-#ifndef __CTREE__
-#define __CTREE__
+#ifndef __BTRFS__
+#define __BTRFS__
-#define CTREE_BLOCKSIZE 256
+#include "list.h"
+#include "kerncompat.h"
-struct key {
+#define BTRFS_BLOCKSIZE 1024
+
+/*
+ * the key defines the order in the tree, and so it also defines (optimal)
+ * block layout. objectid corresonds to the inode number. The flags
+ * tells us things about the object, and is a kind of stream selector.
+ * so for a given inode, keys with flags of 1 might refer to the inode
+ * data, flags of 2 may point to file data in the btree and flags == 3
+ * may point to extents.
+ *
+ * offset is the starting byte offset for this key in the stream.
+ *
+ * btrfs_disk_key is in disk byte order. struct btrfs_key is always
+ * in cpu native order. Otherwise they are identical and their sizes
+ * should be the same (ie both packed)
+ */
+struct btrfs_disk_key {
+ __le64 objectid;
+ __le32 flags;
+ __le64 offset;
+} __attribute__ ((__packed__));
+
+struct btrfs_key {
u64 objectid;
u32 flags;
u64 offset;
} __attribute__ ((__packed__));
-struct header {
- u64 fsid[2]; /* FS specific uuid */
- u64 blocknr;
- u64 parentid;
- u32 csum;
- u32 ham;
- u16 nritems;
- u16 flags;
+/*
+ * every tree block (leaf or node) starts with this header.
+ */
+struct btrfs_header {
+ __le64 fsid[2]; /* FS specific uuid */
+ __le64 blocknr; /* which block this node is supposed to live in */
+ __le64 parentid; /* objectid of the tree root */
+ __le32 csum;
+ __le32 ham;
+ __le16 nritems;
+ __le16 flags;
+ /* generation flags to be added */
} __attribute__ ((__packed__));
-#define NODEPTRS_PER_BLOCK ((CTREE_BLOCKSIZE - sizeof(struct header)) / \
- (sizeof(struct key) + sizeof(u64)))
-
-#define MAX_LEVEL 8
-#define node_level(f) ((f) & (MAX_LEVEL-1))
-#define is_leaf(f) (node_level(f) == 0)
+#define BTRFS_MAX_LEVEL 8
+#define NODEPTRS_PER_BLOCK ((BTRFS_BLOCKSIZE - sizeof(struct btrfs_header)) / \
+ (sizeof(struct btrfs_disk_key) + sizeof(u64)))
-struct tree_buffer;
+struct btrfs_buffer;
-struct ctree_root {
- struct tree_buffer *node;
- struct ctree_root *extent_root;
- struct key current_insert;
+/*
+ * in ram representation of the tree. extent_root is used for all allocations
+ * and for the extent tree extent_root root. current_insert is used
+ * only for the extent tree.
+ */
+struct btrfs_root {
+ struct btrfs_buffer *node;
+ struct btrfs_buffer *commit_root;
+ struct btrfs_root *extent_root;
+ struct btrfs_key current_insert;
+ struct btrfs_key last_insert;
int fp;
struct radix_tree_root cache_radix;
+ struct radix_tree_root pinned_radix;
+ struct list_head trans;
+ struct list_head cache;
+ int cache_size;
};
-struct ctree_root_info {
+/*
+ * describes a tree on disk
+ */
+struct btrfs_root_info {
u64 fsid[2]; /* FS specific uuid */
u64 blocknr; /* blocknr of this block */
u64 objectid; /* inode number of this root */
- u64 tree_root; /* the tree root */
+ u64 tree_root; /* the tree root block */
u32 csum;
u32 ham;
u64 snapuuid[2]; /* root specific uuid */
} __attribute__ ((__packed__));
-struct ctree_super_block {
- struct ctree_root_info root_info;
- struct ctree_root_info extent_info;
+/*
+ * the super block basically lists the main trees of the FS
+ * it currently lacks any block count etc etc
+ */
+struct btrfs_super_block {
+ struct btrfs_root_info root_info;
+ struct btrfs_root_info extent_info;
} __attribute__ ((__packed__));
-struct item {
- struct key key;
- u16 offset;
- u16 size;
+/*
+ * A leaf is full of items. The exact type of item is defined by
+ * the key flags parameter. offset and size tell us where to find
+ * the item in the leaf (relative to the start of the data area)
+ */
+struct btrfs_item {
+ struct btrfs_disk_key key;
+ __le16 offset;
+ __le16 size;
} __attribute__ ((__packed__));
-#define LEAF_DATA_SIZE (CTREE_BLOCKSIZE - sizeof(struct header))
-struct leaf {
- struct header header;
+/*
+ * leaves have an item area and a data area:
+ * [item0, item1....itemN] [free space] [dataN...data1, data0]
+ *
+ * The data is separate from the items to get the keys closer together
+ * during searches.
+ */
+#define LEAF_DATA_SIZE (BTRFS_BLOCKSIZE - sizeof(struct btrfs_header))
+struct btrfs_leaf {
+ struct btrfs_header header;
union {
- struct item items[LEAF_DATA_SIZE/sizeof(struct item)];
- u8 data[CTREE_BLOCKSIZE-sizeof(struct header)];
+ struct btrfs_item items[LEAF_DATA_SIZE/
+ sizeof(struct btrfs_item)];
+ u8 data[BTRFS_BLOCKSIZE - sizeof(struct btrfs_header)];
};
} __attribute__ ((__packed__));
-struct node {
- struct header header;
- struct key keys[NODEPTRS_PER_BLOCK];
- u64 blockptrs[NODEPTRS_PER_BLOCK];
+/*
+ * all non-leaf blocks are nodes, they hold only keys and pointers to
+ * other blocks
+ */
+struct btrfs_node {
+ struct btrfs_header header;
+ struct btrfs_disk_key keys[NODEPTRS_PER_BLOCK];
+ __le64 blockptrs[NODEPTRS_PER_BLOCK];
} __attribute__ ((__packed__));
-struct extent_item {
- u32 refs;
- u64 owner;
+/*
+ * 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 {
+ __le32 refs;
+ __le64 owner;
} __attribute__ ((__packed__));
-struct ctree_path {
- struct tree_buffer *nodes[MAX_LEVEL];
- int slots[MAX_LEVEL];
+/*
+ * btrfs_paths remember the path taken from the root down to the leaf.
+ * level 0 is always the leaf, and nodes[1...BTRFS_MAX_LEVEL] will point
+ * to any other levels that are present.
+ *
+ * The slots array records the index of the item or block pointer
+ * used while walking the tree.
+ */
+struct btrfs_path {
+ struct btrfs_buffer *nodes[BTRFS_MAX_LEVEL];
+ int slots[BTRFS_MAX_LEVEL];
};
+
+static inline u64 btrfs_extent_owner(struct btrfs_extent_item *ei)
+{
+ return le64_to_cpu(ei->owner);
+}
+
+static inline void btrfs_set_extent_owner(struct btrfs_extent_item *ei, u64 val)
+{
+ ei->owner = cpu_to_le64(val);
+}
+
+static inline u32 btrfs_extent_refs(struct btrfs_extent_item *ei)
+{
+ return le32_to_cpu(ei->refs);
+}
+
+static inline void btrfs_set_extent_refs(struct btrfs_extent_item *ei, u32 val)
+{
+ ei->refs = cpu_to_le32(val);
+}
+
+static inline u64 btrfs_node_blockptr(struct btrfs_node *n, int nr)
+{
+ return le64_to_cpu(n->blockptrs[nr]);
+}
+
+static inline void btrfs_set_node_blockptr(struct btrfs_node *n, int nr,
+ u64 val)
+{
+ n->blockptrs[nr] = cpu_to_le64(val);
+}
+
+static inline u16 btrfs_item_offset(struct btrfs_item *item)
+{
+ return le16_to_cpu(item->offset);
+}
+
+static inline void btrfs_set_item_offset(struct btrfs_item *item, u16 val)
+{
+ item->offset = cpu_to_le16(val);
+}
+
+static inline u16 btrfs_item_end(struct btrfs_item *item)
+{
+ return le16_to_cpu(item->offset) + le16_to_cpu(item->size);
+}
+
+static inline u16 btrfs_item_size(struct btrfs_item *item)
+{
+ return le16_to_cpu(item->size);
+}
+
+static inline void btrfs_set_item_size(struct btrfs_item *item, u16 val)
+{
+ item->size = cpu_to_le16(val);
+}
+
+static inline void btrfs_disk_key_to_cpu(struct btrfs_key *cpu,
+ struct btrfs_disk_key *disk)
+{
+ cpu->offset = le64_to_cpu(disk->offset);
+ cpu->flags = le32_to_cpu(disk->flags);
+ cpu->objectid = le64_to_cpu(disk->objectid);
+}
+
+static inline void btrfs_cpu_key_to_disk(struct btrfs_disk_key *disk,
+ struct btrfs_key *cpu)
+{
+ disk->offset = cpu_to_le64(cpu->offset);
+ disk->flags = cpu_to_le32(cpu->flags);
+ disk->objectid = cpu_to_le64(cpu->objectid);
+}
+
+static inline u64 btrfs_key_objectid(struct btrfs_disk_key *disk)
+{
+ return le64_to_cpu(disk->objectid);
+}
+
+static inline void btrfs_set_key_objectid(struct btrfs_disk_key *disk,
+ u64 val)
+{
+ disk->objectid = cpu_to_le64(val);
+}
+
+static inline u64 btrfs_key_offset(struct btrfs_disk_key *disk)
+{
+ return le64_to_cpu(disk->offset);
+}
+
+static inline void btrfs_set_key_offset(struct btrfs_disk_key *disk,
+ u64 val)
+{
+ disk->offset = cpu_to_le64(val);
+}
+
+static inline u32 btrfs_key_flags(struct btrfs_disk_key *disk)
+{
+ return le32_to_cpu(disk->flags);
+}
+
+static inline void btrfs_set_key_flags(struct btrfs_disk_key *disk,
+ u32 val)
+{
+ disk->flags = cpu_to_le32(val);
+}
+
+static inline u64 btrfs_header_blocknr(struct btrfs_header *h)
+{
+ return le64_to_cpu(h->blocknr);
+}
+
+static inline void btrfs_set_header_blocknr(struct btrfs_header *h, u64 blocknr)
+{
+ h->blocknr = cpu_to_le64(blocknr);
+}
+
+static inline u64 btrfs_header_parentid(struct btrfs_header *h)
+{
+ return le64_to_cpu(h->parentid);
+}
+
+static inline void btrfs_set_header_parentid(struct btrfs_header *h,
+ u64 parentid)
+{
+ h->parentid = cpu_to_le64(parentid);
+}
+
+static inline u16 btrfs_header_nritems(struct btrfs_header *h)
+{
+ return le16_to_cpu(h->nritems);
+}
+
+static inline void btrfs_set_header_nritems(struct btrfs_header *h, u16 val)
+{
+ h->nritems = cpu_to_le16(val);
+}
+
+static inline u16 btrfs_header_flags(struct btrfs_header *h)
+{
+ return le16_to_cpu(h->flags);
+}
+
+static inline void btrfs_set_header_flags(struct btrfs_header *h, u16 val)
+{
+ h->flags = cpu_to_le16(val);
+}
+
+static inline int btrfs_header_level(struct btrfs_header *h)
+{
+ return btrfs_header_flags(h) & (BTRFS_MAX_LEVEL - 1);
+}
+
+static inline void btrfs_set_header_level(struct btrfs_header *h, int level)
+{
+ u16 flags;
+ BUG_ON(level > BTRFS_MAX_LEVEL);
+ flags = btrfs_header_flags(h) & ~(BTRFS_MAX_LEVEL - 1);
+ btrfs_set_header_flags(h, flags | level);
+}
+
+static inline int btrfs_is_leaf(struct btrfs_node *n)
+{
+ return (btrfs_header_level(&n->header) == 0);
+}
+
+struct btrfs_buffer *btrfs_alloc_free_block(struct btrfs_root *root);
+int btrfs_inc_ref(struct btrfs_root *root, struct btrfs_buffer *buf);
+int btrfs_free_extent(struct btrfs_root *root, u64 blocknr, u64 num_blocks);
+int btrfs_search_slot(struct btrfs_root *root, struct btrfs_key *key,
+ struct btrfs_path *p, int ins_len, int cow);
+void btrfs_release_path(struct btrfs_root *root, struct btrfs_path *p);
+void btrfs_init_path(struct btrfs_path *p);
+int btrfs_del_item(struct btrfs_root *root, struct btrfs_path *path);
+int btrfs_insert_item(struct btrfs_root *root, struct btrfs_key *key,
+ void *data, int data_size);
+int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path);
+int btrfs_leaf_free_space(struct btrfs_leaf *leaf);
+int btrfs_drop_snapshot(struct btrfs_root *root, struct btrfs_buffer *snap);
+int btrfs_finish_extent_commit(struct btrfs_root *root);
#endif
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff