Re: mount & umount read-only floppy: unmount failed: Input/output error ??

From: Rob Lahaye (lahaye_at_users.sourceforge.net)
Date: 06/30/03

  • Next message: Rob Lahaye: "Windows Mediaplayer equivalent for FreeBSD/Unix ?" 
    Date: Mon, 30 Jun 2003 19:24:06 +0900
To: Rob <listone@deathbeforedecaf.net>, freebsd-questions@freebsd.org

    Rob wrote:
    > That's strange - I get errors as soon as I try and do this, before the
    > filesystem is even available.
    >
    > Perhaps the updates from mounting the floppy aren't being written out to
    > the actual media until you try to unmount it - some kind of caching
    > issue?
    >
    > What happens if you try to touch a file on the (incorrectly) writeable
    > floppy?

    Are you also using FreeBSD 4.8?

    I have created the installation floppy from the kern.flp file.
    I then made this floppy readonly. I put that into my floppy drive
    and...

    # mount -t ufs /dev/fd0 /mnt
    # ls -lo /mnt
    total 1301
    drwxr-xr-x 2 root wheel - 512 Apr 3 20:06 boot
    -r-xr-xr-x 1 root wheel - 1324900 Apr 3 20:06 kernel.gz
    # touch /mnt/kernel.gz
    # ls -lo /mnt
    total 1301
    drwxr-xr-x 2 root wheel - 512 Apr 3 20:06 boot
    -r-xr-xr-x 1 root wheel - 1324900 Jun 30 19:17 kernel.gz
    # umount /mnt
    umount: unmount of /mnt failed: Input/output error
    #

    Notice that the time has changed due to the 'touch' of the file
    despite being readonly!!

    The very little I know about filesystems, I guess the 'touch' has
    been applied to the cache, not to the actual floppy.
    The umount forces a sync, which can't be done due to readonly.

    Something is fishy here, isn't it?

    Rob.

    _______________________________________________
    freebsd-questions@freebsd.org mailing list
    http://lists.freebsd.org/mailman/listinfo/freebsd-questions
    To unsubscribe, send any mail to "freebsd-questions-unsubscribe@freebsd.org"

  • Next message: Rob Lahaye: "Windows Mediaplayer equivalent for FreeBSD/Unix ?"

    Relevant Pages

    • Re: mount & umount read-only floppy: unmount failed: Input/output error ??
      ... Rob wrote: ... Have you tried to umount that floppy? ... Worth a bug report? ... Simply mount and the umount a read/only floppy. ...
      (freebsd-questions)
    • Re: Locking Down a Linux Box
      ... > routers/firewalls on a floppy. ... changes -- there would be no mount or modprobe program left by the ... > administration on this host anymore, but an attacker could ... > then leave the filesystem readonly. ...
      (Focus-Linux)
    • Re: how to reformat floppies that have data on them
      ... I've now got a floppy formatted with a low level format using the ... see if you can put an ext2 filesystem on one of the floppies. ... Warning: could not erase sector 2: Attempt to write block from filesystem ...
      (Fedora)
    • Re: how to reformat floppies that have data on them
      ... I've now got a floppy formatted with a low level format using the ... see if you can put an ext2 filesystem on one of the floppies. ... I looked in the BIOS of the other machine, and the only boot options are ...
      (Fedora)
    • Re: Locking Down a Linux Box
      ... Mine will be a firewall, ... There are several linux routers/firewalls on a floppy. ... It currently doesn't use (mount) any hard drive ... > The permissions on the filesystem are stripped to bare minimums, ...
      (Focus-Linux)