Date: Fri, 9 Nov 2007 14:35:54 -0500
From: Chris Mason <chris.mason@oracle.com>
To: Zach Brown <zach.brown@oracle.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>,
       Peter Zijlstra <peterz@infradead.org>,
       Jens Axboe <jens.axboe@oracle.com>, linux-kernel@vger.kernel.org,
       akpm@linux-foundation.org, linux-aio@kvack.org
Subject: Re: dio_get_page() lockdep complaints
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On Fri, 09 Nov 2007 11:16:53 -0800
Zach Brown <zach.brown@oracle.com> wrote:

> > Ugh, I thought the preallocation was getting freed elsewhere, but it
> > looks like I was wrong.  We can't just skip the i_mutex after all,
> > sorry.
> 
> Ah, so none of those tests at the top will stop tail packing if
> there's been pre-allocation?
> 
> Like, uh, the inode reference count test?
> 

It always drops prealloc, regardless of i_count.  One fix is to change
the prealloc routines to take/drop a reference on the inode.
preallocation is already dropped when the transaction ends, so things
would continue working.

-chris
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