[Linux-cachefs] Distribution package changes to allow 'fsc' support

[Eli Stair]

I'm working towards getting fscache support working for (testing on) all 
NFS mountpoints and hardware at my facility, and the next step in the 
process is to allow the automounter (autofs4) to mount on-demand with 
the proper flags and support.  In tracking through the source for autofs 
and util-linux, it became apparent there is no need to touch those 
packages:  if it __is present__* util-linux's 'mount' binary will use 
'/sbin/mount.nfs' for NFS mounts, even taking precedence over its 
compiled-in NFS support*.  Since 'automount' makes a direct exec() call 
to the /bin/mount binary, this chain of dependencies makes it 
exceedingly simple (hindsight is 20/20) to enable full system-wide 
FScache support for NFS mounts.

So, in short, to enable standard system cmdline and automounter support 
of FSCache:

  - copy the mount.nfs binary to /sbin/mount.nfs from patched util-linux
  - modify automount command line to append 'fsc' as a local mount flag
  - do the normal ext3, fscache.ko, cachefiles.ko, and cachefilesd setup


This may be known to some, but it was opaque enough to me that I'd like 
to mention this since it makes deployment much simpler than any other 
method I just went through to accomplish this ;)  If this is correct 
enough (or could use clarification), I think this would do well in the 
various wiki pages for CacheFS and will add if that sounds good.

NOTE: some (*) of these statements appear to be configure options for 
these packages, and may not work on all distros exactly.

Cheers,

/eli