mount.nfs mapage: clear up confusion between 'proto' and 'transport'

The mount option "proto=" actually set the "transport" which in
netconfig usage is the pairing of a protocol (e.g. UDP, TCP) with
a protocol family (e.g. INET, INET6).

This can cause confusion if people naively except "proto=udp" to work
equally well on IPv6.

So add some text to both nfs(5) and nfsmount.conf(5) to hopefully
clarify this.

Acked-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Steve Dickson <steved@redhat.com>

1 files changed, 25 insertions, 40 deletions

diff --git a/utils/mount/nfs.man b/utils/mount/nfs.man
index da6d6d3..c15de98 100644
--- a/utils/mount/nfs.man
+++ b/utils/mount/nfs.man
@@ -1,5 +1,5 @@
 .\"@(#)nfs.5"
-.TH NFS 5 "2 November 2007"
+.TH NFS 5 "9 October 2012"
 .SH NAME
 nfs \- fstab format and options for the
 .B nfs
@@ -472,24 +472,15 @@ Use these options, along with the options in the above subsection,
 for NFS versions 2 and 3 only.
 .TP 1.5i
 .BI proto= netid
-The transport protocol name and protocol family the NFS client uses
-to transmit requests to the NFS server for this mount point.
-If an NFS server has both an IPv4 and an IPv6 address, using a specific
-netid will force the use of IPv4 or IPv6 networking to communicate
-with that server.
-.IP
-If support for TI-RPC is built into the
-.B mount.nfs
-command,
-.I netid
-is a valid netid listed in
-.IR /etc/netconfig .
-The value "rdma" may also be specified.
-If the
-.B mount.nfs
-command does not have TI-RPC support, then
+The
 .I netid
-is one of "tcp," "udp," or "rdma," and only IPv4 may be used.
+determines the transport that is used to communicate with the NFS
+server.  Available options are
+.BR udp ", " udp6 ", "tcp ", " tcp6 ", and " rdma .
+Those which end in
+.B 6
+use IPv6 addresses and are only available if support for TI-RPC is
+built in. Others use IPv4 addresses.
 .IP
 Each transport protocol uses different default
 .B retrans
@@ -569,19 +560,18 @@ This option can be used when mounting an NFS server
 through a firewall that blocks the rpcbind protocol.
 .TP 1.5i
 .BI mountproto= netid
-The transport protocol name and protocol family the NFS client uses
+The transport the NFS client uses
 to transmit requests to the NFS server's mountd service when performing
 this mount request, and when later unmounting this mount point.
 .IP
-If support for TI-RPC is built into the
+.I netid
+may be one of
+.BR udp ", and " tcp
+which use IPv4 address or, if TI-RPC is built into the
 .B mount.nfs
 command,
-.I netid
-is a valid netid listed in
-.IR /etc/netconfig .
-Otherwise,
-.I netid
-is one of "tcp" or "udp," and only IPv4 may be used.
+.BR udp6 ", and " tcp6
+which use IPv6 addresses.
 .IP
 This option can be used when mounting an NFS server
 through a firewall that blocks a particular transport.
@@ -773,21 +763,14 @@ Use these options, along with the options in the first subsection above,
 for NFS version 4 and newer.
 .TP 1.5i
 .BI proto= netid
-The transport protocol name and protocol family the NFS client uses
-to transmit requests to the NFS server for this mount point.
-If an NFS server has both an IPv4 and an IPv6 address, using a specific
-netid will force the use of IPv4 or IPv6 networking to communicate
-with that server.
-.IP
-If support for TI-RPC is built into the
-.B mount.nfs
-command,
-.I netid
-is a valid netid listed in
-.IR /etc/netconfig .
-Otherwise,
+The
 .I netid
-is one of "tcp" or "udp," and only IPv4 may be used.
+determines the transport that is used to communicate with the NFS
+server.  Supported options are
+.BR tcp ", " tcp6 ", and " rdma .
+.B tcp6
+use IPv6 addresses and is only available if support for TI-RPC is
+built in. Both others use IPv4 addresses.
 .IP
 All NFS version 4 servers are required to support TCP,
 so if this mount option is not specified, the NFS version 4 client
@@ -851,6 +834,8 @@ The DATA AND METADATA COHERENCE section discusses
 the behavior of this option in more detail.
 .TP 1.5i
 .BI clientaddr= n.n.n.n
+.TP 1.5i
+.BI clientaddr= n:n: ... :n
 Specifies a single IPv4 address (in dotted-quad form),
 or a non-link-local IPv6 address,
 that the NFS client advertises to allow servers