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

[Rob Lahaye]

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.