From c17bb4951752d3e0f49cd1ea9d2e868422f9e0d6 Mon Sep 17 00:00:00 2001 From: Akinobu Mita Date: Fri, 8 Dec 2006 02:39:46 -0800 Subject: [PATCH] fault-injection capability for disk IO This patch provides fault-injection capability for disk IO. Boot option: fail_make_request=,,, -- specifies the interval of failures. -- specifies how often it should fail in percent. -- specifies the size of free space where disk IO can be issued safely in bytes. -- 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 Signed-off-by: Akinobu Mita Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- block/genhd.c | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) (limited to 'block/genhd.c') diff --git a/block/genhd.c b/block/genhd.c index 653919d50cd4..457fdac4c17d 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -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, }; -- cgit v1.2.3-59-g8ed1b