Coda File System

the purpose of RealmId?

From: <>
Date: Tue, 5 Aug 2014 13:20:45 +0200
Hello Jan,

One of the most valuable features of Coda is its global file name space.
Coda was one of the first file systems to implement this, OpenAFS
followed the suit a bit later (I think DCE/DFS was first but it was
not opensource).

Big kudos to you Jan who implemented globality (in the form of realms).

Now I am studying the data structures being used in the corresponding code
and your guidance would be invaluable.

My impression is that the RealmId item (being passed around as a reference
to a realm and also for building inode numbers in dir_DirEntry2VDirent()
in coda-src/dir/dirbody.c) could be replaced by a direct use of the
pointer to the realm object.

The pointer seems to have a persistent unique value during Venus cache
life time, as well as the RealmId (unless I misunderstand the usage
of RVM).

It seems in other words to have the same scope of validity as RealmId
and could be possibly used directly, skipping the lookup associated
with the mapping from RealmId to the realm object.

I appreciate if you would explain the rationale behind relying to this
additional identifier.

Received on 2014-08-05 07:27:24