root/drivers/nvme/host/fault_inject.c

DEFINITIONS

1. nvme_fault_inject_init
2. nvme_fault_inject_fini
3. nvme_should_fail

   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 
  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 
  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 
  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);