[PATCH 3/4] RDMA/rtrs-srv: Inject a fault at heart-beat sending

[Gioh Kim <gi-oh.kim@xxxxxxxxx>]

From: Gioh Kim <gi-oh.kim@xxxxxxxxxxxxxxx>

If the fault-injection is enabled, it does not send a heart-beat
and generates the error on the client side.

Signed-off-by: Gioh Kim <gi-oh.kim@xxxxxxxxxxxxxxx>
Signed-off-by: Jack Wang <jinpu.wang@xxxxxxxxxxxxxxx>
---
 drivers/infiniband/ulp/rtrs/rtrs-srv-sysfs.c | 44 ++++++++++++++++++++
 drivers/infiniband/ulp/rtrs/rtrs-srv.c       |  5 +++
 drivers/infiniband/ulp/rtrs/rtrs-srv.h       | 13 ++++++
 3 files changed, 62 insertions(+)

diff --git a/drivers/infiniband/ulp/rtrs/rtrs-srv-sysfs.c b/drivers/infiniband/ulp/rtrs/rtrs-srv-sysfs.c
index a9288175fbb5..57af9e7c3588 100644
--- a/drivers/infiniband/ulp/rtrs/rtrs-srv-sysfs.c
+++ b/drivers/infiniband/ulp/rtrs/rtrs-srv-sysfs.c
@@ -309,3 +309,47 @@ void rtrs_srv_destroy_sess_files(struct rtrs_srv_sess *sess)
 		rtrs_srv_destroy_once_sysfs_root_folders(sess);
 	}
 }
+
+#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
+void rtrs_srv_fault_inject_init(struct rtrs_srv_fault_inject *fault_inject,
+				struct rtrs_srv_sess *sess)
+{
+	char str[NAME_MAX];
+	int cnt;
+
+	cnt = sockaddr_to_str((struct sockaddr *)&sess->s.src_addr,
+			      str, sizeof(str));
+	cnt += scnprintf(str + cnt, sizeof(str) - cnt, "@");
+	sockaddr_to_str((struct sockaddr *)&sess->s.dst_addr,
+			str + cnt, sizeof(str) - cnt);
+
+	rtrs_fault_inject_init(&fault_inject->fj, str, -EBUSY);
+	/* injection points */
+	rtrs_fault_inject_add(fault_inject->fj.dir,
+			      "fail-hb-ack", &fault_inject->fail_hb_ack);
+}
+
+void rtrs_srv_fault_inject_final(struct rtrs_srv_fault_inject *fault_inject)
+{
+	rtrs_fault_inject_final(&fault_inject->fj);
+}
+
+int rtrs_should_fail_hb_ack(struct rtrs_srv_fault_inject *fault_inject)
+{
+	if (fault_inject->fail_hb_ack && should_fail(&fault_inject->fj.attr, 1))
+		return fault_inject->fj.status;
+	return 0;
+}
+#else
+void rtrs_srv_fault_inject_init(struct rtrs_srv_fault_inject *fault_inject,
+				struct rtrs_srv_sess *sess_name)
+{
+}
+void rtrs_srv_fault_inject_final(struct rtrs_srv_fault_inject *fault_inject)
+{
+}
+int rtrs_should_fail_hb_ack(struct rtrs_srv_fault_inject *fault_inject)
+{
+	return 0;
+}
+#endif
diff --git a/drivers/infiniband/ulp/rtrs/rtrs-srv.c b/drivers/infiniband/ulp/rtrs/rtrs-srv.c
index 5e9bb7bf5ef3..6e53dac0d22c 100644
--- a/drivers/infiniband/ulp/rtrs/rtrs-srv.c
+++ b/drivers/infiniband/ulp/rtrs/rtrs-srv.c
@@ -1232,6 +1232,8 @@ static void rtrs_srv_rdma_done(struct ib_cq *cq, struct ib_wc *wc)
 			}
 		} else if (imm_type == RTRS_HB_MSG_IMM) {
 			WARN_ON(con->c.cid);
+			if (unlikely(rtrs_should_fail_hb_ack(&sess->fault_inject)))
+				break;
 			rtrs_send_hb_ack(&sess->s);
 		} else if (imm_type == RTRS_HB_ACK_IMM) {
 			WARN_ON(con->c.cid);
@@ -1489,6 +1491,7 @@ static void rtrs_srv_close_work(struct work_struct *work)
 
 	sess = container_of(work, typeof(*sess), close_work);
 
+	rtrs_srv_fault_inject_final(&sess->fault_inject);
 	rtrs_srv_destroy_sess_files(sess);
 	rtrs_srv_stop_hb(sess);
 
@@ -1748,6 +1751,8 @@ static struct rtrs_srv_sess *__alloc_sess(struct rtrs_srv *srv,
 
 	__add_path_to_srv(srv, sess);
 
+	rtrs_srv_fault_inject_init(&sess->fault_inject, sess);
+
 	return sess;
 
 err_unmap_bufs:
diff --git a/drivers/infiniband/ulp/rtrs/rtrs-srv.h b/drivers/infiniband/ulp/rtrs/rtrs-srv.h
index 9543ae19996c..001889e148ac 100644
--- a/drivers/infiniband/ulp/rtrs/rtrs-srv.h
+++ b/drivers/infiniband/ulp/rtrs/rtrs-srv.h
@@ -13,6 +13,7 @@
 #include <linux/device.h>
 #include <linux/refcount.h>
 #include "rtrs-pri.h"
+#include "rtrs-fault.h"
 
 /*
  * enum rtrs_srv_state - Server states.
@@ -73,6 +74,13 @@ struct rtrs_srv_mr {
 	struct rtrs_iu	*iu;		/* send buffer for new rkey msg */
 };
 
+struct rtrs_srv_fault_inject {
+#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
+	struct rtrs_fault_inject fj;
+	bool fail_hb_ack;
+#endif
+};
+
 struct rtrs_srv_sess {
 	struct rtrs_sess	s;
 	struct rtrs_srv	*srv;
@@ -90,6 +98,7 @@ struct rtrs_srv_sess {
 	unsigned int		mem_bits;
 	struct kobject		kobj;
 	struct rtrs_srv_stats	*stats;
+	struct rtrs_srv_fault_inject	fault_inject;
 };
 
 struct rtrs_srv {
@@ -152,4 +161,8 @@ ssize_t rtrs_srv_reset_all_help(struct rtrs_srv_stats *stats,
 int rtrs_srv_create_sess_files(struct rtrs_srv_sess *sess);
 void rtrs_srv_destroy_sess_files(struct rtrs_srv_sess *sess);
 
+void rtrs_srv_fault_inject_init(struct rtrs_srv_fault_inject *fault_inject,
+				struct rtrs_srv_sess *sess);
+void rtrs_srv_fault_inject_final(struct rtrs_srv_fault_inject *fault_inject);
+int rtrs_should_fail_hb_ack(struct rtrs_srv_fault_inject *fault_inject);
 #endif /* RTRS_SRV_H */
-- 
2.25.1