[PATCH v2] f2fs: improve print log in f2fs_sanity_check_ckpt()

[Chao Yu]

As Park Ju Hyung suggested:

"I'd like to suggest to write down an actual version of f2fs-tools
here as we've seen older versions of fsck doing even more damage
and the users might not have the latest f2fs-tools installed."

This patch give a more detailed info of how we fix such corruption
to user to avoid damageable repair with low version fsck.

Signed-off-by: Park Ju Hyung <qkrwngud825@xxxxxxxxx>
Signed-off-by: Chao Yu <yuchao0@xxxxxxxxxx>
---
v2:
- add fixing patch's title in log suggested by Jaegeuk.
 fs/f2fs/super.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 1a6d82d558e4..47dae7c3ae4f 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -2696,7 +2696,9 @@ int f2fs_sanity_check_ckpt(struct f2fs_sb_info *sbi)
 
 	if (__is_set_ckpt_flags(ckpt, CP_LARGE_NAT_BITMAP_FLAG) &&
 		le32_to_cpu(ckpt->checksum_offset) != CP_MIN_CHKSUM_OFFSET) {
-		f2fs_warn(sbi, "layout of large_nat_bitmap is deprecated, run fsck to repair, chksum_offset: %u",
+		f2fs_warn(sbi, "using deprecated layout of large_nat_bitmap, "
+			  "please run fsck v1.13.0 or higher to repair, chksum_offset: %u, "
+			  "fixed with patch: \"f2fs-tools: relocate chksum_offset for large_nat_bitmap feature\"",
 			  le32_to_cpu(ckpt->checksum_offset));
 		return 1;
 	}
-- 
2.18.0.rc1