GlusterFS 3.3 does not enforce the quota correctly, fails before reaching the full quota value.

Issue

• Gluster 3.3 does not enforce the quota correctly and throws quota exceeded exception well below the limit

1) Assign a simple 100 MB directory quota

# gluster volume quota glster-home-kripav list
      path              limit_set          size
--------------------------------------------------------
/quota-test               100Mb               0Bytes

2) Run 'dd' in a for loop each creating a 10MB file :

-bash-4.1$ for i in $(seq 1 10); do dd if=/dev/zero of=test-${i}.iso count=10 bs=1024k; done
10+0 records in
10+0 records out
10485760 bytes (10 MB) copied, 0.257901 s, 40.7 MB/s
10+0 records in
10+0 records out
10485760 bytes (10 MB) copied, 0.212406 s, 49.4 MB/s
10+0 records in
10+0 records out
10485760 bytes (10 MB) copied, 0.214757 s, 48.8 MB/s
10+0 records in
10+0 records out
10485760 bytes (10 MB) copied, 0.199653 s, 52.5 MB/s
10+0 records in
10+0 records out
10485760 bytes (10 MB) copied, 0.194755 s, 53.8 MB/s
10+0 records in
10+0 records out
10485760 bytes (10 MB) copied, 0.209479 s, 50.1 MB/s
dd: closing output file 'test-7.iso': Input/output error
dd: opening 'test-8.iso': Disk quota exceeded
dd: opening 'test-9.iso': Disk quota exceeded

NOTE : The write process fails at 65MB even though the quota is 100MB.