1// SPDX-License-Identifier: GPL-2.0
2/*
3 * fault injection support for nvme.
4 *
5 * Copyright (c) 2018, Oracle and/or its affiliates
6 */
7
8#include <linux/moduleparam.h>
9#include "nvme.h"
10
11static DECLARE_FAULT_ATTR(fail_default_attr);
12/* optional fault injection attributes boot time option:
13 * nvme_core.fail_request=<interval>,<probability>,<space>,<times>
14 */
15static char *fail_request;
16module_param(fail_request, charp, 0000);
17
18void nvme_fault_inject_init(struct nvme_fault_inject *fault_inj,
19			    const char *dev_name)
20{
21	struct dentry *dir, *parent;
22	struct fault_attr *attr = &fault_inj->attr;
23
24	/* set default fault injection attribute */
25	if (fail_request)
26		setup_fault_attr(&fail_default_attr, fail_request);
27
28	/* create debugfs directory and attribute */
29	parent = debugfs_create_dir(dev_name, NULL);
30	if (IS_ERR(parent)) {
31		pr_warn("%s: failed to create debugfs directory\n", dev_name);
32		return;
33	}
34
35	*attr = fail_default_attr;
36	dir = fault_create_debugfs_attr("fault_inject", parent, attr);
37	if (IS_ERR(dir)) {
38		pr_warn("%s: failed to create debugfs attr\n", dev_name);
39		debugfs_remove_recursive(parent);
40		return;
41	}
42	fault_inj->parent = parent;
43
44	/* create debugfs for status code and dont_retry */
45	fault_inj->status = NVME_SC_INVALID_OPCODE;
46	fault_inj->dont_retry = true;
47	debugfs_create_x16("status", 0600, dir,	&fault_inj->status);
48	debugfs_create_bool("dont_retry", 0600, dir, &fault_inj->dont_retry);
49}
50
51void nvme_fault_inject_fini(struct nvme_fault_inject *fault_inject)
52{
53	/* remove debugfs directories */
54	debugfs_remove_recursive(fault_inject->parent);
55}
56
57void nvme_should_fail(struct request *req)
58{
59	struct gendisk *disk = req->q->disk;
60	struct nvme_fault_inject *fault_inject = NULL;
61	u16 status;
62
63	if (disk) {
64		struct nvme_ns *ns = disk->private_data;
65
66		if (ns)
67			fault_inject = &ns->fault_inject;
68		else
69			WARN_ONCE(1, "No namespace found for request\n");
70	} else {
71		fault_inject = &nvme_req(req)->ctrl->fault_inject;
72	}
73
74	if (fault_inject && should_fail(&fault_inject->attr, 1)) {
75		/* inject status code and DNR bit */
76		status = fault_inject->status;
77		if (fault_inject->dont_retry)
78			status |= NVME_SC_DNR;
79		nvme_req(req)->status =	status;
80	}
81}
82EXPORT_SYMBOL_GPL(nvme_should_fail);
83