🚀 go-pugleaf

In article <1092@sas.UUCP> toebes@sas.UUCP (John Toebes) writes:
>I hate to pop your bubble on this, but from the standpoint of writing an
>AmigaDos filing system (and experience to back it :-) softlinks are 
>*SIGNIFICANTLY* more difficult to implement than hardlinks.  With 
>softlinks, the file system needs to be able to communicate with other
>filing systems *ASYNCHRONOUSLY*.  This is an important point because
>of the problem where a file may be linked to another device which in 
>turn is a link back to a different place on the original device.  We
>haven't even started to scratch the surface of handling details such
>as links from filesystems to handlers which support a subset of packet
>types or even worse handling any newly defined packets.

	John is making an incorrect assumption here: that soft links will be
implemented by the filesystems.  What is planned is for the dos library to
implement them (note that this may have some gotchas for people using packet
interfaces right now, depending on how we implement it).

	There are two obvious ways to implement links: one with files with
a link bit set, the other using a couple of new packets to deal with
links and opening files.  Both will affect asych packet io people (if they
Lock/Open using asych - Read/Write/etc won't be affected); one requires
no modification to filesystems (and therefor can be used on OFS floppies,
over NFS, etc immediately), the other is a bit more robust in dealing 
with asynch IO and old dir/delete/etc programs.

	Comments?

>Look at how long it took Bill Hawes to get Pathman correct - there are
>many loopholes to be handled and some subtle interactions.

	One reason we don't plan on having a path-handler ala Bill's in 1.4.

-- 
Randell Jesup, Keeper of AmigaDos, Commodore Engineering.
{uunet|rutgers}!cbmvax!jesup, jesup@cbmvax.cbm.commodore.com  BIX: rjesup  
Common phrase heard at Amiga Devcon '89: "It's in there!"