2988 nfssrv: need ability to go to submounts for v3 and v2 protocols
Portions contributed by: Marcel Telka <marcel.telka@nexenta.com>
Portions contributed by: Jean McCormack <jean.mccormack@nexenta.com>
Reviewed by: Yuri Pankov <yuri.pankov@nexenta.com>
Reviewed by: Alek Pinchuk <alek.pinchuk@nexenta.com>
Reviewed by: Dan Fields <dan.fields@nexenta.com>
Reviewed by: Dan McDonald <danmcd@joyent.com>
Change-Id: I6fdf110cc17e789353c4442b83a46cb80643456e

*** 170,179 ****
--- 170,198 ----
  is specified, the default values associated with the global tag in
  .Pa /etc/nfs/nfslog.conf
  are used.
  Support of NFS server logging is only available for NFS Version 2 and
  Version 3 requests.
+ .It Sy nohide
+ By default, if server exports two filesystems, one of which is mounted as a
+ child of the other, NFS Version 2 and Version 3 clients must mount both
+ filesystems explicitly in order to access them.
+ If a client only mounts the parent, it will see an empty directory at the
+ location where the other filesystem is mounted.
+ .Pp
+ Setting the
+ .Sy nohide
+ option on a filesystem causes it to no longer be hidden in this manner, and the
+ client will be able to move from the parent filesystem to this one without
+ noticing the change.
+ However, some NFS clients or applications may not function correctly when
+ this option is used.
+ In particular, files on different underlying filesystems may appear to have
+ the same inode numbers.
+ The
+ .Sy nohide
+ option only applies to NFS Version 2 and Version 3 requests.
  .It Sy noaclfab
  By default, the NFS server will fabricate POSIX-draft style ACLs in response
  to ACL requests from NFS Version 2 or Version 3 clients accessing shared
  file systems that do not support POSIX-draft ACLs (such as ZFS).
  Specifying
*** 784,788 ****
--- 803,818 ----
  use of
  .Pa /export/foo
  does not work as it does with NFS Version 2 and Version 3 and the client
  receives an error when attempting to mount
  .Pa /export/foo .
+ .Pp
+ The
+ .Sy nohide
+ option violates RFC 1094,
+ .%T "Network File System Protocol Specification"
+ and RFC 1813,
+ .%T "NFS: Network File System Version 3 Protocol Specification"
+ .Pp
+ The
+ .Sy nohide
+ option is provided for compatibility with Linux NFS.