f2fs: introduce macro __cp_payload

This patch introduce macro __cp_payload.

Signed-off-by: Wanpeng Li <wanpeng.li@linux.intel.com>
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index 6faffce..c7cafd8 100644
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -471,8 +471,7 @@
 
 	set_sbi_flag(sbi, SBI_POR_DOING);
 
-	start_blk = __start_cp_addr(sbi) + 1 +
-		le32_to_cpu(F2FS_RAW_SUPER(sbi)->cp_payload);
+	start_blk = __start_cp_addr(sbi) + 1 + __cp_payload(sbi);
 	orphan_blkaddr = __start_sum_addr(sbi) - 1;
 
 	ra_meta_pages(sbi, start_blk, orphan_blkaddr, META_CP);
@@ -615,7 +614,7 @@
 	unsigned long blk_size = sbi->blocksize;
 	unsigned long long cp1_version = 0, cp2_version = 0;
 	unsigned long long cp_start_blk_no;
-	unsigned int cp_blks = 1 + le32_to_cpu(F2FS_RAW_SUPER(sbi)->cp_payload);
+	unsigned int cp_blks = 1 + __cp_payload(sbi);
 	block_t cp_blk_no;
 	int i;
 
@@ -884,7 +883,7 @@
 	__u32 crc32 = 0;
 	void *kaddr;
 	int i;
-	int cp_payload_blks = le32_to_cpu(F2FS_RAW_SUPER(sbi)->cp_payload);
+	int cp_payload_blks = __cp_payload(sbi);
 
 	/*
 	 * This avoids to conduct wrong roll-forward operations and uses
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 51d97f7..7ced71b 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -982,12 +982,17 @@
 	return 0;
 }
 
+static inline block_t __cp_payload(struct f2fs_sb_info *sbi)
+{
+	return le32_to_cpu(F2FS_RAW_SUPER(sbi)->cp_payload);
+}
+
 static inline void *__bitmap_ptr(struct f2fs_sb_info *sbi, int flag)
 {
 	struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
 	int offset;
 
-	if (le32_to_cpu(F2FS_RAW_SUPER(sbi)->cp_payload) > 0) {
+	if (__cp_payload(sbi) > 0) {
 		if (flag == NAT_BITMAP)
 			return &ckpt->sit_nat_version_bitmap;
 		else