From mboxrd@z Thu Jan  1 00:00:00 1970
From: Christoph Hellwig <hch@infradead.org>
Subject: Re: [PATCH 13/18] fs: split locking of inode writeback and LRU lists
Date: Fri, 8 Oct 2010 04:18:16 -0400
Message-ID: <20101008081816.GA17577@infradead.org>
References: <1286515292-15882-1-git-send-email-david@fromorbit.com>
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 <20101008074243.GB24089@infradead.org>
 <20101008080018.GV4681@dastard>
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Cc: Christoph Hellwig <hch@infradead.org>,
	linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
To: Dave Chinner <david@fromorbit.com>
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On Fri, Oct 08, 2010 at 07:00:18PM +1100, Dave Chinner wrote:
> > >  
> > > -		if (inode->i_state & (I_NEW | I_WILL_FREE)) {
> > > +		if (inode->i_state & (I_NEW | I_WILL_FREE | I_FREEING)) {
> > >  			requeue_io(inode);
> > >  			continue;
> > >  		}
> > 
> > What does this have to do with the rest of the patch?
> 
> That's because there's now a window between setting I_FREEING and taking
> the inode off the writeback list which means that we can see inodes
> in that state here. Generally it means that the code setting
> I_FREEING is spinning waiting for the wb->b_lock that this thread
> currently holds so it can be removed from the list.. Hence the requeue
> to move the inode out of the way and keep processing inodes for
> writeback.

That needs some documentation both in the changelog and in the code
I think.