Btrfs-progs: Add chunk recover function - using old chunk items

Add chunk-recover program to check or rebuild chunk tree when the system
chunk array or chunk tree is broken.

Due to the importance of the system chunk array and chunk tree, if one of
them is broken, the whole btrfs will be broken even other data are OK.

But we have some hint(fsid, checksum...) to salvage the old metadata.
So this function will first scan the whole file system and collect the
needed data(chunk/block group/dev extent), and check for the references
between them. If the references are OK, the chunk tree can be rebuilt and
luckily the file system will be mountable.

Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

1 files changed, 64 insertions, 0 deletions

diff --git a/btrfsck.h b/btrfsck.h
index 37ac1303..a6151d5a 100644
--- a/btrfsck.h
+++ b/btrfsck.h
@@ -35,6 +35,8 @@ struct block_group_record {
 	/* Used to identify the orphan block groups */
 	struct list_head list;
 
+	u64 generation;
+
 	u64 objectid;
 	u8  type;
 	u64 offset;
@@ -51,6 +53,8 @@ struct device_record {
 	struct rb_node node;
 	u64 devid;
 
+	u64 generation;
+
 	u64 objectid;
 	u8  type;
 	u64 offset;
@@ -64,19 +68,31 @@ struct device_record {
 struct stripe {
 	u64 devid;
 	u64 offset;
+	u8 dev_uuid[BTRFS_UUID_SIZE];
 };
 
 struct chunk_record {
 	struct cache_extent cache;
 
+	struct list_head list;
+	struct list_head dextents;
+	struct block_group_record *bg_rec;
+
+	u64 generation;
+
 	u64 objectid;
 	u8  type;
 	u64 offset;
 
+	u64 owner;
 	u64 length;
 	u64 type_flags;
+	u64 stripe_len;
 	u16 num_stripes;
 	u16 sub_stripes;
+	u32 io_align;
+	u32 io_width;
+	u32 sector_size;
 	struct stripe stripes[0];
 };
 
@@ -89,6 +105,8 @@ struct device_extent_record {
 	struct list_head chunk_list;
 	struct list_head device_list;
 
+	u64 generation;
+
 	u64 objectid;
 	u8  type;
 	u64 offset;
@@ -115,4 +133,50 @@ struct device_extent_tree {
 	struct list_head no_device_orphans;
 };
 
+static inline unsigned long btrfs_chunk_record_size(int num_stripes)
+{
+	return sizeof(struct chunk_record) +
+	       sizeof(struct stripe) * num_stripes;
+}
+void free_chunk_cache_tree(struct cache_tree *chunk_cache);
+
+/* For block group tree */
+static inline void block_group_tree_init(struct block_group_tree *tree)
+{
+	cache_tree_init(&tree->tree);
+	INIT_LIST_HEAD(&tree->block_groups);
+}
+
+int insert_block_group_record(struct block_group_tree *tree,
+			      struct block_group_record *bg_rec);
+void free_block_group_tree(struct block_group_tree *tree);
+
+/* For device extent tree */
+static inline void device_extent_tree_init(struct device_extent_tree *tree)
+{
+	cache_tree_init(&tree->tree);
+	INIT_LIST_HEAD(&tree->no_chunk_orphans);
+	INIT_LIST_HEAD(&tree->no_device_orphans);
+}
+
+int insert_device_extent_record(struct device_extent_tree *tree,
+				struct device_extent_record *de_rec);
+void free_device_extent_tree(struct device_extent_tree *tree);
+
+
+/* Create various in-memory record by on-disk data */
+struct chunk_record *btrfs_new_chunk_record(struct extent_buffer *leaf,
+					    struct btrfs_key *key,
+					    int slot);
+struct block_group_record *
+btrfs_new_block_group_record(struct extent_buffer *leaf, struct btrfs_key *key,
+			     int slot);
+struct device_extent_record *
+btrfs_new_device_extent_record(struct extent_buffer *leaf,
+			       struct btrfs_key *key, int slot);
+
+int check_chunks(struct cache_tree *chunk_cache,
+		 struct block_group_tree *block_group_cache,
+		 struct device_extent_tree *dev_extent_cache,
+		 struct list_head *good, struct list_head *bad, int silent);
 #endif