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Date: Mon, 7 Jan 2013 08:00:37 -0500
From: Chris Mason <chris.mason@fusionio.com>
To: David Sterba <dave@jikos.cz>
CC: Tom Gundersen <teg@jklm.no>, linux-btrfs <linux-btrfs@vger.kernel.org>
Subject: Re: [bug] oops in linux-3.8-rc2
Message-ID: <20130107130037.GA30947@shiny>
References: <CAG-2HqV_pHerHwVVCPhnbUbKwVrA9yyd8GOWdcgNtiv92F5BEA@mail.gmail.com>
 <20130107111037.GB12992@twin.jikos.cz>
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On Mon, Jan 07, 2013 at 04:10:37AM -0700, David Sterba wrote:
> Hi,
> 
> On Mon, Jan 07, 2013 at 01:51:21AM +0100, Tom Gundersen wrote:
> > I ran into a bug today with 3.8-rc2 [0], following an "make
> > modules_install && make install" of the kernel.
> > 
> > I have been using the same kernel without problems for some days, the
> > only change immediately before the oops was that I switched from plain
> > partitions to using multi-device and subvolumes.
> > 
> > [0]: <https://plus.google.com/114015603831160344127/posts/fzEYnF64NkZ>
> 
> BUG at mm/page-writeback.c:2164
> 
> 2160 int clear_page_dirty_for_io(struct page *page)
> 2161 {
> 2162         struct address_space *mapping = page_mapping(page);
> 2163
> 2164         BUG_ON(!PageLocked(page));
> 
> btrfs on the stack is only __btrfs_buffered_write +
> btrfs_file_aio_write, ie. just a buffered write, originating from
> pwrite64.
> 
> The bug_on condition is clear, the question is why the page is not
> locked.

The big question is, can you make it happen again?

-chris