[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/fs/partitions/check.c b/fs/partitions/check.c
index 1901137..3d73d94 100644
--- a/fs/partitions/check.c
+++ b/fs/partitions/check.c
@@ -276,12 +276,39 @@
.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,
};