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author | Thomas Tai <thomas.tai@oracle.com> | 2018-02-08 13:38:29 -0500 |
---|---|---|
committer | Jens Axboe <axboe@kernel.dk> | 2018-03-26 08:53:43 -0600 |
commit | b9e03857f2e22788db6ccb67512a6604a6b4f6db (patch) | |
tree | c226cf1f92dc7b61b11c64ca7e9f7d30fae3ab92 /drivers/nvme/host/fault_inject.c | |
parent | 42595eb7d0095897823b89344e497b69d08d91c1 (diff) | |
download | linux-b9e03857f2e22788db6ccb67512a6604a6b4f6db.tar.bz2 |
nvme: Add fault injection feature
Linux's fault injection framework provides a systematic way to support
error injection via debugfs in the /sys/kernel/debug directory. This
patch uses the framework to add error injection to NVMe driver. The
fault injection source code is stored in a separate file and only linked
if CONFIG_FAULT_INJECTION_DEBUG_FS kernel config is selected.
Once the error injection is enabled, 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 debufs. Following example
shows how to enable and inject an error. For more examples, refer to
Documentation/fault-injection/nvme-fault-injection.txt
How to enable nvme fault injection:
First, enable CONFIG_FAULT_INJECTION_DEBUG_FS kernel config,
recompile the kernel. After booting up the kernel, do the
following.
How to inject an error:
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
Signed-off-by: Thomas Tai <thomas.tai@oracle.com>
Reviewed-by: Eric Saint-Etienne <eric.saint.etienne@oracle.com>
Signed-off-by: Karl Volz <karl.volz@oracle.com>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'drivers/nvme/host/fault_inject.c')
-rw-r--r-- | drivers/nvme/host/fault_inject.c | 79 |
1 files changed, 79 insertions, 0 deletions
diff --git a/drivers/nvme/host/fault_inject.c b/drivers/nvme/host/fault_inject.c new file mode 100644 index 000000000000..02632266ac06 --- /dev/null +++ b/drivers/nvme/host/fault_inject.c @@ -0,0 +1,79 @@ +/* + * fault injection support for nvme. + * + * Copyright (c) 2018, Oracle and/or its affiliates + * + */ + +#include <linux/moduleparam.h> +#include "nvme.h" + +static DECLARE_FAULT_ATTR(fail_default_attr); +/* optional fault injection attributes boot time option: + * nvme_core.fail_request=<interval>,<probability>,<space>,<times> + */ +static char *fail_request; +module_param(fail_request, charp, 0000); + +void nvme_fault_inject_init(struct nvme_ns *ns) +{ + struct dentry *dir, *parent; + char *name = ns->disk->disk_name; + struct nvme_fault_inject *fault_inj = &ns->fault_inject; + struct fault_attr *attr = &fault_inj->attr; + + /* set default fault injection attribute */ + if (fail_request) + setup_fault_attr(&fail_default_attr, fail_request); + + /* create debugfs directory and attribute */ + parent = debugfs_create_dir(name, NULL); + if (!parent) { + pr_warn("%s: failed to create debugfs directory\n", name); + return; + } + + *attr = fail_default_attr; + dir = fault_create_debugfs_attr("fault_inject", parent, attr); + if (IS_ERR(dir)) { + pr_warn("%s: failed to create debugfs attr\n", name); + debugfs_remove_recursive(parent); + return; + } + ns->fault_inject.parent = parent; + + /* create debugfs for status code and dont_retry */ + fault_inj->status = NVME_SC_INVALID_OPCODE; + fault_inj->dont_retry = true; + debugfs_create_x16("status", 0600, dir, &fault_inj->status); + debugfs_create_bool("dont_retry", 0600, dir, &fault_inj->dont_retry); +} + +void nvme_fault_inject_fini(struct nvme_ns *ns) +{ + /* remove debugfs directories */ + debugfs_remove_recursive(ns->fault_inject.parent); +} + +void nvme_should_fail(struct request *req) +{ + struct gendisk *disk = req->rq_disk; + struct nvme_ns *ns = NULL; + u16 status; + + /* + * make sure this request is coming from a valid namespace + */ + if (!disk) + return; + + ns = disk->private_data; + if (ns && should_fail(&ns->fault_inject.attr, 1)) { + /* inject status code and DNR bit */ + status = ns->fault_inject.status; + if (ns->fault_inject.dont_retry) + status |= NVME_SC_DNR; + nvme_req(req)->status = status; + } +} +EXPORT_SYMBOL_GPL(nvme_should_fail); |