[Bug 31968] umounting cd fails, hangs system

[Kris Loimaala]

Public bug reported:
https://launchpad.net/malone/bugs/31968

Affects: linux-meta linux-amd64-k8 (Ubuntu)
       Severity: Normal
       Priority: (none set)
         Status: Unconfirmed

Description:
Going through some old cd-r's the third one can't be unmounted. Reports
/dev/hdc is not mounted. When mounting /dev/hdc to /media/cdrom0 process
hangs. ps -e shows multiple mount -processes and a mount-hald process.
They cannot be killed (ie. no warnings but remain in process list).


Sys.log and kern.log says it's a bug in kernel:

localhost kernel [  391.092629] Kernel BUG at "mm/filemap.c":459