[PATCH 1/2] fault-inject: Restore support for task-independent fault injection

From: Bart Van Assche
Date: Tue Aug 22 2017 - 12:53:57 EST


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'.

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 | 9 +++++++--
lib/fault-inject.c | 4 +++-
2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/include/linux/fault-inject.h b/include/linux/fault-inject.h
index 728d4e0292aa..8851646d2698 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 +31,21 @@ 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 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