Rename the extent_map code to extent_io

[btrfs-progs-unstable/devel.git] / ctree.h

/*
 * Copyright (C) 2007 Oracle.  All rights reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public
 * License v2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public
 * License along with this program; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 021110-1307, USA.
 */

#ifndef __BTRFS__
#define __BTRFS__

#include "list.h"
#include "kerncompat.h"
#include "radix-tree.h"
#include "extent-cache.h"
#include "extent_io.h"

struct btrfs_root;
struct btrfs_trans_handle;
#define BTRFS_MAGIC "_B4RfS_M"

#define BTRFS_MAX_LEVEL 8
#define BTRFS_ROOT_TREE_OBJECTID 1ULL
#define BTRFS_EXTENT_TREE_OBJECTID 2ULL
#define BTRFS_FS_TREE_OBJECTID 3ULL
#define BTRFS_ROOT_TREE_DIR_OBJECTID 4ULL
#define BTRFS_FIRST_FREE_OBJECTID 256ULL

/*
 * we can actually store much bigger names, but lets not confuse the rest
 * of linux
 */
#define BTRFS_NAME_LEN 255

/* 32 bytes in various csum fields */
#define BTRFS_CSUM_SIZE 32
/* four bytes for CRC32 */
#define BTRFS_CRC32_SIZE 4
#define BTRFS_EMPTY_DIR_SIZE 0

#define BTRFS_FT_UNKNOWN        0
#define BTRFS_FT_REG_FILE       1
#define BTRFS_FT_DIR            2
#define BTRFS_FT_CHRDEV         3
#define BTRFS_FT_BLKDEV         4
#define BTRFS_FT_FIFO           5
#define BTRFS_FT_SOCK           6
#define BTRFS_FT_SYMLINK        7
#define BTRFS_FT_XATTR          8
#define BTRFS_FT_MAX            9

/*
 * 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;
        u8 type;
        __le64 offset;
} __attribute__ ((__packed__));

struct btrfs_key {
        u64 objectid;
        u8 type;
        u64 offset;
} __attribute__ ((__packed__));

#define BTRFS_FSID_SIZE 16
/*
 * every tree block (leaf or node) starts with this header.
 */
struct btrfs_header {
        u8 csum[BTRFS_CSUM_SIZE];
        u8 fsid[BTRFS_FSID_SIZE]; /* FS specific uuid */
        __le64 bytenr; /* which block this node is supposed to live in */
        __le64 generation;
        __le64 owner;
        __le32 nritems;
        __le16 flags;
        u8 level;
} __attribute__ ((__packed__));

#define BTRFS_NODEPTRS_PER_BLOCK(r) (((r)->nodesize - \
                                sizeof(struct btrfs_header)) / \
                                sizeof(struct btrfs_key_ptr))
#define __BTRFS_LEAF_DATA_SIZE(bs) ((bs) - sizeof(struct btrfs_header))
#define BTRFS_LEAF_DATA_SIZE(r) (__BTRFS_LEAF_DATA_SIZE(r->leafsize))
#define BTRFS_MAX_INLINE_DATA_SIZE(r) (BTRFS_LEAF_DATA_SIZE(r) - \
                                        sizeof(struct btrfs_item) - \
                                        sizeof(struct btrfs_file_extent_item))
/*
 * the super block basically lists the main trees of the FS
 * it currently lacks any block count etc etc
 */
struct btrfs_super_block {
        u8 csum[BTRFS_CSUM_SIZE];
        /* the first 3 fields must match struct btrfs_header */
        u8 fsid[BTRFS_FSID_SIZE];    /* FS specific uuid */
        __le64 bytenr; /* this block number */
        __le64 magic;
        __le64 generation;
        __le64 root;
        __le64 total_bytes;
        __le64 bytes_used;
        __le64 root_dir_objectid;
        __le32 sectorsize;
        __le32 nodesize;
        __le32 leafsize;
        __le32 stripesize;
        u8 root_level;
} __attribute__ ((__packed__));

/*
 * A leaf is full of items. 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;
        __le32 offset;
        __le32 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.
 */
struct btrfs_leaf {
        struct btrfs_header header;
        struct btrfs_item items[];
} __attribute__ ((__packed__));

/*
 * all non-leaf blocks are nodes, they hold only keys and pointers to
 * other blocks
 */
struct btrfs_key_ptr {
        struct btrfs_disk_key key;
        __le64 blockptr;
        __le64 generation;
} __attribute__ ((__packed__));

struct btrfs_node {
        struct btrfs_header header;
        struct btrfs_key_ptr ptrs[];
} __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 extent_buffer *nodes[BTRFS_MAX_LEVEL];
        int slots[BTRFS_MAX_LEVEL];
        int reada;
        int lowest_level;
};

/*
 * 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;
} __attribute__ ((__packed__));

struct btrfs_extent_ref {
        __le64 root;
        __le64 generation;
        __le64 objectid;
        __le64 offset;
} __attribute__ ((__packed__));

struct btrfs_inode_ref {
        __le16 name_len;
        /* name goes here */
} __attribute__ ((__packed__));

struct btrfs_inode_timespec {
        __le64 sec;
        __le32 nsec;
} __attribute__ ((__packed__));

/*
 * there is no padding here on purpose.  If you want to extent the inode,
 * make a new item type
 */
struct btrfs_inode_item {
        __le64 generation;
        __le64 size;
        __le64 nblocks;
        __le64 block_group;
        __le32 nlink;
        __le32 uid;
        __le32 gid;
        __le32 mode;
        __le32 rdev;
        __le16 flags;
        __le16 compat_flags;
        struct btrfs_inode_timespec atime;
        struct btrfs_inode_timespec ctime;
        struct btrfs_inode_timespec mtime;
        struct btrfs_inode_timespec otime;
} __attribute__ ((__packed__));

struct btrfs_dir_item {
        struct btrfs_disk_key location;
        __le16 data_len;
        __le16 name_len;
        u8 type;
} __attribute__ ((__packed__));

struct btrfs_root_item {
        struct btrfs_inode_item inode;
        __le64 root_dirid;
        __le64 bytenr;
        __le64 byte_limit;
        __le64 bytes_used;
        __le32 flags;
        __le32 refs;
        struct btrfs_disk_key drop_progress;
        u8 drop_level;
        u8 level;
} __attribute__ ((__packed__));

#define BTRFS_FILE_EXTENT_REG 0
#define BTRFS_FILE_EXTENT_INLINE 1

struct btrfs_file_extent_item {
        __le64 generation;
        u8 type;
        /*
         * disk space consumed by the extent, checksum blocks are included
         * in these numbers
         */
        __le64 disk_bytenr;
        __le64 disk_num_bytes;
        /*
         * the logical offset in file blocks (no csums)
         * this extent record is for.  This allows a file extent to point
         * into the middle of an existing extent on disk, sharing it
         * between two snapshots (useful if some bytes in the middle of the
         * extent have changed
         */
        __le64 offset;
        /*
         * the logical number of file blocks (no csums included)
         */
        __le64 num_bytes;
} __attribute__ ((__packed__));

struct btrfs_csum_item {
        u8 csum;
} __attribute__ ((__packed__));

/* tag for the radix tree of block groups in ram */
#define BTRFS_BLOCK_GROUP_SIZE (256 * 1024 * 1024)

#define BTRFS_BLOCK_GROUP_DATA 1
#define BTRFS_BLOCK_GROUP_MIXED 2

struct btrfs_block_group_item {
        __le64 used;
        u8 flags;
} __attribute__ ((__packed__));

struct btrfs_block_group_cache {
        struct cache_extent cache;
        struct btrfs_key key;
        struct btrfs_block_group_item item;
        int data;
        int cached;
        u64 pinned;
};
struct btrfs_extent_ops {
       int (*alloc_extent)(struct btrfs_root *root, u64 num_bytes,
                           u64 hint_byte, struct btrfs_key *ins);
       int (*free_extent)(struct btrfs_root *root, u64 bytenr,
                          u64 num_bytes);
};

struct btrfs_fs_info {
        u8 fsid[BTRFS_FSID_SIZE];
        struct btrfs_root *fs_root;
        struct btrfs_root *extent_root;
        struct btrfs_root *tree_root;

        struct extent_io_tree extent_cache;
        struct extent_io_tree free_space_cache;
        struct extent_io_tree block_group_cache;
        struct extent_io_tree pinned_extents;
        struct extent_io_tree pending_del;
        struct extent_io_tree extent_ins;

        u64 generation;
        u64 last_trans_committed;
        struct btrfs_trans_handle *running_transaction;
        struct btrfs_super_block super_copy;
        struct extent_buffer *sb_buffer;
        struct mutex fs_mutex;
        int fp;
        u64 total_pinned;

        struct btrfs_extent_ops *extent_ops;
        void *priv_data;
};
/*
 * in ram representation of the tree.  extent_root is used for all allocations
 * and for the extent tree extent_root root.
 */
struct btrfs_root {
        struct extent_buffer *node;
        struct extent_buffer *commit_root;
        struct btrfs_root_item root_item;
        struct btrfs_key root_key;
        struct btrfs_fs_info *fs_info;
        u64 objectid;
        u64 last_trans;

        /* data allocations are done in sectorsize units */
        u32 sectorsize;

        /* node allocations are done in nodesize units */
        u32 nodesize;

        /* leaf allocations are done in leafsize units */
        u32 leafsize;

        /* leaf allocations are done in leafsize units */
        u32 stripesize;

        int ref_cows;

        u32 type;
        u64 highest_inode;
        u64 last_inode_alloc;
};

/*
 * inode items have the data typically returned from stat and store other
 * info about object characteristics.  There is one for every file and dir in
 * the FS
 */
#define BTRFS_INODE_ITEM_KEY            1
#define BTRFS_INODE_REF_KEY             2
#define BTRFS_XATTR_ITEM_KEY            8

/* reserve 3-15 close to the inode for later flexibility */

/*
 * dir items are the name -> inode pointers in a directory.  There is one
 * for every name in a directory.
 */
#define BTRFS_DIR_ITEM_KEY      16
#define BTRFS_DIR_INDEX_KEY     17
/*
 * extent data is for file data
 */
#define BTRFS_EXTENT_DATA_KEY   18
/*
 * csum items have the checksums for data in the extents
 */
#define BTRFS_CSUM_ITEM_KEY     19

/* reserve 20-31 for other file stuff */

/*
 * root items point to tree roots.  There are typically in the root
 * tree used by the super block to find all the other trees
 */
#define BTRFS_ROOT_ITEM_KEY     32
/*
 * extent items are in the extent map tree.  These record which blocks
 * are used, and how many references there are to each block
 */
#define BTRFS_EXTENT_ITEM_KEY   33
#define BTRFS_EXTENT_REF_KEY    34

/*
 * block groups give us hints into the extent allocation trees.  Which
 * blocks are free etc etc
 */
#define BTRFS_BLOCK_GROUP_ITEM_KEY 50

/*
 * string items are for debugging.  They just store a short string of
 * data in the FS
 */
#define BTRFS_STRING_ITEM_KEY   253
/*
 * Inode flags
 */
#define BTRFS_INODE_NODATASUM           (1 << 0)
#define BTRFS_INODE_NODATACOW           (1 << 1)
#define BTRFS_INODE_READONLY            (1 << 2)

#define read_eb_member(eb, ptr, type, member, result) (                 \
        read_extent_buffer(eb, (char *)(result),                        \
                           ((unsigned long)(ptr)) +                     \
                            offsetof(type, member),                     \
                           sizeof(((type *)0)->member)))

#define write_eb_member(eb, ptr, type, member, result) (                \
        write_extent_buffer(eb, (char *)(result),                       \
                           ((unsigned long)(ptr)) +                     \
                            offsetof(type, member),                     \
                           sizeof(((type *)0)->member)))

#define BTRFS_SETGET_HEADER_FUNCS(name, type, member, bits)             \
static inline u##bits btrfs_##name(struct extent_buffer *eb)            \
{                                                                       \
        struct btrfs_header *h = (struct btrfs_header *)eb->data;       \
        return le##bits##_to_cpu(h->member);                            \
}                                                                       \
static inline void btrfs_set_##name(struct extent_buffer *eb,           \
                                    u##bits val)                        \
{                                                                       \
        struct btrfs_header *h = (struct btrfs_header *)eb->data;       \
        h->member = cpu_to_le##bits(val);                               \
}

#define BTRFS_SETGET_FUNCS(name, type, member, bits)                    \
static inline u##bits btrfs_##name(struct extent_buffer *eb,            \
                                   type *s)                             \
{                                                                       \
        unsigned long offset = (unsigned long)s;                        \
        type *p = (type *) (eb->data + offset);                         \
        return le##bits##_to_cpu(p->member);                            \
}                                                                       \
static inline void btrfs_set_##name(struct extent_buffer *eb,           \
                                    type *s, u##bits val)               \
{                                                                       \
        unsigned long offset = (unsigned long)s;                        \
        type *p = (type *) (eb->data + offset);                         \
        p->member = cpu_to_le##bits(val);                               \
}

#define BTRFS_SETGET_STACK_FUNCS(name, type, member, bits)              \
static inline u##bits btrfs_##name(type *s)                             \
{                                                                       \
        return le##bits##_to_cpu(s->member);                            \
}                                                                       \
static inline void btrfs_set_##name(type *s, u##bits val)               \
{                                                                       \
        s->member = cpu_to_le##bits(val);                               \
}

/* struct btrfs_block_group_item */
BTRFS_SETGET_STACK_FUNCS(block_group_used, struct btrfs_block_group_item,
                         used, 64);
BTRFS_SETGET_FUNCS(disk_block_group_used, struct btrfs_block_group_item,
                         used, 64);

/* struct btrfs_inode_ref */
BTRFS_SETGET_FUNCS(inode_ref_name_len, struct btrfs_inode_ref, name_len, 16);

/* struct btrfs_inode_item */
BTRFS_SETGET_FUNCS(inode_generation, struct btrfs_inode_item, generation, 64);
BTRFS_SETGET_FUNCS(inode_size, struct btrfs_inode_item, size, 64);
BTRFS_SETGET_FUNCS(inode_nblocks, struct btrfs_inode_item, nblocks, 64);
BTRFS_SETGET_FUNCS(inode_block_group, struct btrfs_inode_item, block_group, 64);
BTRFS_SETGET_FUNCS(inode_nlink, struct btrfs_inode_item, nlink, 32);
BTRFS_SETGET_FUNCS(inode_uid, struct btrfs_inode_item, uid, 32);
BTRFS_SETGET_FUNCS(inode_gid, struct btrfs_inode_item, gid, 32);
BTRFS_SETGET_FUNCS(inode_mode, struct btrfs_inode_item, mode, 32);
BTRFS_SETGET_FUNCS(inode_rdev, struct btrfs_inode_item, rdev, 32);
BTRFS_SETGET_FUNCS(inode_flags, struct btrfs_inode_item, flags, 16);
BTRFS_SETGET_FUNCS(inode_compat_flags, struct btrfs_inode_item,
                   compat_flags, 16);

BTRFS_SETGET_STACK_FUNCS(stack_inode_generation,
                         struct btrfs_inode_item, generation, 64);
BTRFS_SETGET_STACK_FUNCS(stack_inode_size,
                         struct btrfs_inode_item, size, 64);
BTRFS_SETGET_STACK_FUNCS(stack_inode_nblocks,
                         struct btrfs_inode_item, nblocks, 64);
BTRFS_SETGET_STACK_FUNCS(stack_inode_block_group,
                         struct btrfs_inode_item, block_group, 64);
BTRFS_SETGET_STACK_FUNCS(stack_inode_nlink,
                         struct btrfs_inode_item, nlink, 32);
BTRFS_SETGET_STACK_FUNCS(stack_inode_uid,
                         struct btrfs_inode_item, uid, 32);
BTRFS_SETGET_STACK_FUNCS(stack_inode_gid,
                         struct btrfs_inode_item, gid, 32);
BTRFS_SETGET_STACK_FUNCS(stack_inode_mode,
                         struct btrfs_inode_item, mode, 32);
BTRFS_SETGET_STACK_FUNCS(stack_inode_rdev,
                         struct btrfs_inode_item, rdev, 32);
BTRFS_SETGET_STACK_FUNCS(stack_inode_flags,
                         struct btrfs_inode_item, flags, 16);
BTRFS_SETGET_STACK_FUNCS(stack_inode_compat_flags,
                         struct btrfs_inode_item, compat_flags, 16);

static inline struct btrfs_inode_timespec *
btrfs_inode_atime(struct btrfs_inode_item *inode_item)
{
        unsigned long ptr = (unsigned long)inode_item;
        ptr += offsetof(struct btrfs_inode_item, atime);
        return (struct btrfs_inode_timespec *)ptr;
}

static inline struct btrfs_inode_timespec *
btrfs_inode_mtime(struct btrfs_inode_item *inode_item)
{
        unsigned long ptr = (unsigned long)inode_item;
        ptr += offsetof(struct btrfs_inode_item, mtime);
        return (struct btrfs_inode_timespec *)ptr;
}

static inline struct btrfs_inode_timespec *
btrfs_inode_ctime(struct btrfs_inode_item *inode_item)
{
        unsigned long ptr = (unsigned long)inode_item;
        ptr += offsetof(struct btrfs_inode_item, ctime);
        return (struct btrfs_inode_timespec *)ptr;
}

static inline struct btrfs_inode_timespec *
btrfs_inode_otime(struct btrfs_inode_item *inode_item)
{
        unsigned long ptr = (unsigned long)inode_item;
        ptr += offsetof(struct btrfs_inode_item, otime);
        return (struct btrfs_inode_timespec *)ptr;
}

BTRFS_SETGET_FUNCS(timespec_sec, struct btrfs_inode_timespec, sec, 64);
BTRFS_SETGET_FUNCS(timespec_nsec, struct btrfs_inode_timespec, nsec, 32);
BTRFS_SETGET_STACK_FUNCS(stack_timespec_sec, struct btrfs_inode_timespec,
                         sec, 64);
BTRFS_SETGET_STACK_FUNCS(stack_timespec_nsec, struct btrfs_inode_timespec,
                         nsec, 32);

/* struct btrfs_extent_item */
BTRFS_SETGET_FUNCS(extent_refs, struct btrfs_extent_item, refs, 32);

/* 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_offset, struct btrfs_extent_ref, offset, 64);

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_offset, struct btrfs_extent_ref, offset, 64);

BTRFS_SETGET_STACK_FUNCS(stack_extent_refs, struct btrfs_extent_item,
                         refs, 32);

/* struct btrfs_node */
BTRFS_SETGET_FUNCS(key_blockptr, struct btrfs_key_ptr, blockptr, 64);
BTRFS_SETGET_FUNCS(key_generation, struct btrfs_key_ptr, generation, 64);

static inline u64 btrfs_node_blockptr(struct extent_buffer *eb, int nr)
{
        unsigned long ptr;
        ptr = offsetof(struct btrfs_node, ptrs) +
                sizeof(struct btrfs_key_ptr) * nr;
        return btrfs_key_blockptr(eb, (struct btrfs_key_ptr *)ptr);
}

static inline void btrfs_set_node_blockptr(struct extent_buffer *eb,
                                           int nr, u64 val)
{
        unsigned long ptr;
        ptr = offsetof(struct btrfs_node, ptrs) +
                sizeof(struct btrfs_key_ptr) * nr;
        btrfs_set_key_blockptr(eb, (struct btrfs_key_ptr *)ptr, val);
}

static inline u64 btrfs_node_ptr_generation(struct extent_buffer *eb, int nr)
{
        unsigned long ptr;
        ptr = offsetof(struct btrfs_node, ptrs) +
                sizeof(struct btrfs_key_ptr) * nr;
        return btrfs_key_generation(eb, (struct btrfs_key_ptr *)ptr);
}

static inline void btrfs_set_node_ptr_generation(struct extent_buffer *eb,
                                                 int nr, u64 val)
{
        unsigned long ptr;
        ptr = offsetof(struct btrfs_node, ptrs) +
                sizeof(struct btrfs_key_ptr) * nr;
        btrfs_set_key_generation(eb, (struct btrfs_key_ptr *)ptr, val);
}

static inline unsigned long btrfs_node_key_ptr_offset(int nr)
{
        return offsetof(struct btrfs_node, ptrs) +
                sizeof(struct btrfs_key_ptr) * nr;
}

static inline void btrfs_node_key(struct extent_buffer *eb,
                                  struct btrfs_disk_key *disk_key, int nr)
{
        unsigned long ptr;
        ptr = btrfs_node_key_ptr_offset(nr);
        read_eb_member(eb, (struct btrfs_key_ptr *)ptr,
                       struct btrfs_key_ptr, key, disk_key);
}

static inline void btrfs_set_node_key(struct extent_buffer *eb,
                                      struct btrfs_disk_key *disk_key, int nr)
{
        unsigned long ptr;
        ptr = btrfs_node_key_ptr_offset(nr);
        write_eb_member(eb, (struct btrfs_key_ptr *)ptr,
                       struct btrfs_key_ptr, key, disk_key);
}

/* struct btrfs_item */
BTRFS_SETGET_FUNCS(item_offset, struct btrfs_item, offset, 32);
BTRFS_SETGET_FUNCS(item_size, struct btrfs_item, size, 32);

static inline unsigned long btrfs_item_nr_offset(int nr)
{
        return offsetof(struct btrfs_leaf, items) +
                sizeof(struct btrfs_item) * nr;
}

static inline struct btrfs_item *btrfs_item_nr(struct extent_buffer *eb,
                                               int nr)
{
        return (struct btrfs_item *)btrfs_item_nr_offset(nr);
}

static inline u32 btrfs_item_end(struct extent_buffer *eb,
                                 struct btrfs_item *item)
{
        return btrfs_item_offset(eb, item) + btrfs_item_size(eb, item);
}

static inline u32 btrfs_item_end_nr(struct extent_buffer *eb, int nr)
{
        return btrfs_item_end(eb, btrfs_item_nr(eb, nr));
}

static inline u32 btrfs_item_offset_nr(struct extent_buffer *eb, int nr)
{
        return btrfs_item_offset(eb, btrfs_item_nr(eb, nr));
}

static inline u32 btrfs_item_size_nr(struct extent_buffer *eb, int nr)
{
        return btrfs_item_size(eb, btrfs_item_nr(eb, nr));
}

static inline void btrfs_item_key(struct extent_buffer *eb,
                           struct btrfs_disk_key *disk_key, int nr)
{
        struct btrfs_item *item = btrfs_item_nr(eb, nr);
        read_eb_member(eb, item, struct btrfs_item, key, disk_key);
}

static inline void btrfs_set_item_key(struct extent_buffer *eb,
                               struct btrfs_disk_key *disk_key, int nr)
{
        struct btrfs_item *item = btrfs_item_nr(eb, nr);
        write_eb_member(eb, item, struct btrfs_item, key, disk_key);
}

/* struct btrfs_dir_item */
BTRFS_SETGET_FUNCS(dir_data_len, struct btrfs_dir_item, data_len, 16);
BTRFS_SETGET_FUNCS(dir_type, struct btrfs_dir_item, type, 8);
BTRFS_SETGET_FUNCS(dir_name_len, struct btrfs_dir_item, name_len, 16);

static inline void btrfs_dir_item_key(struct extent_buffer *eb,
                                      struct btrfs_dir_item *item,
                                      struct btrfs_disk_key *key)
{
        read_eb_member(eb, item, struct btrfs_dir_item, location, key);
}

static inline void btrfs_set_dir_item_key(struct extent_buffer *eb,
                                          struct btrfs_dir_item *item,
                                          struct btrfs_disk_key *key)
{
        write_eb_member(eb, item, struct btrfs_dir_item, location, key);
}

/* struct btrfs_disk_key */
BTRFS_SETGET_STACK_FUNCS(disk_key_objectid, struct btrfs_disk_key,
                         objectid, 64);
BTRFS_SETGET_STACK_FUNCS(disk_key_offset, struct btrfs_disk_key, offset, 64);
BTRFS_SETGET_STACK_FUNCS(disk_key_type, struct btrfs_disk_key, type, 8);

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->type = disk->type;
        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->type = cpu->type;
        disk->objectid = cpu_to_le64(cpu->objectid);
}

static inline void btrfs_node_key_to_cpu(struct extent_buffer *eb,
                                  struct btrfs_key *key, int nr)
{
        struct btrfs_disk_key disk_key;
        btrfs_node_key(eb, &disk_key, nr);
        btrfs_disk_key_to_cpu(key, &disk_key);
}

static inline void btrfs_item_key_to_cpu(struct extent_buffer *eb,
                                  struct btrfs_key *key, int nr)
{
        struct btrfs_disk_key disk_key;
        btrfs_item_key(eb, &disk_key, nr);
        btrfs_disk_key_to_cpu(key, &disk_key);
}

static inline void btrfs_dir_item_key_to_cpu(struct extent_buffer *eb,
                                      struct btrfs_dir_item *item,
                                      struct btrfs_key *key)
{
        struct btrfs_disk_key disk_key;
        btrfs_dir_item_key(eb, item, &disk_key);
        btrfs_disk_key_to_cpu(key, &disk_key);
}


static inline u8 btrfs_key_type(struct btrfs_key *key)
{
        return key->type;
}

static inline void btrfs_set_key_type(struct btrfs_key *key, u8 val)
{
        key->type = val;
}

/* struct btrfs_header */
BTRFS_SETGET_HEADER_FUNCS(header_bytenr, struct btrfs_header, bytenr, 64);
BTRFS_SETGET_HEADER_FUNCS(header_generation, struct btrfs_header,
                          generation, 64);
BTRFS_SETGET_HEADER_FUNCS(header_owner, struct btrfs_header, owner, 64);
BTRFS_SETGET_HEADER_FUNCS(header_nritems, struct btrfs_header, nritems, 32);
BTRFS_SETGET_HEADER_FUNCS(header_flags, struct btrfs_header, flags, 16);
BTRFS_SETGET_HEADER_FUNCS(header_level, struct btrfs_header, level, 8);

static inline u8 *btrfs_header_fsid(struct extent_buffer *eb)
{
        unsigned long ptr = offsetof(struct btrfs_header, fsid);
        return (u8 *)ptr;
}

static inline u8 *btrfs_super_fsid(struct extent_buffer *eb)
{
        unsigned long ptr = offsetof(struct btrfs_super_block, fsid);
        return (u8 *)ptr;
}

static inline u8 *btrfs_header_csum(struct extent_buffer *eb)
{
        unsigned long ptr = offsetof(struct btrfs_header, csum);
        return (u8 *)ptr;
}

static inline struct btrfs_node *btrfs_buffer_node(struct extent_buffer *eb)
{
        return NULL;
}

static inline struct btrfs_leaf *btrfs_buffer_leaf(struct extent_buffer *eb)
{
        return NULL;
}

static inline struct btrfs_header *btrfs_buffer_header(struct extent_buffer *eb)
{
        return NULL;
}

static inline int btrfs_is_leaf(struct extent_buffer *eb)
{
        return (btrfs_header_level(eb) == 0);
}

/* struct btrfs_root_item */
BTRFS_SETGET_FUNCS(disk_root_refs, struct btrfs_root_item, refs, 32);
BTRFS_SETGET_FUNCS(disk_root_bytenr, struct btrfs_root_item, bytenr, 64);
BTRFS_SETGET_FUNCS(disk_root_level, struct btrfs_root_item, level, 8);

BTRFS_SETGET_STACK_FUNCS(root_bytenr, struct btrfs_root_item, bytenr, 64);
BTRFS_SETGET_STACK_FUNCS(root_level, struct btrfs_root_item, level, 8);
BTRFS_SETGET_STACK_FUNCS(root_dirid, struct btrfs_root_item, root_dirid, 64);
BTRFS_SETGET_STACK_FUNCS(root_refs, struct btrfs_root_item, refs, 32);
BTRFS_SETGET_STACK_FUNCS(root_flags, struct btrfs_root_item, flags, 32);
BTRFS_SETGET_STACK_FUNCS(root_used, struct btrfs_root_item, bytes_used, 64);
BTRFS_SETGET_STACK_FUNCS(root_limit, struct btrfs_root_item, byte_limit, 64);

/* struct btrfs_super_block */
BTRFS_SETGET_STACK_FUNCS(super_bytenr, struct btrfs_super_block, bytenr, 64);
BTRFS_SETGET_STACK_FUNCS(super_generation, struct btrfs_super_block,
                         generation, 64);
BTRFS_SETGET_STACK_FUNCS(super_root, struct btrfs_super_block, root, 64);
BTRFS_SETGET_STACK_FUNCS(super_root_level, struct btrfs_super_block,
                         root_level, 8);
BTRFS_SETGET_STACK_FUNCS(super_total_bytes, struct btrfs_super_block,
                         total_bytes, 64);
BTRFS_SETGET_STACK_FUNCS(super_bytes_used, struct btrfs_super_block,
                         bytes_used, 64);
BTRFS_SETGET_STACK_FUNCS(super_sectorsize, struct btrfs_super_block,
                         sectorsize, 32);
BTRFS_SETGET_STACK_FUNCS(super_nodesize, struct btrfs_super_block,
                         nodesize, 32);
BTRFS_SETGET_STACK_FUNCS(super_leafsize, struct btrfs_super_block,
                         leafsize, 32);
BTRFS_SETGET_STACK_FUNCS(super_stripesize, struct btrfs_super_block,
                         stripesize, 32);
BTRFS_SETGET_STACK_FUNCS(super_root_dir, struct btrfs_super_block,
                         root_dir_objectid, 64);

static inline unsigned long btrfs_leaf_data(struct extent_buffer *l)
{
        return offsetof(struct btrfs_leaf, items);
}

/* struct btrfs_file_extent_item */
BTRFS_SETGET_FUNCS(file_extent_type, struct btrfs_file_extent_item, type, 8);

static inline unsigned long btrfs_file_extent_inline_start(struct
                                                   btrfs_file_extent_item *e)
{
        unsigned long offset = (unsigned long)e;
        offset += offsetof(struct btrfs_file_extent_item, disk_bytenr);
        return offset;
}

static inline u32 btrfs_file_extent_calc_inline_size(u32 datasize)
{
        return offsetof(struct btrfs_file_extent_item, disk_bytenr) + datasize;
}

static inline u32 btrfs_file_extent_inline_len(struct extent_buffer *eb,
                                               struct btrfs_item *e)
{
        unsigned long offset;
        offset = offsetof(struct btrfs_file_extent_item, disk_bytenr);
        return btrfs_item_size(eb, e) - offset;
}

BTRFS_SETGET_FUNCS(file_extent_disk_bytenr, struct btrfs_file_extent_item,
                   disk_bytenr, 64);
BTRFS_SETGET_FUNCS(file_extent_generation, struct btrfs_file_extent_item,
                   generation, 64);
BTRFS_SETGET_FUNCS(file_extent_disk_num_bytes, struct btrfs_file_extent_item,
                   disk_num_bytes, 64);
BTRFS_SETGET_FUNCS(file_extent_offset, struct btrfs_file_extent_item,
                  offset, 64);
BTRFS_SETGET_FUNCS(file_extent_num_bytes, struct btrfs_file_extent_item,
                   num_bytes, 64);

static inline u32 btrfs_level_size(struct btrfs_root *root, int level) {
        if (level == 0)
                return root->leafsize;
        return root->nodesize;
}

/* helper function to cast into the data area of the leaf. */
#define btrfs_item_ptr(leaf, slot, type) \
        ((type *)(btrfs_leaf_data(leaf) + \
        btrfs_item_offset_nr(leaf, slot)))

#define btrfs_item_ptr_offset(leaf, slot) \
        ((unsigned long)(btrfs_leaf_data(leaf) + \
        btrfs_item_offset_nr(leaf, slot)))

/* extent-tree.c */
u32 btrfs_count_snapshots_in_path(struct btrfs_root *root,
                                  struct btrfs_path *count_path,
                                  u64 first_extent);
int btrfs_extent_post_op(struct btrfs_trans_handle *trans,
                         struct btrfs_root *root);
int btrfs_copy_pinned(struct btrfs_root *root, struct extent_io_tree *copy);
struct btrfs_block_group_cache *btrfs_lookup_block_group(struct
                                                         btrfs_fs_info *info,
                                                         u64 bytenr);
struct btrfs_block_group_cache *btrfs_find_block_group(struct btrfs_root *root,
                                                 struct btrfs_block_group_cache
                                                 *hint, u64 search_start,
                                                 int data, int owner);
int btrfs_inc_root_ref(struct btrfs_trans_handle *trans,
                       struct btrfs_root *root, u64 owner_objectid);
struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
                                            struct btrfs_root *root, u32 size,
                                            u64 root_objectid,
                                            u64 hint, u64 empty_size);
struct extent_buffer *__btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
                                             struct btrfs_root *root,
                                             u32 blocksize,
                                             u64 root_objectid,
                                             u64 ref_generation,
                                             u64 first_objectid,
                                             int level,
                                             u64 hint,
                                             u64 empty_size);
int btrfs_grow_extent_tree(struct btrfs_trans_handle *trans,
                           struct btrfs_root *root, u64 new_size);
int btrfs_shrink_extent_tree(struct btrfs_root *root, u64 new_size);
int btrfs_insert_extent_backref(struct btrfs_trans_handle *trans,
                                 struct btrfs_root *root,
                                 struct btrfs_path *path, u64 bytenr,
                                 u64 root_objectid, u64 ref_generation,
                                 u64 owner, u64 owner_offset);
int btrfs_alloc_extent(struct btrfs_trans_handle *trans,
                       struct btrfs_root *root,
                       u64 num_bytes, u64 root_objectid, u64 ref_generation,
                       u64 owner, u64 owner_offset,
                       u64 empty_size, u64 hint_byte,
                       u64 search_end, struct btrfs_key *ins, int data);
int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
                  struct extent_buffer *buf);
int btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
                      *root, u64 bytenr, u64 num_bytes,
                      u64 root_objectid, u64 ref_generation,
                      u64 owner_objectid, u64 owner_offset, int pin);
int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans,
                               struct btrfs_root *root,
                               struct extent_io_tree *unpin);
int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
                                struct btrfs_root *root,
                                u64 bytenr, u64 num_bytes,
                                u64 root_objectid, u64 ref_generation,
                                u64 owner, u64 owner_offset);
int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
                                    struct btrfs_root *root);
int btrfs_free_block_groups(struct btrfs_fs_info *info);
int btrfs_read_block_groups(struct btrfs_root *root);
int btrfs_make_block_groups(struct btrfs_trans_handle *trans,
                            struct btrfs_root *root);
u64 btrfs_hash_extent_ref(u64 root_objectid, u64 ref_generation,
                          u64 owner, u64 owner_offset);
int btrfs_update_block_group(struct btrfs_trans_handle *trans,
                             struct btrfs_root *root, u64 bytenr, u64 num,
                             int alloc, int mark_free, int data);
/* ctree.c */
int btrfs_comp_keys(struct btrfs_disk_key *disk, struct btrfs_key *k2);
int btrfs_cow_block(struct btrfs_trans_handle *trans,
                    struct btrfs_root *root, struct extent_buffer *buf,
                    struct extent_buffer *parent, int parent_slot,
                    struct extent_buffer **cow_ret);
int btrfs_copy_root(struct btrfs_trans_handle *trans,
                      struct btrfs_root *root,
                      struct extent_buffer *buf,
                      struct extent_buffer **cow_ret, u64 new_root_objectid);
int btrfs_extend_item(struct btrfs_trans_handle *trans, struct btrfs_root
                      *root, struct btrfs_path *path, u32 data_size);
int btrfs_truncate_item(struct btrfs_trans_handle *trans,
                        struct btrfs_root *root,
                        struct btrfs_path *path,
                        u32 new_size, int from_end);
int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root
                      *root, struct btrfs_key *key, struct btrfs_path *p, int
                      ins_len, int cow);
int btrfs_realloc_node(struct btrfs_trans_handle *trans,
                       struct btrfs_root *root, struct extent_buffer *parent,
                       int start_slot, int cache_only, u64 *last_ret,
                       struct btrfs_key *progress);
void btrfs_release_path(struct btrfs_root *root, struct btrfs_path *p);
struct btrfs_path *btrfs_alloc_path(void);
void btrfs_free_path(struct btrfs_path *p);
void btrfs_init_path(struct btrfs_path *p);
int btrfs_del_item(struct btrfs_trans_handle *trans, struct btrfs_root *root,
                   struct btrfs_path *path);
int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root
                      *root, struct btrfs_key *key, void *data, u32 data_size);
int btrfs_insert_empty_item(struct btrfs_trans_handle *trans, struct btrfs_root
                            *root, struct btrfs_path *path, struct btrfs_key
                            *cpu_key, u32 data_size);
int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path);
int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path);
int btrfs_leaf_free_space(struct btrfs_root *root, struct extent_buffer *leaf);
int btrfs_drop_snapshot(struct btrfs_trans_handle *trans, struct btrfs_root
                        *root);


/* root-item.c */
int btrfs_del_root(struct btrfs_trans_handle *trans, struct btrfs_root *root,
                   struct btrfs_key *key);
int btrfs_insert_root(struct btrfs_trans_handle *trans, struct btrfs_root
                      *root, struct btrfs_key *key, struct btrfs_root_item
                      *item);
int btrfs_update_root(struct btrfs_trans_handle *trans, 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);
int btrfs_find_dead_roots(struct btrfs_root *root, u64 objectid,
                          struct btrfs_root *latest_root);
/* dir-item.c */
int btrfs_insert_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root
                          *root, const char *name, int name_len, u64 dir,
                          struct btrfs_key *location, u8 type);
struct btrfs_dir_item *btrfs_lookup_dir_item(struct btrfs_trans_handle *trans,
                                             struct btrfs_root *root,
                                             struct btrfs_path *path, u64 dir,
                                             const char *name, int name_len,
                                             int mod);
struct btrfs_dir_item *
btrfs_lookup_dir_index_item(struct btrfs_trans_handle *trans,
                            struct btrfs_root *root,
                            struct btrfs_path *path, u64 dir,
                            u64 objectid, const char *name, int name_len,
                            int mod);
struct btrfs_dir_item *btrfs_match_dir_item_name(struct btrfs_root *root,
                              struct btrfs_path *path,
                              const char *name, int name_len);
int btrfs_delete_one_dir_name(struct btrfs_trans_handle *trans,
                              struct btrfs_root *root,
                              struct btrfs_path *path,
                              struct btrfs_dir_item *di);
int btrfs_insert_xattr_item(struct btrfs_trans_handle *trans,
                            struct btrfs_root *root, const char *name,
                            u16 name_len, const void *data, u16 data_len,
                            u64 dir);
struct btrfs_dir_item *btrfs_lookup_xattr(struct btrfs_trans_handle *trans,
                                          struct btrfs_root *root,
                                          struct btrfs_path *path, u64 dir,
                                          const char *name, u16 name_len,
                                          int mod);
/* inode-map.c */
int btrfs_find_free_objectid(struct btrfs_trans_handle *trans,
                             struct btrfs_root *fs_root,
                             u64 dirid, u64 *objectid);
int btrfs_find_highest_inode(struct btrfs_root *fs_root, u64 *objectid);

/* inode-item.c */
int btrfs_insert_inode_ref(struct btrfs_trans_handle *trans,
                           struct btrfs_root *root,
                           const char *name, int name_len,
                           u64 inode_objectid, u64 ref_objectid);
int btrfs_del_inode_ref(struct btrfs_trans_handle *trans,
                           struct btrfs_root *root,
                           const char *name, int name_len,
                           u64 inode_objectid, u64 ref_objectid);
int btrfs_insert_empty_inode(struct btrfs_trans_handle *trans,
                             struct btrfs_root *root,
                             struct btrfs_path *path, u64 objectid);
int btrfs_insert_inode(struct btrfs_trans_handle *trans, struct btrfs_root
                       *root, u64 objectid, struct btrfs_inode_item
                       *inode_item);
int btrfs_lookup_inode(struct btrfs_trans_handle *trans, struct btrfs_root
                       *root, struct btrfs_path *path,
                       struct btrfs_key *location, int mod);

/* file-item.c */
int btrfs_insert_file_extent(struct btrfs_trans_handle *trans,
                             struct btrfs_root *root,
                             u64 objectid, u64 pos, u64 offset,
                             u64 disk_num_bytes,
                             u64 num_bytes);
int btrfs_insert_inline_extent(struct btrfs_trans_handle *trans,
                                struct btrfs_root *root, u64 objectid,
                                u64 offset, char *buffer, size_t size);
int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
                             struct btrfs_root *root,
                             struct btrfs_path *path, u64 objectid,
                             u64 bytenr, int mod);
int btrfs_csum_file_block(struct btrfs_trans_handle *trans,
                          struct btrfs_root *root,
                          struct btrfs_inode_item *inode,
                          u64 objectid, u64 offset,
                          char *data, size_t len);
struct btrfs_csum_item *btrfs_lookup_csum(struct btrfs_trans_handle *trans,
                                          struct btrfs_root *root,
                                          struct btrfs_path *path,
                                          u64 objectid, u64 offset,
                                          int cow);
int btrfs_csum_truncate(struct btrfs_trans_handle *trans,
                        struct btrfs_root *root, struct btrfs_path *path,
                        u64 isize);
#endif