Unmounting a busy NFS share reports success

[Andrew Parker]

Has anybody noticed that unmounting a busy NFS share:

1.  Reports success (the first time you try)
2.  Leaves the mount point mounted (as expected)
3.  Removes the entry from /etc/mtab (and hence from df)
4.  Entry is still listed in /proc/fs/nfsfs/* (as expected)
5.  Reports an error the second time you try to umount it (i.e. what
you'd expect the first time round)

I've only tried this on one host, so I don't know if its isolated to
my hardware (although I'd be interested in hearing how this could be
hardware related).

Its been happening since at least 7.91.

https://bugzilla.redhat.com/show_bug.cgi?id=312241