summaryrefslogtreecommitdiffstats
path: root/Documentation/fault-injection/nvme-fault-injection.rst
blob: cdb2e829228e3efc7104b411cc7323173ac45c5e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
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_end_request. 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