From mboxrd@z Thu Jan  1 00:00:00 1970
From: Dave Hansen <dave@linux.vnet.ibm.com>
Subject: Re: [patch 00/13] vfs: add helpers to check r/o bind mounts
Date: Thu, 01 May 2008 09:40:18 -0700
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Cc: viro@zeniv.linux.org.uk, akpm@linux-foundation.org,
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To: Miklos Szeredi <miklos@szeredi.hu>
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On Thu, 2008-05-01 at 10:08 +0200, Miklos Szeredi wrote:
> Sorry for the claptrap.  I'm going to resubmit this one more time
> with some slight modifications and additions, and it'd be really nice
> if you or other interested parties would provide comments and opinions
> (either way), because I don't think me and Al have anything new to say
> to each other.

I was trying to stay out of it a bit, since you both have very good
points. :)

But, from a purely aesthetic point of view, I like the patches.  They do
make r/o mount detection less error-prone in coding.  They also remove
more code than they add.

I also certainly understand Al's point about why it puts vfsmounts in a
place where they probably shouldn't be exposed.

Is there a way we could pass around a vfs-internal object to these
things?  Maybe something that is like an opaque token only known to the
vfs?

linux/mount.h:

	struct hidden_mount;

fs/namespace.c:

struct hidden_mount {
	struct vfsmount *mnt;
};

int mnt_want_write(struct hidden_mount *hidmnt)
{
	return __mnt_want_write(hidmnt->mnt);
}

We could have *that* passed down the way that you're currently passing
the vfsmount.

-- Dave