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authorAkinobu Mita <akinobu.mita@gmail.com>2006-12-08 02:39:46 -0800
committerLinus Torvalds <torvalds@woody.osdl.org>2006-12-08 08:29:02 -0800
commitc17bb4951752d3e0f49cd1ea9d2e868422f9e0d6 (patch)
treedcd23ef706ba09edae462528dc11a507b1d17af6 /block
parent933e312e73f8fc39652bd4d216a5393cc3a014b9 (diff)
downloadlinux-linaro-stable-c17bb4951752d3e0f49cd1ea9d2e868422f9e0d6.tar.gz
[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>
Diffstat (limited to 'block')
-rw-r--r--block/genhd.c31
-rw-r--r--block/ll_rw_blk.c40
2 files changed, 71 insertions, 0 deletions
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,
};
diff --git a/block/ll_rw_blk.c b/block/ll_rw_blk.c
index 31512cd9f3ad..4f83fd922377 100644
--- a/block/ll_rw_blk.c
+++ b/block/ll_rw_blk.c
@@ -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 @@ end_io:
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.