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From: "J. R. Okajima" <hooanon05@yahoo.co.jp>
Subject: Re: [RFC PATCH] Show data flow for file copyup in unions
To: Valerie Aurora <vaurora@redhat.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>,
       Miklos Szeredi <miklos@szeredi.hu>,
       Dmitry Monakhov <dmonakhov@openvz.org>,
       Jeff Layton <jlayton@redhat.com>, Christoph Hellwig <hch@infradead.org>,
       linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
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Date: Fri, 19 Mar 2010 04:18:44 +0900
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Valerie Aurora:
> Hm, I don't understand how handing it off to another thread would
> help.  The thing I am worried about is some internal assumption in the
> file system that a directory without write permission can't be
> changed.  Totally manufactured example:
>
> somefs_create()
> {
> 	BUG_ON(IS_RDONLY(dir->d_inode);
> [...]
> }

While I don't know whether there suce fs exists or not, for such fs we
cannot create files. I agree with you.


J. R. Okajima