[PATCH 1/2] f2fs: cover large section in sanity check of super

[Jaegeuk Kim]

This patch fixes the bug which does not cover a large section case when checking
the sanity of superblock.

Reported-by: Matthias Prager <linux@xxxxxxxxxxxxxxxxx>
Reported-by: David Gnedt <david.gnedt@xxxxxxxxxxx>
Cc: stable 4.5+ <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
---
 fs/f2fs/super.c | 19 +++++++++++++++++--
 1 file changed, 17 insertions(+), 2 deletions(-)

diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 15bb81f..fc9147f 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -1000,6 +1000,7 @@ static inline bool sanity_check_area_boundary(struct super_block *sb,
 	u32 segment_count_main = le32_to_cpu(raw_super->segment_count_main);
 	u32 segment_count = le32_to_cpu(raw_super->segment_count);
 	u32 log_blocks_per_seg = le32_to_cpu(raw_super->log_blocks_per_seg);
+	u32 segs_per_sec = le32_to_cpu(raw_super->segs_per_sec);
 
 	if (segment0_blkaddr != cp_blkaddr) {
 		f2fs_msg(sb, KERN_INFO,
@@ -1044,12 +1045,26 @@ static inline bool sanity_check_area_boundary(struct super_block *sb,
 		return true;
 	}
 
-	if (main_blkaddr + (segment_count_main << log_blocks_per_seg) !=
+	if (segs_per_sec == 1 &&
+		main_blkaddr + (segment_count_main << log_blocks_per_seg) !=
 		segment0_blkaddr + (segment_count << log_blocks_per_seg)) {
 		f2fs_msg(sb, KERN_INFO,
 			"Wrong MAIN_AREA boundary, start(%u) end(%u) blocks(%u)",
 			main_blkaddr,
-			segment0_blkaddr + (segment_count << log_blocks_per_seg),
+			segment0_blkaddr +
+			(segment_count << log_blocks_per_seg),
+			segment_count_main << log_blocks_per_seg);
+		return true;
+	}
+
+	if (segs_per_sec > 1 &&
+		main_blkaddr + (segment_count_main << log_blocks_per_seg) >
+		segment0_blkaddr + (segment_count << log_blocks_per_seg)) {
+		f2fs_msg(sb, KERN_INFO,
+			"Wrong MAIN_AREA boundary in large section, start(%u) end(%u) blocks(%u)",
+			main_blkaddr,
+			segment0_blkaddr +
+			(segment_count << log_blocks_per_seg),
 			segment_count_main << log_blocks_per_seg);
 		return true;
 	}
-- 
2.6.3