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 <linux/debugfs.h>
10 #include "nvme.h"
11
12 static DECLARE_FAULT_ATTR(fail_default_attr);
13 /* optional fault injection attributes boot time option:
14 * nvme_core.fail_request=<interval>,<probability>,<space>,<times>
15 */
16 static char *fail_request;
17 module_param(fail_request, charp, 0000);
18
nvme_fault_inject_init(struct nvme_fault_inject * fault_inj,const char * dev_name)19 void nvme_fault_inject_init(struct nvme_fault_inject *fault_inj,
20 const char *dev_name)
21 {
22 struct dentry *dir, *parent;
23 struct fault_attr *attr = &fault_inj->attr;
24
25 /* set default fault injection attribute */
26 if (fail_request)
27 setup_fault_attr(&fail_default_attr, fail_request);
28
29 /* create debugfs directory and attribute */
30 parent = debugfs_create_dir(dev_name, NULL);
31 if (IS_ERR(parent)) {
32 pr_warn("%s: failed to create debugfs directory\n", dev_name);
33 return;
34 }
35
36 *attr = fail_default_attr;
37 dir = fault_create_debugfs_attr("fault_inject", parent, attr);
38 if (IS_ERR(dir)) {
39 pr_warn("%s: failed to create debugfs attr\n", dev_name);
40 debugfs_remove_recursive(parent);
41 return;
42 }
43 fault_inj->parent = parent;
44
45 /* create debugfs for opcode, status code, and dont_retry */
46 fault_inj->opcode = 0xffff;
47 fault_inj->status = NVME_SC_INVALID_OPCODE;
48 fault_inj->dont_retry = true;
49 debugfs_create_x16("opcode", 0600, dir, &fault_inj->opcode);
50 debugfs_create_x16("status", 0600, dir, &fault_inj->status);
51 debugfs_create_bool("dont_retry", 0600, dir, &fault_inj->dont_retry);
52 }
53
nvme_fault_inject_fini(struct nvme_fault_inject * fault_inject)54 void nvme_fault_inject_fini(struct nvme_fault_inject *fault_inject)
55 {
56 /* remove debugfs directories */
57 debugfs_remove_recursive(fault_inject->parent);
58 }
59
nvme_should_fail(struct request * req)60 void nvme_should_fail(struct request *req)
61 {
62 struct gendisk *disk = req->q->disk;
63 struct nvme_fault_inject *fault_inject = NULL;
64 struct nvme_command *cmd = nvme_req(req)->cmd;
65 u16 status;
66
67 if (disk) {
68 struct nvme_ns *ns = disk->private_data;
69
70 if (ns)
71 fault_inject = &ns->fault_inject;
72 else
73 WARN_ONCE(1, "No namespace found for request\n");
74 } else {
75 fault_inject = &nvme_req(req)->ctrl->fault_inject;
76 }
77
78 if (!fault_inject)
79 return;
80
81 if (fault_inject->opcode <= 0xff &&
82 fault_inject->opcode != cmd->common.opcode)
83 return;
84
85 if (should_fail(&fault_inject->attr, 1)) {
86 /* inject status code and DNR bit */
87 status = fault_inject->status;
88 if (fault_inject->dont_retry)
89 status |= NVME_STATUS_DNR;
90 nvme_req(req)->status = status;
91 }
92 }
93 EXPORT_SYMBOL_GPL(nvme_should_fail);
94