f2fs: add a help func F2FS_STAT() to get the f2fs_stat_info

Add a help func F2FS_STAT() to get the f2fs_stat_info.

Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
diff --git a/fs/f2fs/debug.c b/fs/f2fs/debug.c
index 0d6c6aa..fd12b7f 100644
--- a/fs/f2fs/debug.c
+++ b/fs/f2fs/debug.c
@@ -29,7 +29,7 @@
 
 static void update_general_status(struct f2fs_sb_info *sbi)
 {
-	struct f2fs_stat_info *si = sbi->stat_info;
+	struct f2fs_stat_info *si = F2FS_STAT(sbi);
 	int i;
 
 	/* valid check of the segment numbers */
@@ -83,7 +83,7 @@
  */
 static void update_sit_info(struct f2fs_sb_info *sbi)
 {
-	struct f2fs_stat_info *si = sbi->stat_info;
+	struct f2fs_stat_info *si = F2FS_STAT(sbi);
 	unsigned int blks_per_sec, hblks_per_sec, total_vblocks, bimodal, dist;
 	struct sit_info *sit_i = SIT_I(sbi);
 	unsigned int segno, vblocks;
@@ -118,7 +118,7 @@
  */
 static void update_mem_info(struct f2fs_sb_info *sbi)
 {
-	struct f2fs_stat_info *si = sbi->stat_info;
+	struct f2fs_stat_info *si = F2FS_STAT(sbi);
 	unsigned npages;
 
 	if (si->base_mem)
@@ -305,11 +305,10 @@
 	struct f2fs_super_block *raw_super = F2FS_RAW_SUPER(sbi);
 	struct f2fs_stat_info *si;
 
-	sbi->stat_info = kzalloc(sizeof(struct f2fs_stat_info), GFP_KERNEL);
-	if (!sbi->stat_info)
+	si = kzalloc(sizeof(struct f2fs_stat_info), GFP_KERNEL);
+	if (!si)
 		return -ENOMEM;
 
-	si = sbi->stat_info;
 	si->all_area_segs = le32_to_cpu(raw_super->segment_count);
 	si->sit_area_segs = le32_to_cpu(raw_super->segment_count_sit);
 	si->nat_area_segs = le32_to_cpu(raw_super->segment_count_nat);
@@ -319,6 +318,7 @@
 	si->main_area_zones = si->main_area_sections /
 				le32_to_cpu(raw_super->secs_per_zone);
 	si->sbi = sbi;
+	sbi->stat_info = si;
 
 	mutex_lock(&f2fs_stat_mutex);
 	list_add_tail(&si->stat_list, &f2fs_stat_list);
@@ -329,13 +329,13 @@
 
 void f2fs_destroy_stats(struct f2fs_sb_info *sbi)
 {
-	struct f2fs_stat_info *si = sbi->stat_info;
+	struct f2fs_stat_info *si = F2FS_STAT(sbi);
 
 	mutex_lock(&f2fs_stat_mutex);
 	list_del(&si->stat_list);
 	mutex_unlock(&f2fs_stat_mutex);
 
-	kfree(sbi->stat_info);
+	kfree(si);
 }
 
 void __init f2fs_create_root_stats(void)
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index c7620b9..0a352b6 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -1113,11 +1113,16 @@
 	unsigned base_mem, cache_mem;
 };
 
+static inline struct f2fs_stat_info *F2FS_STAT(struct f2fs_sb_info *sbi)
+{
+	return (struct f2fs_stat_info*)sbi->stat_info;
+}
+
 #define stat_inc_call_count(si)	((si)->call_count++)
 
 #define stat_inc_seg_count(sbi, type)					\
 	do {								\
-		struct f2fs_stat_info *si = sbi->stat_info;		\
+		struct f2fs_stat_info *si = F2FS_STAT(sbi);		\
 		(si)->tot_segs++;					\
 		if (type == SUM_TYPE_DATA)				\
 			si->data_segs++;				\
@@ -1130,14 +1135,14 @@
 
 #define stat_inc_data_blk_count(sbi, blks)				\
 	do {								\
-		struct f2fs_stat_info *si = sbi->stat_info;		\
+		struct f2fs_stat_info *si = F2FS_STAT(sbi);		\
 		stat_inc_tot_blk_count(si, blks);			\
 		si->data_blks += (blks);				\
 	} while (0)
 
 #define stat_inc_node_blk_count(sbi, blks)				\
 	do {								\
-		struct f2fs_stat_info *si = sbi->stat_info;		\
+		struct f2fs_stat_info *si = F2FS_STAT(sbi);		\
 		stat_inc_tot_blk_count(si, blks);			\
 		si->node_blks += (blks);				\
 	} while (0)