f2fs: add fault injection to sysfs

This patch introduces a new struct f2fs_fault_info and a global f2fs_fault
to save fault injection status. Fault injection entries are created in
/sys/fs/f2fs/fault_injection/ during initializing f2fs module.

Signed-off-by: Sheng Yong <shengyong1@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

1 files changed, 26 insertions, 5 deletions

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index ec978b44d546..1351178b2b58 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -48,15 +48,36 @@ enum {
 	FAULT_MAX,
 };
 
-extern u32 f2fs_fault_rate;
-extern atomic_t f2fs_ops;
+struct f2fs_fault_info {
+	atomic_t inject_ops;
+	unsigned int inject_rate;
+	unsigned int inject_type;
+};
+
+extern struct f2fs_fault_info f2fs_fault;
 extern char *fault_name[FAULT_MAX];
+#define IS_FAULT_SET(type) (f2fs_fault.inject_type & (1 << (type)))
 
 static inline bool time_to_inject(int type)
 {
-	atomic_inc(&f2fs_ops);
-	if (f2fs_fault_rate && (atomic_read(&f2fs_ops) >= f2fs_fault_rate)) {
-		atomic_set(&f2fs_ops, 0);
+	if (!f2fs_fault.inject_rate)
+		return false;
+	if (type == FAULT_KMALLOC && !IS_FAULT_SET(type))
+		return false;
+	else if (type == FAULT_PAGE_ALLOC && !IS_FAULT_SET(type))
+		return false;
+	else if (type == FAULT_ALLOC_NID && !IS_FAULT_SET(type))
+		return false;
+	else if (type == FAULT_ORPHAN && !IS_FAULT_SET(type))
+		return false;
+	else if (type == FAULT_BLOCK && !IS_FAULT_SET(type))
+		return false;
+	else if (type == FAULT_DIR_DEPTH && !IS_FAULT_SET(type))
+		return false;
+
+	atomic_inc(&f2fs_fault.inject_ops);
+	if (atomic_read(&f2fs_fault.inject_ops) >= f2fs_fault.inject_rate) {
+		atomic_set(&f2fs_fault.inject_ops, 0);
 		printk("%sF2FS-fs : inject %s in %pF\n",
 				KERN_INFO,
 				fault_name[type],