Description of problem:
================================
Bitd crashed on tier volume

Version-Release number of selected component (if applicable):
=======================================
glusterfs-server-3.7.0beta2-0.0.el6.x86_64


How reproducible:


Steps to Reproduce:
========================
1.Create EC(4+2) volume and enable bitrot and do some IO
2.After some time attach tier and do IO and after some time bitd crashed
3.

Actual results:


Expected results:
=================
Bitd should not crashed


Additional info:

(gdb) bt
#0  x86_64_fallback_frame_state (context=0x7f2140df8a10, fs=0x7f2140df8890) at ../../../gcc/config/i386/linux-unwind.h:47
#1  uw_frame_state_for (context=0x7f2140df8a10, fs=0x7f2140df8890) at ../../../gcc/unwind-dw2.c:1210
#2  0x0000003ec3010119 in _Unwind_Backtrace (trace=0x3ebc4fe8d0 <backtrace_helper>, trace_argument=0x7f2140df8b50) at ../../../gcc/unwind.inc:290
#3  0x0000003ebc4fea66 in __backtrace (array=<value optimized out>, size=200) at ../sysdeps/ia64/backtrace.c:110
#4  0x0000003d78424b96 in _gf_msg_backtrace_nomem (level=<value optimized out>, stacksize=200) at logging.c:1097
#5  0x0000003d784435af in gf_print_trace (signum=11, ctx=0xcd6010) at common-utils.c:618
#6  <signal handler called>
#7  0x0000000100004b92 in ?? ()
#8  0x00007f2148df8caa in gf_changelog_reborp_rpcsvc_notify (rpc=<value optimized out>, mydata=0x7f2128001850, event=<value optimized out>, data=<value optimized out>)
    at gf-changelog-reborp.c:169
#9  0x0000003d78808535 in rpcsvc_handle_disconnect (svc=0x7f2128002c40, trans=0x7f21440d1700) at rpcsvc.c:754
#10 0x0000003d7880a090 in rpcsvc_notify (trans=0x7f21440d1700, mydata=<value optimized out>, event=<value optimized out>, data=0x7f21440d1700) at rpcsvc.c:792
#11 0x0000003d7880b8e8 in rpc_transport_notify (this=<value optimized out>, event=<value optimized out>, data=<value optimized out>) at rpc-transport.c:543
#12 0x00007f214a07c6a1 in socket_event_poll_err (fd=<value optimized out>, idx=<value optimized out>, data=0x7f21440d1700, poll_in=<value optimized out>, poll_out=0, poll_err=16)
    at socket.c:1205
#13 socket_event_handler (fd=<value optimized out>, idx=<value optimized out>, data=0x7f21440d1700, poll_in=<value optimized out>, poll_out=0, poll_err=16) at socket.c:2410
#14 0x0000003d78480f80 in event_dispatch_epoll_handler (data=0x7f21440175b0) at event-epoll.c:572
#15 event_dispatch_epoll_worker (data=0x7f21440175b0) at event-epoll.c:674
#16 0x0000003ebc8079d1 in start_thread (arg=0x7f2140dfa700) at pthread_create.c:301
#17 0x0000003ebc4e89dd in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:115