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Date: Tue, 11 Sep 2012 18:39:08 +0200
From: Maarten Lankhorst <maarten.lankhorst@canonical.com>
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To: al viro <viro@zeniv.linux.org.uk>
CC: linux-fsdevel@vger.kernel.org, LKML <linux-kernel@vger.kernel.org>
Subject: [regression] __d_unalias() should refuse to move mountpoints
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Hey Al,

Your vfs commit ee3efa91e240f513898050ef305a49a653c8ed90 caused my laptop
with a nfs root filesystem to stop working.

My testcase is simply booting through netboot with / and ~/nfs as separate
nfs filesystems, then doing 'ls ~/nfs' followed by 'ls ~' in a gnome-terminal
window, then I get:

ls: cannot access nfs: Device or resource busy

Similar things seem to happen with ls /, /dev /proc and /sys will no longer work.

Reverting this patch seems to make things work again.

~Maarten