[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>
diff --git a/include/linux/genhd.h b/include/linux/genhd.h
index 41f276f..0a022b2 100644
--- a/include/linux/genhd.h
+++ b/include/linux/genhd.h
@@ -83,6 +83,9 @@
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 @@
#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 */