Description of problem:
======================= 
Calculating are-equal checksum while add brick or rebalance is in progress shows the wrong count of files 

Version-Release number of selected component (if applicable):
=============================================================
glusterfs 3.4.0.35rhs


How reproducible:
================ 
faced the issue twice till now  

Steps to Reproduce:
==================
1.Create a distributed volume and mount it 

2.Create files on the mount point
for i in {1..500} ; do dd if=/dev/urandom of=$i bs=10M count=1; done

3. After file creation is complete , calculate are equal checksum and simultaneously perform add brick 

[root@dhcp-0-180 vol1]# /opt/qa/tools/arequal-checksum /mnt/vol1/

Entry counts
Regular files   : 531
Directories     : 1
Symbolic links  : 0
Other           : 0
Total           : 532

Metadata checksums
Regular files   : 486e85
Directories     : 24d74c
Symbolic links  : 3e9
Other           : 3e9

Checksums
Regular files   : d86485c837e47820527cefaba6ba3f78
Directories     : 301f04
Symbolic links  : 0
Other           : 0
Total           : 8a186a63916e585c

files created were 500 , but arequal shows 531 files 

However, after add brick is completed , arequal shows the right count of files 

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The same behavior is seen while calculating arequal while rebalance is in progress. 


1. Create a distribute replicate volume 

2. fuse mount the volume and create 500 files 
for i in {1..500} ; do dd if=/dev/urandom of=z"$i" bs=10M count=1; done

3. Add brick and start rebalance , while rebalance is in progress , calculate arequal check sum on mount point


[root@dhcp-0-180 vol2]# /opt/qa/tools/arequal-checksum /mnt/vol2/

Entry counts
Regular files   : 729
Directories     : 1
Symbolic links  : 0
Other           : 0
Total           : 730

Metadata checksums
Regular files   : 486e85
Directories     : 24d74c
Symbolic links  : 3e9
Other           : 3e9

Checksums
Regular files   : a11326d2eea663a94c91da22c01a9fd1
Directories     : 30312a00
Symbolic links  : 0
Other           : 0
Total           : ed82fcf01e8dd678


Files created were 500 , arequal output shows 729 files 

However, after rebalance is completed , arequal shows the right count of files :

[root@dhcp-0-180 vol2]# /opt/qa/tools/arequal-checksum /mnt/vol2/

Entry counts
Regular files   : 500
Directories     : 1
Symbolic links  : 0
Other           : 0
Total           : 501

Metadata checksums
Regular files   : 3e9
Directories     : 24d74c
Symbolic links  : 3e9
Other           : 3e9

Checksums
Regular files   : 9f9422325890ec45d2500a16276042bd
Directories     : 30312a00
Symbolic links  : 0
Other           : 0
Total           : 4dc428244fc184f8


Actual results:
===============
arequal shows wrong count of files while add-brick or rebalance is in progress .

Expected results:
=================
arequal should not show the wrong count of files while add-brick or rebalance is in progress .


Additional info: