f2fs: inject kmalloc failure

This patch injects kmalloc failure given a fault injection rate.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 2234879..9a56f54 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -41,6 +41,11 @@
 
 #ifdef CONFIG_F2FS_FAULT_INJECTION
 u32 f2fs_fault_rate = 0;
+atomic_t f2fs_ops;
+
+char *fault_name[FAULT_MAX] = {
+	[FAULT_KMALLOC]		= "kmalloc",
+};
 #endif
 
 /* f2fs-wide shrinker description */
@@ -447,6 +452,7 @@
 				return -EINVAL;
 #ifdef CONFIG_F2FS_FAULT_INJECTION
 			f2fs_fault_rate = arg;
+			atomic_set(&f2fs_ops, 0);
 #else
 			f2fs_msg(sb, KERN_INFO,
 				"FAULT_INJECTION was not selected");