Patch "f2fs: cover large section in sanity check of super" has been added to the 4.5-stable tree

@@ -926,9 +926,25 @@ static loff_t max_file_blocks(void)
 	return result;
 }
 
+static int __f2fs_commit_super(struct buffer_head *bh,
+			struct f2fs_super_block *super)
+{
+	lock_buffer(bh);
+	if (super)
+		memcpy(bh->b_data + F2FS_SUPER_OFFSET, super, sizeof(*super));
+	set_buffer_uptodate(bh);
+	set_buffer_dirty(bh);
+	unlock_buffer(bh);
+
+	/* it's rare case, we can do fua all the time */
+	return __sync_dirty_buffer(bh, WRITE_FLUSH_FUA);
+}
+
 static inline bool sanity_check_area_boundary(struct super_block *sb,
-					struct f2fs_super_block *raw_super)
+					struct buffer_head *bh)
 {
+	struct f2fs_super_block *raw_super = (struct f2fs_super_block *)
+					(bh->b_data + F2FS_SUPER_OFFSET);
 	u32 segment0_blkaddr = le32_to_cpu(raw_super->segment0_blkaddr);
 	u32 cp_blkaddr = le32_to_cpu(raw_super->cp_blkaddr);
 	u32 sit_blkaddr = le32_to_cpu(raw_super->sit_blkaddr);

@@ -942,6 +958,10 @@ static inline bool sanity_check_area_bou
 	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);
+	u64 main_end_blkaddr = main_blkaddr +
+				(segment_count_main << log_blocks_per_seg);
+	u64 seg_end_blkaddr = segment0_blkaddr +
+				(segment_count << log_blocks_per_seg);
 
 	if (segment0_blkaddr != cp_blkaddr) {
 		f2fs_msg(sb, KERN_INFO,

@@ -986,22 +1006,45 @@ static inline bool sanity_check_area_bou
 		return true;
 	}
 
-	if (main_blkaddr + (segment_count_main << log_blocks_per_seg) !=
-		segment0_blkaddr + (segment_count << log_blocks_per_seg)) {
+	if (main_end_blkaddr > seg_end_blkaddr) {
 		f2fs_msg(sb, KERN_INFO,
-			"Wrong MAIN_AREA boundary, start(%u) end(%u) blocks(%u)",
+			"Wrong MAIN_AREA boundary, start(%u) end(%u) block(%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;
+	} else if (main_end_blkaddr < seg_end_blkaddr) {
+		int err = 0;
+		char *res;
+
+		/* fix in-memory information all the time */
+		raw_super->segment_count = cpu_to_le32((main_end_blkaddr -
+				segment0_blkaddr) >> log_blocks_per_seg);
+
+		if (f2fs_readonly(sb) || bdev_read_only(sb->s_bdev)) {
+			res = "internally";
+		} else {
+			err = __f2fs_commit_super(bh, NULL);
+			res = err ? "failed" : "done";
+		}
+		f2fs_msg(sb, KERN_INFO,
+			"Fix alignment : %s, start(%u) end(%u) block(%u)",
+			res, main_blkaddr,
+			segment0_blkaddr +
+				(segment_count << log_blocks_per_seg),
+			segment_count_main << log_blocks_per_seg);
+		if (err)
+			return true;
 	}
-
 	return false;
 }
 
 static int sanity_check_raw_super(struct super_block *sb,
-			struct f2fs_super_block *raw_super)
+				struct buffer_head *bh)
 {
+	struct f2fs_super_block *raw_super = (struct f2fs_super_block *)
+					(bh->b_data + F2FS_SUPER_OFFSET);
 	unsigned int blocksize;
 
 	if (F2FS_SUPER_MAGIC != le32_to_cpu(raw_super->magic)) {

@@ -1068,7 +1111,7 @@ static int sanity_check_raw_super(struct
 	}
 
 	/* check CP/SIT/NAT/SSA/MAIN_AREA area boundary */
-	if (sanity_check_area_boundary(sb, raw_super))
+	if (sanity_check_area_boundary(sb, bh))
 		return 1;
 
 	return 0;

@@ -1144,7 +1187,7 @@ static int read_raw_super_block(struct s
 {
 	int block;
 	struct buffer_head *bh;
-	struct f2fs_super_block *super, *buf;
+	struct f2fs_super_block *super;
 	int err = 0;
 
 	super = kzalloc(sizeof(struct f2fs_super_block), GFP_KERNEL);

@@ -1160,11 +1203,8 @@ static int read_raw_super_block(struct s
 			continue;
 		}
 
-		buf = (struct f2fs_super_block *)
-				(bh->b_data + F2FS_SUPER_OFFSET);
-
 		/* sanity checking of raw super */
-		if (sanity_check_raw_super(sb, buf)) {
+		if (sanity_check_raw_super(sb, bh)) {
 			f2fs_msg(sb, KERN_ERR,
 				"Can't find valid F2FS filesystem in %dth superblock",
 				block + 1);

@@ -1174,7 +1214,8 @@ static int read_raw_super_block(struct s
 		}
 
 		if (!*raw_super) {
-			memcpy(super, buf, sizeof(*super));
+			memcpy(super, bh->b_data + F2FS_SUPER_OFFSET,
+							sizeof(*super));
 			*valid_super_block = block;
 			*raw_super = super;
 		}

@@ -1194,42 +1235,29 @@ static int read_raw_super_block(struct s
 	return err;
 }
 
-static int __f2fs_commit_super(struct f2fs_sb_info *sbi, int block)
+int f2fs_commit_super(struct f2fs_sb_info *sbi, bool recover)
 {
-	struct f2fs_super_block *super = F2FS_RAW_SUPER(sbi);
 	struct buffer_head *bh;
 	int err;
 
-	bh = sb_getblk(sbi->sb, block);
+	/* write back-up superblock first */
+	bh = sb_getblk(sbi->sb, sbi->valid_super_block ? 0: 1);
 	if (!bh)
 		return -EIO;
-
-	lock_buffer(bh);
-	memcpy(bh->b_data + F2FS_SUPER_OFFSET, super, sizeof(*super));
-	set_buffer_uptodate(bh);
-	set_buffer_dirty(bh);
-	unlock_buffer(bh);
-
-	/* it's rare case, we can do fua all the time */
-	err = __sync_dirty_buffer(bh, WRITE_FLUSH_FUA);
+	err = __f2fs_commit_super(bh, F2FS_RAW_SUPER(sbi));
 	brelse(bh);
 
-	return err;
-}
-
-int f2fs_commit_super(struct f2fs_sb_info *sbi, bool recover)
-{
-	int err;
-
-	/* write back-up superblock first */
-	err = __f2fs_commit_super(sbi, sbi->valid_super_block ? 0 : 1);
-
 	/* if we are in recovery path, skip writing valid superblock */
 	if (recover || err)
 		return err;
 
 	/* write current valid superblock */
-	return __f2fs_commit_super(sbi, sbi->valid_super_block);
+	bh = sb_getblk(sbi->sb, sbi->valid_super_block);
+	if (!bh)
+		return -EIO;
+	err = __f2fs_commit_super(bh, F2FS_RAW_SUPER(sbi));
+	brelse(bh);
+	return err;
 }
 
 static int f2fs_fill_super(struct super_block *sb, void *data, int silent)