aboutsummaryrefslogtreecommitdiffstats
path: root/block
diff options
context:
space:
mode:
authorJens Axboe2008-09-14 07:56:33 -0500
committerJens Axboe2008-10-09 01:56:17 -0500
commit581d4e28d9195aa8b2231383dbabc288988d615e (patch)
tree093bcac9a538ef67edcf91826f7532bdb88e6248 /block
parent0a0d96b03a1f3bfd6bc3ea08008699e8e59fccd9 (diff)
downloadkernel-common-581d4e28d9195aa8b2231383dbabc288988d615e.tar.gz
kernel-common-581d4e28d9195aa8b2231383dbabc288988d615e.tar.xz
kernel-common-581d4e28d9195aa8b2231383dbabc288988d615e.zip
block: add fault injection mechanism for faking request timeouts
Only works for the generic request timer handling. Allows one to sporadically ignore request completions, thus exercising the timeout handling. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Diffstat (limited to 'block')
-rw-r--r--block/blk-softirq.c2
-rw-r--r--block/blk-timeout.c59
-rw-r--r--block/blk.h12
-rw-r--r--block/genhd.c8
4 files changed, 81 insertions, 0 deletions
diff --git a/block/blk-softirq.c b/block/blk-softirq.c
index 7ab344afb16..e660d26ca65 100644
--- a/block/blk-softirq.c
+++ b/block/blk-softirq.c
@@ -154,6 +154,8 @@ do_local:
154 **/ 154 **/
155void blk_complete_request(struct request *req) 155void blk_complete_request(struct request *req)
156{ 156{
157 if (unlikely(blk_should_fake_timeout(req->q)))
158 return;
157 if (!blk_mark_rq_complete(req)) 159 if (!blk_mark_rq_complete(req))
158 __blk_complete_request(req); 160 __blk_complete_request(req);
159} 161}
diff --git a/block/blk-timeout.c b/block/blk-timeout.c
index 6e5c781c5af..9b4ad138bb3 100644
--- a/block/blk-timeout.c
+++ b/block/blk-timeout.c
@@ -4,9 +4,68 @@
4#include <linux/kernel.h> 4#include <linux/kernel.h>
5#include <linux/module.h> 5#include <linux/module.h>
6#include <linux/blkdev.h> 6#include <linux/blkdev.h>
7#include <linux/fault-inject.h>
7 8
8#include "blk.h" 9#include "blk.h"
9 10
11#ifdef CONFIG_FAIL_IO_TIMEOUT
12
13static DECLARE_FAULT_ATTR(fail_io_timeout);
14
15static int __init setup_fail_io_timeout(char *str)
16{
17 return setup_fault_attr(&fail_io_timeout, str);
18}
19__setup("fail_io_timeout=", setup_fail_io_timeout);
20
21int blk_should_fake_timeout(struct request_queue *q)
22{
23 if (!test_bit(QUEUE_FLAG_FAIL_IO, &q->queue_flags))
24 return 0;
25
26 return should_fail(&fail_io_timeout, 1);
27}
28
29static int __init fail_io_timeout_debugfs(void)
30{
31 return init_fault_attr_dentries(&fail_io_timeout, "fail_io_timeout");
32}
33
34late_initcall(fail_io_timeout_debugfs);
35
36ssize_t part_timeout_show(struct device *dev, struct device_attribute *attr,
37 char *buf)
38{
39 struct gendisk *disk = dev_to_disk(dev);
40 int set = test_bit(QUEUE_FLAG_FAIL_IO, &disk->queue->queue_flags);
41
42 return sprintf(buf, "%d\n", set != 0);
43}
44
45ssize_t part_timeout_store(struct device *dev, struct device_attribute *attr,
46 const char *buf, size_t count)
47{
48 struct gendisk *disk = dev_to_disk(dev);
49 int val;
50
51 if (count) {
52 struct request_queue *q = disk->queue;
53 char *p = (char *) buf;
54
55 val = simple_strtoul(p, &p, 10);
56 spin_lock_irq(q->queue_lock);
57 if (val)
58 queue_flag_set(QUEUE_FLAG_FAIL_IO, q);
59 else
60 queue_flag_clear(QUEUE_FLAG_FAIL_IO, q);
61 spin_unlock_irq(q->queue_lock);
62 }
63
64 return count;
65}
66
67#endif /* CONFIG_FAIL_IO_TIMEOUT */
68
10/* 69/*
11 * blk_delete_timer - Delete/cancel timer for a given function. 70 * blk_delete_timer - Delete/cancel timer for a given function.
12 * @req: request that we are canceling timer for 71 * @req: request that we are canceling timer for
diff --git a/block/blk.h b/block/blk.h
index a4f4a50aefa..e5c57976996 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -42,6 +42,18 @@ static inline void blk_clear_rq_complete(struct request *rq)
42 clear_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags); 42 clear_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags);
43} 43}
44 44
45#ifdef CONFIG_FAIL_IO_TIMEOUT
46int blk_should_fake_timeout(struct request_queue *);
47ssize_t part_timeout_show(struct device *, struct device_attribute *, char *);
48ssize_t part_timeout_store(struct device *, struct device_attribute *,
49 const char *, size_t);
50#else
51static inline int blk_should_fake_timeout(struct request_queue *q)
52{
53 return 0;
54}
55#endif
56
45struct io_context *current_io_context(gfp_t gfp_flags, int node); 57struct io_context *current_io_context(gfp_t gfp_flags, int node);
46 58
47int ll_back_merge_fn(struct request_queue *q, struct request *req, 59int ll_back_merge_fn(struct request_queue *q, struct request *req,
diff --git a/block/genhd.c b/block/genhd.c
index 8acaff0154e..4cd3433c99a 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -817,6 +817,11 @@ static DEVICE_ATTR(stat, S_IRUGO, part_stat_show, NULL);
817static struct device_attribute dev_attr_fail = 817static struct device_attribute dev_attr_fail =
818 __ATTR(make-it-fail, S_IRUGO|S_IWUSR, part_fail_show, part_fail_store); 818 __ATTR(make-it-fail, S_IRUGO|S_IWUSR, part_fail_show, part_fail_store);
819#endif 819#endif
820#ifdef CONFIG_FAIL_IO_TIMEOUT
821static struct device_attribute dev_attr_fail_timeout =
822 __ATTR(io-timeout-fail, S_IRUGO|S_IWUSR, part_timeout_show,
823 part_timeout_store);
824#endif
820 825
821static struct attribute *disk_attrs[] = { 826static struct attribute *disk_attrs[] = {
822 &dev_attr_range.attr, 827 &dev_attr_range.attr,
@@ -829,6 +834,9 @@ static struct attribute *disk_attrs[] = {
829#ifdef CONFIG_FAIL_MAKE_REQUEST 834#ifdef CONFIG_FAIL_MAKE_REQUEST
830 &dev_attr_fail.attr, 835 &dev_attr_fail.attr,
831#endif 836#endif
837#ifdef CONFIG_FAIL_IO_TIMEOUT
838 &dev_attr_fail_timeout.attr,
839#endif
832 NULL 840 NULL
833}; 841};
834 842