inotify - new directory change notification and cifs

[Steve French]

Looks like inotify has finally been added to the Linux kernel (yesterday
it was merged to mainline).  Not sure how well this will map to the CIFS
protocol's NOTIFY facility.  Although inotify does not use a file
descriptor and in theory should scale better than the current
FCNTL(D_NOTIFY), it is not obvious to me yet whether Samba could use it
on the server side.

I have not figured out a way for network filesystem clients such as cifs
vfs to hook the client side of it yet either, nor whether it will
require more CIFS POSIX protocol extensions to be able to implement it
over the wire.  Seems like file/directory change notification mechanisms
would be most useful for network/cluster filesystem cases (remote
changes are harder to track for users than changes to the their own
system) but looks like we have some analysis to do to see whether this
facility would work with cifs/Samba much less with nfs.