sunrpc: display xprt's queuelen of assigned tasks via sysfs

Once a task grabs a trasnport it's reflected in the queuelen of
the rpc_xprt structure. Add display of that value in the xprt's
info file in sysfs.
Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

net/sunrpc/sysfs.c

@@ -113,13 +113,15 @@ static ssize_t rpc_sysfs_xprt_info_show(struct kobject *kobj,
 	ret = sprintf(buf, "last_used=%lu\ncur_cong=%lu\ncong_win=%lu\n"
 		       "max_num_slots=%u\nmin_num_slots=%u\nnum_reqs=%u\n"
 		       "binding_q_len=%u\nsending_q_len=%u\npending_q_len=%u\n"
-		       "backlog_q_len=%u\nmain_xprt=%d\nsrc_port=%u\n",
+		       "backlog_q_len=%u\nmain_xprt=%d\nsrc_port=%u\n"
+		       "tasks_queuelen=%ld\n",
 		       xprt->last_used, xprt->cong, xprt->cwnd, xprt->max_reqs,
 		       xprt->min_reqs, xprt->num_reqs, xprt->binding.qlen,
 		       xprt->sending.qlen, xprt->pending.qlen,
 		       xprt->backlog.qlen, xprt->main,
 		       (xprt->xprt_class->ident == XPRT_TRANSPORT_TCP) ?
-		       get_srcport(xprt) : 0);
+		       get_srcport(xprt) : 0,
+		       atomic_long_read(&xprt->queuelen));
 	xprt_put(xprt);
 	return ret + 1;
 }