While running 3.1.0qa12, 2 server with 3 clients running iozone - one server crashed .

core file - 

#0  0x00002aaaad567cfa in afr_nonblocking_inodelk (frame=0x2aaaac5381d0, this=0x638118) at afr-lk-common.c:1388
	int_lock = (afr_internal_lock_t *) 0x649320
	local = (afr_local_t *) 0x649268
	priv = (afr_private_t *) 0x63ef98
	fd_ctx = (afr_fd_ctx_t *) 0x643e58
	call_count = 1
	ctx = 6569560
	i = 1
	ret = 0
	flock = {l_type = 1, l_whence = 16720, l_start = 1048576, l_len = 131072, l_pid = 36}
	__FUNCTION__ = "afr_nonblocking_inodelk"
#1  0x00002aaaad54959f in afr_lock_rec (frame=0x2aaaac5381d0, this=0x638118) at afr-transaction.c:1038
	int_lock = (afr_internal_lock_t *) 0x649320
	local = (afr_local_t *) 0x649268
	__PRETTY_FUNCTION__ = "afr_lock_rec"
#2  0x00002aaaad54965e in afr_lock (frame=0x2aaaac5381d0, this=0x638118) at afr-transaction.c:1074
No locals.
#3  0x00002aaaad549944 in afr_transaction (frame=0x2aaaac5381d0, this=0x638118, type=AFR_DATA_TRANSACTION) at afr-transaction.c:1180
	local = (afr_local_t *) 0x649268
	priv = (afr_private_t *) 0x63ef98
#4  0x00002aaaad53cfc3 in afr_do_writev (frame=0x2aaaac337d38, this=0x638118) at afr-inode-write.c:246
	transaction_frame = (call_frame_t *) 0x2aaaac5381d0
	local = (afr_local_t *) 0x649268
	op_ret = -1
	op_errno = 0
	__FUNCTION__ = "afr_do_writev"
#5  0x00002aaaad53d765 in afr_writev (frame=0x2aaaac337d38, this=0x638118, fd=0x2aaab08ea198, vector=0x2aaab40016a8, count=1, offset=1048576, iobref=0x2aaab40016e8)
    at afr-inode-write.c:316
	priv = (afr_private_t *) 0x63ef98
	local = (afr_local_t *) 0x649268
	ret = 0
	op_ret = -1
	op_errno = 0
	ctx = 6569560
	fd_ctx = (afr_fd_ctx_t *) 0x643e58
	__FUNCTION__ = "afr_writev"
#6  0x00002aaaad790400 in iot_writev_wrapper (frame=0x2aaaac3373b8, this=0x639328, fd=0x2aaab08ea198, vector=0x2aaab40016a8, count=1, offset=1048576, 
---Type <return> to continue, or q <return> to quit--- 
    iobref=0x2aaab40016e8) at io-threads.c:955
	_new = (call_frame_t *) 0x2aaaac337d38
	old_THIS = (xlator_t *) 0x639328
	tmp_cbk = (fop_writev_cbk_t) 0x2aaaad790078 <iot_writev_cbk>
	__FUNCTION__ = "iot_writev_wrapper"
#7  0x00002aaaaacf893d in call_resume_wind (stub=0x2aaaac75b360) at call-stub.c:2235
	__FUNCTION__ = "call_resume_wind"
#8  0x00002aaaaacfee2e in call_resume (stub=0x2aaaac75b360) at call-stub.c:3861
	old_THIS = (xlator_t *) 0x639328
	__FUNCTION__ = "call_resume"
#9  0x00002aaaad78ad8e in iot_worker (data=0x63e1d8) at io-threads.c:118
	conf = (iot_conf_t *) 0x63e1d8
	this = (xlator_t *) 0x639328
	stub = (call_stub_t *) 0x2aaaac75b360
	sleep_till = {tv_sec = 1283269828, tv_nsec = 0}
	ret = 0
	timeout = 0 '\0'
	bye = 0 '\0'
	__FUNCTION__ = "iot_worker"
#10 0x00002aaaab568407 in start_thread () from /lib64/libpthread.so.0
No locals.
#11 0x00002aaaab851b0d in clone () from /lib64/libc.so.6
	fstab_state = {fs_fp = 0x0, fs_buffer = 0x0, fs_mntres = {mnt_fsname = 0x0, mnt_dir = 0x0, mnt_type = 0x0, mnt_opts = 0x0, mnt_freq = 0, mnt_passno = 0}, 
  fs_ret = {fs_spec = 0x0, fs_file = 0x0, fs_vfstype = 0x0, fs_mntops = 0x0, fs_type = 0x0, fs_freq = 0, fs_passno = 0}}
	__elf_set___libc_subfreeres_element_fstab_free__ = (const void *) 0x2aaaab888eb0