[PATCH 5/5] fsck.f2fs: try to recover cp_payload from valid cp pack

[Junling Zheng <zhengjunling@huawei.com>]

From: Chao Yu <yuchao0@huawei.com>

If sb checksum is not enabled, and cp pack is valid due to no
crc inconsistence, let's try to recover cp_payload based on
cp_pack_start_sum in cp pack.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
---
 fsck/f2fs.h  |  5 +++++
 fsck/mount.c | 10 +++++++---
 2 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/fsck/f2fs.h b/fsck/f2fs.h
index d216444..0d0d5e2 100644
--- a/fsck/f2fs.h
+++ b/fsck/f2fs.h
@@ -259,6 +259,11 @@ static inline unsigned long __bitmap_size(struct f2fs_sb_info *sbi, int flag)
 	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);
diff --git a/fsck/mount.c b/fsck/mount.c
index 9019921..0e8fa41 100644
--- a/fsck/mount.c
+++ b/fsck/mount.c
@@ -975,12 +975,16 @@ int sanity_check_ckpt(struct f2fs_sb_info *sbi)
 	}
 
 	cp_pack_start_sum = __start_sum_addr(sbi);
-	cp_payload = get_sb(cp_payload);
+	cp_payload = __cp_payload(sbi);
 	if (cp_pack_start_sum < cp_payload + 1 ||
 		cp_pack_start_sum > blocks_per_seg - 1 -
 			NR_CURSEG_TYPE) {
-		MSG(0, "\tWrong cp_pack_start_sum(%u)\n", cp_pack_start_sum);
-		return 1;
+		MSG(0, "\tWrong cp_pack_start_sum(%u) or cp_payload(%u)\n",
+			cp_pack_start_sum, cp_payload);
+		if ((get_sb(feature) & F2FS_FEATURE_SB_CHKSUM))
+			return 1;
+		set_sb(cp_payload, cp_pack_start_sum - 1);
+		update_superblock(sb, SB_MASK_ALL);
 	}
 
 	return 0;
-- 
2.19.0