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_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
  52void nvme_fault_inject_fini(struct nvme_ns *ns)
  53{
  54        /* remove debugfs directories */
  55        debugfs_remove_recursive(ns->fault_inject.parent);
  56}
  57
  58void 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}
  79EXPORT_SYMBOL_GPL(nvme_should_fail);
  80