[OpenAFS] RO v. RW path not behaving on setup

[Derrick J Brashear]

On Sat, 28 Jun 2003, Steven N. Hirsch wrote:

> > > At this juncture, 'fs examine' should be showing the *.readonly volumes on
> > > /afs and /afs/my_cell respectively.  Unfortunately, this does not happen.
> > > I continue to see the rw volumes on both mount points - even after doing
> > > fs checkvol.
> >
> > No it shouldn't. You mounted root.afs, not root.afs.readonly. You get
> > root.afs.
>
> On p. 2-71 of the Transarc manual:
>
> ".. Verify that both volumes are now released.  First issue fs
> checkvolumes to force the Cache Manager to notice that you have released
> ReadOnly versions of the volumes, then issue fs examine again. This time
> the output should mention root.afs.readonly and root.cell.readonly instead
> of the ReadWrite versions, since the Cache Manager has a built-in bias to
> access the ReadOnly version of root.afs if it exists."
>
> This is not how it works.  I continue to see the root.afs and root.cell
> volumes until after an oops, shutdown and reboot cycle, at which point the
> *.readonly volumes show up on those mount points!

For the Linux client, at least, what you see is as far as I know how it's
always been.

> > > everything _seems_ to look right!  Both /afs and /afs/my_cell show up as
> > > being the *.readonly variants.  But, now I am unable to get proper RO/RW
> > > pathing behavior.
> >
> > I've seen this bug but it went away when I switched to a newer kernel;
> > What are you running?
>
> 2.4.21-pre2, which ran stable and flawlessly for months before I
> accidently nuked the /vicepa partition.  Never had a shutdown problem.

Well, it only happens when you mount a RW root.afs and then replicate it,
or at least that was the only time I could make it happen.

> > That sounds like how it's supposed to work. /afs/my_cell is RO, you make
> > an RO, you get an RO. You want writes, you do into /afs/.my_cell, or you
> > donm't replicate the volume.
>
> Color me confused, then.  Previously, as a user I never needed to go into
> the /afs/.my_cell explicitly to create/write a file.  Assuming that I have
> the correct permissions, I would simply go to /afs/my_cell/blah, blah and
> write.  Per the documentation, I assumed the cache manager was silently
> accessing the rw volume in such cases.

Sure. *Your directory* isn't replicated, so the right thing happens.

> I thought the entire point of replication was to always read from an RO
> volume, but force writes down the RW path?  Perhaps I'm either
> misunderstanding you or am completely lost...

I think you're missing something.