linux/fs/btrfs/ctree.h

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#ifndef __BTRFS__
#define __BTRFS__
#include "list.h"
#include "kerncompat.h"
#define BTRFS_MAGIC "_BtRfS_M"
#define BTRFS_BLOCKSIZE 1024
#define BTRFS_ROOT_TREE_OBJECTID 1
#define BTRFS_EXTENT_TREE_OBJECTID 2
#define BTRFS_FS_TREE_OBJECTID 3
/*
* 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__));
/*
* every tree block (leaf or node) starts with this header.
*/
struct btrfs_header {
u8 fsid[16]; /* 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 BTRFS_MAX_LEVEL 8
#define NODEPTRS_PER_BLOCK ((BTRFS_BLOCKSIZE - sizeof(struct btrfs_header)) / \
(sizeof(struct btrfs_disk_key) + sizeof(u64)))
struct btrfs_buffer;
struct btrfs_root_item {
__le64 blocknr;
__le32 flags;
__le64 block_limit;
__le64 blocks_used;
__le32 refs;
};
/*
* 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_root *tree_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;
int ref_cows;
struct btrfs_root_item root_item;
struct btrfs_key root_key;
};
/*
* the super block basically lists the main trees of the FS
* it currently lacks any block count etc etc
*/
struct btrfs_super_block {
u8 fsid[16]; /* FS specific uuid */
__le64 blocknr; /* this block number */
__le32 csum;
__le64 magic;
__le16 blocksize;
__le64 generation;
__le64 root;
__le64 total_blocks;
__le64 blocks_used;
} __attribute__ ((__packed__));
/*
* 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__));
/*
* 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 btrfs_item items[LEAF_DATA_SIZE/
sizeof(struct btrfs_item)];
u8 data[BTRFS_BLOCKSIZE - sizeof(struct btrfs_header)];
};
} __attribute__ ((__packed__));
/*
* 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__));
/*
* 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__));
/*
* 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);
}
static inline u64 btrfs_root_blocknr(struct btrfs_root_item *item)
{
return le64_to_cpu(item->blocknr);
}
static inline void btrfs_set_root_blocknr(struct btrfs_root_item *item, u64 val)
{
item->blocknr = cpu_to_le64(val);
}
static inline u32 btrfs_root_refs(struct btrfs_root_item *item)
{
return le32_to_cpu(item->refs);
}
static inline void btrfs_set_root_refs(struct btrfs_root_item *item, u32 val)
{
item->refs = cpu_to_le32(val);
}
static inline u64 btrfs_super_blocknr(struct btrfs_super_block *s)
{
return le64_to_cpu(s->blocknr);
}
static inline void btrfs_set_super_blocknr(struct btrfs_super_block *s, u64 val)
{
s->blocknr = cpu_to_le64(val);
}
static inline u64 btrfs_super_root(struct btrfs_super_block *s)
{
return le64_to_cpu(s->root);
}
static inline void btrfs_set_super_root(struct btrfs_super_block *s, u64 val)
{
s->root = cpu_to_le64(val);
}
static inline u64 btrfs_super_total_blocks(struct btrfs_super_block *s)
{
return le64_to_cpu(s->total_blocks);
}
static inline void btrfs_set_super_total_blocks(struct btrfs_super_block *s,
u64 val)
{
s->total_blocks = cpu_to_le64(val);
}
static inline u64 btrfs_super_blocks_used(struct btrfs_super_block *s)
{
return le64_to_cpu(s->blocks_used);
}
static inline void btrfs_set_super_blocks_used(struct btrfs_super_block *s,
u64 val)
{
s->blocks_used = cpu_to_le64(val);
}
static inline u16 btrfs_super_blocksize(struct btrfs_super_block *s)
{
return le16_to_cpu(s->blocksize);
}
static inline void btrfs_set_super_blocksize(struct btrfs_super_block *s,
u16 val)
{
s->blocksize = cpu_to_le16(val);
}
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);
int btrfs_del_root(struct btrfs_root *root, struct btrfs_key *key);
int btrfs_insert_root(struct btrfs_root *root, struct btrfs_key *key,
struct btrfs_root_item *item);
int btrfs_update_root(struct btrfs_root *root, struct btrfs_key *key,
struct btrfs_root_item *item);
int btrfs_find_last_root(struct btrfs_root *root, u64 objectid,
struct btrfs_root_item *item, struct btrfs_key *key);
#endif