From mboxrd@z Thu Jan  1 00:00:00 1970
From: Al Viro <viro@ftp.linux.org.uk>
Subject: Re: Move across mount,sb
Date: Thu, 15 Mar 2007 01:46:55 +0000
Message-ID: <20070315014655.GO4095@ftp.linux.org.uk>
References: <Pine.LNX.4.61.0703150211500.1199@yvahk01.tjqt.qr>
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Cc: linux-fsdevel@vger.kernel.org
To: Jan Engelhardt <jengelh@linux01.gwdg.de>
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On Thu, Mar 15, 2007 at 02:20:25AM +0100, Jan Engelhardt wrote:
> Why is EXDEV returned when _vfs mountpoints_ are crossed? Should not it 
> be more like the following?
> 
> 	error = -EXDEV;
> 	if (oldnd.mnt->mnt_sb != newnd.mnt->mnt_sb)
> 		goto exit2;
> 

	No.  This is absolutely deliberate - mountpoint creates a boundary and
such boundaries are very useful for restricting modifications of filesystem.
IOW, it's not a bug and it applies to other operations as well (link(), for
example).