LXR linux/drivers/nvme/host/fault

   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(&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
  51void nvme_fault_inject_fini(struct nvme_fault_inject *fault_inject)
  52{
  53        /* remove debugfs directories */
  54        debugfs_remove_recursive(fault_inject->parent);
  55}
  56
  57void 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}
  82EXPORT_SYMBOL_GPL(nvme_should_fail);
  83