[PATCH] fault-injection capabilities infrastructure

This patch provides base functions implement to fault-injection
capabilities.

- The function should_fail() is taken from failmalloc-1.0
  (http://www.nongnu.org/failmalloc/)

[akpm@osdl.org: cleanups, comments, add __init]
Cc: <okuji@enbug.org>
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Don Mullis <dwm@meer.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 69 insertions, 0 deletions

diff --git a/include/linux/fault-inject.h b/include/linux/fault-inject.h
new file mode 100644
index 00000000000..4df4902bc8d
--- /dev/null
+++ b/include/linux/fault-inject.h
@@ -0,0 +1,69 @@
+#ifndef _LINUX_FAULT_INJECT_H
+#define _LINUX_FAULT_INJECT_H
+
+#ifdef CONFIG_FAULT_INJECTION
+
+#include <linux/types.h>
+#include <linux/debugfs.h>
+#include <asm/atomic.h>
+
+/*
+ * For explanation of the elements of this struct, see
+ * Documentation/fault-injection/fault-injection.txt
+ */
+struct fault_attr {
+	unsigned long probability;
+	unsigned long interval;
+	atomic_t times;
+	atomic_t space;
+	unsigned long verbose;
+
+	unsigned long count;
+
+#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
+
+	struct {
+		struct dentry *dir;
+
+		struct dentry *probability_file;
+		struct dentry *interval_file;
+		struct dentry *times_file;
+		struct dentry *space_file;
+		struct dentry *verbose_file;
+	} dentries;
+
+#endif
+};
+
+#define FAULT_ATTR_INITIALIZER {				\
+		.interval = 1,					\
+		.times = ATOMIC_INIT(1),			\
+	}
+
+#define DECLARE_FAULT_ATTR(name) struct fault_attr name = FAULT_ATTR_INITIALIZER
+int setup_fault_attr(struct fault_attr *attr, char *str);
+void should_fail_srandom(unsigned long entropy);
+int should_fail(struct fault_attr *attr, ssize_t size);
+
+#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
+
+int init_fault_attr_dentries(struct fault_attr *attr, const char *name);
+void cleanup_fault_attr_dentries(struct fault_attr *attr);
+
+#else /* CONFIG_FAULT_INJECTION_DEBUG_FS */
+
+static inline int init_fault_attr_dentries(struct fault_attr *attr,
+					  const char *name)
+{
+	return -ENODEV;
+}
+
+static inline void cleanup_fault_attr_dentries(struct fault_attr *attr)
+{
+}
+
+#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
+
+#endif /* CONFIG_FAULT_INJECTION */
+
+#endif /* _LINUX_FAULT_INJECT_H */