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(attr: &fail_default_attr, str: fail_request);
27
28 /* create debugfs directory and attribute */
29 parent = debugfs_create_dir(name: dev_name, NULL);
30 if (IS_ERR(ptr: 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(name: "fault_inject", parent, attr);
37 if (IS_ERR(ptr: dir)) {
38 pr_warn("%s: failed to create debugfs attr\n", dev_name);
39 debugfs_remove_recursive(dentry: 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(name: "status", mode: 0600, parent: dir, value: &fault_inj->status);
48 debugfs_create_bool(name: "dont_retry", mode: 0600, parent: dir, value: &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(dentry: 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(attr: &fault_inject->attr, size: 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

source code of linux/drivers/nvme/host/fault_inject.c