Bug 147254

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Description of problem:
If you create any filesystems that are mounted below a directory other
than the root directory, Fedora will barf on shutdown. For example,
if I create and mount filesystems "/hello" and "/hello/world",
shutdown gives a message like this:

------------------------------------
umount2: Device or resource busy
umount: /hello: device is busy
umount2: Device or resource busy
umount: /hello: device is busy
------------------------------------


Version-Release number of selected component (if applicable):
initscripts-7.93.5-1

How reproducible:
Always

Steps to Reproduce:
1. mount a filesystem as "/hello".
2. mount a filesystem as "/hello/world".
3. run, "shutdown -h now".
4. watch the console.
    

Actual Results:  
------------------------------------
umount2: Device or resource busy
umount: /hello: device is busy
umount2: Device or resource busy
umount: /hello: device is busy
------------------------------------

There is then a delay until the machine forcibly reboots. As such,
this bug is causing an unnecessary performance problem.

Expected Results:  I would expect no output and no errors from the
umount commands.

Additional info:

The problem appears to lie in "/etc/init.d/halt" line 201:

------------------------------------
# Try all file systems other than root and RAM disks, one last time.
mount |  awk '!/( \/ |^\/dev\/root|^\/dev\/ram| \/proc )/ { print $3 }'
| \
  while read line; do
    umount -f $line
done
------------------------------------
This code is incorrect since it does not reverse the order of the
mounts as returned by the "mount" command. As such, if I have these
two filesystems mounted:

/hello
/hello/world

The code will fail to unmount "/hello" (since "/hello/world" is still
mounted), but will succeed in unmounting "/hello/world".

The fix is to reverse sort the output:

------------------------------------
# Try all file systems other than root and RAM disks, one last time.
mount |  awk '!/( \/ |^\/dev\/root|^\/dev\/ram| \/proc )/ { print $3 }'
| sort -r \
  while read line; do
    umount -f $line
done
------------------------------------