| NVMe Fault Injection |
| ==================== |
| Linux's fault injection framework provides a systematic way to support |
| error injection via debugfs in the /sys/kernel/debug directory. When |
| enabled, the default NVME_SC_INVALID_OPCODE with no retry will be |
| injected into the nvme_try_complete_req. Users can change the default status |
| code and no retry flag via the debugfs. The list of Generic Command |
| Status can be found in include/linux/nvme.h |
| |
| Following examples show how to inject an error into the nvme. |
| |
| First, enable CONFIG_FAULT_INJECTION_DEBUG_FS kernel config, |
| recompile the kernel. After booting up the kernel, do the |
| following. |
| |
| Example 1: Inject default status code with no retry |
| --------------------------------------------------- |
| |
| :: |
| |
| mount /dev/nvme0n1 /mnt |
| echo 1 > /sys/kernel/debug/nvme0n1/fault_inject/times |
| echo 100 > /sys/kernel/debug/nvme0n1/fault_inject/probability |
| cp a.file /mnt |
| |
| Expected Result:: |
| |
| cp: cannot stat ‘/mnt/a.file’: Input/output error |
| |
| Message from dmesg:: |
| |
| FAULT_INJECTION: forcing a failure. |
| name fault_inject, interval 1, probability 100, space 0, times 1 |
| CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.15.0-rc8+ #2 |
| Hardware name: innotek GmbH VirtualBox/VirtualBox, |
| BIOS VirtualBox 12/01/2006 |
| Call Trace: |
| <IRQ> |
| dump_stack+0x5c/0x7d |
| should_fail+0x148/0x170 |
| nvme_should_fail+0x2f/0x50 [nvme_core] |
| nvme_process_cq+0xe7/0x1d0 [nvme] |
| nvme_irq+0x1e/0x40 [nvme] |
| __handle_irq_event_percpu+0x3a/0x190 |
| handle_irq_event_percpu+0x30/0x70 |
| handle_irq_event+0x36/0x60 |
| handle_fasteoi_irq+0x78/0x120 |
| handle_irq+0xa7/0x130 |
| ? tick_irq_enter+0xa8/0xc0 |
| do_IRQ+0x43/0xc0 |
| common_interrupt+0xa2/0xa2 |
| </IRQ> |
| RIP: 0010:native_safe_halt+0x2/0x10 |
| RSP: 0018:ffffffff82003e90 EFLAGS: 00000246 ORIG_RAX: ffffffffffffffdd |
| RAX: ffffffff817a10c0 RBX: ffffffff82012480 RCX: 0000000000000000 |
| RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 |
| RBP: 0000000000000000 R08: 000000008e38ce64 R09: 0000000000000000 |
| R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff82012480 |
| R13: ffffffff82012480 R14: 0000000000000000 R15: 0000000000000000 |
| ? __sched_text_end+0x4/0x4 |
| default_idle+0x18/0xf0 |
| do_idle+0x150/0x1d0 |
| cpu_startup_entry+0x6f/0x80 |
| start_kernel+0x4c4/0x4e4 |
| ? set_init_arg+0x55/0x55 |
| secondary_startup_64+0xa5/0xb0 |
| print_req_error: I/O error, dev nvme0n1, sector 9240 |
| EXT4-fs error (device nvme0n1): ext4_find_entry:1436: |
| inode #2: comm cp: reading directory lblock 0 |
| |
| Example 2: Inject default status code with retry |
| ------------------------------------------------ |
| |
| :: |
| |
| mount /dev/nvme0n1 /mnt |
| echo 1 > /sys/kernel/debug/nvme0n1/fault_inject/times |
| echo 100 > /sys/kernel/debug/nvme0n1/fault_inject/probability |
| echo 1 > /sys/kernel/debug/nvme0n1/fault_inject/status |
| echo 0 > /sys/kernel/debug/nvme0n1/fault_inject/dont_retry |
| |
| cp a.file /mnt |
| |
| Expected Result:: |
| |
| command success without error |
| |
| Message from dmesg:: |
| |
| FAULT_INJECTION: forcing a failure. |
| name fault_inject, interval 1, probability 100, space 0, times 1 |
| CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.15.0-rc8+ #4 |
| Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006 |
| Call Trace: |
| <IRQ> |
| dump_stack+0x5c/0x7d |
| should_fail+0x148/0x170 |
| nvme_should_fail+0x30/0x60 [nvme_core] |
| nvme_loop_queue_response+0x84/0x110 [nvme_loop] |
| nvmet_req_complete+0x11/0x40 [nvmet] |
| nvmet_bio_done+0x28/0x40 [nvmet] |
| blk_update_request+0xb0/0x310 |
| blk_mq_end_request+0x18/0x60 |
| flush_smp_call_function_queue+0x3d/0xf0 |
| smp_call_function_single_interrupt+0x2c/0xc0 |
| call_function_single_interrupt+0xa2/0xb0 |
| </IRQ> |
| RIP: 0010:native_safe_halt+0x2/0x10 |
| RSP: 0018:ffffc9000068bec0 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff04 |
| RAX: ffffffff817a10c0 RBX: ffff88011a3c9680 RCX: 0000000000000000 |
| RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 |
| RBP: 0000000000000001 R08: 000000008e38c131 R09: 0000000000000000 |
| R10: 0000000000000000 R11: 0000000000000000 R12: ffff88011a3c9680 |
| R13: ffff88011a3c9680 R14: 0000000000000000 R15: 0000000000000000 |
| ? __sched_text_end+0x4/0x4 |
| default_idle+0x18/0xf0 |
| do_idle+0x150/0x1d0 |
| cpu_startup_entry+0x6f/0x80 |
| start_secondary+0x187/0x1e0 |
| secondary_startup_64+0xa5/0xb0 |
| |
| Example 3: Inject an error into the 10th admin command |
| ------------------------------------------------------ |
| |
| :: |
| |
| echo 100 > /sys/kernel/debug/nvme0/fault_inject/probability |
| echo 10 > /sys/kernel/debug/nvme0/fault_inject/space |
| echo 1 > /sys/kernel/debug/nvme0/fault_inject/times |
| nvme reset /dev/nvme0 |
| |
| Expected Result:: |
| |
| After NVMe controller reset, the reinitialization may or may not succeed. |
| It depends on which admin command is actually forced to fail. |
| |
| Message from dmesg:: |
| |
| nvme nvme0: resetting controller |
| FAULT_INJECTION: forcing a failure. |
| name fault_inject, interval 1, probability 100, space 1, times 1 |
| CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.2.0-rc2+ #2 |
| Hardware name: MSI MS-7A45/B150M MORTAR ARCTIC (MS-7A45), BIOS 1.50 04/25/2017 |
| Call Trace: |
| <IRQ> |
| dump_stack+0x63/0x85 |
| should_fail+0x14a/0x170 |
| nvme_should_fail+0x38/0x80 [nvme_core] |
| nvme_irq+0x129/0x280 [nvme] |
| ? blk_mq_end_request+0xb3/0x120 |
| __handle_irq_event_percpu+0x84/0x1a0 |
| handle_irq_event_percpu+0x32/0x80 |
| handle_irq_event+0x3b/0x60 |
| handle_edge_irq+0x7f/0x1a0 |
| handle_irq+0x20/0x30 |
| do_IRQ+0x4e/0xe0 |
| common_interrupt+0xf/0xf |
| </IRQ> |
| RIP: 0010:cpuidle_enter_state+0xc5/0x460 |
| Code: ff e8 8f 5f 86 ff 80 7d c7 00 74 17 9c 58 0f 1f 44 00 00 f6 c4 02 0f 85 69 03 00 00 31 ff e8 62 aa 8c ff fb 66 0f 1f 44 00 00 <45> 85 ed 0f 88 37 03 00 00 4c 8b 45 d0 4c 2b 45 b8 48 ba cf f7 53 |
| RSP: 0018:ffffffff88c03dd0 EFLAGS: 00000246 ORIG_RAX: ffffffffffffffdc |
| RAX: ffff9dac25a2ac80 RBX: ffffffff88d53760 RCX: 000000000000001f |
| RDX: 0000000000000000 RSI: 000000002d958403 RDI: 0000000000000000 |
| RBP: ffffffff88c03e18 R08: fffffff75e35ffb7 R09: 00000a49a56c0b48 |
| R10: ffffffff88c03da0 R11: 0000000000001b0c R12: ffff9dac25a34d00 |
| R13: 0000000000000006 R14: 0000000000000006 R15: ffffffff88d53760 |
| cpuidle_enter+0x2e/0x40 |
| call_cpuidle+0x23/0x40 |
| do_idle+0x201/0x280 |
| cpu_startup_entry+0x1d/0x20 |
| rest_init+0xaa/0xb0 |
| arch_call_rest_init+0xe/0x1b |
| start_kernel+0x51c/0x53b |
| x86_64_start_reservations+0x24/0x26 |
| x86_64_start_kernel+0x74/0x77 |
| secondary_startup_64+0xa4/0xb0 |
| nvme nvme0: Could not set queue count (16385) |
| nvme nvme0: IO queues not created |
