[PATCH] fault-injection capability for disk IO

This patch provides fault-injection capability for disk IO.

Boot option:

fail_make_request=<probability>,<interval>,<space>,<times>

	<interval> -- specifies the interval of failures.

	<probability> -- specifies how often it should fail in percent.

	<space> -- specifies the size of free space where disk IO can be issued
		   safely in bytes.

	<times> -- specifies how many times failures may happen at most.

Debugfs:

/debug/fail_make_request/interval
/debug/fail_make_request/probability
/debug/fail_make_request/specifies
/debug/fail_make_request/times

Example:

	fail_make_request=10,100,0,-1
	echo 1 > /sys/blocks/hda/hda1/make-it-fail

generic_make_request() on /dev/hda1 fails once per 10 times.

Cc: Jens Axboe <axboe@suse.de>
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Akinobu Mita 2006-12-08 02:39:46 -08:00 committed by Linus Torvalds
parent 933e312e73
commit c17bb49517
5 changed files with 109 additions and 0 deletions

View file

@ -417,6 +417,34 @@ static struct disk_attribute disk_attr_stat = {
.show = disk_stats_read
};
#ifdef CONFIG_FAIL_MAKE_REQUEST
static ssize_t disk_fail_store(struct gendisk * disk,
const char *buf, size_t count)
{
int i;
if (count > 0 && sscanf(buf, "%d", &i) > 0) {
if (i == 0)
disk->flags &= ~GENHD_FL_FAIL;
else
disk->flags |= GENHD_FL_FAIL;
}
return count;
}
static ssize_t disk_fail_read(struct gendisk * disk, char *page)
{
return sprintf(page, "%d\n", disk->flags & GENHD_FL_FAIL ? 1 : 0);
}
static struct disk_attribute disk_attr_fail = {
.attr = {.name = "make-it-fail", .mode = S_IRUGO | S_IWUSR },
.store = disk_fail_store,
.show = disk_fail_read
};
#endif
static struct attribute * default_attrs[] = {
&disk_attr_uevent.attr,
&disk_attr_dev.attr,
@ -424,6 +452,9 @@ static struct attribute * default_attrs[] = {
&disk_attr_removable.attr,
&disk_attr_size.attr,
&disk_attr_stat.attr,
#ifdef CONFIG_FAIL_MAKE_REQUEST
&disk_attr_fail.attr,
#endif
NULL,
};

View file

@ -28,6 +28,7 @@
#include <linux/interrupt.h>
#include <linux/cpu.h>
#include <linux/blktrace_api.h>
#include <linux/fault-inject.h>
/*
* for max sense size
@ -3056,6 +3057,42 @@ static void handle_bad_sector(struct bio *bio)
set_bit(BIO_EOF, &bio->bi_flags);
}
#ifdef CONFIG_FAIL_MAKE_REQUEST
static DECLARE_FAULT_ATTR(fail_make_request);
static int __init setup_fail_make_request(char *str)
{
return setup_fault_attr(&fail_make_request, str);
}
__setup("fail_make_request=", setup_fail_make_request);
static int should_fail_request(struct bio *bio)
{
if ((bio->bi_bdev->bd_disk->flags & GENHD_FL_FAIL) ||
(bio->bi_bdev->bd_part && bio->bi_bdev->bd_part->make_it_fail))
return should_fail(&fail_make_request, bio->bi_size);
return 0;
}
static int __init fail_make_request_debugfs(void)
{
return init_fault_attr_dentries(&fail_make_request,
"fail_make_request");
}
late_initcall(fail_make_request_debugfs);
#else /* CONFIG_FAIL_MAKE_REQUEST */
static inline int should_fail_request(struct bio *bio)
{
return 0;
}
#endif /* CONFIG_FAIL_MAKE_REQUEST */
/**
* generic_make_request: hand a buffer to its device driver for I/O
* @bio: The bio describing the location in memory and on the device.
@ -3141,6 +3178,9 @@ void generic_make_request(struct bio *bio)
if (unlikely(test_bit(QUEUE_FLAG_DEAD, &q->queue_flags)))
goto end_io;
if (should_fail_request(bio))
goto end_io;
/*
* If this device has partitions, remap block n
* of partition p to block n+start(p) of the disk.

View file

@ -276,12 +276,39 @@ static struct part_attribute part_attr_stat = {
.show = part_stat_read
};
#ifdef CONFIG_FAIL_MAKE_REQUEST
static ssize_t part_fail_store(struct hd_struct * p,
const char *buf, size_t count)
{
int i;
if (count > 0 && sscanf(buf, "%d", &i) > 0)
p->make_it_fail = (i == 0) ? 0 : 1;
return count;
}
static ssize_t part_fail_read(struct hd_struct * p, char *page)
{
return sprintf(page, "%d\n", p->make_it_fail);
}
static struct part_attribute part_attr_fail = {
.attr = {.name = "make-it-fail", .mode = S_IRUGO | S_IWUSR },
.store = part_fail_store,
.show = part_fail_read
};
#endif
static struct attribute * default_attrs[] = {
&part_attr_uevent.attr,
&part_attr_dev.attr,
&part_attr_start.attr,
&part_attr_size.attr,
&part_attr_stat.attr,
#ifdef CONFIG_FAIL_MAKE_REQUEST
&part_attr_fail.attr,
#endif
NULL,
};

View file

@ -83,6 +83,9 @@ struct hd_struct {
struct kobject *holder_dir;
unsigned ios[2], sectors[2]; /* READs and WRITEs */
int policy, partno;
#ifdef CONFIG_FAIL_MAKE_REQUEST
int make_it_fail;
#endif
};
#define GENHD_FL_REMOVABLE 1
@ -90,6 +93,7 @@ struct hd_struct {
#define GENHD_FL_CD 8
#define GENHD_FL_UP 16
#define GENHD_FL_SUPPRESS_PARTITION_INFO 32
#define GENHD_FL_FAIL 64
struct disk_stats {
unsigned long sectors[2]; /* READs and WRITEs */

View file

@ -431,6 +431,13 @@ config FAIL_PAGE_ALLOC
help
This option provides fault-injection capabilitiy for alloc_pages().
config FAIL_MAKE_REQUEST
bool "Fault-injection capabilitiy for disk IO"
depends on DEBUG_KERNEL
select FAULT_INJECTION
help
This option provides fault-injection capabilitiy to disk IO.
config FAULT_INJECTION_DEBUG_FS
bool "Debugfs entries for fault-injection capabilities"
depends on FAULT_INJECTION && SYSFS