Re: [PATCH] [RFC] fs: Possible filp_open race experiment

From	Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Newsgroups	linux.kernel
Subject	Re: [PATCH] [RFC] fs: Possible filp_open race experiment
Date	2017-01-31 14:20 +0100
Message-ID	<t5GvN-19j-49@gated-at.bofh.it> (permalink)
References	(1 earlier) <t5zuk-5gO-85@gated-at.bofh.it> <t5AJH-6bL-11@gated-at.bofh.it> <t5DHB-7V9-51@gated-at.bofh.it> <t5EaC-84y-33@gated-at.bofh.it> <t5Gcp-Nz-7@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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On Tue, Jan 31, 2017 at 01:58:14PM +0100, Christoph Hellwig wrote:
> On Tue, Jan 31, 2017 at 11:21:02AM +0100, Greg Kroah-Hartman wrote:
> > 
> > -next isn't Linus's tree, sometimes stuff sits in there for years :)
> > 
> > Anyway, if this is a configfs issue, Christoph and Joel can take a look
> > at it.  Any reason you didn't cc: Joel as well (the MAINTAINERS file is
> > your friend...)
> 
> It's really a mismatched assumption.  The configfs binary file
> code just chunks updates up into a buffer, which only gets flushed
> at ->release time.  If we'd move that to ->flush the issue Marek reports
> would be fixed.
> 
> But I don't think we want that - triggering a filp_open from the update
> of a _binary_ attribute for a start is wrong.  And second doing this
> using ->fs of a random calling process is bound to cause problems.
> 
> I think he is using the wrong kind of interface for the job.

Ah, that's why no one has seen this before :)

So, the DT overlay code needs to be fixed...

thanks,

greg k-h

Thread

Re: [PATCH] [RFC] fs: Possible filp_open race experiment Marek Vasut <marex@denx.de> - 2017-01-31 06:50 +0100
  Re: [PATCH] [RFC] fs: Possible filp_open race experiment Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-01-31 08:10 +0100
    Re: [PATCH] [RFC] fs: Possible filp_open race experiment Marek Vasut <marex@denx.de> - 2017-01-31 11:20 +0100
      Re: [PATCH] [RFC] fs: Possible filp_open race experiment Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-01-31 11:50 +0100
        Re: [PATCH] [RFC] fs: Possible filp_open race experiment Christoph Hellwig <hch@lst.de> - 2017-01-31 14:00 +0100
          Re: [PATCH] [RFC] fs: Possible filp_open race experiment Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-01-31 14:20 +0100
            Re: [PATCH] [RFC] fs: Possible filp_open race experiment Marek Vasut <marex@denx.de> - 2017-01-31 22:10 +0100

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