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/