[OpenAFS-devel] Re: Breaking callbacks on unlink

[Troy Benjegerdes]

If I ever feel sufficiently motivated, then I suppose I can create a special
".trash" volume, which basically holds all the orphaned vnodes until 'vos
backup' is run, at which time they can be moved into the backup volume.

It seems like no new RPCs are needed at all, just keep the callback alive, and
maybe some hooks for a client process disconnected operation manager to pull
all files for open FD's into cache.

(I'm also thinking a short doc page summarizing our discussion here would be
usefull)

Now.. to throw another wrench in the works... does this make read/write
replication more or less complicated?



On Mon, Feb 27, 2012 at 02:50:04PM -0500, Matt W. Benjamin wrote:
> Hi,
> 
> Thanks, I think that clarifies.
> 
> Matt
> 
> ----- "Andrew Deason" <adeason@sinenomine.net> wrote:
> 
> > On Mon, 27 Feb 2012 14:13:09 -0500 (EST)
> > "Matt W. Benjamin" <matt@linuxbox.com> wrote:
> > 
> > > Ok, thanks for clarifying.  With this model, are the intended
> > > semantics of unlink/rm that the "operation succeeds, but the object
> > is
> > > still there and will be seen by the next ordinary
> > > lookup/stat/readdir?"
> > 
> > No, the parent dir is modified so the entry doesn't exist in the dir
> > (and you still get a callback break on the dir). The vnode just
> > exists
> > on disk, not referenced by any dir in the volume. So the only way you
> > can keep it "alive" from an application-level point of view is by
> > keeping an fd open, which is what we wanted.
> > 
> > > (I should say, I did hear Troy's suggestion of a wholly different
> > sort
> > > of use case involving mutating the backup volume, I'm staying
> > entirely
> > > out of that...)
> > 
> > Well, I don't think this is entirely different. You do the same
> > thing,
> > but you have some button you can press that says "gimme back the
> > to-be-deleted vnodes". While I can imagine that existing, I have a
> > hard
> > time justfying the effort to create it.
> > 
> > And you can do this anyway without extra development by with just a
> > 'pkill -9 fileserver' and then salvaging with '-orphans attach'. 
> > 
> > -- 
> > Andrew Deason
> > adeason@sinenomine.net
> > 
> > _______________________________________________
> > OpenAFS-devel mailing list
> > OpenAFS-devel@openafs.org
> > https://lists.openafs.org/mailman/listinfo/openafs-devel
> 
> -- 
> Matt Benjamin
> The Linux Box
> 206 South Fifth Ave. Suite 150
> Ann Arbor, MI  48104
> 
> http://linuxbox.com
> 
> tel. 734-761-4689
> fax. 734-769-8938
> cel. 734-216-5309
> _______________________________________________
> OpenAFS-devel mailing list
> OpenAFS-devel@openafs.org
> https://lists.openafs.org/mailman/listinfo/openafs-devel

-- 
----------------------------------------------------------------------------
Troy Benjegerdes                 'da hozer'                hozer@hozed.org  
7 elements Farm						TerraCarbo biofuels

If you're going through hell, keep going. ~ Winston Churchill

The challenge in changing the world is not in having great ideas, it's in
having stupid simple ideas, as those are the ones that cause change.