* [PATCH] fault-inject: fix wrong should_fail() decision in task context
@ 2017-08-02 0:28 Akinobu Mita
2017-08-02 4:15 ` Lu Fengqi
0 siblings, 1 reply; 2+ messages in thread
From: Akinobu Mita @ 2017-08-02 0:28 UTC (permalink / raw)
To: akpm, linux-kernel; +Cc: Akinobu Mita, Dmitry Vyukov, Lu Fengqi
Commit 1203c8e6fb0a ("fault-inject: simplify access check for fail-nth")
unintentionally broke a conditional statement in should_fail(). Any faults
are not injected in the task context by the change when the systematic
fault injection is not used.
This change restores to the previous correct behaviour.
Fixes: 1203c8e6fb0a ("fault-inject: simplify access check for fail-nth")
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Lu Fengqi <lufq.fnst@cn.fujitsu.com>
Reported-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com>
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
---
lib/fault-inject.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/lib/fault-inject.c b/lib/fault-inject.c
index 7d315fd..cf7b129 100644
--- a/lib/fault-inject.c
+++ b/lib/fault-inject.c
@@ -110,10 +110,12 @@ bool should_fail(struct fault_attr *attr, ssize_t size)
if (in_task()) {
unsigned int fail_nth = READ_ONCE(current->fail_nth);
- if (fail_nth && !WRITE_ONCE(current->fail_nth, fail_nth - 1))
- goto fail;
+ if (fail_nth) {
+ if (!WRITE_ONCE(current->fail_nth, fail_nth - 1))
+ goto fail;
- return false;
+ return false;
+ }
}
/* No need to check any other properties if the probability is 0 */
--
2.7.4
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] fault-inject: fix wrong should_fail() decision in task context
2017-08-02 0:28 [PATCH] fault-inject: fix wrong should_fail() decision in task context Akinobu Mita
@ 2017-08-02 4:15 ` Lu Fengqi
0 siblings, 0 replies; 2+ messages in thread
From: Lu Fengqi @ 2017-08-02 4:15 UTC (permalink / raw)
To: Akinobu Mita; +Cc: akpm, linux-kernel, Dmitry Vyukov
On Wed, Aug 02, 2017 at 09:28:20AM +0900, Akinobu Mita wrote:
>Commit 1203c8e6fb0a ("fault-inject: simplify access check for fail-nth")
>unintentionally broke a conditional statement in should_fail(). Any faults
>are not injected in the task context by the change when the systematic
>fault injection is not used.
>
>This change restores to the previous correct behaviour.
>
>Fixes: 1203c8e6fb0a ("fault-inject: simplify access check for fail-nth")
>Cc: Dmitry Vyukov <dvyukov@google.com>
>Cc: Lu Fengqi <lufq.fnst@cn.fujitsu.com>
>Reported-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com>
>Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
>---
> lib/fault-inject.c | 8 +++++---
> 1 file changed, 5 insertions(+), 3 deletions(-)
>
>diff --git a/lib/fault-inject.c b/lib/fault-inject.c
>index 7d315fd..cf7b129 100644
>--- a/lib/fault-inject.c
>+++ b/lib/fault-inject.c
>@@ -110,10 +110,12 @@ bool should_fail(struct fault_attr *attr, ssize_t size)
> if (in_task()) {
> unsigned int fail_nth = READ_ONCE(current->fail_nth);
>
>- if (fail_nth && !WRITE_ONCE(current->fail_nth, fail_nth - 1))
>- goto fail;
>+ if (fail_nth) {
>+ if (!WRITE_ONCE(current->fail_nth, fail_nth - 1))
>+ goto fail;
>
>- return false;
>+ return false;
>+ }
> }
>
> /* No need to check any other properties if the probability is 0 */
>--
>2.7.4
>
>
>
With this fix, I can produce the IO ERROR by the fail_make_request.
--
Thanks,
Lu
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