gluster volume info <VOLNAME> should display all volume options, regardless of their value. 

The behavior of 'gluster volume info all' should not change.

Example of proposed behavior - 

Volume Name: localdata
Type: Distribute
Status: Started
Number of Bricks: 1
Transport-type: tcp
Bricks:
Brick1: 10.1.30.130:/glu-export
performance.cache-refresh-timeout     1sec
cluster.stripe-block-size             128KB
cluster.self-heal-window-size         16
network.frame-timeout                 1800
network.ping-timeout                  42
auth.allow                            *
auth.reject                           None 
performance.cache-size                32MB
performance.write-behind-window-size  1MB
diagnostics.latency-measurement       off
diagnostics.dump-fd-stats             off
diagnostics.brick-log-level           NONE
diagnostics.client-log-level          NONE
nfs.enable-ino32                      off

The natural complement to "gluster volume set" is "gluster volume get".

I propose that "gluster volume get" with no arguments should display all options and their values, and an indicator if the value is the default:

# gluster volume get <VOLNAME>
                                                                Current    Default
performance.cache-refresh-timeout     1sec          1sec
cluster.stripe-block-size             128KB                 128KB
cluster.self-heal-window-size         128                16
[...]

# gluster volume get <VOLNAME> performance.stat-prefetch
Option                                            Current        Default
performance.stat-prefetch             on               on

I concur. That's logical and conforms with the current best practice for cli syntax.

Closing as wontfix. File a new bug if this is required.

"volume set help" shows the defaults for options in master. This should help getting all the options.

(Sorry for the unsatisfactory comment while closing.)