Re: [Jfs-discussion] JFS as root FS update

[Ian R. J. <ia...@ch...>]

On Thu, 24 May 2001, Dave Kleikamp wrote:

> Ian,
> I don't know if this had anything to do with your devfs problem, but I did
> find a problem with symlinks.  Sometimes they were not being null-terminated.
> I ripped out too much code when I fixed a bug that the null-terminator was
> being counted in i_size.  Here is a patch.  This won't fix existing symlinks
> that are bad, but any newly created ones should be okay.

Your fix was right on the money, but the real problem was that devfsd
wasn't starting.

Given my kernel parameters (devfs notation) and /etc/fstab's reference
(traditional notation), it could not properly find the root filesystem.

There is a reference in /etc/rcS.d which starts it was--guess what--a
(fubared) symlink to the appropriate /etc/init.d script.

I discovered that when I decided to investigate things a bit further.
There was a symlink named /etc/rcS.d/S01devfsd, which is supposed to point
to ../init.d/devfsd.  Instead, it looked like this:

ianj@meiling:/root$ cat devfsd-link-fubar
lrwxrwxrwx    1 root     root           16 May 24  2001 S01devfsd ->
../init.d/devfsdC) || defined(CONFIG_ALPHA_GAMMA)
#undef GAMMA_BIAS
#define GAMMA_BIAS _GAMMA_BIAS
struct alpha_machine_vector sable_gamma_mv __initmv = {
        vector_name:            "Sable-Gamma",
        DO_EV5_MMU,
        DO_DEFAULT_RTC,
        DO_T2_IO,
        DO_T2_BUS,
        machine_check:          t

No amount of relinking would help with the unpatched kernel.

However, after I applied your patch and booted my normal system with that
kernel, I mounted my test JFS root filesystem to re-establish the symlink,
then unmounted, then remounted the filesystem, then verified the symlink.
The link remained as it should per what you had said.

Then I used that same patched kernel and used the test JFS root filesystem
as the real root filesystem, using the same method as I'd mentioned above
(devfs notation on the kernel command line to specify root, then legacy
notation in /etc/fstab).  System fired up devfsd, found the root
filesystem, and came up just fine.

Basically, the problem wasn't related to devfs(d) at all, but both DID
point to a symptom, which was indeed symlink-related.

Now, the only "problem" with JFS as the root filesystem is that it drops
to asking for the root password for maintenance or a CTRL-D to resume a
"normal startup" when I go to reboot or halt the system from the command
line.  Minor, but this much better than before.

--Ian.

-----
Ian R. Justman 	         Postmaster, System Administrator, ChocoboNet
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