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From: Al Viro <viro@ZenIV.linux.org.uk>
To: Josh Boyer <jwboyer@gmail.com>
Cc: "Justin P. Mattock" <justinmattock@gmail.com>,
	Peter Zijlstra <peterz@infradead.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: INFO: possible circular locking dependency detected 3.1.0-rc2-00190-g3210d19
Date: Mon, 22 Aug 2011 14:16:21 +0100	[thread overview]
Message-ID: <20110822131621.GS2203@ZenIV.linux.org.uk> (raw)
In-Reply-To: <CA+5PVA6KUMDEygjxrqwvpRDNfJ3WobUs7rwyP+pZrX9-atZUgw@mail.gmail.com>

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?

  reply	other threads:[~2011-08-22 13:16 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-08-22  3:41 INFO: possible circular locking dependency detected 3.1.0-rc2-00190-g3210d19 Justin P. Mattock
2011-08-22 13:09 ` Josh Boyer
2011-08-22 13:16   ` Al Viro [this message]
2011-08-22 13:27     ` Josh Boyer
2011-08-22 13:27     ` Al Viro
2011-08-22 13:33       ` Josh Boyer
2011-08-22 13:56         ` Al Viro
2011-08-22 15:24           ` Josh Boyer

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