f2fs: new helper cur_cp_crc() getting crc in f2fs_checkpoint

There are four places that getting the crc value in f2fs_checkpoint,
just add a new helper cur_cp_crc for them.
Signed-off-by: NKinglong Mee <kinglongmee@gmail.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/checkpoint.c

@@ -683,8 +683,7 @@ static int get_checkpoint_version(struct f2fs_sb_info *sbi, block_t cp_addr,
 		return -EINVAL;
 	}
 
-	crc = le32_to_cpu(*((__le32 *)((unsigned char *)*cp_block
-							+ crc_offset)));
+	crc = cur_cp_crc(*cp_block);
 	if (!f2fs_crc_valid(sbi, crc, *cp_block, crc_offset)) {
 		f2fs_msg(sbi->sb, KERN_WARNING, "invalid crc value");
 		return -EINVAL;

fs/f2fs/f2fs.h

@@ -1126,6 +1126,12 @@ static inline unsigned long long cur_cp_version(struct f2fs_checkpoint *cp)
 	return le64_to_cpu(cp->checkpoint_ver);
 }
 
+static inline __u64 cur_cp_crc(struct f2fs_checkpoint *cp)
+{
+	size_t crc_offset = le32_to_cpu(cp->checksum_offset);
+	return le32_to_cpu(*((__le32 *)((unsigned char *)cp + crc_offset)));
+}
+
 static inline bool __is_set_ckpt_flags(struct f2fs_checkpoint *cp, unsigned int f)
 {
 	unsigned int ckpt_flags = le32_to_cpu(cp->ckpt_flags);

fs/f2fs/node.c

@@ -2462,9 +2462,6 @@ static int __get_nat_bitmaps(struct f2fs_sb_info *sbi)
 	unsigned int nat_bits_bytes = nm_i->nat_blocks / BITS_PER_BYTE;
 	unsigned int i;
 	__u64 cp_ver = cur_cp_version(ckpt);
-	size_t crc_offset = le32_to_cpu(ckpt->checksum_offset);
-	__u64 crc = le32_to_cpu(*((__le32 *)
-				((unsigned char *)ckpt + crc_offset)));
 	block_t nat_bits_addr;
 
 	if (!enabled_nat_bits(sbi, NULL))
@@ -2487,7 +2484,7 @@ static int __get_nat_bitmaps(struct f2fs_sb_info *sbi)
 		f2fs_put_page(page, 1);
 	}
 
-	cp_ver |= (crc << 32);
+	cp_ver |= (cur_cp_crc(ckpt) << 32);
 	if (cpu_to_le64(cp_ver) != *(__le64 *)nm_i->nat_bits) {
 		disable_nat_bits(sbi, true);
 		return 0;

fs/f2fs/node.h

@@ -300,14 +300,11 @@ static inline void fill_node_footer_blkaddr(struct page *page, block_t blkaddr)
 {
 	struct f2fs_checkpoint *ckpt = F2FS_CKPT(F2FS_P_SB(page));
 	struct f2fs_node *rn = F2FS_NODE(page);
-	size_t crc_offset = le32_to_cpu(ckpt->checksum_offset);
-	__u64 cp_ver = le64_to_cpu(ckpt->checkpoint_ver);
+	__u64 cp_ver = cur_cp_version(ckpt);
+
+	if (__is_set_ckpt_flags(ckpt, CP_CRC_RECOVERY_FLAG))
+		cp_ver |= (cur_cp_crc(ckpt) << 32);
 
-	if (__is_set_ckpt_flags(ckpt, CP_CRC_RECOVERY_FLAG)) {
-		__u64 crc = le32_to_cpu(*((__le32 *)
-				((unsigned char *)ckpt + crc_offset)));
-		cp_ver |= (crc << 32);
-	}
 	rn->footer.cp_ver = cpu_to_le64(cp_ver);
 	rn->footer.next_blkaddr = cpu_to_le32(blkaddr);
 }
@@ -315,14 +312,11 @@ static inline void fill_node_footer_blkaddr(struct page *page, block_t blkaddr)
 static inline bool is_recoverable_dnode(struct page *page)
 {
 	struct f2fs_checkpoint *ckpt = F2FS_CKPT(F2FS_P_SB(page));
-	size_t crc_offset = le32_to_cpu(ckpt->checksum_offset);
 	__u64 cp_ver = cur_cp_version(ckpt);
 
-	if (__is_set_ckpt_flags(ckpt, CP_CRC_RECOVERY_FLAG)) {
-		__u64 crc = le32_to_cpu(*((__le32 *)
-				((unsigned char *)ckpt + crc_offset)));
-		cp_ver |= (crc << 32);
-	}
+	if (__is_set_ckpt_flags(ckpt, CP_CRC_RECOVERY_FLAG))
+		cp_ver |= (cur_cp_crc(ckpt) << 32);
+
 	return cp_ver == cpver_of_node(page);
 }