Improve man page for AmazonEFS mounts.

PR#250770 was actually just a misunderstanding of what
NFS mount options are needed for AmazonEFS mounts.
This patch attempts to clarify the manpage to clarify this.

This is a content change.

PR:		250770
Reviewed by:	bcr
MFC after:	1 week
Differential Revision:	https://reviews.freebsd.org/D27430

1 files changed, 11 insertions, 2 deletions

diff --git a/sbin/mount_nfs/mount_nfs.8 b/sbin/mount_nfs/mount_nfs.8
index 1f1d4bdad7a8..44490d6945fe 100644
--- a/sbin/mount_nfs/mount_nfs.8
+++ b/sbin/mount_nfs/mount_nfs.8
@@ -28,7 +28,7 @@
 .\"	@(#)mount_nfs.8	8.3 (Berkeley) 3/29/95
 .\" $FreeBSD$
 .\"
-.Dd November 20, 2020
+.Dd November 30, 2020
 .Dt MOUNT_NFS 8
 .Os
 .Sh NAME
@@ -217,9 +217,18 @@ Make a minor version 1 or 2 of the NFS Version 4 protocol mount use a single
 OpenOwner for all Opens.
 This may be useful for a server with a very low limit on OpenOwners, such as
 AmazonEFS.
-It ca only be used with an NFSv4.1 or NFSv4.2 mount.
+This option cannot be used for an NFS Version 4, minor version 0 mount.
+As such, this option requires the
+.Cm minorversion
+option be specified with a value of 1 for AmazonEFS, because AmazonEFS does
+not support minor version 2 at this time.
 It may not work correctly when Delegations are being issued by a server,
 but note that the AmazonEFS server does not issued delegations at this time.
+This option is only meaningful when used with the
+.Cm nfsv4
+and
+.Cm minorversion
+options.
 .It Cm pnfs
 Enable support for parallel NFS (pNFS) for minor version 1 or 2 of the
 NFS Version 4 protocol.