Btrfs: Add a leaf reference cache

[safe/jmp/linux-2.6] / fs / btrfs / 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_CTREE__
#define __BTRFS_CTREE__

#include <linux/version.h>
#include <linux/mm.h>
#include <linux/highmem.h>
#include <linux/fs.h>
#include <linux/completion.h>
#include <linux/backing-dev.h>
#include <linux/wait.h>
#include <asm/kmap_types.h>
#include "bit-radix.h"
#include "extent_io.h"
#include "extent_map.h"
#include "async-thread.h"

struct btrfs_trans_handle;
struct btrfs_transaction;
extern struct kmem_cache *btrfs_trans_handle_cachep;
extern struct kmem_cache *btrfs_transaction_cachep;
extern struct kmem_cache *btrfs_bit_radix_cachep;
extern struct kmem_cache *btrfs_path_cachep;
struct btrfs_ordered_sum;

#define BTRFS_MAGIC "_B6RfS_M"

#define BTRFS_ACL_NOT_CACHED    ((void *)-1)

#ifdef CONFIG_LOCKDEP
# define BTRFS_MAX_LEVEL 7
#else
# define BTRFS_MAX_LEVEL 8
#endif

/* holds pointers to all of the tree roots */
#define BTRFS_ROOT_TREE_OBJECTID 1ULL

/* stores information about which extents are in use, and reference counts */
#define BTRFS_EXTENT_TREE_OBJECTID 2ULL

/*
 * chunk tree stores translations from logical -> physical block numbering
 * the super block points to the chunk tree
 */
#define BTRFS_CHUNK_TREE_OBJECTID 3ULL

/*
 * stores information about which areas of a given device are in use.
 * one per device.  The tree of tree roots points to the device tree
 */
#define BTRFS_DEV_TREE_OBJECTID 4ULL

/* one per subvolume, storing files and directories */
#define BTRFS_FS_TREE_OBJECTID 5ULL

/* directory objectid inside the root tree */
#define BTRFS_ROOT_TREE_DIR_OBJECTID 6ULL

/* orhpan objectid for tracking unlinked/truncated files */
#define BTRFS_ORPHAN_OBJECTID -5ULL

/*
 * All files have objectids higher than this.
 */
#define BTRFS_FIRST_FREE_OBJECTID 256ULL
#define BTRFS_FIRST_CHUNK_TREE_OBJECTID 256ULL


/*
 * the device items go into the chunk tree.  The key is in the form
 * [ 1 BTRFS_DEV_ITEM_KEY device_id ]
 */
#define BTRFS_DEV_ITEMS_OBJECTID 1ULL

/*
 * 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__));

struct btrfs_mapping_tree {
        struct extent_map_tree map_tree;
};

#define BTRFS_UUID_SIZE 16
struct btrfs_dev_item {
        /* the internal btrfs device id */
        __le64 devid;

        /* size of the device */
        __le64 total_bytes;

        /* bytes used */
        __le64 bytes_used;

        /* optimal io alignment for this device */
        __le32 io_align;

        /* optimal io width for this device */
        __le32 io_width;

        /* minimal io size for this device */
        __le32 sector_size;

        /* type and info about this device */
        __le64 type;

        /* grouping information for allocation decisions */
        __le32 dev_group;

        /* seek speed 0-100 where 100 is fastest */
        u8 seek_speed;

        /* bandwidth 0-100 where 100 is fastest */
        u8 bandwidth;

        /* btrfs generated uuid for this device */
        u8 uuid[BTRFS_UUID_SIZE];
} __attribute__ ((__packed__));

struct btrfs_stripe {
        __le64 devid;
        __le64 offset;
        u8 dev_uuid[BTRFS_UUID_SIZE];
} __attribute__ ((__packed__));

struct btrfs_chunk {
        /* size of this chunk in bytes */
        __le64 length;

        /* objectid of the root referencing this chunk */
        __le64 owner;

        __le64 stripe_len;
        __le64 type;

        /* optimal io alignment for this chunk */
        __le32 io_align;

        /* optimal io width for this chunk */
        __le32 io_width;

        /* minimal io size for this chunk */
        __le32 sector_size;

        /* 2^16 stripes is quite a lot, a second limit is the size of a single
         * item in the btree
         */
        __le16 num_stripes;

        /* sub stripes only matter for raid10 */
        __le16 sub_stripes;
        struct btrfs_stripe stripe;
        /* additional stripes go here */
} __attribute__ ((__packed__));

static inline unsigned long btrfs_chunk_item_size(int num_stripes)
{
        BUG_ON(num_stripes == 0);
        return sizeof(struct btrfs_chunk) +
                sizeof(struct btrfs_stripe) * (num_stripes - 1);
}

#define BTRFS_FSID_SIZE 16
#define BTRFS_HEADER_FLAG_WRITTEN (1 << 0)

/*
 * every tree block (leaf or node) starts with this header.
 */
struct btrfs_header {
        /* these first four must match the super block */
        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 flags;

        /* allowed to be different from the super from here on down */
        u8 chunk_tree_uuid[BTRFS_UUID_SIZE];
        __le64 generation;
        __le64 owner;
        __le32 nritems;
        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))


/*
 * this is a very generous portion of the super block, giving us
 * room to translate 14 chunks with 3 stripes each.
 */
#define BTRFS_SYSTEM_CHUNK_ARRAY_SIZE 2048
#define BTRFS_LABEL_SIZE 256

/*
 * 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 4 fields must match struct btrfs_header */
        u8 fsid[16];    /* FS specific uuid */
        __le64 bytenr; /* this block number */
        __le64 flags;

        /* allowed to be different from the btrfs_header from here own down */
        __le64 magic;
        __le64 generation;
        __le64 root;
        __le64 chunk_root;
        __le64 total_bytes;
        __le64 bytes_used;
        __le64 root_dir_objectid;
        __le64 num_devices;
        __le32 sectorsize;
        __le32 nodesize;
        __le32 leafsize;
        __le32 stripesize;
        __le32 sys_chunk_array_size;
        u8 root_level;
        u8 chunk_root_level;
        struct btrfs_dev_item dev_item;
        char label[BTRFS_LABEL_SIZE];
        u8 sys_chunk_array[BTRFS_SYSTEM_CHUNK_ARRAY_SIZE];
} __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];
        /* 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 keep_locks;
        int skip_locking;
        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__));

/* dev extents record free space on individual devices.  The owner
 * field points back to the chunk allocation mapping tree that allocated
 * the extent.  The chunk tree uuid field is a way to double check the owner
 */
struct btrfs_dev_extent {
        __le64 chunk_tree;
        __le64 chunk_objectid;
        __le64 chunk_offset;
        __le64 length;
        u8 chunk_tree_uuid[BTRFS_UUID_SIZE];
} __attribute__ ((__packed__));

struct btrfs_inode_ref {
        __le64 index;
        __le16 name_len;
        /* name goes here */
} __attribute__ ((__packed__));

struct btrfs_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;
        __le64 rdev;
        __le16 flags;
        __le16 compat_flags;
        struct btrfs_timespec atime;
        struct btrfs_timespec ctime;
        struct btrfs_timespec mtime;
        struct btrfs_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__));

/* different types of block groups (and chunks) */
#define BTRFS_BLOCK_GROUP_DATA     (1 << 0)
#define BTRFS_BLOCK_GROUP_SYSTEM   (1 << 1)
#define BTRFS_BLOCK_GROUP_METADATA (1 << 2)
#define BTRFS_BLOCK_GROUP_RAID0    (1 << 3)
#define BTRFS_BLOCK_GROUP_RAID1    (1 << 4)
#define BTRFS_BLOCK_GROUP_DUP      (1 << 5)
#define BTRFS_BLOCK_GROUP_RAID10   (1 << 6)


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

struct btrfs_space_info {
        u64 flags;
        u64 total_bytes;
        u64 bytes_used;
        u64 bytes_pinned;
        int full;
        int force_alloc;
        struct list_head list;
};

struct btrfs_block_group_cache {
        struct btrfs_key key;
        struct btrfs_block_group_item item;
        struct btrfs_space_info *space_info;
        spinlock_t lock;
        u64 pinned;
        u64 flags;
        int cached;
        int ro;
};

struct btrfs_device;
struct btrfs_fs_devices;
struct btrfs_fs_info {
        u8 fsid[BTRFS_FSID_SIZE];
        u8 chunk_tree_uuid[BTRFS_UUID_SIZE];
        struct btrfs_root *extent_root;
        struct btrfs_root *tree_root;
        struct btrfs_root *chunk_root;
        struct btrfs_root *dev_root;
        struct radix_tree_root fs_roots_radix;

        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;

        /* logical->physical extent mapping */
        struct btrfs_mapping_tree mapping_tree;

        u64 generation;
        u64 last_trans_committed;
        unsigned long mount_opt;
        u64 max_extent;
        u64 max_inline;
        u64 alloc_start;
        struct btrfs_transaction *running_transaction;
        wait_queue_head_t transaction_throttle;
        wait_queue_head_t transaction_wait;
        struct btrfs_super_block super_copy;
        struct btrfs_super_block super_for_commit;
        struct block_device *__bdev;
        struct super_block *sb;
        struct inode *btree_inode;
        struct backing_dev_info bdi;
        spinlock_t hash_lock;
        struct mutex trans_mutex;
        struct mutex transaction_kthread_mutex;
        struct mutex cleaner_mutex;
        struct mutex alloc_mutex;
        struct mutex chunk_mutex;
        struct mutex drop_mutex;
        struct mutex volume_mutex;
        struct list_head trans_list;
        struct list_head hashers;
        struct list_head dead_roots;
        atomic_t nr_async_submits;

        /*
         * this is used by the balancing code to wait for all the pending
         * ordered extents
         */
        spinlock_t ordered_extent_lock;
        struct list_head ordered_extents;

        /*
         * there is a pool of worker threads for checksumming during writes
         * and a pool for checksumming after reads.  This is because readers
         * can run with FS locks held, and the writers may be waiting for
         * those locks.  We don't want ordering in the pending list to cause
         * deadlocks, and so the two are serviced separately.
         *
         * A third pool does submit_bio to avoid deadlocking with the other
         * two
         */
        struct btrfs_workers workers;
        struct btrfs_workers endio_workers;
        struct btrfs_workers endio_write_workers;
        struct btrfs_workers submit_workers;
        /*
         * fixup workers take dirty pages that didn't properly go through
         * the cow mechanism and make them safe to write.  It happens
         * for the sys_munmap function call path
         */
        struct btrfs_workers fixup_workers;
        struct task_struct *transaction_kthread;
        struct task_struct *cleaner_kthread;
        int thread_pool_size;

        struct kobject super_kobj;
        struct completion kobj_unregister;
        int do_barriers;
        int closing;
        atomic_t throttles;

        u64 total_pinned;
        struct list_head dirty_cowonly_roots;

        struct btrfs_fs_devices *fs_devices;
        struct list_head space_info;
        spinlock_t delalloc_lock;
        spinlock_t new_trans_lock;
        u64 delalloc_bytes;
        u64 last_alloc;
        u64 last_data_alloc;

        spinlock_t ref_cache_lock;
        u64 total_ref_cache_size;
        u64 running_ref_cache_size;

        u64 avail_data_alloc_bits;
        u64 avail_metadata_alloc_bits;
        u64 avail_system_alloc_bits;
        u64 data_alloc_profile;
        u64 metadata_alloc_profile;
        u64 system_alloc_profile;

        void *bdev_holder;
};

/*
 * 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;

        /* the node lock is held while changing the node pointer */
        spinlock_t node_lock;

        struct extent_buffer *commit_root;
        struct btrfs_leaf_ref_tree *ref_tree;

        struct btrfs_root_item root_item;
        struct btrfs_key root_key;
        struct btrfs_fs_info *fs_info;
        struct inode *inode;
        struct kobject root_kobj;
        struct completion kobj_unregister;
        struct mutex objectid_mutex;
        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;

        u32 stripesize;

        u32 type;
        u64 highest_inode;
        u64 last_inode_alloc;
        int ref_cows;
        int track_dirty;
        u64 defrag_trans_start;
        struct btrfs_key defrag_progress;
        struct btrfs_key defrag_max;
        int defrag_running;
        int defrag_level;
        char *name;
        int in_sysfs;

        /* the dirty list is only used by non-reference counted roots */
        struct list_head dirty_list;

        spinlock_t orphan_lock;
        struct list_head orphan_list;
};

/*

 * 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
#define BTRFS_ORPHAN_ITEM_KEY           9
/* reserve 2-15 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

#define BTRFS_DEV_EXTENT_KEY    75
#define BTRFS_DEV_ITEM_KEY      76
#define BTRFS_CHUNK_ITEM_KEY    77

/*
 * string items are for debugging.  They just store a short string of
 * data in the FS
 */
#define BTRFS_STRING_ITEM_KEY   253

#define BTRFS_MOUNT_NODATASUM           (1 << 0)
#define BTRFS_MOUNT_NODATACOW           (1 << 1)
#define BTRFS_MOUNT_NOBARRIER           (1 << 2)
#define BTRFS_MOUNT_SSD                 (1 << 3)
#define BTRFS_MOUNT_DEGRADED            (1 << 4)

#define btrfs_clear_opt(o, opt)         ((o) &= ~BTRFS_MOUNT_##opt)
#define btrfs_set_opt(o, opt)           ((o) |= BTRFS_MOUNT_##opt)
#define btrfs_test_opt(root, opt)       ((root)->fs_info->mount_opt & \
                                         BTRFS_MOUNT_##opt)
/*
 * Inode flags
 */
#define BTRFS_INODE_NODATASUM           (1 << 0)
#define BTRFS_INODE_NODATACOW           (1 << 1)
#define BTRFS_INODE_READONLY            (1 << 2)
#define btrfs_clear_flag(inode, flag)   (BTRFS_I(inode)->flags &= \
                                         ~BTRFS_INODE_##flag)
#define btrfs_set_flag(inode, flag)     (BTRFS_I(inode)->flags |= \
                                         BTRFS_INODE_##flag)
#define btrfs_test_flag(inode, flag)    (BTRFS_I(inode)->flags & \
                                         BTRFS_INODE_##flag)
/* some macros to generate set/get funcs for the struct fields.  This
 * assumes there is a lefoo_to_cpu for every type, so lets make a simple
 * one for u8:
 */
#define le8_to_cpu(v) (v)
#define cpu_to_le8(v) (v)
#define __le8 u8

#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)))

#ifndef BTRFS_SETGET_FUNCS
#define BTRFS_SETGET_FUNCS(name, type, member, bits)                    \
u##bits btrfs_##name(struct extent_buffer *eb, type *s);                \
void btrfs_set_##name(struct extent_buffer *eb, type *s, u##bits val);
#endif

#define BTRFS_SETGET_HEADER_FUNCS(name, type, member, bits)             \
static inline u##bits btrfs_##name(struct extent_buffer *eb)            \
{                                                                       \
        type *p = kmap_atomic(eb->first_page, KM_USER0);                \
        u##bits res = le##bits##_to_cpu(p->member);                     \
        kunmap_atomic(p, KM_USER0);                                     \
        return res;                                                     \
}                                                                       \
static inline void btrfs_set_##name(struct extent_buffer *eb,           \
                                    u##bits val)                        \
{                                                                       \
        type *p = kmap_atomic(eb->first_page, KM_USER0);                \
        p->member = cpu_to_le##bits(val);                               \
        kunmap_atomic(p, KM_USER0);                                     \
}

#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);                               \
}

BTRFS_SETGET_FUNCS(device_type, struct btrfs_dev_item, type, 64);
BTRFS_SETGET_FUNCS(device_total_bytes, struct btrfs_dev_item, total_bytes, 64);
BTRFS_SETGET_FUNCS(device_bytes_used, struct btrfs_dev_item, bytes_used, 64);
BTRFS_SETGET_FUNCS(device_io_align, struct btrfs_dev_item, io_align, 32);
BTRFS_SETGET_FUNCS(device_io_width, struct btrfs_dev_item, io_width, 32);
BTRFS_SETGET_FUNCS(device_sector_size, struct btrfs_dev_item, sector_size, 32);
BTRFS_SETGET_FUNCS(device_id, struct btrfs_dev_item, devid, 64);
BTRFS_SETGET_FUNCS(device_group, struct btrfs_dev_item, dev_group, 32);
BTRFS_SETGET_FUNCS(device_seek_speed, struct btrfs_dev_item, seek_speed, 8);
BTRFS_SETGET_FUNCS(device_bandwidth, struct btrfs_dev_item, bandwidth, 8);

BTRFS_SETGET_STACK_FUNCS(stack_device_type, struct btrfs_dev_item, type, 64);
BTRFS_SETGET_STACK_FUNCS(stack_device_total_bytes, struct btrfs_dev_item,
                         total_bytes, 64);
BTRFS_SETGET_STACK_FUNCS(stack_device_bytes_used, struct btrfs_dev_item,
                         bytes_used, 64);
BTRFS_SETGET_STACK_FUNCS(stack_device_io_align, struct btrfs_dev_item,
                         io_align, 32);
BTRFS_SETGET_STACK_FUNCS(stack_device_io_width, struct btrfs_dev_item,
                         io_width, 32);
BTRFS_SETGET_STACK_FUNCS(stack_device_sector_size, struct btrfs_dev_item,
                         sector_size, 32);
BTRFS_SETGET_STACK_FUNCS(stack_device_id, struct btrfs_dev_item, devid, 64);
BTRFS_SETGET_STACK_FUNCS(stack_device_group, struct btrfs_dev_item,
                         dev_group, 32);
BTRFS_SETGET_STACK_FUNCS(stack_device_seek_speed, struct btrfs_dev_item,
                         seek_speed, 8);
BTRFS_SETGET_STACK_FUNCS(stack_device_bandwidth, struct btrfs_dev_item,
                         bandwidth, 8);

static inline char *btrfs_device_uuid(struct btrfs_dev_item *d)
{
        return (char *)d + offsetof(struct btrfs_dev_item, uuid);
}

BTRFS_SETGET_FUNCS(chunk_length, struct btrfs_chunk, length, 64);
BTRFS_SETGET_FUNCS(chunk_owner, struct btrfs_chunk, owner, 64);
BTRFS_SETGET_FUNCS(chunk_stripe_len, struct btrfs_chunk, stripe_len, 64);
BTRFS_SETGET_FUNCS(chunk_io_align, struct btrfs_chunk, io_align, 32);
BTRFS_SETGET_FUNCS(chunk_io_width, struct btrfs_chunk, io_width, 32);
BTRFS_SETGET_FUNCS(chunk_sector_size, struct btrfs_chunk, sector_size, 32);
BTRFS_SETGET_FUNCS(chunk_type, struct btrfs_chunk, type, 64);
BTRFS_SETGET_FUNCS(chunk_num_stripes, struct btrfs_chunk, num_stripes, 16);
BTRFS_SETGET_FUNCS(chunk_sub_stripes, struct btrfs_chunk, sub_stripes, 16);
BTRFS_SETGET_FUNCS(stripe_devid, struct btrfs_stripe, devid, 64);
BTRFS_SETGET_FUNCS(stripe_offset, struct btrfs_stripe, offset, 64);

static inline char *btrfs_stripe_dev_uuid(struct btrfs_stripe *s)
{
        return (char *)s + offsetof(struct btrfs_stripe, dev_uuid);
}

BTRFS_SETGET_STACK_FUNCS(stack_chunk_length, struct btrfs_chunk, length, 64);
BTRFS_SETGET_STACK_FUNCS(stack_chunk_owner, struct btrfs_chunk, owner, 64);
BTRFS_SETGET_STACK_FUNCS(stack_chunk_stripe_len, struct btrfs_chunk,
                         stripe_len, 64);
BTRFS_SETGET_STACK_FUNCS(stack_chunk_io_align, struct btrfs_chunk,
                         io_align, 32);
BTRFS_SETGET_STACK_FUNCS(stack_chunk_io_width, struct btrfs_chunk,
                         io_width, 32);
BTRFS_SETGET_STACK_FUNCS(stack_chunk_sector_size, struct btrfs_chunk,
                         sector_size, 32);
BTRFS_SETGET_STACK_FUNCS(stack_chunk_type, struct btrfs_chunk, type, 64);
BTRFS_SETGET_STACK_FUNCS(stack_chunk_num_stripes, struct btrfs_chunk,
                         num_stripes, 16);
BTRFS_SETGET_STACK_FUNCS(stack_chunk_sub_stripes, struct btrfs_chunk,
                         sub_stripes, 16);
BTRFS_SETGET_STACK_FUNCS(stack_stripe_devid, struct btrfs_stripe, devid, 64);
BTRFS_SETGET_STACK_FUNCS(stack_stripe_offset, struct btrfs_stripe, offset, 64);

static inline struct btrfs_stripe *btrfs_stripe_nr(struct btrfs_chunk *c,
                                                   int nr)
{
        unsigned long offset = (unsigned long)c;
        offset += offsetof(struct btrfs_chunk, stripe);
        offset += nr * sizeof(struct btrfs_stripe);
        return (struct btrfs_stripe *)offset;
}

static inline char *btrfs_stripe_dev_uuid_nr(struct btrfs_chunk *c, int nr)
{
        return btrfs_stripe_dev_uuid(btrfs_stripe_nr(c, nr));
}

static inline u64 btrfs_stripe_offset_nr(struct extent_buffer *eb,
                                         struct btrfs_chunk *c, int nr)
{
        return btrfs_stripe_offset(eb, btrfs_stripe_nr(c, nr));
}

static inline void btrfs_set_stripe_offset_nr(struct extent_buffer *eb,
                                             struct btrfs_chunk *c, int nr,
                                             u64 val)
{
        btrfs_set_stripe_offset(eb, btrfs_stripe_nr(c, nr), val);
}

static inline u64 btrfs_stripe_devid_nr(struct extent_buffer *eb,
                                         struct btrfs_chunk *c, int nr)
{
        return btrfs_stripe_devid(eb, btrfs_stripe_nr(c, nr));
}

static inline void btrfs_set_stripe_devid_nr(struct extent_buffer *eb,
                                             struct btrfs_chunk *c, int nr,
                                             u64 val)
{
        btrfs_set_stripe_devid(eb, btrfs_stripe_nr(c, nr), 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);
BTRFS_SETGET_STACK_FUNCS(block_group_chunk_objectid,
                        struct btrfs_block_group_item, chunk_objectid, 64);

BTRFS_SETGET_FUNCS(disk_block_group_chunk_objectid,
                   struct btrfs_block_group_item, chunk_objectid, 64);
BTRFS_SETGET_FUNCS(disk_block_group_flags,
                   struct btrfs_block_group_item, flags, 64);
BTRFS_SETGET_STACK_FUNCS(block_group_flags,
                        struct btrfs_block_group_item, flags, 64);

/* struct btrfs_inode_ref */
BTRFS_SETGET_FUNCS(inode_ref_name_len, struct btrfs_inode_ref, name_len, 16);
BTRFS_SETGET_FUNCS(inode_ref_index, struct btrfs_inode_ref, index, 64);

/* 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, 64);
BTRFS_SETGET_FUNCS(inode_flags, struct btrfs_inode_item, flags, 16);
BTRFS_SETGET_FUNCS(inode_compat_flags, struct btrfs_inode_item,
                   compat_flags, 16);

static inline struct btrfs_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_timespec *)ptr;
}

static inline struct btrfs_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_timespec *)ptr;
}

static inline struct btrfs_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_timespec *)ptr;
}

static inline struct btrfs_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_timespec *)ptr;
}

BTRFS_SETGET_FUNCS(timespec_sec, struct btrfs_timespec, sec, 64);
BTRFS_SETGET_FUNCS(timespec_nsec, struct btrfs_timespec, nsec, 32);

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

/* struct btrfs_dev_extent */
BTRFS_SETGET_FUNCS(dev_extent_chunk_tree, struct btrfs_dev_extent,
                   chunk_tree, 64);
BTRFS_SETGET_FUNCS(dev_extent_chunk_objectid, struct btrfs_dev_extent,
                   chunk_objectid, 64);
BTRFS_SETGET_FUNCS(dev_extent_chunk_offset, struct btrfs_dev_extent,
                   chunk_offset, 64);
BTRFS_SETGET_FUNCS(dev_extent_length, struct btrfs_dev_extent, length, 64);

static inline u8 *btrfs_dev_extent_chunk_tree_uuid(struct btrfs_dev_extent *dev)
{
        unsigned long ptr = offsetof(struct btrfs_dev_extent, chunk_tree_uuid);
        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_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;
}

void btrfs_node_key(struct extent_buffer *eb,
                    struct btrfs_disk_key *disk_key, int nr);

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, 64);
BTRFS_SETGET_HEADER_FUNCS(header_level, struct btrfs_header, level, 8);

static inline int btrfs_header_flag(struct extent_buffer *eb, u64 flag)
{
        return (btrfs_header_flags(eb) & flag) == flag;
}

static inline int btrfs_set_header_flag(struct extent_buffer *eb, u64 flag)
{
        u64 flags = btrfs_header_flags(eb);
        btrfs_set_header_flags(eb, flags | flag);
        return (flags & flag) == flag;
}

static inline int btrfs_clear_header_flag(struct extent_buffer *eb, u64 flag)
{
        u64 flags = btrfs_header_flags(eb);
        btrfs_set_header_flags(eb, flags & ~flag);
        return (flags & flag) == flag;
}

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_header_chunk_tree_uuid(struct extent_buffer *eb)
{
        unsigned long ptr = offsetof(struct btrfs_header, chunk_tree_uuid);
        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_flags, struct btrfs_super_block, flags, 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_sys_array_size,
                         struct btrfs_super_block, sys_chunk_array_size, 32);
BTRFS_SETGET_STACK_FUNCS(super_root_level, struct btrfs_super_block,
                         root_level, 8);
BTRFS_SETGET_STACK_FUNCS(super_chunk_root, struct btrfs_super_block,
                         chunk_root, 64);
BTRFS_SETGET_STACK_FUNCS(super_chunk_root_level, struct btrfs_super_block,
                         chunk_root_level, 64);
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);
BTRFS_SETGET_STACK_FUNCS(super_num_devices, struct btrfs_super_block,
                         num_devices, 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 struct btrfs_root *btrfs_sb(struct super_block *sb)
{
        return sb->s_fs_info;
}

static inline int btrfs_set_root_name(struct btrfs_root *root,
                                      const char *name, int len)
{
        /* if we already have a name just free it */
        if (root->name)
                kfree(root->name);

        root->name = kmalloc(len+1, GFP_KERNEL);
        if (!root->name)
                return -ENOMEM;

        memcpy(root->name, name, len);
        root->name[len] ='\0';

        return 0;
}

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)))

static inline struct dentry *fdentry(struct file *file) {
#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,18)
        return file->f_dentry;
#else
        return file->f_path.dentry;
#endif
}

/* extent-tree.c */
u32 btrfs_count_snapshots_in_path(struct btrfs_root *root,
                                  struct btrfs_path *count_path,
                                  u64 expected_owner, 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);
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_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 min_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, u64 data);
int btrfs_alloc_reserved_extent(struct btrfs_trans_handle *trans,
                                struct btrfs_root *root,
                                u64 root_objectid, u64 ref_generation,
                                u64 owner, u64 owner_offset,
                                struct btrfs_key *ins);
int btrfs_reserve_extent(struct btrfs_trans_handle *trans,
                                  struct btrfs_root *root,
                                  u64 num_bytes, u64 min_alloc_size,
                                  u64 empty_size, u64 hint_byte,
                                  u64 search_end, struct btrfs_key *ins,
                                  u64 data);
int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
                  struct extent_buffer *buf, int cache_ref);
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_group(struct btrfs_trans_handle *trans,
                           struct btrfs_root *root, u64 bytes_used,
                           u64 type, u64 chunk_objectid, u64 chunk_offset,
                           u64 size);
/* ctree.c */
int btrfs_previous_item(struct btrfs_root *root,
                        struct btrfs_path *path, u64 min_objectid,
                        int type);

struct extent_buffer *btrfs_root_node(struct btrfs_root *root);
struct extent_buffer *btrfs_lock_root_node(struct btrfs_root *root);
int btrfs_find_next_key(struct btrfs_root *root, struct btrfs_path *path,
                        struct btrfs_key *key, int lowest_level,
                        int cache_only, u64 min_trans);
int btrfs_search_forward(struct btrfs_root *root, struct btrfs_key *min_key,
                         struct btrfs_path *path, int cache_only,
                         u64 min_trans);

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_items(struct btrfs_trans_handle *trans, struct btrfs_root *root,
                   struct btrfs_path *path, int slot, int nr);

static inline int btrfs_del_item(struct btrfs_trans_handle *trans,
                                 struct btrfs_root *root,
                                 struct btrfs_path *path)
{
        return btrfs_del_items(trans, root, path, path->slots[0], 1);
}

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_items(struct btrfs_trans_handle *trans,
                             struct btrfs_root *root,
                             struct btrfs_path *path,
                             struct btrfs_key *cpu_key, u32 *data_size, int nr);

static inline int btrfs_insert_empty_item(struct btrfs_trans_handle *trans,
                                          struct btrfs_root *root,
                                          struct btrfs_path *path,
                                          struct btrfs_key *key,
                                          u32 data_size)
{
        return btrfs_insert_empty_items(trans, root, path, key, &data_size, 1);
}

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_search_root(struct btrfs_root *root, u64 search_start,
                      u64 *found_objectid);
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, u64 index);
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);

/* orphan.c */
int btrfs_insert_orphan_item(struct btrfs_trans_handle *trans,
                             struct btrfs_root *root, u64 offset);
int btrfs_del_orphan_item(struct btrfs_trans_handle *trans,
                          struct btrfs_root *root, u64 offset);

/* 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, u64 index);
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, u64 *index);
int btrfs_insert_empty_inode(struct btrfs_trans_handle *trans,
                             struct btrfs_root *root,
                             struct btrfs_path *path, u64 objectid);
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 disk_offset,
                               u64 disk_num_bytes,
                             u64 num_bytes, u64 offset);
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_blocks(struct btrfs_trans_handle *trans,
                           struct btrfs_root *root, struct inode *inode,
                           struct btrfs_ordered_sum *sums);
int btrfs_csum_one_bio(struct btrfs_root *root, struct inode *inode,
                       struct bio *bio);
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);
/* inode.c */

/* RHEL and EL kernels have a patch that renames PG_checked to FsMisc */
#ifdef ClearPageFsMisc
#define ClearPageChecked ClearPageFsMisc
#define SetPageChecked SetPageFsMisc
#define PageChecked PageFsMisc
#endif

int btrfs_writepages(struct address_space *mapping,
                     struct writeback_control *wbc);
int btrfs_create_subvol_root(struct btrfs_root *new_root,
                struct btrfs_trans_handle *trans, u64 new_dirid,
                struct btrfs_block_group_cache *block_group);

void btrfs_invalidate_dcache_root(struct btrfs_root *root, char *name,
                                  int namelen);

int btrfs_merge_bio_hook(struct page *page, unsigned long offset,
                         size_t size, struct bio *bio);

static inline void dec_i_blocks(struct inode *inode, u64 dec)
{
        dec = dec >> 9;
        if (dec <= inode->i_blocks)
                inode->i_blocks -= dec;
        else
                inode->i_blocks = 0;
}

unsigned long btrfs_force_ra(struct address_space *mapping,
                              struct file_ra_state *ra, struct file *file,
                              pgoff_t offset, pgoff_t last_index);
int btrfs_check_free_space(struct btrfs_root *root, u64 num_required,
                           int for_del);
int btrfs_page_mkwrite(struct vm_area_struct *vma, struct page *page);
int btrfs_readpage(struct file *file, struct page *page);
void btrfs_delete_inode(struct inode *inode);
void btrfs_put_inode(struct inode *inode);
void btrfs_read_locked_inode(struct inode *inode);
int btrfs_write_inode(struct inode *inode, int wait);
void btrfs_dirty_inode(struct inode *inode);
struct inode *btrfs_alloc_inode(struct super_block *sb);
void btrfs_destroy_inode(struct inode *inode);
int btrfs_init_cachep(void);
void btrfs_destroy_cachep(void);
long btrfs_ioctl_trans_end(struct file *file);
struct inode *btrfs_iget_locked(struct super_block *s, u64 objectid,
                                struct btrfs_root *root);
struct inode *btrfs_ilookup(struct super_block *s, u64 objectid,
                            u64 root_objectid);
int btrfs_commit_write(struct file *file, struct page *page,
                       unsigned from, unsigned to);
struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page,
                                    size_t page_offset, u64 start, u64 end,
                                    int create);
int btrfs_update_inode(struct btrfs_trans_handle *trans,
                              struct btrfs_root *root,
                              struct inode *inode);

/* ioctl.c */
long btrfs_ioctl(struct file *file, unsigned int cmd, unsigned long arg);

/* file.c */
int btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end);
int btrfs_check_file(struct btrfs_root *root, struct inode *inode);
extern struct file_operations btrfs_file_operations;
int btrfs_drop_extents(struct btrfs_trans_handle *trans,
                       struct btrfs_root *root, struct inode *inode,
                       u64 start, u64 end, u64 inline_limit, u64 *hint_block);
int btrfs_release_file(struct inode *inode, struct file *file);

/* tree-defrag.c */
int btrfs_defrag_leaves(struct btrfs_trans_handle *trans,
                        struct btrfs_root *root, int cache_only);

/* sysfs.c */
int btrfs_init_sysfs(void);
void btrfs_exit_sysfs(void);
int btrfs_sysfs_add_super(struct btrfs_fs_info *fs);
int btrfs_sysfs_add_root(struct btrfs_root *root);
void btrfs_sysfs_del_root(struct btrfs_root *root);
void btrfs_sysfs_del_super(struct btrfs_fs_info *root);

/* xattr.c */
ssize_t btrfs_listxattr(struct dentry *dentry, char *buffer, size_t size);

/* super.c */
u64 btrfs_parse_size(char *str);
int btrfs_parse_options(struct btrfs_root *root, char *options);
int btrfs_sync_fs(struct super_block *sb, int wait);

/* acl.c */
int btrfs_check_acl(struct inode *inode, int mask);
int btrfs_init_acl(struct inode *inode, struct inode *dir);
int btrfs_acl_chmod(struct inode *inode);
#endif