Re: [PATCH] rpc.nfsd: mount up nfsdfs is it doesn't appear to be mounted yet (try #2)

[Neil Brown <neilb@suse.de>]

Hi,
 I was musing about this and thought I would share my musings - not to be
 taken too seriously unless they resonate with you.

 If rpc.nfsd is mounting /proc/fs/nfsd, should it also be starting rpc.statd,
 which should be running before nfsd is started?
 Should it 'exportfs -av' too?

 Should mount.nfs be mounting /var/lib/nfs/rpc_pipefs too?
 It already runs statd as requimred, which in-turn runs sm-notify, though it
 is really best to run that much earlier.

 How far do we really want to go with this "just do the right thing" approach?

 Should "rpc.nfsd" be a replacement for /etc/init.d/nfs-kernel-server or
 whatever your favourite distro calls it?  Or should it just be a tool for
 managing the nfsd threads?


 I could imagine that it would be OK to add a '-L' flag to say 'use legacy
 interface' and have rpc.nfsd fail noisily if nfsdfs wasn't mounted, and -L
 wasn't given.

 I could imagine that if protocol options were specified with -L, that would
 be an error.

 And if protocol options are specified which differ from what is currently
 in-force, and there are active threads, rpc.nfsd could:
    reduce the number of threads to 0
    change the protocol options
    restore the number of threads



 I think it is (long past) time to deprecate the legacy support in the kernel
 at least.  I suggest we add a printk to sys_nfsservctl to warn of pending
 deprecation, and probably add an entry to
 Documentation/feature-removal-schedule.txt.
 Aim for removing it all in 2.6.40 ?? and make it a CONFIG option before that.

 BTW, the 'new' cache has was added during 2.5 - definitely before Jan 2003.
 So the old stuff really is quite old now.

NeilBrown