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Date:   Wed, 18 Apr 2018 09:38:45 -0400
From:   Steven Rostedt <rostedt@goodmis.org>
To:     Miklos Szeredi <miklos@szeredi.hu>
Cc:     Amir Goldstein <amir73il@gmail.com>,
        Miklos Szeredi <mszeredi@redhat.com>,
        overlayfs <linux-unionfs@vger.kernel.org>,
        linux-fsdevel <linux-fsdevel@vger.kernel.org>,
        linux-kernel <linux-kernel@vger.kernel.org>,
        Howard McLauchlan <hmclauchlan@fb.com>
Subject: Re: [RFC PATCH 31/35] Revert "vfs: add d_real_inode() helper"
Message-ID: <20180418093845.19ca33f3@gandalf.local.home>
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On Wed, 18 Apr 2018 13:42:03 +0200
Miklos Szeredi <miklos@szeredi.hu> wrote:

> On Wed, Apr 18, 2018 at 10:19 AM, Amir Goldstein <amir73il@gmail.com> wrote:
> > On Thu, Apr 12, 2018 at 6:08 PM, Miklos Szeredi <mszeredi@redhat.com> wrote:  
> >> This reverts commit a118084432d642eeccb961c7c8cc61525a941fcb.
> >>
> >> No user of d_real_inode() remains, so it can be removed.
> >>  
> >
> > FYI, there is a new user in v4.17-rc1 added by commit
> > f0a2aa5a2a40 tracing/uprobe: Add support for overlayfs
> >
> > Seems like this patch got merged without any CC to overlayfs
> > mailing list nor maintainer?

It appeared to be a small change with lots of reviewers. I didn't think
it was something to notify the overlayfs folks with. But perhaps I was
wrong.

> >
> > Not sure yet if overlayfs-rorw patches would allow reverting this
> > change.  
> 
> Not trivial, because uprobe is looking at i_mapping to get a list of
> current memory maps.   We could set i_mapping at overlay inode
> initialization time, but we definitely can't *change* i_mapping at
> copy up.  Which is bound to result in some weird inconsistencies.  So
> likely we'll need to keep d_real_inode() for the time being.

I just received this patch:

 http://lkml.kernel.org/r/20180418062907.3210386-1-songliubraving@fb.com

Which removes this code. Can you review it and I'll take it.

-- Steve