[lug] Mount process in uninterruptible sleep

[Chris Riddoch]

Hi, everyone.

This should be simple, for somebody...

I used 'dd' to copy a vfat-formatted floppy to a file, disk.img.  Then
I made a 'mnt' directory in the current directory.  And then:

socket at magrathea:~/old-disks$ sudo mount -t vfat -o ro,loop disk.img mnt/

It hung.  It was about 2:00 AM last night when this happened, and
decided there wouldn't be any harm in leaving it until later to fix.
Too tired to think.

And now, I've just discovered that terminal under a pile of others...

socket at magrathea:~$ ps 10105
  PID TTY      STAT   TIME COMMAND
10105 pts/2    D      0:00 mount -t vfat -o ro,loop disk.img mnt/
socket at magrathea:~$

This mount process is unkillable - even by root, even by -9.  I'm
tempted to just try to kill its parent terminal, but I'm wary of
potentially leaving a random mount process lying about.  That 'D' in
the stat column, according to the manpage, means it's blocked in
uninterruptible sleep (usually waiting for IO) Well, it's been waiting
an awfully long time on a highly responsive hard drive, so I suspect
it's not IO.

What's going on, anyway?

--
Chris Riddoch         |  epistemological  | Send spam to: uce at ftc.gov
socket at peakpeak.com   |  humility         |