[PATCH 1/4] RDMA/rtrs: Enable the fault-injection

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

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

This patch introduces some functions to enable the fault-injection
for RTRS.
* rtrs_fault_inject_init/final initialize the fault-injection
and create a debugfs directory.
* rtrs_fault_inject_add creates a debugfs entry to enable
the fault-injection point.

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/Makefile     |  2 +
 drivers/infiniband/ulp/rtrs/rtrs-fault.c | 52 ++++++++++++++++++++++++
 drivers/infiniband/ulp/rtrs/rtrs-fault.h | 28 +++++++++++++
 3 files changed, 82 insertions(+)
 create mode 100644 drivers/infiniband/ulp/rtrs/rtrs-fault.c
 create mode 100644 drivers/infiniband/ulp/rtrs/rtrs-fault.h

diff --git a/drivers/infiniband/ulp/rtrs/Makefile b/drivers/infiniband/ulp/rtrs/Makefile
index 3898509be270..3490f66bb7f2 100644
--- a/drivers/infiniband/ulp/rtrs/Makefile
+++ b/drivers/infiniband/ulp/rtrs/Makefile
@@ -3,10 +3,12 @@
 rtrs-client-y := rtrs-clt.o \
 		  rtrs-clt-stats.o \
 		  rtrs-clt-sysfs.o
+rtrs-client-$(CONFIG_FAULT_INJECTION_DEBUG_FS) += rtrs-fault.o
 
 rtrs-server-y := rtrs-srv.o \
 		  rtrs-srv-stats.o \
 		  rtrs-srv-sysfs.o
+rtrs-server-$(CONFIG_FAULT_INJECTION_DEBUG_FS) += rtrs-fault.o
 
 rtrs-core-y := rtrs.o
 
diff --git a/drivers/infiniband/ulp/rtrs/rtrs-fault.c b/drivers/infiniband/ulp/rtrs/rtrs-fault.c
new file mode 100644
index 000000000000..af475c814c29
--- /dev/null
+++ b/drivers/infiniband/ulp/rtrs/rtrs-fault.c
@@ -0,0 +1,52 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * RDMA Transport Layer
+ *
+ * Copyright (c) 2014 - 2018 ProfitBricks GmbH. All rights reserved.
+ * Copyright (c) 2018 - 2019 1&1 IONOS Cloud GmbH. All rights reserved.
+ * Copyright (c) 2019 - 2020 1&1 IONOS SE. All rights reserved.
+ */
+
+#include "rtrs-fault.h"
+
+static DECLARE_FAULT_ATTR(fail_default_attr);
+
+void rtrs_fault_inject_init(struct rtrs_fault_inject *fj,
+			    const char *dir_name,
+			    u32 err_status)
+{
+	struct dentry *dir, *parent;
+	struct fault_attr *attr = &fj->attr;
+
+	/* create debugfs directory and attribute */
+	parent = debugfs_create_dir(dir_name, NULL);
+	if (!parent) {
+		pr_warn("%s: failed to create debugfs directory\n", dir_name);
+		return;
+	}
+
+	*attr = fail_default_attr;
+	dir = fault_create_debugfs_attr("fault_inject", parent, attr);
+	if (IS_ERR(dir)) {
+		pr_warn("%s: failed to create debugfs attr\n", dir_name);
+		debugfs_remove_recursive(parent);
+		return;
+	}
+	fj->parent = parent;
+	fj->dir = dir;
+
+	/* create debugfs for status code */
+	fj->status = err_status;
+	debugfs_create_u32("status", 0600, dir,	&fj->status);
+}
+
+void rtrs_fault_inject_final(struct rtrs_fault_inject *fj)
+{
+	/* remove debugfs directories */
+	debugfs_remove_recursive(fj->parent);
+}
+
+void rtrs_fault_inject_add(struct dentry *dir, const char *fname, bool *value)
+{
+	debugfs_create_bool(fname, 0600, dir, value);
+}
diff --git a/drivers/infiniband/ulp/rtrs/rtrs-fault.h b/drivers/infiniband/ulp/rtrs/rtrs-fault.h
new file mode 100644
index 000000000000..8c1acffb2b16
--- /dev/null
+++ b/drivers/infiniband/ulp/rtrs/rtrs-fault.h
@@ -0,0 +1,28 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * RDMA Transport Layer
+ *
+ * Copyright (c) 2014 - 2018 ProfitBricks GmbH. All rights reserved.
+ * Copyright (c) 2018 - 2019 1&1 IONOS Cloud GmbH. All rights reserved.
+ * Copyright (c) 2019 - 2020 1&1 IONOS SE. All rights reserved.
+ */
+
+#ifndef RTRS_FAULT_H
+#define RTRS_FAULT_H
+
+#include <linux/fault-inject.h>
+
+struct rtrs_fault_inject {
+#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
+	struct fault_attr attr;
+	struct dentry *parent;
+	struct dentry *dir;
+	u32 status;
+#endif
+};
+
+void rtrs_fault_inject_init(struct rtrs_fault_inject *fj,
+			    const char *dev_name, u32 err_status);
+void rtrs_fault_inject_add(struct dentry *dir, const char *fname, bool *value);
+void rtrs_fault_inject_final(struct rtrs_fault_inject *fj);
+#endif /* RTRS_FAULT_H */
-- 
2.25.1