Re: CVS commit: src/sys/fs/union

[Alan Barrett <apb%cequrux.com@localhost>]

> > My vote would be to remove [unionfs]; it doesn't work and the 
> > only reason it was ever brought in had to do with alleged 
> > locking improvements.
>
> Is anyone using it?

I used to make heavy use of unionfs, and I had no problems.  (That 
was on a uniprocessor machine several years ago.)  I sometimes 
used five layers: a base set of sources; a unionfs layer for third 
party changes; a unionfs layer for my own changes; a unionfs layer 
for the "obj" directories; and a final unionfs layer for files 
created or changed at build time.  For example, I could easily 
blow away all the build products but keep the obj directories, 
by unmounting the top layer unionfs, removing the files in its 
backing store, and then re-mounting it.

Today, I'd use a smarter revision control system instead of the 
unionfs layers to manage the source files, but I might still want 
a unionfs layer to isolate changes made at build time.

I have not used unionfs in the past few years, but it would be a 
pity to lose this functionality.

--apb (Alan Barrett)