Al,
After thinking about it, I got it. a code fix is in that remembers the
last position passed from readdir(). 2.3.99Pre4++++ is on tonight's
fare.
Thanks,
Jeff
"Jeff V. Merkey" wrote:
>
> Alexander Viro wrote:
> >
> > On Thu, 30 Mar 2000, Jeff V. Merkey wrote:
> >
> > > [.... However, I suspect that something like an address of entry might
> > > be good enough. ...]
> > >
> > > Al,
> > >
> > > Please explain how I should implement this with an address of entry --
> > > I'll get right on it. :-)
> >
> > OK, do you have _anything_ that would (a) stay constant and (b) would be
> > easy for search? The underlying assumption in getdents() is that offsets
> > stay constant - just as with the contents of file. I'm too lazy to look
> > into the POSIX, but I suspect that it is in standards.
> >
> > Let's do it that way: could you describe the structure of your
> > directories? Then I would probably be able to help with that.
>
> Structure
> ---------
>
> The directory is comprised of several components, all of which stay
> around in memory:
>
> 1. Dir Block Hash (for rapid indexing of directory file offsets
> 128-byte aligned).
> 2. Name Hashes (1 per namespace per volume);
> 3. Parent Hash (this looks at lot like the dcache -- this is probably
> where we should do what you suggest. Each parent hash has a hash chain
> head that is persisent, but several directories might share it since it
> hashes 4096 - 1 hash buckets. This is where I derive the child-parent
> relatioships.
> 4. Dir Number hash (hash of all dir entries by positinal number IN THE
> DIRECTOY FILE ITSELF).
> Dir numbers are persistent but not always sequential).
>
> I don't keep trees around. Each directory has an in-memory hash record
> that also has links to the dir record number in the directory file and
> trustees, quotas, namespace links, etc. I am storing the hash address
> for each entry in the inode->generic_ip pointer.
>
> Jeff
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