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Subject: Re: [PATCH] nfs: fix NR_FILE_DIRTY underflow
From: Trond Myklebust <trond.myklebust@fys.uio.no>
To: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Andrew Morton <akpm@osdl.org>, linux-kernel <linux-kernel@vger.kernel.org>
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Date: Wed, 13 Dec 2006 07:26:21 -0500
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On Wed, 2006-12-13 at 13:12 +0100, Peter Zijlstra wrote:
> Still testing this patch, but it looks good so far.
> 
> ---
> Just setting PG_dirty can cause NR_FILE_DIRTY to underflow
> which is bad (TM).
> 
> Use set_page_dirty() which will do the right thing.

Actually, I'd prefer to have it do the right thing by getting rid of
that call to test_clear_page_dirty() inside
invalidate_inode_pages2_range(). That is causing loss of data integrity,
and is what is causing us to have to hack NFS in the first place.

Cheers
  Trond


> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
> ---
>  fs/nfs/file.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> Index: linux-2.6-git2/fs/nfs/file.c
> ===================================================================
> --- linux-2.6-git2.orig/fs/nfs/file.c	2006-12-13 12:54:55.000000000 +0100
> +++ linux-2.6-git2/fs/nfs/file.c	2006-12-13 12:55:12.000000000 +0100
> @@ -321,7 +321,7 @@ static int nfs_release_page(struct page 
>  	if (!(gfp & __GFP_FS))
>  		return 0;
>  	/* Hack... Force nfs_wb_page() to write out the page */
> -	SetPageDirty(page);
> +	set_page_dirty(page);
>  	return !nfs_wb_page(page->mapping->host, page);
>  }
>  
> 
>