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 
11 static DECLARE_FAULT_ATTR(fail_default_attr);
12 /* optional fault injection attributes boot time option:
13  * nvme_core.fail_request=<interval>,<probability>,<space>,<times>
14  */
15 static char *fail_request;
16 module_param(fail_request, charp, 0000);
17 
nvme_fault_inject_init(struct nvme_fault_inject * fault_inj,const char * dev_name)18 void 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 (!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 
nvme_fault_inject_fini(struct nvme_fault_inject * fault_inject)51 void nvme_fault_inject_fini(struct nvme_fault_inject *fault_inject)
52 {
53 	/* remove debugfs directories */
54 	debugfs_remove_recursive(fault_inject->parent);
55 }
56 
nvme_should_fail(struct request * req)57 void nvme_should_fail(struct request *req)
58 {
59 	struct gendisk *disk = req->rq_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 }
82 EXPORT_SYMBOL_GPL(nvme_should_fail);
83