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From: Peng Tao <lkml.bergwolf@gmail.com>
Date: Fri, 19 Nov 2010 01:22:01 +0800
Message-ID: <AANLkTik6cGbhyAPBKVoq49ePEfxgVaNL16ghXgztya1V@mail.gmail.com>
Subject: Re: Question about nfs_page_async_flush assertion
To: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: linux-nfs@vger.kernel.org, linux-kernel@vger.kernel.org
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On Thu, Nov 18, 2010 at 11:27 PM, Trond Myklebust
<trond.myklebust@fys.uio.no> wrote:
> On Thu, 2010-11-18 at 18:53 +0800, Peng Tao wrote:
>> Hi, all,
>>
>> nfs_writepages calls into
>> write_cache_pages()->nfs_writepages_callback()->nfs_do_writepage()->nfs_page_async_flush(),
>> where it asserts BUG_ON(test_bit(PG_CLEAN, &req->wb_flags)).
>> My question is: how do we guarantee the request has PG_CLEAN flag set?
>
> We don't. We guarantee that the request has PG_CLEAN cleared, and that
> is done when we dirty the page (see nfs_try_to_update_request()).
Ah, I missed. It is test_bit() other than !test_bit(). Thank you Trond
for pointing it out.
Sorry for the spam :)

-- 
Thanks,
-Bergwolf