Union file system is killed when shutting down (SQUASHFS errors)

[Michael Terry]

Binary package hint: casper

I was debugging a shutdown issue on a system where there was a ntfs recovery partition on the disk. That is, a casper system and a ubiquity install on, say, /dev/sda1.

One thing I noticed is that I was getting all sorts of crazy SQUASHFS errors on shutdown, appearing shortly after Ubuntu turned swap off.

However, I believe it was because /etc/rc6.d/S20sendsigs was killing the aufsd processes (as well as mount.ntfs). The following trivial patch fixed it for me. It may not be the ideal fix, but it's a start.

diff -Nru casper-1.236/scripts/casper casper-1.236test1/scripts/casper
--- casper-1.236/scripts/casper 2010-04-12 23:36:20.000000000 +0100
+++ casper-1.236test1/scripts/casper 2010-07-01 02:01:23.000000000 +0100
@@ -487,6 +487,10 @@
         fi
         break
     done
+
+ # Protect the union and any possible ntfs backing from shutdown
+ pgrep ${UNIONFS} >> /var/run/sendsigs.omit
+ pgrep mount.ntfs >> /var/run/sendsigs.omit
 }

 check_dev ()

[Stéphane Graber (stgraber)]

Marking as Invalid because aufsd and overlayfsd are kernel threads and as such aren't killable so don't need to be explicitly protected.
As for the ntfs mount, the standard shutdown sequence should be syncing and unmounting all filesystems, I don't see why we should be special casing this one.