> In contrast, the hang reported by Mariusz Kozlowski has a slightly
> different feel to it, but there's a tantalizing pattern in there too:
>
>
http://www.ussg.iu.edu/hypermail/linux/kernel/0703.0/1243.html
>
> Call Trace:
> [<c03ec87e>] io_schedule+0x42/0x59
> [<c0184915>] sleep_on_buffer+0x8/0xc
> [<c03ed217>] __wait_on_bit+0x47/0x6c
> [<c03ed297>] out_of_line_wait_on_bit+0x5b/0x64
> [<c01848a8>] __wait_on_buffer+0x27/0x2d
> [<c01b4228>] journal_commit_transaction+0x707/0x127f
> [<c01b868b>] kjournald+0xac/0x1ed
> [<c0126af5>] kthread+0xa2/0xc9
> [<c010422b>] kernel_thread_helper+0x7/0x1c
>
> which certainly also looks like an IO never completed (or completed but
> never woke anything up).
>
> It also seems to be related to *buffers*. Maybe the whole bh layer thing
> is a fluke, but it's not waiting for normal data, it's very much waiting
> for those journal things that all use buffer heads.Which just makes me
> worry about those patches by Nick (which did come in through Andrew). I
> don't think it's the memorder one (it looks safe and shouldn't matter on
> x86 anyway!), but what about the
>
> fs: fix __block_write_full_page error case buffer submission
>
> locking change for example? Or that "fs: fix nobh data leak" thing with
> its fix? It uses "SetPageUptodate(page);" without waking up anybody who
> might wait for it (but the waiters here seem to wait on buffers, so that's
> probably not it)..
