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Date:   Tue, 3 Sep 2019 08:39:30 -0700
From:   Christoph Hellwig <hch@infradead.org>
To:     Al Viro <viro@zeniv.linux.org.uk>
Cc:     Christoph Hellwig <hch@infradead.org>, Qian Cai <cai@lca.pw>,
        linux-fsdevel@vger.kernel.org, LKML <linux-kernel@vger.kernel.org>,
        Linus Torvalds <torvalds@linux-foundation.org>
Subject: Re: "fs/namei.c: keep track of nd->root refcount status" causes boot
 panic
Message-ID: <20190903153930.GA2791@infradead.org>
References: <7C6CCE98-1E22-433C-BF70-A3CBCDED4635@lca.pw>
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 <20190903130456.GA9567@infradead.org>
 <20190903134832.GH1131@ZenIV.linux.org.uk>
 <20190903135024.GA8274@infradead.org>
 <20190903135354.GI1131@ZenIV.linux.org.uk>
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On Tue, Sep 03, 2019 at 02:53:54PM +0100, Al Viro wrote:
> On Tue, Sep 03, 2019 at 06:50:24AM -0700, Christoph Hellwig wrote:
> > On Tue, Sep 03, 2019 at 02:48:32PM +0100, Al Viro wrote:
> > > Not sure what would be the best way to do it...  I don't mind breaking
> > > the out-of-tree modules, whatever their license is; what I would rather
> > > avoid is _quiet_ breaking of such.
> > 
> > Any out of tree module running against an upstream kernel will need
> > a recompile for a new version anyway.  So I would not worry about it
> > at all.
> 
> There's much nastier situation than "new upstream kernel released,
> need to rebuild" - it's bisect in mainline trying to locate something...

I really don't get the point.  And it's not like we've card about
this anywhere else.  And jumping wildly around with the numeric values
for constants will lead to bugs like the one you added and fixed again
and again.