Description of problem:
While running regression, quick-read-with-upcall.t script fails intermittently.

Please debug and fix the problem.

Version-Release number of selected component (if applicable):
master

How reproducible:
1/10

Steps to Reproduce:
1. Submit a patch and run regression.


Additional info:

Error is normally like below:

08:59:24 ok  11 [     10/      3] <  36> 'write_to /mnt/glusterfs/0/test.txt test-message1'
08:59:24 ok  12 [     10/      6] <  37> 'test-message1 cat /mnt/glusterfs/0/test.txt'
08:59:24 ok  13 [     10/      4] <  38> 'test-message0 cat /mnt/glusterfs/1/test.txt'
08:59:24 not ok  14 [   3715/      6] <  45> 'test-message1 cat /mnt/glusterfs/1/test.txt' -> 'Got "test-message0" instead of "test-message1"'
08:59:24 ok  15 [     10/    162] <  47> 'gluster --mode=script --wignore volume set patchy features.cache-invalidation on'
08:59:24 ok  16 [     10/    148] <  48> 'gluster --mode=script --wignore volume set patchy performance.qr-cache-timeout 15'