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 opcode, status code, and dont_retry */ 46 fault_inj->opcode = 0xffff; 47 fault_inj->status = NVME_SC_INVALID_OPCODE; 48 fault_inj->dont_retry = true; 49 debugfs_create_x16("opcode", 0600, dir, &fault_inj->opcode); 50 debugfs_create_x16("status", 0600, dir, &fault_inj->status); 51 debugfs_create_bool("dont_retry", 0600, dir, &fault_inj->dont_retry); 52 } 53 54 void nvme_fault_inject_fini(struct nvme_fault_inject *fault_inject) 55 { 56 /* remove debugfs directories */ 57 debugfs_remove_recursive(fault_inject->parent); 58 } 59 60 void nvme_should_fail(struct request *req) 61 { 62 struct gendisk *disk = req->q->disk; 63 struct nvme_fault_inject *fault_inject = NULL; 64 struct nvme_command *cmd = nvme_req(req)->cmd; 65 u16 status; 66 67 if (disk) { 68 struct nvme_ns *ns = disk->private_data; 69 70 if (ns) 71 fault_inject = &ns->fault_inject; 72 else 73 WARN_ONCE(1, "No namespace found for request\n"); 74 } else { 75 fault_inject = &nvme_req(req)->ctrl->fault_inject; 76 } 77 78 if (!fault_inject) 79 return; 80 81 if (fault_inject->opcode <= 0xff && 82 fault_inject->opcode != cmd->common.opcode) 83 return; 84 85 if (should_fail(&fault_inject->attr, 1)) { 86 /* inject status code and DNR bit */ 87 status = fault_inject->status; 88 if (fault_inject->dont_retry) 89 status |= NVME_STATUS_DNR; 90 nvme_req(req)->status = status; 91 } 92 } 93 EXPORT_SYMBOL_GPL(nvme_should_fail); 94