2017-08-23 8:00 GMT+09:00 Bart Van Assche <bart.vanassche@xxxxxxx>:
> Certain faults should be injected independent of the context
> in which these occur. Commit e41d58185f14 made it impossible to
> inject faults independent of their context. Restore support for
> task-independent fault injection by adding the attribute 'global'.
There was a the problem reported by fail-make-request user and the
problem is introduced by the follow-up patches for systematic
fault injection.
Please check the commit 9eeb52ae712e ("fault-inject: fix wrong
should_fail() decision in task context") and see if the problem
you reported is identical to the commit.
> References: commit e41d58185f14 ("fault-inject: support systematic fault injection")
> Signed-off-by: Bart Van Assche <bart.vanassche@xxxxxxx>
> Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
> Cc: Akinobu Mita <akinobu.mita@xxxxxxxxx>
> Cc: Michal Hocko <mhocko@xxxxxxxxxx>
> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> ---
> include/linux/fault-inject.h | 11 +++++++++--
> lib/fault-inject.c | 4 +++-
> 2 files changed, 12 insertions(+), 3 deletions(-)
>
> diff --git a/include/linux/fault-inject.h b/include/linux/fault-inject.h
> index 728d4e0292aa..88dae2f21881 100644
> --- a/include/linux/fault-inject.h
> +++ b/include/linux/fault-inject.h
> @@ -18,6 +18,7 @@ struct fault_attr {
> atomic_t times;
> atomic_t space;
> unsigned long verbose;
> + bool global;
> bool task_filter;
> unsigned long stacktrace_depth;
> unsigned long require_start;
> @@ -30,17 +31,23 @@ struct fault_attr {
> struct dentry *dname;
> };
>
> -#define FAULT_ATTR_INITIALIZER { \
> +#define __FAULT_ATTR_INITIALIZER(__global) { \
> .interval = 1, \
> .times = ATOMIC_INIT(1), \
> .require_end = ULONG_MAX, \
> + .global = (__global), \
> .stacktrace_depth = 32, \
> .ratelimit_state = RATELIMIT_STATE_INIT_DISABLED, \
> .verbose = 2, \
> .dname = NULL, \
> }
>
> -#define DECLARE_FAULT_ATTR(name) struct fault_attr name = FAULT_ATTR_INITIALIZER
> +#define FAULT_ATTR_INITIALIZER __FAULT_ATTR_INITIALIZER(false)
> +
> +#define DECLARE_FAULT_ATTR(name) \
> + struct fault_attr name = __FAULT_ATTR_INITIALIZER(false)
> +#define DECLARE_GLOBAL_FAULT_ATTR(name) \
> + struct fault_attr name = __FAULT_ATTR_INITIALIZER(true)
> int setup_fault_attr(struct fault_attr *attr, char *str);
> bool should_fail(struct fault_attr *attr, ssize_t size);
>
> diff --git a/lib/fault-inject.c b/lib/fault-inject.c
> index 7d315fdb9f13..c8f6ef5df3c6 100644
> --- a/lib/fault-inject.c
> +++ b/lib/fault-inject.c
> @@ -107,7 +107,7 @@ static inline bool fail_stacktrace(struct fault_attr *attr)
>
> bool should_fail(struct fault_attr *attr, ssize_t size)
> {
> - if (in_task()) {
> + if (!attr->global && in_task()) {
> unsigned int fail_nth = READ_ONCE(current->fail_nth);
>
> if (fail_nth && !WRITE_ONCE(current->fail_nth, fail_nth - 1))
> @@ -224,6 +224,8 @@ struct dentry *fault_create_debugfs_attr(const char *name,
> if (!debugfs_create_u32("verbose_ratelimit_burst", mode, dir,
> &attr->ratelimit_state.burst))
> goto fail;
> + if (!debugfs_create_bool("global", mode, dir, &attr->global))
> + goto fail;
> if (!debugfs_create_bool("task-filter", mode, dir, &attr->task_filter))
> goto fail;
>
> --
> 2.14.0
>
