Re: nfs3 problem with -rc{2,3} : blame

From: Myklebust, Trond
Date: Tue Jun 19 2012 - 12:23:20 EST


On Tue, 2012-06-19 at 12:20 -0400, Trond Myklebust wrote:
> On Tue, 2012-06-19 at 02:06 +0100, Ken Moffat wrote:
> > On Mon, Jun 18, 2012 at 11:10:52PM +0100, Ken Moffat wrote:
> > > On Mon, Jun 18, 2012 at 10:03:24PM +0000, Myklebust, Trond wrote:
> > > >
> > > > Doesn't 4f97615d19 fix the fs/nfs/direct.c problem too? It should.
> > > >
> > > > Anyhow, if you can apply that on top of the commits that didn't compile,
> > > > and then continue the bisection, that would be great. We definitely do
> > > > want the !defined(CONFIG_NFS_V4) case to work in 3.5-final...
> > > >
> > > OK (I was assuming errors in different places were from different
> > > causes). I'll do that after I've rerun rc3 without NFS_V4 with
> > > SUNRPC_DEBUG. Thanks.
> >
> > Bisection now points to:
> >
> > 6d74743b088d116e31fe1b73f47e782ee2016b94 is the first bad commit
> > commit 6d74743b088d116e31fe1b73f47e782ee2016b94
> > Author: Trond Myklebust <Trond.Myklebust@xxxxxxxxxx>
> > Date: Mon Apr 30 13:27:31 2012 -0400
> >
> > NFS: Simplify O_DIRECT page referencing
> >
> > The O_DIRECT code shouldn't need to hold 2 references to each
> > page. The
> > reference held by the struct nfs_page should suffice.
> >
> > Signed-off-by: Trond Myklebust <Trond.Myklebust@xxxxxxxxxx>
> > Cc: Fred Isaman <iisaman@xxxxxxxxxx>
> >
> > I was going to revert that from 3.5.0-rc3 to confirm that my
> > problem with backups was gone, and then give it more extended
> > testing to prove firefox downloads were ok, but 6 of 11 hunks
> > failed, the code has changed and I'm not familiar with it.
>
> However you are saying that the problem is there when you compile a
> kernel with this commit as the head, and it goes away when you compile a
> kernel with commit 3e9e0ca3f19e911ce13c2e6c9858fcb41a37496c as the head?
>
> I'm confused as to how a bug in that patch could depend on
> CONFIG_NFS_V4, but I'll see what I can find.

By the way, I thought your test-case was doing firefox downloads. Do
those really use O_DIRECT?

--
Trond Myklebust
Linux NFS client maintainer

NetApp
Trond.Myklebust@xxxxxxxxxx
www.netapp.com

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