summaryrefslogtreecommitdiff
path: root/ctree.h
diff options
context:
space:
mode:
authorChris Mason <chris.mason@oracle.com>2009-05-29 16:35:30 -0400
committerChris Mason <chris.mason@oracle.com>2009-06-08 13:30:36 -0400
commit95d3f20b51e9b2ee21822313ad4f31279396407b (patch)
treeb120e33ca9ad3f04a0a32b62451e6ba5926b2ca0 /ctree.h
parent2d39a83829bfc26f0c79b33fca64540c634f7f18 (diff)
Mixed back reference (FORWARD ROLLING FORMAT CHANGE)
This commit introduces a new kind of back reference for btrfs metadata. Once a filesystem has been mounted with this commit, IT WILL NO LONGER BE MOUNTABLE BY OLDER KERNELS. The new back ref provides information about pointer's key, level and in which tree the pointer lives. This information allow us to find the pointer by searching the tree. The shortcoming of the new back ref is that it only works for pointers in tree blocks referenced by their owner trees. This is mostly a problem for snapshots, where resolving one of these fuzzy back references would be O(number_of_snapshots) and quite slow. The solution used here is to use the fuzzy back references in the common case where a given tree block is only referenced by one root, and use the full back references when multiple roots have a reference
Diffstat (limited to 'ctree.h')
-rw-r--r--ctree.h221
1 files changed, 176 insertions, 45 deletions
diff --git a/ctree.h b/ctree.h
index 8e7f8845..a9062ea8 100644
--- a/ctree.h
+++ b/ctree.h
@@ -31,6 +31,8 @@ struct btrfs_trans_handle;
#define BTRFS_MAX_LEVEL 8
+#define BTRFS_COMPAT_EXTENT_TREE_V0
+
/* holds pointers to all of the tree roots */
#define BTRFS_ROOT_TREE_OBJECTID 1ULL
@@ -249,7 +251,18 @@ static inline unsigned long btrfs_chunk_item_size(int num_stripes)
}
#define BTRFS_FSID_SIZE 16
-#define BTRFS_HEADER_FLAG_WRITTEN (1 << 0)
+#define BTRFS_HEADER_FLAG_WRITTEN (1ULL << 0)
+#define BTRFS_HEADER_FLAG_RELOC (1ULL << 1)
+#define BTRFS_SUPER_FLAG_SEEDING (1ULL << 32)
+#define BTRFS_SUPER_FLAG_METADUMP (1ULL << 33)
+
+#define BTRFS_BACKREF_REV_MAX 256
+#define BTRFS_BACKREF_REV_SHIFT 56
+#define BTRFS_BACKREF_REV_MASK (((u64)BTRFS_BACKREF_REV_MAX - 1) << \
+ BTRFS_BACKREF_REV_SHIFT)
+
+#define BTRFS_OLD_BACKREF_REV 0
+#define BTRFS_MIXED_BACKREF_REV 1
/*
* every tree block (leaf or node) starts with this header.
@@ -278,8 +291,6 @@ struct btrfs_header {
sizeof(struct btrfs_item) - \
sizeof(struct btrfs_file_extent_item))
-#define BTRFS_SUPER_FLAG_SEEDING (1ULL << 32)
-#define BTRFS_SUPER_FLAG_METADUMP (1ULL << 33)
/*
* this is a very generous portion of the super block, giving us
@@ -338,9 +349,12 @@ struct btrfs_super_block {
* Compat flags that we support. If any incompat flags are set other than the
* ones specified below then we will fail to mount
*/
-#define BTRFS_FEATURE_COMPAT_SUPP 0x0
-#define BTRFS_FEATURE_COMPAT_RO_SUPP 0x0
-#define BTRFS_FEATURE_INCOMPAT_SUPP 0x0
+#define BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF (1ULL << 0)
+
+#define BTRFS_FEATURE_COMPAT_SUPP 0ULL
+#define BTRFS_FEATURE_COMPAT_RO_SUPP 0ULL
+#define BTRFS_FEATURE_INCOMPAT_SUPP \
+ BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF
/*
* A leaf is full of items. offset and size tell us where to find
@@ -387,32 +401,78 @@ struct btrfs_node {
* The slots array records the index of the item or block pointer
* used while walking the tree.
*/
+
struct btrfs_path {
struct extent_buffer *nodes[BTRFS_MAX_LEVEL];
int slots[BTRFS_MAX_LEVEL];
+ /* if there is real range locking, this locks field will change */
+ int locks[BTRFS_MAX_LEVEL];
int reada;
+ /* keep some upper locks as we walk down */
int lowest_level;
/*
* set by btrfs_split_item, tells search_slot to keep all locks
* and to force calls to keep space in the nodes
*/
- int search_for_split;
+ unsigned int search_for_split:1;
+ unsigned int keep_locks:1;
+ unsigned int skip_locking:1;
+ unsigned int leave_spinning:1;
};
/*
* items in the extent btree are used to record the objectid of the
* owner of the block and the number of references
*/
+
struct btrfs_extent_item {
+ __le64 refs;
+ __le64 generation;
+ __le64 flags;
+} __attribute__ ((__packed__));
+
+struct btrfs_extent_item_v0 {
__le32 refs;
} __attribute__ ((__packed__));
-struct btrfs_extent_ref {
+#define BTRFS_MAX_EXTENT_ITEM_SIZE(r) ((BTRFS_LEAF_DATA_SIZE(r) >> 4) - \
+ sizeof(struct btrfs_item))
+
+#define BTRFS_EXTENT_FLAG_DATA (1ULL << 0)
+#define BTRFS_EXTENT_FLAG_TREE_BLOCK (1ULL << 1)
+
+/* following flags only apply to tree blocks */
+
+/* use full backrefs for extent pointers in the block*/
+#define BTRFS_BLOCK_FLAG_FULL_BACKREF (1ULL << 8)
+
+struct btrfs_tree_block_info {
+ struct btrfs_disk_key key;
+ u8 level;
+} __attribute__ ((__packed__));
+
+struct btrfs_extent_data_ref {
+ __le64 root;
+ __le64 objectid;
+ __le64 offset;
+ __le32 count;
+} __attribute__ ((__packed__));
+
+struct btrfs_shared_data_ref {
+ __le32 count;
+} __attribute__ ((__packed__));
+
+struct btrfs_extent_inline_ref {
+ u8 type;
+ u64 offset;
+} __attribute__ ((__packed__));
+
+struct btrfs_extent_ref_v0 {
__le64 root;
__le64 generation;
__le64 objectid;
- __le32 num_refs;
+ __le32 count;
} __attribute__ ((__packed__));
/* dev extents record free space on individual devices. The owner
@@ -626,6 +686,8 @@ struct btrfs_fs_info {
struct btrfs_root *dev_root;
struct btrfs_root *csum_root;
+ struct cache_tree fs_root_cache;
+
/* the log root tree is a directory of all the other log roots */
struct btrfs_root *log_root_tree;
@@ -701,6 +763,7 @@ struct btrfs_root {
/* the dirty list is only used by non-reference counted roots */
struct list_head dirty_list;
+ struct cache_extent cache;
};
/*
@@ -761,7 +824,18 @@ struct btrfs_root {
* are used, and how many references there are to each block
*/
#define BTRFS_EXTENT_ITEM_KEY 168
-#define BTRFS_EXTENT_REF_KEY 180
+
+#define BTRFS_TREE_BLOCK_REF_KEY 176
+
+#define BTRFS_EXTENT_DATA_REF_KEY 178
+
+/* old style extent backrefs */
+#define BTRFS_EXTENT_REF_V0_KEY 180
+
+#define BTRFS_SHARED_BLOCK_REF_KEY 182
+
+#define BTRFS_SHARED_DATA_REF_KEY 184
+
/*
* block groups give us hints into the extent allocation trees. Which
@@ -1066,24 +1140,68 @@ static inline u8 *btrfs_dev_extent_chunk_tree_uuid(struct btrfs_dev_extent *dev)
return (u8 *)((unsigned long)dev + ptr);
}
-/* struct btrfs_extent_ref */
-BTRFS_SETGET_FUNCS(ref_root, struct btrfs_extent_ref, root, 64);
-BTRFS_SETGET_FUNCS(ref_generation, struct btrfs_extent_ref, generation, 64);
-BTRFS_SETGET_FUNCS(ref_objectid, struct btrfs_extent_ref, objectid, 64);
-BTRFS_SETGET_FUNCS(ref_num_refs, struct btrfs_extent_ref, num_refs, 32);
-
-BTRFS_SETGET_STACK_FUNCS(stack_ref_root, struct btrfs_extent_ref, root, 64);
-BTRFS_SETGET_STACK_FUNCS(stack_ref_generation, struct btrfs_extent_ref,
- generation, 64);
-BTRFS_SETGET_STACK_FUNCS(stack_ref_objectid, struct btrfs_extent_ref,
- objectid, 64);
-BTRFS_SETGET_STACK_FUNCS(stack_ref_num_refs, struct btrfs_extent_ref,
- num_refs, 32);
/* struct btrfs_extent_item */
-BTRFS_SETGET_FUNCS(extent_refs, struct btrfs_extent_item, refs, 32);
-BTRFS_SETGET_STACK_FUNCS(stack_extent_refs, struct btrfs_extent_item,
- refs, 32);
+BTRFS_SETGET_FUNCS(extent_refs, struct btrfs_extent_item, refs, 64);
+BTRFS_SETGET_FUNCS(extent_generation, struct btrfs_extent_item,
+ generation, 64);
+BTRFS_SETGET_FUNCS(extent_flags, struct btrfs_extent_item, flags, 64);
+
+BTRFS_SETGET_FUNCS(extent_refs_v0, struct btrfs_extent_item_v0, refs, 32);
+
+BTRFS_SETGET_FUNCS(tree_block_level, struct btrfs_tree_block_info, level, 8);
+
+static inline void btrfs_tree_block_key(struct extent_buffer *eb,
+ struct btrfs_tree_block_info *item,
+ struct btrfs_disk_key *key)
+{
+ read_eb_member(eb, item, struct btrfs_tree_block_info, key, key);
+}
+
+static inline void btrfs_set_tree_block_key(struct extent_buffer *eb,
+ struct btrfs_tree_block_info *item,
+ struct btrfs_disk_key *key)
+{
+ write_eb_member(eb, item, struct btrfs_tree_block_info, key, key);
+}
+
+BTRFS_SETGET_FUNCS(extent_data_ref_root, struct btrfs_extent_data_ref,
+ root, 64);
+BTRFS_SETGET_FUNCS(extent_data_ref_objectid, struct btrfs_extent_data_ref,
+ objectid, 64);
+BTRFS_SETGET_FUNCS(extent_data_ref_offset, struct btrfs_extent_data_ref,
+ offset, 64);
+BTRFS_SETGET_FUNCS(extent_data_ref_count, struct btrfs_extent_data_ref,
+ count, 32);
+
+BTRFS_SETGET_FUNCS(shared_data_ref_count, struct btrfs_shared_data_ref,
+ count, 32);
+
+BTRFS_SETGET_FUNCS(extent_inline_ref_type, struct btrfs_extent_inline_ref,
+ type, 8);
+BTRFS_SETGET_FUNCS(extent_inline_ref_offset, struct btrfs_extent_inline_ref,
+ offset, 64);
+
+static inline u32 btrfs_extent_inline_ref_size(int type)
+{
+ if (type == BTRFS_TREE_BLOCK_REF_KEY ||
+ type == BTRFS_SHARED_BLOCK_REF_KEY)
+ return sizeof(struct btrfs_extent_inline_ref);
+ if (type == BTRFS_SHARED_DATA_REF_KEY)
+ return sizeof(struct btrfs_shared_data_ref) +
+ sizeof(struct btrfs_extent_inline_ref);
+ if (type == BTRFS_EXTENT_DATA_REF_KEY)
+ return sizeof(struct btrfs_extent_data_ref) +
+ offsetof(struct btrfs_extent_inline_ref, offset);
+ BUG();
+ return 0;
+}
+
+BTRFS_SETGET_FUNCS(ref_root_v0, struct btrfs_extent_ref_v0, root, 64);
+BTRFS_SETGET_FUNCS(ref_generation_v0, struct btrfs_extent_ref_v0,
+ generation, 64);
+BTRFS_SETGET_FUNCS(ref_objectid_v0, struct btrfs_extent_ref_v0, objectid, 64);
+BTRFS_SETGET_FUNCS(ref_count_v0, struct btrfs_extent_ref_v0, count, 32);
/* struct btrfs_node */
BTRFS_SETGET_FUNCS(key_blockptr, struct btrfs_key_ptr, blockptr, 64);
@@ -1313,6 +1431,21 @@ static inline int btrfs_clear_header_flag(struct extent_buffer *eb, u64 flag)
return (flags & flag) == flag;
}
+static inline int btrfs_header_backref_rev(struct extent_buffer *eb)
+{
+ u64 flags = btrfs_header_flags(eb);
+ return flags >> BTRFS_BACKREF_REV_SHIFT;
+}
+
+static inline void btrfs_set_header_backref_rev(struct extent_buffer *eb,
+ int rev)
+{
+ u64 flags = btrfs_header_flags(eb);
+ flags &= ~BTRFS_BACKREF_REV_MASK;
+ flags |= (u64)rev << BTRFS_BACKREF_REV_SHIFT;
+ btrfs_set_header_flags(eb, flags);
+}
+
static inline u8 *btrfs_header_fsid(struct extent_buffer *eb)
{
unsigned long ptr = offsetof(struct btrfs_header, fsid);
@@ -1521,32 +1654,30 @@ struct btrfs_block_group_cache *btrfs_find_block_group(struct btrfs_root *root,
*hint, u64 search_start,
int data, int owner);
struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
- struct btrfs_root *root,
- u32 blocksize, u64 parent,
- u64 root_objectid,
- u64 ref_generation,
- int level,
- u64 hint,
- u64 empty_size);
+ struct btrfs_root *root,
+ u32 blocksize, u64 root_objectid,
+ struct btrfs_disk_key *key, int level,
+ u64 hint, u64 empty_size);
int btrfs_alloc_extent(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 num_bytes, u64 parent,
u64 root_objectid, u64 ref_generation,
u64 owner, u64 empty_size, u64 hint_byte,
u64 search_end, struct btrfs_key *ins, int data);
-int btrfs_lookup_extent_ref(struct btrfs_trans_handle *trans,
- struct btrfs_root *root, u64 bytenr,
- u64 num_bytes, u32 *refs);
+int btrfs_lookup_extent_info(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, u64 bytenr,
+ u64 num_bytes, u64 *refs, u64 *flags);
+int btrfs_set_block_flags(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ u64 bytenr, u64 num_bytes, u64 flags);
int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
- struct extent_buffer *orig_buf, struct extent_buffer *buf,
- u32 *nr_extents);
-int btrfs_update_ref(struct btrfs_trans_handle *trans,
- struct btrfs_root *root, struct extent_buffer *orig_buf,
- struct extent_buffer *buf, int start_slot, int nr);
-int btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
- *root, u64 bytenr, u64 num_bytes, u64 parent,
- u64 root_objectid, u64 ref_generation,
- u64 owner_objectid, int pin);
+ struct extent_buffer *buf, int record_parent);
+int btrfs_dec_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
+ struct extent_buffer *buf, int record_parent);
+int btrfs_free_extent(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ u64 bytenr, u64 num_bytes, u64 parent,
+ u64 root_objectid, u64 owner, u64 offset);
int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct extent_io_tree *unpin);