[PATCH 2/4] RDMA/rtrs-clt: Inject a fault at request processing

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

From: Gioh Kim <gi-oh.kim@cloud.ionos.com>

If the fault-injection is enabled, it does not sent a request to the
server and returns error.

Signed-off-by: Gioh Kim <gi-oh.kim@cloud.ionos.com>
Signed-off-by: Jack Wang <jinpu.wang@cloud.ionos.com>
---
 drivers/infiniband/ulp/rtrs/rtrs-clt-sysfs.c | 44 ++++++++++++++++++++
 drivers/infiniband/ulp/rtrs/rtrs-clt.c       |  7 ++++
 drivers/infiniband/ulp/rtrs/rtrs-clt.h       | 13 ++++++
 3 files changed, 64 insertions(+)

diff --git a/drivers/infiniband/ulp/rtrs/rtrs-clt-sysfs.c b/drivers/infiniband/ulp/rtrs/rtrs-clt-sysfs.c
index eb92ec13cb57..c502dcbae9bb 100644
--- a/drivers/infiniband/ulp/rtrs/rtrs-clt-sysfs.c
+++ b/drivers/infiniband/ulp/rtrs/rtrs-clt-sysfs.c
@@ -479,3 +479,47 @@ void rtrs_clt_destroy_sysfs_root(struct rtrs_clt *clt)
 		kobject_put(clt->kobj_paths);
 	}
 }
+
+#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
+void rtrs_clt_fault_inject_init(struct rtrs_clt_fault_inject *fault_inject,
+				struct rtrs_clt_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-request", &fault_inject->fail_request);
+}
+
+void rtrs_clt_fault_inject_final(struct rtrs_clt_fault_inject *fault_inject)
+{
+	rtrs_fault_inject_final(&fault_inject->fj);
+}
+
+int rtrs_clt_should_fail_request(struct rtrs_clt_fault_inject *fault_inject)
+{
+	if (fault_inject->fail_request && should_fail(&fault_inject->fj.attr, 1))
+		return fault_inject->fj.status;
+	return 0;
+}
+#else
+void rtrs_clt_fault_inject_init(struct rtrs_clt_fault_inject *fault_inject,
+				struct rtrs_clt_sess *sess)
+{
+}
+void rtrs_clt_fault_inject_final(struct rtrs_clt_fault_inject *fault_inject)
+{
+}
+int rtrs_clt_should_fail_request(struct rtrs_clt_fault_inject *fault_inject)
+{
+	return 0;
+}
+#endif
diff --git a/drivers/infiniband/ulp/rtrs/rtrs-clt.c b/drivers/infiniband/ulp/rtrs/rtrs-clt.c
index 64990df81937..5062328ac577 100644
--- a/drivers/infiniband/ulp/rtrs/rtrs-clt.c
+++ b/drivers/infiniband/ulp/rtrs/rtrs-clt.c
@@ -1469,6 +1469,7 @@ static struct rtrs_clt_sess *alloc_sess(struct rtrs_clt *clt,
 
 void free_sess(struct rtrs_clt_sess *sess)
 {
+	rtrs_clt_fault_inject_final(&sess->fault_inject);
 	free_percpu(sess->mp_skip_entry);
 	mutex_destroy(&sess->init_mutex);
 	kfree(sess->s.con);
@@ -2686,6 +2687,8 @@ struct rtrs_clt *rtrs_clt_open(struct rtrs_clt_ops *ops,
 			free_sess(sess);
 			goto close_all_sess;
 		}
+
+		rtrs_clt_fault_inject_init(&sess->fault_inject, sess);
 	}
 	err = alloc_permits(clt);
 	if (err)
@@ -2858,6 +2861,10 @@ int rtrs_clt_request(int dir, struct rtrs_clt_req_ops *ops,
 		if (unlikely(READ_ONCE(sess->state) != RTRS_CLT_CONNECTED))
 			continue;
 
+		err = rtrs_clt_should_fail_request(&sess->fault_inject);
+		if (unlikely(err))
+			continue;
+
 		if (unlikely(usr_len + hdr_len > sess->max_hdr_size)) {
 			rtrs_wrn_rl(sess->clt,
 				     "%s request failed, user message size is %zu and header length %zu, but max size is %u\n",
diff --git a/drivers/infiniband/ulp/rtrs/rtrs-clt.h b/drivers/infiniband/ulp/rtrs/rtrs-clt.h
index 692bc83e1f09..59ea2ec44fe5 100644
--- a/drivers/infiniband/ulp/rtrs/rtrs-clt.h
+++ b/drivers/infiniband/ulp/rtrs/rtrs-clt.h
@@ -12,6 +12,7 @@
 
 #include <linux/device.h>
 #include "rtrs-pri.h"
+#include "rtrs-fault.h"
 
 /**
  * enum rtrs_clt_state - Client states.
@@ -122,6 +123,13 @@ struct rtrs_rbuf {
 	u32 rkey;
 };
 
+struct rtrs_clt_fault_inject {
+#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
+	struct rtrs_fault_inject fj;
+	bool fail_request;
+#endif
+};
+
 struct rtrs_clt_sess {
 	struct rtrs_sess	s;
 	struct rtrs_clt	*clt;
@@ -150,6 +158,7 @@ struct rtrs_clt_sess {
 	char                    hca_name[IB_DEVICE_NAME_MAX];
 	struct list_head __percpu
 				*mp_skip_entry;
+	struct rtrs_clt_fault_inject	fault_inject;
 };
 
 struct rtrs_clt {
@@ -250,4 +259,8 @@ int rtrs_clt_create_sess_files(struct rtrs_clt_sess *sess);
 void rtrs_clt_destroy_sess_files(struct rtrs_clt_sess *sess,
 				  const struct attribute *sysfs_self);
 
+void rtrs_clt_fault_inject_init(struct rtrs_clt_fault_inject *fault_inject,
+				struct rtrs_clt_sess *sess);
+void rtrs_clt_fault_inject_final(struct rtrs_clt_fault_inject *fault_inject);
+int rtrs_clt_should_fail_request(struct rtrs_clt_fault_inject *fault_inject);
 #endif /* RTRS_CLT_H */
-- 
2.25.1