linux-kernel - Re: [NFS] blocks of zeros (NULLs) in NFS files in kernels >= 2.6.20

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Date:	Tue, 9 Sep 2008 12:46:44 -0700
From:	Aaron Straus <aaron@...finllc.com>
To:	chucklever@...il.com
Cc:	Neil Brown <neilb@...e.de>,
	Linux NFS Mailing List <linux-nfs@...r.kernel.org>,
	Trond Myklebust <trond.myklebust@....uio.no>,
	LKML Kernel <linux-kernel@...r.kernel.org>
Subject: Re: [NFS] blocks of zeros (NULLs) in NFS files in kernels >= 2.6.20

Hi,

On Sep 08 05:15 PM, Chuck Lever wrote:
> I think I saw some recent work in Trond's development branch that
> makes some changes in this area.  I will wait for him to respond to
> this thread.

One other piece of information.

Of the bisected offending commit:

commit e261f51f25b98c213e0b3d7f2109b117d714f69d
Author: Trond Myklebust <Trond.Myklebust@...app.com>
Date:   Tue Dec 5 00:35:41 2006 -0500

    NFS: Make nfs_updatepage() mark the page as dirty.
    
    This will ensure that we can call set_page_writeback() from within
    nfs_writepage(), which is always called with the page lock set.
    
    Signed-off-by: Trond Myklebust <Trond.Myklebust@...app.com>


It seems to be this hunk which introduces the problem:


@@ -628,7 +667,6 @@ static struct nfs_page * nfs_update_request(struct nfs_open_context* ctx,
 				return ERR_PTR(error);
 			}
 			spin_unlock(&nfsi->req_lock);
-			nfs_mark_request_dirty(new);
 			return new;
 		}
 		spin_unlock(&nfsi->req_lock);



If I add that function call back in... the problem disappears.  I don't
know if this just papers over the real problem though?  


					Thanks,
					=a=





-- 
===================
Aaron Straus
aaron@...finllc.com

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