drivers/nvme/host/fault_inject.c

   1 /*
   2  * fault injection support for nvme.
   3  *
   4  * Copyright (c) 2018, Oracle and/or its affiliates
   5  *
   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_ns *ns)
  19 {
  20         struct dentry *dir, *parent;
  21         char *name = ns->disk->disk_name;
  22         struct nvme_fault_inject *fault_inj = &ns->fault_inject;
  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(name, NULL);
  31         if (!parent) {
  32                 pr_warn("%s: failed to create debugfs directory\n", 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", name);
  40                 debugfs_remove_recursive(parent);
  41                 return;
  42         }
  43         ns->fault_inject.parent = parent;
  44
  45         /* create debugfs for status code and dont_retry */
  46         fault_inj->status = NVME_SC_INVALID_OPCODE;
  47         fault_inj->dont_retry = true;
  48         debugfs_create_x16("status", 0600, dir, &fault_inj->status);
  49         debugfs_create_bool("dont_retry", 0600, dir, &fault_inj->dont_retry);
  50 }
  51
  52 void nvme_fault_inject_fini(struct nvme_ns *ns)
  53 {
  54         /* remove debugfs directories */
  55         debugfs_remove_recursive(ns->fault_inject.parent);
  56 }
  57
  58 void nvme_should_fail(struct request *req)
  59 {
  60         struct gendisk *disk = req->rq_disk;
  61         struct nvme_ns *ns = NULL;
  62         u16 status;
  63
  64         /*
  65          * make sure this request is coming from a valid namespace
  66          */
  67         if (!disk)
  68                 return;
  69
  70         ns = disk->private_data;
  71         if (ns && should_fail(&ns->fault_inject.attr, 1)) {
  72                 /* inject status code and DNR bit */
  73                 status = ns->fault_inject.status;
  74                 if (ns->fault_inject.dont_retry)
  75                         status |= NVME_SC_DNR;
  76                 nvme_req(req)->status = status;
  77         }
  78 }
  79 EXPORT_SYMBOL_GPL(nvme_should_fail);