Bug 983015

Description of problem:
========================
While trying to add a brick with an existing brick name , we are getting Staging failed error instead of the message :
Brick: <Brick_name> not available. Brick may be containing or be contained by an existing brick

Version-Release number of selected component (if applicable):
================================================================ 
3.4.0.12rhs.beta3-1.el6rhs.x86_64


How reproducible

Steps to Reproduce:
===================
1.Create a distributed volume with 2 bricks 
gluster volume create vol9 10.70.34.85:/rhs/brick1/K1 10.70.34.105:/rhs/brick1/K2
volume create: vol9: success: please start the volume to access data


gluster v i vol9
 
Volume Name: vol9
Type: Distribute
Volume ID: 5f38ad2a-da5a-4e2c-8d10-1fc87e740973
Status: Started
Number of Bricks: 2
Transport-type: tcp
Bricks:
Brick1: 10.70.34.85:/rhs/brick1/K1
Brick2: 10.70.34.105:/rhs/brick1/K2


2.Add brick with the same existing brick name 
gluster volume add-brick vol9 10.70.34.85:/rhs/brick1/K1
volume add-brick: failed: Staging failed on 10.70.34.85. Please check the log file for more details.

---------------Part of the Log---------------------

3.[2013-07-10 09:43:23.897720] E [glusterd-utils.c:5161:glusterd_new_brick_validate] 0-management: Brick: 10.70.34.85:/rhs/brick1/K1 not available. Brick may be containing or be contained by an existing brick
[2013-07-10 09:43:23.897754] E [glusterd-op-sm.c:3558:glusterd_op_ac_stage_op] 0-management: Stage failed on operation 'Volume Add brick', Status : -1
[2013-07-10 09:43:34.302425] W [socket.c:522:__socket_rwv] 0-management: readv on /var/run/561c8f40d5032ac71c0003fa660ede5c.socket failed (No data available)
---------------------------------------------------

Actual results:
=============== 
User gets a message that Staging has failed while trying to add a brick with an existing brick name


Expected results:
================
User should get a meaningful message that the brick is already contained by an existing brick 


Additional info: