Re: Oops when accessing /dev/fd0 (kernel 2.4.7 and devfsd 1.3.11)

[Taylor Carpenter <taylorcc@codecafe.com>]

On Tue, Aug 21, 2001 at 11:07:06PM -0600, Richard Gooch wrote:
> Taylor Carpenter writes:
> > 
> Well, the following line suggests a devfs interaction (provided you
> are sure that you used the correct System.map:
> > Trace; c015469b <devfs_unregister_blkdev+12eb/1960>

I can check again, but I am fairly certain it was the correct System.map (I
looked before and after when running ksymoops).

> Are you unloading the floppy driver at some point? Or using module
> autoloading?

I am using module autoloading.  It seems that right after the mountall script
is called this happens.


> Interesting. What happens if you use /dev/floppy/0 instead of /dev/fd0
> in the /etc/fstab? Still an Oops?

I will try that...  

I did not get the oops, but I could not access the device until I manually
loaded the floppy module (the /dev/fd0 was created as usual).

After booting w/the floppy module not loaded I can start and stop devfsd and
load and unload the floppy module in any order w/o an oops. I only get the
oops if the module is loaded during boot.

Also when I get the oops during boot, the floppy module is not loaded once the
system is through booting and I login, but /dev/fd* are all there!  With out
the oops /dev/fd* is only there when I load the floppy module (and disappears
as usual when I rmmod the module).


> Strange. I tried the following sequence, without problems:
> # devfsd /dev
> # mount /floppy
> # ls -lF /dev/floppy

I could not mount the floppy until I manually loaded the floppy module!  This
is after editing /etc/fstab as you said below.

> 
> where /etc/fstab has:
> /dev/floppy/0  /floppy  ext2  defaults,noauto,user  0 0
> 
> I have nothing in my /etc/devfsd.conf which refers to the floppy.

I only reference floppy in my perms file.

> In addition, I don't have any LOOKUP entries. I did this with 2.4.9 with
> devfs-patch-v188.

I have many LOOKUP entries.  I did not have any specific to /dev/fd*, but that
was caught by the .* LOOKUP entry.  I commented that out, which is probably
why mdir and other commands do not work w/o manually loading floppy.o.

> Could you please try reproducing the problem with the setup and sequence I
> used?

I believe I followed your steps, and had no oops during boot w/the /etc/fstab
change.  I do not think that made the difference though.  I think telling
devfsd to not autoload floppy is what let me boot w/o oops.  So I think there
still is a problem w/loading the floppy module during boot.