drivers/nvme/host/fault_inject.c

   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 <linux/debugfs.h>
  10 #include "nvme.h"
  11
  12 static DECLARE_FAULT_ATTR(fail_default_attr);
  13 /* optional fault injection attributes boot time option:
  14  * nvme_core.fail_request=<interval>,<probability>,<space>,<times>
  15  */
  16 static char *fail_request;
  17 module_param(fail_request, charp, 0000);
  18
  19 void nvme_fault_inject_init(struct nvme_fault_inject *fault_inj,
  20                             const char *dev_name)
  21 {
  22         struct dentry *dir, *parent;
  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(dev_name, NULL);
  31         if (IS_ERR(parent)) {
  32                 pr_warn("%s: failed to create debugfs directory\n", dev_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", dev_name);
  40                 debugfs_remove_recursive(parent);
  41                 return;
  42         }
  43         fault_inj->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_fault_inject *fault_inject)
  53 {
  54         /* remove debugfs directories */
  55         debugfs_remove_recursive(fault_inject->parent);
  56 }
  57
  58 void nvme_should_fail(struct request *req)
  59 {
  60         struct gendisk *disk = req->q->disk;
  61         struct nvme_fault_inject *fault_inject = NULL;
  62         u16 status;
  63
  64         if (disk) {
  65                 struct nvme_ns *ns = disk->private_data;
  66
  67                 if (ns)
  68                         fault_inject = &ns->fault_inject;
  69                 else
  70                         WARN_ONCE(1, "No namespace found for request\n");
  71         } else {
  72                 fault_inject = &nvme_req(req)->ctrl->fault_inject;
  73         }
  74
  75         if (fault_inject && should_fail(&fault_inject->attr, 1)) {
  76                 /* inject status code and DNR bit */
  77                 status = fault_inject->status;
  78                 if (fault_inject->dont_retry)
  79                         status |= NVME_STATUS_DNR;
  80                 nvme_req(req)->status = status;
  81         }
  82 }
  83 EXPORT_SYMBOL_GPL(nvme_should_fail);