[PATCH 2/3] fine tune the nvme-discover manpage

[Christoph Hellwig]

 - remove the device argument, which as far as I can tell does not
   exist.
 - mention the /etc/nvme/hostnqn file, the default host nqn and explain
   host nqns a bit more
 - mention the loopback transport
 - be a bit more specific about IP addressing as a concept separate from
   the RDMA transport
 - improve the introduction a bit.

Signed-off-by: Christoph Hellwig <hch at lst.de>
---
 Documentation/nvme-discover.txt | 37 ++++++++++++++++++++++---------------
 1 file changed, 22 insertions(+), 15 deletions(-)

diff --git a/Documentation/nvme-discover.txt b/Documentation/nvme-discover.txt
index 9140f84..96c21f6 100644
--- a/Documentation/nvme-discover.txt
+++ b/Documentation/nvme-discover.txt
@@ -3,12 +3,12 @@ nvme-discover(1)
 
 NAME
 ----
-nvme-discover - Send Get Log Page request to Discovery Controller.
+nvme-discover - Send Discovery requests to Fabrics Discovery Controllers.
 
 SYNOPSIS
 --------
 [verse]
-'nvme discover'	[device]
+'nvme discover'
 		[--transport=<trtype> | -t <trtype>]
 		[--traddr=<traddr>    | -a <traddr>]
 		[--trsvcid=<trsvcid>  | -s <trsvcid>]
@@ -17,17 +17,18 @@ SYNOPSIS
 
 DESCRIPTION
 -----------
-For a given NVMe Host, send a Discovery Get Log Page request
-to a Discovery Controller on the network.
-
-The [device] parameter is OPTIONAL and will default to
-/dev/nvme-fabrics if none is given.
+Send one or more Discovery requests to a NVMe over Fabrics Discovery
+Controller.
 
 If no parameters are given, then 'nvme discover' will attempt to 
-find a /etc/nvme/discovery.conf file to use to supply the
-the discover command options.  If no /etc/nvme/discovery.conf file
+find a /etc/nvme/discovery.conf file to use to supply a list of
+Discovery commands to run.  If no /etc/nvme/discovery.conf file
 exists, the command will quit with an error.
 
+Otherwise a specific Discovery Controller should be specified using the
+--transport, --traddr and if nessecary the --trsvcid and a Diѕcovery
+request will be sent to the specified Discovery Controller.
+
 BACKGROUND
 ----------
 The NVMe-over-Fabrics specification defines the concept of a 
@@ -61,23 +62,29 @@ OPTIONS
 |Value|Definition
 |rdma|The network fabric is an rdma network (RoCE, iWARP, Infiniband, basic rdma, etc)
 |fc  |*WIP* The network fabric is a Fibre Channel network.
+|loop|Connect to a NVMe over Fabrics target on the local host
 |=================
 
 -a <traddr>::
 --traddr=<traddr>::
 	This field specifies the network address of the Discovery Controller.
+	For transports using IP addressing (e.g. rdma) this should be an IPv4
+	address.
 
 -s <trsvcid>::
 --trsvcid=<trsvcid>::
-	This field specifies the transport service id.  For IP addresses,
-	this field is the port number. By default, the IP port number
-	is 4420.
+	This field specifies the transport service id.  For transports using IP
+	addressing (e.g. rdma) this field is the port number. By default, the IP
+	port number for the RDMA transport is 4420.
  
 -q <hostnqn>::
 --hostnqn=<hostnqn>::
-	This field is the unique NQN of a NVMe Host. This field
-	will be used by the Discovery Controller to check what NVMe
-	Target resources are allocated to the NVMe Host for a connection.
+	Overrides the default host NQN that identifies the NVMe Host.  If this
+	option is not specified the default is read from /etc/nvme/hostnqn or
+	autogenerated by the kernel (in that order).
+	The Host NQN uniquely identifies the NVMe Host, and may be used by the
+	the Discovery Controller to control what NVMe Target resources are
+	allocated to the NVMe Host for a connection.
 
 -r <filename>::
 --raw=<filename>::
-- 
2.10.1.382.ga23ca1b