f2fs: return error during fill_super

Let's avoid BUG_ON during fill_super, when on-disk was totall corrupted.

Reviewed-by: Chao Yu <[email protected]>
Signed-off-by: Jaegeuk Kim <[email protected]>
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 40e1d20..b03f65e 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -3476,7 +3476,7 @@ static int build_curseg(struct f2fs_sb_info *sbi)
 	return restore_curseg_summaries(sbi);
 }
 
-static void build_sit_entries(struct f2fs_sb_info *sbi)
+static int build_sit_entries(struct f2fs_sb_info *sbi)
 {
 	struct sit_info *sit_i = SIT_I(sbi);
 	struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_COLD_DATA);
@@ -3486,6 +3486,7 @@ static void build_sit_entries(struct f2fs_sb_info *sbi)
 	int sit_blk_cnt = SIT_BLK_CNT(sbi);
 	unsigned int i, start, end;
 	unsigned int readed, start_blk = 0;
+	int err = 0;
 
 	do {
 		readed = ra_meta_pages(sbi, start_blk, BIO_MAX_PAGES,
@@ -3504,7 +3505,9 @@ static void build_sit_entries(struct f2fs_sb_info *sbi)
 			sit = sit_blk->entries[SIT_ENTRY_OFFSET(sit_i, start)];
 			f2fs_put_page(page, 1);
 
-			check_block_count(sbi, start, &sit);
+			err = check_block_count(sbi, start, &sit);
+			if (err)
+				return err;
 			seg_info_from_raw_sit(se, &sit);
 
 			/* build discard map only one time */
@@ -3539,7 +3542,9 @@ static void build_sit_entries(struct f2fs_sb_info *sbi)
 
 		old_valid_blocks = se->valid_blocks;
 
-		check_block_count(sbi, start, &sit);
+		err = check_block_count(sbi, start, &sit);
+		if (err)
+			break;
 		seg_info_from_raw_sit(se, &sit);
 
 		if (f2fs_discard_en(sbi)) {
@@ -3559,6 +3564,7 @@ static void build_sit_entries(struct f2fs_sb_info *sbi)
 				se->valid_blocks - old_valid_blocks;
 	}
 	up_read(&curseg->journal_rwsem);
+	return err;
 }
 
 static void init_free_segmap(struct f2fs_sb_info *sbi)
@@ -3733,7 +3739,9 @@ int build_segment_manager(struct f2fs_sb_info *sbi)
 		return err;
 
 	/* reinit free segmap based on SIT */
-	build_sit_entries(sbi);
+	err = build_sit_entries(sbi);
+	if (err)
+		return err;
 
 	init_free_segmap(sbi);
 	err = build_dirty_segmap(sbi);