NFSD: Update help text for CONFIG_NFSD

Clean up: refresh the help text for Kconfig items related to the NFS
server.  Remove obsolete URLs, and make the language consistent among
the options.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

fs/Kconfig

@@ -1702,56 +1702,74 @@ config NFSD
 	select PROC_FS if NFSD_V4
 	select PROC_FS if SUNRPC_GSS
 	help
-	  If you want your Linux box to act as an NFS *server*, so that other
-	  computers on your local network which support NFS can access certain
-	  directories on your box transparently, you have two options: you can
-	  use the self-contained user space program nfsd, in which case you
-	  should say N here, or you can say Y and use the kernel based NFS
-	  server. The advantage of the kernel based solution is that it is
-	  faster.
+	  Choose Y here if you want to allow other computers to access
+	  files residing on this system using Sun's Network File System
+	  protocol.  To compile the NFS server support as a module,
+	  choose M here: the module will be called nfsd.
 
-	  In either case, you will need support software; the respective
-	  locations are given in the file <file:Documentation/Changes> in the
-	  NFS section.
+	  You may choose to use a user-space NFS server instead, in which
+	  case you can choose N here.
 
-	  If you say Y here, you will get support for version 2 of the NFS
-	  protocol (NFSv2). If you also want NFSv3, say Y to the next question
-	  as well.
+	  To export local file systems using NFS, you also need to install
+	  user space programs which can be found in the Linux nfs-utils
+	  package, available from http://linux-nfs.org/.  More detail about
+	  the Linux NFS server implementation is available via the
+	  exports(5) man page.
 
-	  Please read the NFS-HOWTO, available from
-	  <http://www.tldp.org/docs.html#howto>.
+	  Below you can choose which versions of the NFS protocol are
+	  available to clients mounting the NFS server on this system.
+	  Support for NFS version 2 (RFC 1094) is always available when
+	  CONFIG_NFSD is selected.
 
-	  To compile the NFS server support as a module, choose M here: the
-	  module will be called nfsd.  If unsure, say N.
+	  If unsure, say N.
 
 config NFSD_V2_ACL
 	bool
 	depends on NFSD
 
 config NFSD_V3
-	bool "Provide NFSv3 server support"
+	bool "NFS server support for NFS version 3"
 	depends on NFSD
 	help
-	  If you would like to include the NFSv3 server as well as the NFSv2
-	  server, say Y here.  If unsure, say Y.
+	  This option enables support in your system's NFS server for
+	  version 3 of the NFS protocol (RFC 1813).
+
+	  If unsure, say Y.
 
 config NFSD_V3_ACL
-	bool "Provide server support for the NFSv3 ACL protocol extension"
+	bool "NFS server support for the NFSv3 ACL protocol extension"
 	depends on NFSD_V3
 	help
-	  Implement the NFSv3 ACL protocol extension for manipulating POSIX
-	  Access Control Lists on exported file systems. NFS clients should
-	  be compiled with the NFSv3 ACL protocol extension; see the
-	  CONFIG_NFS_V3_ACL option.  If unsure, say N.
+	  Solaris NFS servers support an auxiliary NFSv3 ACL protocol that
+	  never became an official part of the NFS version 3 protocol.
+	  This protocol extension allows applications on NFS clients to
+	  manipulate POSIX Access Control Lists on files residing on NFS
+	  servers.  NFS servers enforce POSIX ACLs on local files whether
+	  this protocol is available or not.
+
+	  This option enables support in your system's NFS server for the
+	  NFSv3 ACL protocol extension allowing NFS clients to manipulate
+	  POSIX ACLs on files exported by your system's NFS server.  NFS
+	  clients which support the Solaris NFSv3 ACL protocol can then
+	  access and modify ACLs on your NFS server.
+
+	  To store ACLs on your NFS server, you also need to enable ACL-
+	  related CONFIG options for your local file systems of choice.
+
+	  If unsure, say N.
 
 config NFSD_V4
-	bool "Provide NFSv4 server support (EXPERIMENTAL)"
+	bool "NFS server support for NFS version 4 (EXPERIMENTAL)"
 	depends on NFSD && NFSD_V3 && EXPERIMENTAL
 	select RPCSEC_GSS_KRB5
 	help
-	  If you would like to include the NFSv4 server as well as the NFSv2
-	  and NFSv3 servers, say Y here.  This feature is experimental, and
-	  should only be used if you are interested in helping to test NFSv4.
+	  This option enables support in your system's NFS server for
+	  version 4 of the NFS protocol (RFC 3530).
+
+	  To export files using NFSv4, you need to install additional user
+	  space programs which can be found in the Linux nfs-utils package,
+	  available from http://linux-nfs.org/.
+
 	  If unsure, say N.
 
 config ROOT_NFS