Quilt spewdebian/3.17-1

6 files changed, 4435 insertions, 0 deletions

diff --git a/.pc/.quilt_patches b/.pc/.quilt_patches
new file mode 100644
index 0000000..6857a8d
--- /dev/null
+++ b/.pc/.quilt_patches
@@ -0,0 +1 @@
+debian/patches
diff --git a/.pc/.quilt_series b/.pc/.quilt_series
new file mode 100644
index 0000000..c206706
--- /dev/null
+++ b/.pc/.quilt_series
@@ -0,0 +1 @@
+series
diff --git a/.pc/.version b/.pc/.version
new file mode 100644
index 0000000..0cfbf08
--- /dev/null
+++ b/.pc/.version
@@ -0,0 +1 @@
+2
diff --git a/.pc/0001-Fixing-unaligned-memory-accesses.patch/ctree.h b/.pc/0001-Fixing-unaligned-memory-accesses.patch/ctree.h
new file mode 100644
index 0000000..89036de
--- /dev/null
+++ b/.pc/0001-Fixing-unaligned-memory-accesses.patch/ctree.h
@@ -0,0 +1,2423 @@
+/*
+ * 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__
+
+#if BTRFS_FLAT_INCLUDES
+#include "list.h"
+#include "kerncompat.h"
+#include "radix-tree.h"
+#include "extent-cache.h"
+#include "extent_io.h"
+#include "ioctl.h"
+#else
+#include <btrfs/list.h>
+#include <btrfs/kerncompat.h>
+#include <btrfs/radix-tree.h>
+#include <btrfs/extent-cache.h>
+#include <btrfs/extent_io.h>
+#include <btrfs/ioctl.h>
+#endif /* BTRFS_FLAT_INCLUDES */
+
+struct btrfs_root;
+struct btrfs_trans_handle;
+struct btrfs_free_space_ctl;
+#define BTRFS_MAGIC 0x4D5F53665248425FULL /* ascii _BHRfS_M, no null */
+
+#define BTRFS_MAX_MIRRORS 3
+
+#define BTRFS_MAX_LEVEL 8
+
+#define BTRFS_COMPAT_EXTENT_TREE_V0
+
+/* holds pointers to all of the tree roots */
+#define BTRFS_ROOT_TREE_OBJECTID 1ULL
+
+/* 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
+/* holds checksums of all the data extents */
+#define BTRFS_CSUM_TREE_OBJECTID 7ULL
+#define BTRFS_QUOTA_TREE_OBJECTID 8ULL
+
+/* for storing items that use the BTRFS_UUID_KEY* */
+#define BTRFS_UUID_TREE_OBJECTID 9ULL
+
+/* for storing balance parameters in the root tree */
+#define BTRFS_BALANCE_OBJECTID -4ULL
+
+/* oprhan objectid for tracking unlinked/truncated files */
+#define BTRFS_ORPHAN_OBJECTID -5ULL
+
+/* does write ahead logging to speed up fsyncs */
+#define BTRFS_TREE_LOG_OBJECTID -6ULL
+#define BTRFS_TREE_LOG_FIXUP_OBJECTID -7ULL
+
+/* space balancing */
+#define BTRFS_TREE_RELOC_OBJECTID -8ULL
+#define BTRFS_DATA_RELOC_TREE_OBJECTID -9ULL
+
+/*
+ * extent checksums all have this objectid
+ * this allows them to share the logging tree
+ * for fsyncs
+ */
+#define BTRFS_EXTENT_CSUM_OBJECTID -10ULL
+
+/* For storing free space cache */
+#define BTRFS_FREE_SPACE_OBJECTID -11ULL
+
+/*
+ * The inode number assigned to the special inode for sotring
+ * free ino cache
+ */
+#define BTRFS_FREE_INO_OBJECTID -12ULL
+
+/* dummy objectid represents multiple objectids */
+#define BTRFS_MULTIPLE_OBJECTIDS -255ULL
+
+/*
+ * All files have objectids in this range.
+ */
+#define BTRFS_FIRST_FREE_OBJECTID 256ULL
+#define BTRFS_LAST_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
+
+/*
+ * the max metadata block size.  This limit is somewhat artificial,
+ * but the memmove costs go through the roof for larger blocks.
+ */
+#define BTRFS_MAX_METADATA_BLOCKSIZE 65536
+
+/*
+ * we can actually store much bigger names, but lets not confuse the rest
+ * of linux
+ */
+#define BTRFS_NAME_LEN 255
+
+/*
+ * Theoretical limit is larger, but we keep this down to a sane
+ * value. That should limit greatly the possibility of collisions on
+ * inode ref items.
+ */
+#define	BTRFS_LINK_MAX	65535U
+
+/* 32 bytes in various csum fields */
+#define BTRFS_CSUM_SIZE 32
+
+/* csum types */
+#define BTRFS_CSUM_TYPE_CRC32	0
+
+static int btrfs_csum_sizes[] = { 4, 0 };
+
+/* 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
+
+#define BTRFS_ROOT_SUBVOL_RDONLY	(1ULL << 0)
+
+/*
+ * 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 cache_tree cache_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;
+
+	/* expected generation for this device */
+	__le64 generation;
+
+	/*
+	 * starting byte of this partition on the device,
+	 * to allowr for stripe alignment in the future
+	 */
+	__le64 start_offset;
+
+	/* 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];
+
+	/* uuid of FS who owns this device */
+	u8 fsid[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__));
+
+#define BTRFS_FREE_SPACE_EXTENT	1
+#define BTRFS_FREE_SPACE_BITMAP	2
+
+struct btrfs_free_space_entry {
+	__le64 offset;
+	__le64 bytes;
+	u8 type;
+} __attribute__ ((__packed__));
+
+struct btrfs_free_space_header {
+	struct btrfs_disk_key location;
+	__le64 generation;
+	__le64 num_entries;
+	__le64 num_bitmaps;
+} __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_HEADER_FLAG_WRITTEN		(1ULL << 0)
+#define BTRFS_HEADER_FLAG_RELOC			(1ULL << 1)
+#define BTRFS_SUPER_FLAG_SEEDING		(1ULL << 32)
+#define BTRFS_SUPER_FLAG_METADUMP		(1ULL << 33)
+
+#define BTRFS_BACKREF_REV_MAX		256
+#define BTRFS_BACKREF_REV_SHIFT		56
+#define BTRFS_BACKREF_REV_MASK		(((u64)BTRFS_BACKREF_REV_MAX - 1) << \
+					 BTRFS_BACKREF_REV_SHIFT)
+
+#define BTRFS_OLD_BACKREF_REV		0
+#define BTRFS_MIXED_BACKREF_REV		1
+
+/*
+ * every tree block (leaf or node) starts with this header.
+ */
+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))
+#define BTRFS_MAX_XATTR_SIZE(r)	(BTRFS_LEAF_DATA_SIZE(r) - \
+				 sizeof(struct btrfs_item) -\
+				 sizeof(struct btrfs_dir_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
+
+/*
+ * just in case we somehow lose the roots and are not able to mount,
+ * we store an array of the roots from previous transactions
+ * in the super.
+ */
+#define BTRFS_NUM_BACKUP_ROOTS 4
+struct btrfs_root_backup {
+	__le64 tree_root;
+	__le64 tree_root_gen;
+
+	__le64 chunk_root;
+	__le64 chunk_root_gen;
+
+	__le64 extent_root;
+	__le64 extent_root_gen;
+
+	__le64 fs_root;
+	__le64 fs_root_gen;
+
+	__le64 dev_root;
+	__le64 dev_root_gen;
+
+	__le64 csum_root;
+	__le64 csum_root_gen;
+
+	__le64 total_bytes;
+	__le64 bytes_used;
+	__le64 num_devices;
+	/* future */
+	__le64 unsed_64[4];
+
+	u8 tree_root_level;
+	u8 chunk_root_level;
+	u8 extent_root_level;
+	u8 fs_root_level;
+	u8 dev_root_level;
+	u8 csum_root_level;
+	/* future and to align */
+	u8 unused_8[10];
+} __attribute__ ((__packed__));
+
+/*
+ * 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 flags;
+
+	/* allowed to be different from the btrfs_header from here own down */
+	__le64 magic;
+	__le64 generation;
+	__le64 root;
+	__le64 chunk_root;
+	__le64 log_root;
+
+	/* this will help find the new super based on the log root */
+	__le64 log_root_transid;
+	__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;
+	__le64 chunk_root_generation;
+	__le64 compat_flags;
+	__le64 compat_ro_flags;
+	__le64 incompat_flags;
+	__le16 csum_type;
+	u8 root_level;
+	u8 chunk_root_level;
+	u8 log_root_level;
+	struct btrfs_dev_item dev_item;
+
+	char label[BTRFS_LABEL_SIZE];
+
+	__le64 cache_generation;
+	__le64 uuid_tree_generation;
+
+	/* future expansion */
+	__le64 reserved[30];
+	u8 sys_chunk_array[BTRFS_SYSTEM_CHUNK_ARRAY_SIZE];
+	struct btrfs_root_backup super_roots[BTRFS_NUM_BACKUP_ROOTS];
+} __attribute__ ((__packed__));
+
+/*
+ * Compat flags that we support.  If any incompat flags are set other than the
+ * ones specified below then we will fail to mount
+ */
+#define BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF	(1ULL << 0)
+#define BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL	(1ULL << 1)
+#define BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS	(1ULL << 2)
+#define BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO	(1ULL << 3)
+
+/*
+ * some patches floated around with a second compression method
+ * lets save that incompat here for when they do get in
+ * Note we don't actually support it, we're just reserving the
+ * number
+ */
+#define BTRFS_FEATURE_INCOMPAT_COMPRESS_LZOv2   (1ULL << 4)
+
+/*
+ * older kernels tried to do bigger metadata blocks, but the
+ * code was pretty buggy.  Lets not let them try anymore.
+ */
+#define BTRFS_FEATURE_INCOMPAT_BIG_METADATA     (1ULL << 5)
+#define BTRFS_FEATURE_INCOMPAT_EXTENDED_IREF	(1ULL << 6)
+#define BTRFS_FEATURE_INCOMPAT_RAID56		(1ULL << 7)
+#define BTRFS_FEATURE_INCOMPAT_SKINNY_METADATA	(1ULL << 8)
+#define BTRFS_FEATURE_INCOMPAT_NO_HOLES		(1ULL << 9)
+
+
+#define BTRFS_FEATURE_COMPAT_SUPP		0ULL
+#define BTRFS_FEATURE_COMPAT_RO_SUPP		0ULL
+#define BTRFS_FEATURE_INCOMPAT_SUPP			\
+	(BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF |		\
+	 BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL |	\
+	 BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO |		\
+	 BTRFS_FEATURE_INCOMPAT_BIG_METADATA |		\
+	 BTRFS_FEATURE_INCOMPAT_EXTENDED_IREF |		\
+	 BTRFS_FEATURE_INCOMPAT_RAID56 |		\
+	 BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS |		\
+	 BTRFS_FEATURE_INCOMPAT_SKINNY_METADATA |	\
+	 BTRFS_FEATURE_INCOMPAT_NO_HOLES)
+
+/*
+ * 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 lowest_level;
+
+	/*
+	 * set by btrfs_split_item, tells search_slot to keep all locks
+	 * and to force calls to keep space in the nodes
+	 */
+	unsigned int search_for_split:1;
+	unsigned int skip_check_block:1;
+};
+
+/*
+ * items in the extent btree are used to record the objectid of the
+ * owner of the block and the number of references
+ */
+
+struct btrfs_extent_item {
+	__le64 refs;
+	__le64 generation;
+	__le64 flags;
+} __attribute__ ((__packed__));
+
+struct btrfs_extent_item_v0 {
+	__le32 refs;
+} __attribute__ ((__packed__));
+
+#define BTRFS_MAX_EXTENT_ITEM_SIZE(r) ((BTRFS_LEAF_DATA_SIZE(r) >> 4) - \
+					sizeof(struct btrfs_item))
+
+#define BTRFS_EXTENT_FLAG_DATA		(1ULL << 0)
+#define BTRFS_EXTENT_FLAG_TREE_BLOCK	(1ULL << 1)
+
+/* following flags only apply to tree blocks */
+
+/* use full backrefs for extent pointers in the block*/
+#define BTRFS_BLOCK_FLAG_FULL_BACKREF	(1ULL << 8)
+
+struct btrfs_tree_block_info {
+	struct btrfs_disk_key key;
+	u8 level;
+} __attribute__ ((__packed__));
+
+struct btrfs_extent_data_ref {
+	__le64 root;
+	__le64 objectid;
+	__le64 offset;
+	__le32 count;
+} __attribute__ ((__packed__));
+
+struct btrfs_shared_data_ref {
+	__le32 count;
+} __attribute__ ((__packed__));
+
+struct btrfs_extent_inline_ref {
+	u8 type;
+	__le64 offset;
+} __attribute__ ((__packed__));
+
+struct btrfs_extent_ref_v0 {
+	__le64 root;
+	__le64 generation;
+	__le64 objectid;
+	__le32 count;
+} __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_inode_extref {
+	__le64 parent_objectid;
+	__le64 index;
+	__le16 name_len;
+	__u8   name[0]; /* name goes here */
+} __attribute__ ((__packed__));
+
+struct btrfs_timespec {
+	__le64 sec;
+	__le32 nsec;
+} __attribute__ ((__packed__));
+
+typedef enum {
+	BTRFS_COMPRESS_NONE  = 0,
+	BTRFS_COMPRESS_ZLIB  = 1,
+	BTRFS_COMPRESS_LZO   = 2,
+	BTRFS_COMPRESS_TYPES = 2,
+	BTRFS_COMPRESS_LAST  = 3,
+} btrfs_compression_type;
+
+/* we don't understand any encryption methods right now */
+typedef enum {
+	BTRFS_ENCRYPTION_NONE = 0,
+	BTRFS_ENCRYPTION_LAST = 1,
+} btrfs_encryption_type;
+
+enum btrfs_tree_block_status {
+	BTRFS_TREE_BLOCK_CLEAN,
+	BTRFS_TREE_BLOCK_INVALID_NRITEMS,
+	BTRFS_TREE_BLOCK_INVALID_PARENT_KEY,
+	BTRFS_TREE_BLOCK_BAD_KEY_ORDER,
+	BTRFS_TREE_BLOCK_INVALID_LEVEL,
+	BTRFS_TREE_BLOCK_INVALID_FREE_SPACE,
+	BTRFS_TREE_BLOCK_INVALID_OFFSETS,
+};
+
+struct btrfs_inode_item {
+	/* nfs style generation number */
+	__le64 generation;
+	/* transid that last touched this inode */
+	__le64 transid;
+	__le64 size;
+	__le64 nbytes;
+	__le64 block_group;
+	__le32 nlink;
+	__le32 uid;
+	__le32 gid;
+	__le32 mode;
+	__le64 rdev;
+	__le64 flags;
+
+	/* modification sequence number for NFS */
+	__le64 sequence;
+
+	/*
+	 * a little future expansion, for more than this we can
+	 * just grow the inode item and version it
+	 */
+	__le64 reserved[4];
+	struct btrfs_timespec atime;
+	struct btrfs_timespec ctime;
+	struct btrfs_timespec mtime;
+	struct btrfs_timespec otime;
+} __attribute__ ((__packed__));
+
+struct btrfs_dir_log_item {
+	__le64 end;
+} __attribute__ ((__packed__));
+
+struct btrfs_dir_item {
+	struct btrfs_disk_key location;
+	__le64 transid;
+	__le16 data_len;
+	__le16 name_len;
+	u8 type;
+} __attribute__ ((__packed__));
+
+struct btrfs_root_item_v0 {
+	struct btrfs_inode_item inode;
+	__le64 generation;
+	__le64 root_dirid;
+	__le64 bytenr;
+	__le64 byte_limit;
+	__le64 bytes_used;
+	__le64 last_snapshot;
+	__le64 flags;
+	__le32 refs;
+	struct btrfs_disk_key drop_progress;
+	u8 drop_level;
+	u8 level;
+} __attribute__ ((__packed__));
+
+struct btrfs_root_item {
+	struct btrfs_inode_item inode;
+	__le64 generation;
+	__le64 root_dirid;
+	__le64 bytenr;
+	__le64 byte_limit;
+	__le64 bytes_used;
+	__le64 last_snapshot;
+	__le64 flags;
+	__le32 refs;
+	struct btrfs_disk_key drop_progress;
+	u8 drop_level;
+	u8 level;
+
+	/*
+	 * The following fields appear after subvol_uuids+subvol_times
+	 * were introduced.
+	 */
+
+	/*
+	 * This generation number is used to test if the new fields are valid
+	 * and up to date while reading the root item. Everytime the root item
+	 * is written out, the "generation" field is copied into this field. If
+	 * anyone ever mounted the fs with an older kernel, we will have
+	 * mismatching generation values here and thus must invalidate the
+	 * new fields. See btrfs_update_root and btrfs_find_last_root for
+	 * details.
+	 * the offset of generation_v2 is also used as the start for the memset
+	 * when invalidating the fields.
+	 */
+	__le64 generation_v2;
+	u8 uuid[BTRFS_UUID_SIZE];
+	u8 parent_uuid[BTRFS_UUID_SIZE];
+	u8 received_uuid[BTRFS_UUID_SIZE];
+	__le64 ctransid; /* updated when an inode changes */
+	__le64 otransid; /* trans when created */
+	__le64 stransid; /* trans when sent. non-zero for received subvol */
+	__le64 rtransid; /* trans when received. non-zero for received subvol */
+	struct btrfs_timespec ctime;
+	struct btrfs_timespec otime;
+	struct btrfs_timespec stime;
+	struct btrfs_timespec rtime;
+        __le64 reserved[8]; /* for future */
+} __attribute__ ((__packed__));
+
+/*
+ * this is used for both forward and backward root refs
+ */
+struct btrfs_root_ref {
+	__le64 dirid;
+	__le64 sequence;
+	__le16 name_len;
+} __attribute__ ((__packed__));
+
+#define BTRFS_FILE_EXTENT_INLINE 0
+#define BTRFS_FILE_EXTENT_REG 1
+#define BTRFS_FILE_EXTENT_PREALLOC 2
+
+struct btrfs_file_extent_item {
+	/*
+	 * transaction id that created this extent
+	 */
+	__le64 generation;
+	/*
+	 * max number of bytes to hold this extent in ram
+	 * when we split a compressed extent we can't know how big
+	 * each of the resulting pieces will be.  So, this is
+	 * an upper limit on the size of the extent in ram instead of
+	 * an exact limit.
+	 */
+	__le64 ram_bytes;
+
+	/*
+	 * 32 bits for the various ways we might encode the data,
+	 * including compression and encryption.  If any of these
+	 * are set to something a given disk format doesn't understand
+	 * it is treated like an incompat flag for reading and writing,
+	 * but not for stat.
+	 */
+	u8 compression;
+	u8 encryption;
+	__le16 other_encoding; /* spare for later use */
+
+	/* are we inline data or a real extent? */
+	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__));
+
+/*
+ * We don't want to overwrite 1M at the beginning of device, even though
+ * there is our 1st superblock at 64k. Some possible reasons:
+ *  - the first 64k blank is useful for some boot loader/manager
+ *  - the first 1M could be scratched by buggy partitioner or somesuch
+ */
+#define BTRFS_BLOCK_RESERVED_1M_FOR_SUPER	((u64)1024 * 1024)
+
+/* tag for the radix tree of block groups in ram */
+#define BTRFS_BLOCK_GROUP_DATA		(1ULL << 0)
+#define BTRFS_BLOCK_GROUP_SYSTEM	(1ULL << 1)
+#define BTRFS_BLOCK_GROUP_METADATA	(1ULL << 2)
+#define BTRFS_BLOCK_GROUP_RAID0		(1ULL << 3)
+#define BTRFS_BLOCK_GROUP_RAID1		(1ULL << 4)
+#define BTRFS_BLOCK_GROUP_DUP		(1ULL << 5)
+#define BTRFS_BLOCK_GROUP_RAID10	(1ULL << 6)
+#define BTRFS_BLOCK_GROUP_RAID5    (1ULL << 7)
+#define BTRFS_BLOCK_GROUP_RAID6    (1ULL << 8)
+#define BTRFS_BLOCK_GROUP_RESERVED	BTRFS_AVAIL_ALLOC_BIT_SINGLE
+
+#define BTRFS_BLOCK_GROUP_TYPE_MASK	(BTRFS_BLOCK_GROUP_DATA |    \
+					 BTRFS_BLOCK_GROUP_SYSTEM |  \
+					 BTRFS_BLOCK_GROUP_METADATA)
+
+#define BTRFS_BLOCK_GROUP_PROFILE_MASK	(BTRFS_BLOCK_GROUP_RAID0 |   \
+					 BTRFS_BLOCK_GROUP_RAID1 |   \
+					 BTRFS_BLOCK_GROUP_RAID5 |   \
+					 BTRFS_BLOCK_GROUP_RAID6 |   \
+					 BTRFS_BLOCK_GROUP_DUP |     \
+					 BTRFS_BLOCK_GROUP_RAID10)
+
+/* used in struct btrfs_balance_args fields */
+#define BTRFS_AVAIL_ALLOC_BIT_SINGLE	(1ULL << 48)
+
+/*
+ * GLOBAL_RSV does not exist as a on-disk block group type and is used
+ * internally for exporting info about global block reserve from space infos
+ */
+#define BTRFS_SPACE_INFO_GLOBAL_RSV    (1ULL << 49)
+
+#define BTRFS_QGROUP_STATUS_OFF			0
+#define BTRFS_QGROUP_STATUS_ON			1
+#define BTRFS_QGROUP_STATUS_SCANNING		2
+
+#define BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT	(1 << 0)
+
+struct btrfs_qgroup_status_item {
+	__le64 version;
+	__le64 generation;
+	__le64 flags;
+	__le64 scan;		/* progress during scanning */
+} __attribute__ ((__packed__));
+
+struct btrfs_block_group_item {
+	__le64 used;
+	__le64 chunk_objectid;
+	__le64 flags;
+} __attribute__ ((__packed__));
+
+struct btrfs_qgroup_info_item {
+	__le64 generation;
+	__le64 referenced;
+	__le64 referenced_compressed;
+	__le64 exclusive;
+	__le64 exclusive_compressed;
+} __attribute__ ((__packed__));
+
+/* flags definition for qgroup limits */
+#define BTRFS_QGROUP_LIMIT_MAX_RFER	(1ULL << 0)
+#define BTRFS_QGROUP_LIMIT_MAX_EXCL	(1ULL << 1)
+#define BTRFS_QGROUP_LIMIT_RSV_RFER	(1ULL << 2)
+#define BTRFS_QGROUP_LIMIT_RSV_EXCL	(1ULL << 3)
+#define BTRFS_QGROUP_LIMIT_RFER_CMPR	(1ULL << 4)
+#define BTRFS_QGROUP_LIMIT_EXCL_CMPR	(1ULL << 5)
+
+struct btrfs_qgroup_limit_item {
+	__le64 flags;
+	__le64 max_referenced;
+	__le64 max_exclusive;
+	__le64 rsv_referenced;
+	__le64 rsv_exclusive;
+} __attribute__ ((__packed__));
+
+struct btrfs_space_info {
+	u64 flags;
+	u64 total_bytes;
+	u64 bytes_used;
+	u64 bytes_pinned;
+	int full;
+	struct list_head list;
+};
+
+struct btrfs_block_group_cache {
+	struct cache_extent cache;
+	struct btrfs_key key;
+	struct btrfs_block_group_item item;
+	struct btrfs_space_info *space_info;
+	struct btrfs_free_space_ctl *free_space_ctl;
+	u64 pinned;
+	u64 flags;
+	int cached;
+	int ro;
+};
+
+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_device;
+struct btrfs_fs_devices;
+struct btrfs_fs_info {
+	u8 fsid[BTRFS_FSID_SIZE];
+	u8 chunk_tree_uuid[BTRFS_UUID_SIZE];
+	struct btrfs_root *fs_root;
+	struct btrfs_root *extent_root;
+	struct btrfs_root *tree_root;
+	struct btrfs_root *chunk_root;
+	struct btrfs_root *dev_root;
+	struct btrfs_root *csum_root;
+	struct btrfs_root *quota_root;
+
+	struct rb_root fs_root_tree;
+
+	/* the log root tree is a directory of all the other log roots */
+	struct btrfs_root *log_root_tree;
+
+	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;
+
+	/* logical->physical extent mapping */
+	struct btrfs_mapping_tree mapping_tree;
+
+	u64 generation;
+	u64 last_trans_committed;
+
+	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;
+	u64 alloc_start;
+
+	struct btrfs_trans_handle *running_transaction;
+	struct btrfs_super_block *super_copy;
+	struct mutex fs_mutex;
+
+	u64 super_bytenr;
+	u64 total_pinned;
+
+	struct btrfs_extent_ops *extent_ops;
+	struct list_head dirty_cowonly_roots;
+	struct list_head recow_ebs;
+
+	struct btrfs_fs_devices *fs_devices;
+	struct list_head space_info;
+	int system_allocs;
+
+	unsigned int readonly:1;
+	unsigned int on_restoring:1;
+	unsigned int is_chunk_recover:1;
+	unsigned int quota_enabled:1;
+
+	int (*free_extent_hook)(struct btrfs_trans_handle *trans,
+				struct btrfs_root *root,
+				u64 bytenr, u64 num_bytes, u64 parent,
+				u64 root_objectid, u64 owner, u64 offset,
+				int refs_to_drop);
+	struct cache_tree *fsck_extent_cache;
+	struct cache_tree *corrupt_blocks;
+};
+
+/*
+ * 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;
+	int track_dirty;
+
+
+	u32 type;
+	u64 highest_inode;
+	u64 last_inode_alloc;
+
+	/* the dirty list is only used by non-reference counted roots */
+	struct list_head dirty_list;
+	struct rb_node rb_node;
+};
+
+/*
+ * 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		12
+#define BTRFS_INODE_EXTREF_KEY		13
+#define BTRFS_XATTR_ITEM_KEY		24
+#define BTRFS_ORPHAN_ITEM_KEY		48
+
+#define BTRFS_DIR_LOG_ITEM_KEY  60
+#define BTRFS_DIR_LOG_INDEX_KEY 72
+/*
+ * dir items are the name -> inode pointers in a directory.  There is one
+ * for every name in a directory.
+ */
+#define BTRFS_DIR_ITEM_KEY	84
+#define BTRFS_DIR_INDEX_KEY	96
+
+/*
+ * extent data is for file data
+ */
+#define BTRFS_EXTENT_DATA_KEY	108
+
+/*
+ * csum items have the checksums for data in the extents
+ */
+#define BTRFS_CSUM_ITEM_KEY	120
+/*
+ * extent csums are stored in a separate tree and hold csums for
+ * an entire extent on disk.
+ */
+#define BTRFS_EXTENT_CSUM_KEY	128
+
+/*
+ * 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	132
+
+/*
+ * root backrefs tie subvols and snapshots to the directory entries that
+ * reference them
+ */
+#define BTRFS_ROOT_BACKREF_KEY	144
+
+/*
+ * root refs make a fast index for listing all of the snapshots and
+ * subvolumes referenced by a given root.  They point directly to the
+ * directory item in the root that references the subvol
+ */
+#define BTRFS_ROOT_REF_KEY	156
+
+/*
+ * 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	168
+
+/*
+ * The same as the BTRFS_EXTENT_ITEM_KEY, except it's metadata we already know
+ * the length, so we save the level in key->offset instead of the length.
+ */
+#define BTRFS_METADATA_ITEM_KEY	169
+
+#define BTRFS_TREE_BLOCK_REF_KEY	176
+
+#define BTRFS_EXTENT_DATA_REF_KEY	178
+
+/* old style extent backrefs */
+#define BTRFS_EXTENT_REF_V0_KEY		180
+
+#define BTRFS_SHARED_BLOCK_REF_KEY	182
+
+#define BTRFS_SHARED_DATA_REF_KEY	184
+
+
+/*
+ * block groups give us hints into the extent allocation trees.  Which
+ * blocks are free etc etc
+ */
+#define BTRFS_BLOCK_GROUP_ITEM_KEY 192
+
+#define BTRFS_DEV_EXTENT_KEY	204
+#define BTRFS_DEV_ITEM_KEY	216
+#define BTRFS_CHUNK_ITEM_KEY	228
+
+#define BTRFS_BALANCE_ITEM_KEY	248
+
+/*
+ * quota groups
+ */
+#define BTRFS_QGROUP_STATUS_KEY		240
+#define BTRFS_QGROUP_INFO_KEY		242
+#define BTRFS_QGROUP_LIMIT_KEY		244
+#define BTRFS_QGROUP_RELATION_KEY	246
+
+/*
+ * Persistently stores the io stats in the device tree.
+ * One key for all stats, (0, BTRFS_DEV_STATS_KEY, devid).
+ */
+#define BTRFS_DEV_STATS_KEY	249
+
+/*
+ * Persistently stores the device replace state in the device tree.
+ * The key is built like this: (0, BTRFS_DEV_REPLACE_KEY, 0).
+ */
+#define BTRFS_DEV_REPLACE_KEY	250
+
+/*
+ * Stores items that allow to quickly map UUIDs to something else.
+ * These items are part of the filesystem UUID tree.
+ * The key is built like this:
+ * (UUID_upper_64_bits, BTRFS_UUID_KEY*, UUID_lower_64_bits).
+ */
+#if BTRFS_UUID_SIZE != 16
+#error "UUID items require BTRFS_UUID_SIZE == 16!"
+#endif
+#define BTRFS_UUID_KEY_SUBVOL	251	/* for UUIDs assigned to subvols */
+#define BTRFS_UUID_KEY_RECEIVED_SUBVOL	252	/* for UUIDs assigned to
+						 * received subvols */
+
+/*
+ * 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(const struct extent_buffer *eb)	\
+{									\
+	const 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(const struct extent_buffer *eb,	\
+				   const type *s)			\
+{									\
+	unsigned long offset = (unsigned long)s;			\
+	const type *p = (type *) (eb->data + offset);			\
+	return get_unaligned_le##bits(&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);				\
+	put_unaligned_le##bits(val, &p->member);			\
+}
+
+#define BTRFS_SETGET_STACK_FUNCS(name, type, member, bits)		\
+static inline u##bits btrfs_##name(const 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_start_offset, struct btrfs_dev_item,
+		   start_offset, 64);
+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_FUNCS(device_generation, struct btrfs_dev_item, generation, 64);
+
+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);
+BTRFS_SETGET_STACK_FUNCS(stack_device_generation, struct btrfs_dev_item,
+			 generation, 64);
+
+static inline char *btrfs_device_uuid(struct btrfs_dev_item *d)
+{
+	return (char *)d + offsetof(struct btrfs_dev_item, uuid);
+}
+
+static inline char *btrfs_device_fsid(struct btrfs_dev_item *d)
+{
+	return (char *)d + offsetof(struct btrfs_dev_item, fsid);
+}
+
+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_STACK_FUNCS(stack_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_extref */
+BTRFS_SETGET_FUNCS(inode_extref_parent, struct btrfs_inode_extref,
+		   parent_objectid, 64);
+BTRFS_SETGET_FUNCS(inode_extref_name_len, struct btrfs_inode_extref,
+		   name_len, 16);
+BTRFS_SETGET_FUNCS(inode_extref_index, struct btrfs_inode_extref, index, 64);
+
+/* struct btrfs_inode_item */
+BTRFS_SETGET_FUNCS(inode_generation, struct btrfs_inode_item, generation, 64);
+BTRFS_SETGET_FUNCS(inode_sequence, struct btrfs_inode_item, sequence, 64);
+BTRFS_SETGET_FUNCS(inode_transid, struct btrfs_inode_item, transid, 64);
+BTRFS_SETGET_FUNCS(inode_size, struct btrfs_inode_item, size, 64);
+BTRFS_SETGET_FUNCS(inode_nbytes, struct btrfs_inode_item, nbytes, 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, 64);
+
+BTRFS_SETGET_STACK_FUNCS(stack_inode_generation,
+			 struct btrfs_inode_item, generation, 64);
+BTRFS_SETGET_STACK_FUNCS(stack_inode_sequence,
+			 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_nbytes,
+			 struct btrfs_inode_item, nbytes, 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, 64);
+BTRFS_SETGET_STACK_FUNCS(stack_inode_flags,
+			 struct btrfs_inode_item, flags, 64);
+
+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);
+BTRFS_SETGET_STACK_FUNCS(stack_timespec_sec, struct btrfs_timespec,
+			 sec, 64);
+BTRFS_SETGET_STACK_FUNCS(stack_timespec_nsec, struct btrfs_timespec,
+			 nsec, 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_item */
+BTRFS_SETGET_FUNCS(extent_refs, struct btrfs_extent_item, refs, 64);
+BTRFS_SETGET_STACK_FUNCS(stack_extent_refs, struct btrfs_extent_item, refs, 64);
+BTRFS_SETGET_FUNCS(extent_generation, struct btrfs_extent_item,
+		   generation, 64);
+BTRFS_SETGET_FUNCS(extent_flags, struct btrfs_extent_item, flags, 64);
+BTRFS_SETGET_STACK_FUNCS(stack_extent_flags, struct btrfs_extent_item, flags, 64);
+
+BTRFS_SETGET_FUNCS(extent_refs_v0, struct btrfs_extent_item_v0, refs, 32);
+
+BTRFS_SETGET_FUNCS(tree_block_level, struct btrfs_tree_block_info, level, 8);
+
+static inline void btrfs_tree_block_key(struct extent_buffer *eb,
+					struct btrfs_tree_block_info *item,
+					struct btrfs_disk_key *key)
+{
+	read_eb_member(eb, item, struct btrfs_tree_block_info, key, key);
+}
+
+static inline void btrfs_set_tree_block_key(struct extent_buffer *eb,
+					    struct btrfs_tree_block_info *item,
+					    struct btrfs_disk_key *key)
+{
+	write_eb_member(eb, item, struct btrfs_tree_block_info, key, key);
+}
+
+BTRFS_SETGET_FUNCS(extent_data_ref_root, struct btrfs_extent_data_ref,
+		   root, 64);
+BTRFS_SETGET_FUNCS(extent_data_ref_objectid, struct btrfs_extent_data_ref,
+		   objectid, 64);
+BTRFS_SETGET_FUNCS(extent_data_ref_offset, struct btrfs_extent_data_ref,
+		   offset, 64);
+BTRFS_SETGET_FUNCS(extent_data_ref_count, struct btrfs_extent_data_ref,
+		   count, 32);
+
+BTRFS_SETGET_FUNCS(shared_data_ref_count, struct btrfs_shared_data_ref,
+		   count, 32);
+
+BTRFS_SETGET_FUNCS(extent_inline_ref_type, struct btrfs_extent_inline_ref,
+		   type, 8);
+BTRFS_SETGET_FUNCS(extent_inline_ref_offset, struct btrfs_extent_inline_ref,
+		   offset, 64);
+BTRFS_SETGET_STACK_FUNCS(stack_extent_inline_ref_type,
+			 struct btrfs_extent_inline_ref, type, 8);
+BTRFS_SETGET_STACK_FUNCS(stack_extent_inline_ref_offset,
+			 struct btrfs_extent_inline_ref, offset, 64);
+
+static inline u32 btrfs_extent_inline_ref_size(int type)
+{
+	if (type == BTRFS_TREE_BLOCK_REF_KEY ||
+	    type == BTRFS_SHARED_BLOCK_REF_KEY)
+		return sizeof(struct btrfs_extent_inline_ref);
+	if (type == BTRFS_SHARED_DATA_REF_KEY)
+		return sizeof(struct btrfs_shared_data_ref) +
+		       sizeof(struct btrfs_extent_inline_ref);
+	if (type == BTRFS_EXTENT_DATA_REF_KEY)
+		return sizeof(struct btrfs_extent_data_ref) +
+		       offsetof(struct btrfs_extent_inline_ref, offset);
+	BUG();
+	return 0;
+}
+
+BTRFS_SETGET_FUNCS(ref_root_v0, struct btrfs_extent_ref_v0, root, 64);
+BTRFS_SETGET_FUNCS(ref_generation_v0, struct btrfs_extent_ref_v0,
+		   generation, 64);
+BTRFS_SETGET_FUNCS(ref_objectid_v0, struct btrfs_extent_ref_v0, objectid, 64);
+BTRFS_SETGET_FUNCS(ref_count_v0, struct btrfs_extent_ref_v0, count, 32);
+
+/* struct btrfs_node */
+BTRFS_SETGET_FUNCS(key_blockptr, struct btrfs_key_ptr, blockptr, 64);
+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(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(nr));
+}
+
+static inline u32 btrfs_item_offset_nr(struct extent_buffer *eb, int nr)
+{
+	return btrfs_item_offset(eb, btrfs_item_nr(nr));
+}
+
+static inline u32 btrfs_item_size_nr(struct extent_buffer *eb, int nr)
+{
+	return btrfs_item_size(eb, btrfs_item_nr(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(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(nr);
+	write_eb_member(eb, item, struct btrfs_item, key, disk_key);
+}
+
+BTRFS_SETGET_FUNCS(dir_log_end, struct btrfs_dir_log_item, end, 64);
+
+/*
+ * struct btrfs_root_ref
+ */
+BTRFS_SETGET_FUNCS(root_ref_dirid, struct btrfs_root_ref, dirid, 64);
+BTRFS_SETGET_FUNCS(root_ref_sequence, struct btrfs_root_ref, sequence, 64);
+BTRFS_SETGET_FUNCS(root_ref_name_len, struct btrfs_root_ref, name_len, 16);
+
+BTRFS_SETGET_STACK_FUNCS(stack_root_ref_dirid, struct btrfs_root_ref, dirid, 64);
+BTRFS_SETGET_STACK_FUNCS(stack_root_ref_sequence, struct btrfs_root_ref, sequence, 64);
+BTRFS_SETGET_STACK_FUNCS(stack_root_ref_name_len, struct btrfs_root_ref, name_len, 16);
+
+/* 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);
+BTRFS_SETGET_FUNCS(dir_transid, struct btrfs_dir_item, transid, 64);
+
+BTRFS_SETGET_STACK_FUNCS(stack_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_free_space_header */
+BTRFS_SETGET_FUNCS(free_space_entries, struct btrfs_free_space_header,
+		   num_entries, 64);
+BTRFS_SETGET_FUNCS(free_space_bitmaps, struct btrfs_free_space_header,
+		   num_bitmaps, 64);
+BTRFS_SETGET_FUNCS(free_space_generation, struct btrfs_free_space_header,
+		   generation, 64);
+
+static inline void btrfs_free_space_key(struct extent_buffer *eb,
+					struct btrfs_free_space_header *h,
+					struct btrfs_disk_key *key)
+{
+	read_eb_member(eb, h, struct btrfs_free_space_header, location, key);
+}
+
+static inline void btrfs_set_free_space_key(struct extent_buffer *eb,
+					    struct btrfs_free_space_header *h,
+					    struct btrfs_disk_key *key)
+{
+	write_eb_member(eb, h, struct btrfs_free_space_header, 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);
+BTRFS_SETGET_STACK_FUNCS(stack_header_bytenr, struct btrfs_header, bytenr, 64);
+BTRFS_SETGET_STACK_FUNCS(stack_header_nritems, struct btrfs_header, nritems,
+			 32);
+BTRFS_SETGET_STACK_FUNCS(stack_header_owner, struct btrfs_header, owner, 64);
+BTRFS_SETGET_STACK_FUNCS(stack_header_generation, struct btrfs_header,
+			 generation, 64);
+
+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 int btrfs_header_backref_rev(struct extent_buffer *eb)
+{
+	u64 flags = btrfs_header_flags(eb);
+	return flags >> BTRFS_BACKREF_REV_SHIFT;
+}
+
+static inline void btrfs_set_header_backref_rev(struct extent_buffer *eb,
+						int rev)
+{
+	u64 flags = btrfs_header_flags(eb);
+	flags &= ~BTRFS_BACKREF_REV_MASK;
+	flags |= (u64)rev << BTRFS_BACKREF_REV_SHIFT;
+	btrfs_set_header_flags(eb, flags);
+}
+
+static inline unsigned long btrfs_header_fsid(void)
+{
+	return offsetof(struct btrfs_header, fsid);
+}
+
+static inline unsigned long btrfs_header_chunk_tree_uuid(struct extent_buffer *eb)
+{
+	return offsetof(struct btrfs_header, chunk_tree_uuid);
+}
+
+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_generation, struct btrfs_root_item,
+		   generation, 64);
+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_generation, struct btrfs_root_item,
+			 generation, 64);
+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, 64);
+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);
+BTRFS_SETGET_STACK_FUNCS(root_last_snapshot, struct btrfs_root_item,
+			 last_snapshot, 64);
+BTRFS_SETGET_STACK_FUNCS(root_generation_v2, struct btrfs_root_item,
+			 generation_v2, 64);
+BTRFS_SETGET_STACK_FUNCS(root_ctransid, struct btrfs_root_item,
+			 ctransid, 64);
+BTRFS_SETGET_STACK_FUNCS(root_otransid, struct btrfs_root_item,
+			 otransid, 64);
+BTRFS_SETGET_STACK_FUNCS(root_stransid, struct btrfs_root_item,
+			 stransid, 64);
+BTRFS_SETGET_STACK_FUNCS(root_rtransid, struct btrfs_root_item,
+			 rtransid, 64);
+
+/* struct btrfs_root_backup */
+BTRFS_SETGET_STACK_FUNCS(backup_tree_root, struct btrfs_root_backup,
+		   tree_root, 64);
+BTRFS_SETGET_STACK_FUNCS(backup_tree_root_gen, struct btrfs_root_backup,
+		   tree_root_gen, 64);
+BTRFS_SETGET_STACK_FUNCS(backup_tree_root_level, struct btrfs_root_backup,
+		   tree_root_level, 8);
+
+BTRFS_SETGET_STACK_FUNCS(backup_chunk_root, struct btrfs_root_backup,
+		   chunk_root, 64);
+BTRFS_SETGET_STACK_FUNCS(backup_chunk_root_gen, struct btrfs_root_backup,
+		   chunk_root_gen, 64);
+BTRFS_SETGET_STACK_FUNCS(backup_chunk_root_level, struct btrfs_root_backup,
+		   chunk_root_level, 8);
+
+BTRFS_SETGET_STACK_FUNCS(backup_extent_root, struct btrfs_root_backup,
+		   extent_root, 64);
+BTRFS_SETGET_STACK_FUNCS(backup_extent_root_gen, struct btrfs_root_backup,
+		   extent_root_gen, 64);
+BTRFS_SETGET_STACK_FUNCS(backup_extent_root_level, struct btrfs_root_backup,
+		   extent_root_level, 8);
+
+BTRFS_SETGET_STACK_FUNCS(backup_fs_root, struct btrfs_root_backup,
+		   fs_root, 64);
+BTRFS_SETGET_STACK_FUNCS(backup_fs_root_gen, struct btrfs_root_backup,
+		   fs_root_gen, 64);
+BTRFS_SETGET_STACK_FUNCS(backup_fs_root_level, struct btrfs_root_backup,
+		   fs_root_level, 8);
+
+BTRFS_SETGET_STACK_FUNCS(backup_dev_root, struct btrfs_root_backup,
+		   dev_root, 64);
+BTRFS_SETGET_STACK_FUNCS(backup_dev_root_gen, struct btrfs_root_backup,
+		   dev_root_gen, 64);
+BTRFS_SETGET_STACK_FUNCS(backup_dev_root_level, struct btrfs_root_backup,
+		   dev_root_level, 8);
+
+BTRFS_SETGET_STACK_FUNCS(backup_csum_root, struct btrfs_root_backup,
+		   csum_root, 64);
+BTRFS_SETGET_STACK_FUNCS(backup_csum_root_gen, struct btrfs_root_backup,
+		   csum_root_gen, 64);
+BTRFS_SETGET_STACK_FUNCS(backup_csum_root_level, struct btrfs_root_backup,
+		   csum_root_level, 8);
+BTRFS_SETGET_STACK_FUNCS(backup_total_bytes, struct btrfs_root_backup,
+		   total_bytes, 64);
+BTRFS_SETGET_STACK_FUNCS(backup_bytes_used, struct btrfs_root_backup,
+		   bytes_used, 64);
+BTRFS_SETGET_STACK_FUNCS(backup_num_devices, struct btrfs_root_backup,
+		   num_devices, 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_chunk_root_generation,
+			 struct btrfs_super_block, chunk_root_generation, 64);
+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, 8);
+BTRFS_SETGET_STACK_FUNCS(super_log_root, struct btrfs_super_block,
+			 log_root, 64);
+BTRFS_SETGET_STACK_FUNCS(super_log_root_transid, struct btrfs_super_block,
+			 log_root_transid, 64);
+BTRFS_SETGET_STACK_FUNCS(super_log_root_level, struct btrfs_super_block,
+			 log_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);
+BTRFS_SETGET_STACK_FUNCS(super_num_devices, struct btrfs_super_block,
+			 num_devices, 64);
+BTRFS_SETGET_STACK_FUNCS(super_compat_flags, struct btrfs_super_block,
+			 compat_flags, 64);
+BTRFS_SETGET_STACK_FUNCS(super_compat_ro_flags, struct btrfs_super_block,
+			 compat_ro_flags, 64);
+BTRFS_SETGET_STACK_FUNCS(super_incompat_flags, struct btrfs_super_block,
+			 incompat_flags, 64);
+BTRFS_SETGET_STACK_FUNCS(super_csum_type, struct btrfs_super_block,
+			 csum_type, 16);
+BTRFS_SETGET_STACK_FUNCS(super_cache_generation, struct btrfs_super_block,
+			 cache_generation, 64);
+BTRFS_SETGET_STACK_FUNCS(super_uuid_tree_generation, struct btrfs_super_block,
+			 uuid_tree_generation, 64);
+BTRFS_SETGET_STACK_FUNCS(super_magic, struct btrfs_super_block, magic, 64);
+
+static inline int btrfs_super_csum_size(struct btrfs_super_block *s)
+{
+	int t = btrfs_super_csum_type(s);
+	BUG_ON(t >= ARRAY_SIZE(btrfs_csum_sizes));
+	return btrfs_csum_sizes[t];
+}
+
+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);
+BTRFS_SETGET_STACK_FUNCS(stack_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;
+}
+
+BTRFS_SETGET_FUNCS(file_extent_disk_bytenr, struct btrfs_file_extent_item,
+		   disk_bytenr, 64);
+BTRFS_SETGET_STACK_FUNCS(stack_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_STACK_FUNCS(stack_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_STACK_FUNCS(stack_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);
+BTRFS_SETGET_STACK_FUNCS(stack_file_extent_num_bytes, struct btrfs_file_extent_item,
+		   num_bytes, 64);
+BTRFS_SETGET_FUNCS(file_extent_ram_bytes, struct btrfs_file_extent_item,
+		   ram_bytes, 64);
+BTRFS_SETGET_STACK_FUNCS(stack_file_extent_ram_bytes, struct btrfs_file_extent_item,
+		   ram_bytes, 64);
+BTRFS_SETGET_FUNCS(file_extent_compression, struct btrfs_file_extent_item,
+		   compression, 8);
+BTRFS_SETGET_STACK_FUNCS(stack_file_extent_compression, struct btrfs_file_extent_item,
+		   compression, 8);
+BTRFS_SETGET_FUNCS(file_extent_encryption, struct btrfs_file_extent_item,
+		   encryption, 8);
+BTRFS_SETGET_FUNCS(file_extent_other_encoding, struct btrfs_file_extent_item,
+		   other_encoding, 16);
+
+/* btrfs_qgroup_status_item */
+BTRFS_SETGET_FUNCS(qgroup_status_version, struct btrfs_qgroup_status_item,
+		   version, 64);
+BTRFS_SETGET_FUNCS(qgroup_status_generation, struct btrfs_qgroup_status_item,
+		   generation, 64);
+BTRFS_SETGET_FUNCS(qgroup_status_flags, struct btrfs_qgroup_status_item,
+		   flags, 64);
+BTRFS_SETGET_FUNCS(qgroup_status_scan, struct btrfs_qgroup_status_item,
+		   scan, 64);
+
+/* btrfs_qgroup_info_item */
+BTRFS_SETGET_FUNCS(qgroup_info_generation, struct btrfs_qgroup_info_item,
+		   generation, 64);
+BTRFS_SETGET_FUNCS(qgroup_info_referenced, struct btrfs_qgroup_info_item,
+		   referenced, 64);
+BTRFS_SETGET_FUNCS(qgroup_info_referenced_compressed,
+		   struct btrfs_qgroup_info_item, referenced_compressed, 64);
+BTRFS_SETGET_FUNCS(qgroup_info_exclusive, struct btrfs_qgroup_info_item,
+		   exclusive, 64);
+BTRFS_SETGET_FUNCS(qgroup_info_exclusive_compressed,
+		   struct btrfs_qgroup_info_item, exclusive_compressed, 64);
+
+BTRFS_SETGET_STACK_FUNCS(stack_qgroup_info_generation,
+			 struct btrfs_qgroup_info_item, generation, 64);
+BTRFS_SETGET_STACK_FUNCS(stack_qgroup_info_referenced,
+			 struct btrfs_qgroup_info_item, referenced, 64);
+BTRFS_SETGET_STACK_FUNCS(stack_qgroup_info_referenced_compressed,
+		   struct btrfs_qgroup_info_item, referenced_compressed, 64);
+BTRFS_SETGET_STACK_FUNCS(stack_qgroup_info_exclusive,
+			 struct btrfs_qgroup_info_item, exclusive, 64);
+BTRFS_SETGET_STACK_FUNCS(stack_qgroup_info_exclusive_compressed,
+		   struct btrfs_qgroup_info_item, exclusive_compressed, 64);
+
+/* btrfs_qgroup_limit_item */
+BTRFS_SETGET_FUNCS(qgroup_limit_flags, struct btrfs_qgroup_limit_item,
+		   flags, 64);
+BTRFS_SETGET_FUNCS(qgroup_limit_max_referenced, struct btrfs_qgroup_limit_item,
+		   max_referenced, 64);
+BTRFS_SETGET_FUNCS(qgroup_limit_max_exclusive, struct btrfs_qgroup_limit_item,
+		   max_exclusive, 64);
+BTRFS_SETGET_FUNCS(qgroup_limit_rsv_referenced, struct btrfs_qgroup_limit_item,
+		   rsv_referenced, 64);
+BTRFS_SETGET_FUNCS(qgroup_limit_rsv_exclusive, struct btrfs_qgroup_limit_item,
+		   rsv_exclusive, 64);
+
+BTRFS_SETGET_STACK_FUNCS(stack_qgroup_limit_flags,
+			 struct btrfs_qgroup_limit_item, flags, 64);
+BTRFS_SETGET_STACK_FUNCS(stack_qgroup_limit_max_referenced,
+			 struct btrfs_qgroup_limit_item, max_referenced, 64);
+BTRFS_SETGET_STACK_FUNCS(stack_qgroup_limit_max_exclusive,
+			 struct btrfs_qgroup_limit_item, max_exclusive, 64);
+BTRFS_SETGET_STACK_FUNCS(stack_qgroup_limit_rsv_referenced,
+			 struct btrfs_qgroup_limit_item, rsv_referenced, 64);
+BTRFS_SETGET_STACK_FUNCS(stack_qgroup_limit_rsv_exclusive,
+			 struct btrfs_qgroup_limit_item, rsv_exclusive, 64);
+
+/*
+ * this returns the number of bytes used by the item on disk, minus the
+ * size of any extent headers.  If a file is compressed on disk, this is
+ * the compressed size
+ */
+static inline u32 btrfs_file_extent_inline_item_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;
+}
+
+/* this returns the number of file bytes represented by the inline item.
+ * If an item is compressed, this is the uncompressed size
+ */
+static inline u32 btrfs_file_extent_inline_len(struct extent_buffer *eb,
+					       int slot,
+					       struct btrfs_file_extent_item *fi)
+{
+	/*
+	 * return the space used on disk if this item isn't
+	 * compressed or encoded
+	 */
+	if (btrfs_file_extent_compression(eb, fi) == 0 &&
+	    btrfs_file_extent_encryption(eb, fi) == 0 &&
+	    btrfs_file_extent_other_encoding(eb, fi) == 0) {
+		return btrfs_file_extent_inline_item_len(eb,
+							 btrfs_item_nr(slot));
+	}
+
+	/* otherwise use the ram bytes field */
+	return btrfs_file_extent_ram_bytes(eb, fi);
+}
+
+static inline u32 btrfs_level_size(struct btrfs_root *root, int level) {
+	if (level == 0)
+		return root->leafsize;
+	return root->nodesize;
+}
+
+static inline int btrfs_fs_incompat(struct btrfs_fs_info *fs_info, u64 flag)
+{
+	struct btrfs_super_block *disk_super;
+	disk_super = fs_info->super_copy;
+	return !!(btrfs_super_incompat_flags(disk_super) & flag);
+}
+
+/* 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 */
+int btrfs_reserve_extent(struct btrfs_trans_handle *trans,
+			 struct btrfs_root *root,
+			 u64 num_bytes, u64 empty_size,
+			 u64 hint_byte, u64 search_end,
+			 struct btrfs_key *ins, int data);
+int btrfs_fix_block_accounting(struct btrfs_trans_handle *trans,
+				 struct btrfs_root *root);
+void btrfs_pin_extent(struct btrfs_fs_info *fs_info, u64 bytenr, u64 num_bytes);
+void btrfs_unpin_extent(struct btrfs_fs_info *fs_info,
+			u64 bytenr, u64 num_bytes);
+int btrfs_extent_post_op(struct btrfs_trans_handle *trans,
+			 struct btrfs_root *root);
+struct btrfs_block_group_cache *btrfs_lookup_block_group(struct
+							 btrfs_fs_info *info,
+							 u64 bytenr);
+struct btrfs_block_group_cache *btrfs_lookup_first_block_group(struct
+						       btrfs_fs_info *info,
+						       u64 bytenr);
+struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
+					struct btrfs_root *root,
+					u32 blocksize, u64 root_objectid,
+					struct btrfs_disk_key *key, int level,
+					u64 hint, u64 empty_size);
+int btrfs_alloc_extent(struct btrfs_trans_handle *trans,
+		       struct btrfs_root *root,
+		       u64 num_bytes, u64 parent,
+		       u64 root_objectid, u64 ref_generation,
+		       u64 owner, u64 empty_size, u64 hint_byte,
+		       u64 search_end, struct btrfs_key *ins, int data);
+int btrfs_lookup_extent_info(struct btrfs_trans_handle *trans,
+			     struct btrfs_root *root, u64 bytenr,
+			     u64 offset, int metadata, u64 *refs, u64 *flags);
+int btrfs_set_block_flags(struct btrfs_trans_handle *trans,
+			  struct btrfs_root *root,
+			  u64 bytenr, int level, u64 flags);
+int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
+		  struct extent_buffer *buf, int record_parent);
+int btrfs_dec_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
+		  struct extent_buffer *buf, int record_parent);
+int btrfs_free_extent(struct btrfs_trans_handle *trans,
+		      struct btrfs_root *root,
+		      u64 bytenr, u64 num_bytes, u64 parent,
+		      u64 root_objectid, u64 owner, u64 offset);
+int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans,
+			       struct btrfs_root *root,
+			       struct extent_io_tree *unpin);
+int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
+				struct btrfs_root *root,
+				u64 bytenr, u64 num_bytes, u64 parent,
+				u64 root_objectid, u64 ref_generation,
+				u64 owner_objectid);
+int btrfs_update_extent_ref(struct btrfs_trans_handle *trans,
+			    struct btrfs_root *root, u64 bytenr,
+			    u64 orig_parent, u64 parent,
+			    u64 root_objectid, u64 ref_generation,
+			    u64 owner_objectid);
+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);
+struct btrfs_block_group_cache *
+btrfs_add_block_group(struct btrfs_fs_info *fs_info, u64 bytes_used, u64 type,
+		      u64 chunk_objectid, u64 chunk_offset, u64 size);
+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);
+int btrfs_make_block_groups(struct btrfs_trans_handle *trans,
+			    struct btrfs_root *root);
+int btrfs_update_block_group(struct btrfs_trans_handle *trans,
+			     struct btrfs_root *root, u64 bytenr, u64 num,
+			     int alloc, int mark_free);
+int btrfs_record_file_extent(struct btrfs_trans_handle *trans,
+			      struct btrfs_root *root, u64 objectid,
+			      struct btrfs_inode_item *inode,
+			      u64 file_pos, u64 disk_bytenr,
+			      u64 num_bytes);
+/* ctree.c */
+int btrfs_comp_cpu_keys(struct btrfs_key *k1, struct btrfs_key *k2);
+int btrfs_del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
+		   struct btrfs_path *path, int level, int slot);
+enum btrfs_tree_block_status
+btrfs_check_node(struct btrfs_root *root, struct btrfs_disk_key *parent_key,
+		 struct extent_buffer *buf);
+enum btrfs_tree_block_status
+btrfs_check_leaf(struct btrfs_root *root, struct btrfs_disk_key *parent_key,
+		 struct extent_buffer *buf);
+void reada_for_search(struct btrfs_root *root, struct btrfs_path *path,
+			     int level, int slot, u64 objectid);
+struct extent_buffer *read_node_slot(struct btrfs_root *root,
+				   struct extent_buffer *parent, int slot);
+int btrfs_previous_item(struct btrfs_root *root,
+			struct btrfs_path *path, u64 min_objectid,
+			int type);
+int btrfs_previous_extent_item(struct btrfs_root *root,
+			struct btrfs_path *path, u64 min_objectid);
+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_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,
+			     u64 search_start, u64 empty_size);
+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_split_item(struct btrfs_trans_handle *trans,
+		     struct btrfs_root *root,
+		     struct btrfs_path *path,
+		     struct btrfs_key *new_key,
+		     unsigned long split_offset);
+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_find_item(struct btrfs_root *fs_root, struct btrfs_path *found_path,
+		u64 iobjectid, u64 ioff, u8 key_type,
+		struct btrfs_key *found_key);
+void btrfs_release_path(struct btrfs_path *p);
+void add_root_to_dirty_list(struct btrfs_root *root);
+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);
+static inline int btrfs_next_item(struct btrfs_root *root,
+				  struct btrfs_path *p)
+{
+	++p->slots[0];
+	if (p->slots[0] >= btrfs_header_nritems(p->nodes[0]))
+		return btrfs_next_leaf(root, p);
+	return 0;
+}
+
+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);
+void btrfs_fixup_low_keys(struct btrfs_root *root, struct btrfs_path *path,
+			  struct btrfs_disk_key *key, int level);
+int btrfs_set_item_key_safe(struct btrfs_root *root, struct btrfs_path *path,
+			    struct btrfs_key *new_key);
+void btrfs_set_item_key_unsafe(struct btrfs_root *root,
+			       struct btrfs_path *path,
+			       struct btrfs_key *new_key);
+
+/* root-item.c */
+int btrfs_add_root_ref(struct btrfs_trans_handle *trans,
+		       struct btrfs_root *tree_root,
+		       u64 root_id, u8 type, u64 ref_id,
+		       u64 dirid, u64 sequence,
+		       const char *name, int name_len);
+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);
+/* 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(struct btrfs_trans_handle *trans,
+					      struct btrfs_root *root,
+					      struct btrfs_path *path, u64 dir,
+					      const char *name, int name_len,
+					      u64 index, int mod);
+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);
+/* inode-map.c */
+int btrfs_find_free_objectid(struct btrfs_trans_handle *trans,
+			     struct btrfs_root *fs_root,
+			     u64 dirid, 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_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_del_csums(struct btrfs_trans_handle *trans,
+		    struct btrfs_root *root, u64 bytenr, u64 len);
+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_csum_file_block(struct btrfs_trans_handle *trans,
+			  struct btrfs_root *root, u64 alloc_end,
+			  u64 bytenr, char *data, size_t len);
+int btrfs_csum_truncate(struct btrfs_trans_handle *trans,
+			struct btrfs_root *root, struct btrfs_path *path,
+			u64 isize);
+
+/* uuid-tree.c */
+int btrfs_lookup_uuid_subvol_item(int fd, const u8 *uuid, u64 *subvol_id);
+int btrfs_lookup_uuid_received_subvol_item(int fd, const u8 *uuid,
+					   u64 *subvol_id);
+
+static inline int is_fstree(u64 rootid)
+{
+	if (rootid == BTRFS_FS_TREE_OBJECTID ||
+	    (signed long long)rootid >= (signed long long)BTRFS_FIRST_FREE_OBJECTID)
+		return 1;
+	return 0;
+}
+#endif
diff --git a/.pc/0001-Fixing-unaligned-memory-accesses.patch/volumes.c b/.pc/0001-Fixing-unaligned-memory-accesses.patch/volumes.c
new file mode 100644
index 0000000..5b007fc
--- /dev/null
+++ b/.pc/0001-Fixing-unaligned-memory-accesses.patch/volumes.c
@@ -0,0 +1,2008 @@
+/*
+ * 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.
+ */
+#define _XOPEN_SOURCE 600
+#define __USE_XOPEN2K
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <uuid/uuid.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include "ctree.h"
+#include "disk-io.h"
+#include "transaction.h"
+#include "print-tree.h"
+#include "volumes.h"
+#include "math.h"
+
+struct stripe {
+	struct btrfs_device *dev;
+	u64 physical;
+};
+
+static inline int nr_parity_stripes(struct map_lookup *map)
+{
+	if (map->type & BTRFS_BLOCK_GROUP_RAID5)
+		return 1;
+	else if (map->type & BTRFS_BLOCK_GROUP_RAID6)
+		return 2;
+	else
+		return 0;
+}
+
+static inline int nr_data_stripes(struct map_lookup *map)
+{
+	return map->num_stripes - nr_parity_stripes(map);
+}
+
+#define is_parity_stripe(x) ( ((x) == BTRFS_RAID5_P_STRIPE) || ((x) == BTRFS_RAID6_Q_STRIPE) )
+
+static LIST_HEAD(fs_uuids);
+
+static struct btrfs_device *__find_device(struct list_head *head, u64 devid,
+					  u8 *uuid)
+{
+	struct btrfs_device *dev;
+	struct list_head *cur;
+
+	list_for_each(cur, head) {
+		dev = list_entry(cur, struct btrfs_device, dev_list);
+		if (dev->devid == devid &&
+		    !memcmp(dev->uuid, uuid, BTRFS_UUID_SIZE)) {
+			return dev;
+		}
+	}
+	return NULL;
+}
+
+static struct btrfs_fs_devices *find_fsid(u8 *fsid)
+{
+	struct list_head *cur;
+	struct btrfs_fs_devices *fs_devices;
+
+	list_for_each(cur, &fs_uuids) {
+		fs_devices = list_entry(cur, struct btrfs_fs_devices, list);
+		if (memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE) == 0)
+			return fs_devices;
+	}
+	return NULL;
+}
+
+static int device_list_add(const char *path,
+			   struct btrfs_super_block *disk_super,
+			   u64 devid, struct btrfs_fs_devices **fs_devices_ret)
+{
+	struct btrfs_device *device;
+	struct btrfs_fs_devices *fs_devices;
+	u64 found_transid = btrfs_super_generation(disk_super);
+
+	fs_devices = find_fsid(disk_super->fsid);
+	if (!fs_devices) {
+		fs_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
+		if (!fs_devices)
+			return -ENOMEM;
+		INIT_LIST_HEAD(&fs_devices->devices);
+		list_add(&fs_devices->list, &fs_uuids);
+		memcpy(fs_devices->fsid, disk_super->fsid, BTRFS_FSID_SIZE);
+		fs_devices->latest_devid = devid;
+		fs_devices->latest_trans = found_transid;
+		fs_devices->lowest_devid = (u64)-1;
+		device = NULL;
+	} else {
+		device = __find_device(&fs_devices->devices, devid,
+				       disk_super->dev_item.uuid);
+	}
+	if (!device) {
+		device = kzalloc(sizeof(*device), GFP_NOFS);
+		if (!device) {
+			/* we can safely leave the fs_devices entry around */
+			return -ENOMEM;
+		}
+		device->fd = -1;
+		device->devid = devid;
+		device->generation = found_transid;
+		memcpy(device->uuid, disk_super->dev_item.uuid,
+		       BTRFS_UUID_SIZE);
+		device->name = kstrdup(path, GFP_NOFS);
+		if (!device->name) {
+			kfree(device);
+			return -ENOMEM;
+		}
+		device->label = kstrdup(disk_super->label, GFP_NOFS);
+		if (!device->label) {
+			kfree(device->name);
+			kfree(device);
+			return -ENOMEM;
+		}
+		device->total_devs = btrfs_super_num_devices(disk_super);
+		device->super_bytes_used = btrfs_super_bytes_used(disk_super);
+		device->total_bytes =
+			btrfs_stack_device_total_bytes(&disk_super->dev_item);
+		device->bytes_used =
+			btrfs_stack_device_bytes_used(&disk_super->dev_item);
+		list_add(&device->dev_list, &fs_devices->devices);
+		device->fs_devices = fs_devices;
+	} else if (!device->name || strcmp(device->name, path)) {
+		char *name = strdup(path);
+                if (!name)
+                        return -ENOMEM;
+                kfree(device->name);
+                device->name = name;
+        }
+
+
+	if (found_transid > fs_devices->latest_trans) {
+		fs_devices->latest_devid = devid;
+		fs_devices->latest_trans = found_transid;
+	}
+	if (fs_devices->lowest_devid > devid) {
+		fs_devices->lowest_devid = devid;
+	}
+	*fs_devices_ret = fs_devices;
+	return 0;
+}
+
+int btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
+{
+	struct btrfs_fs_devices *seed_devices;
+	struct btrfs_device *device;
+
+again:
+	while (!list_empty(&fs_devices->devices)) {
+		device = list_entry(fs_devices->devices.next,
+				    struct btrfs_device, dev_list);
+		if (device->fd != -1) {
+			fsync(device->fd);
+			if (posix_fadvise(device->fd, 0, 0, POSIX_FADV_DONTNEED))
+				fprintf(stderr, "Warning, could not drop caches\n");
+			close(device->fd);
+			device->fd = -1;
+		}
+		device->writeable = 0;
+		list_del(&device->dev_list);
+		/* free the memory */
+		free(device->name);
+		free(device->label);
+		free(device);
+	}
+
+	seed_devices = fs_devices->seed;
+	fs_devices->seed = NULL;
+	if (seed_devices) {
+		struct btrfs_fs_devices *orig;
+
+		orig = fs_devices;
+		fs_devices = seed_devices;
+		list_del(&orig->list);
+		free(orig);
+		goto again;
+	} else {
+		list_del(&fs_devices->list);
+		free(fs_devices);
+	}
+
+	return 0;
+}
+
+int btrfs_open_devices(struct btrfs_fs_devices *fs_devices, int flags)
+{
+	int fd;
+	struct list_head *head = &fs_devices->devices;
+	struct list_head *cur;
+	struct btrfs_device *device;
+	int ret;
+
+	list_for_each(cur, head) {
+		device = list_entry(cur, struct btrfs_device, dev_list);
+		if (!device->name) {
+			printk("no name for device %llu, skip it now\n", device->devid);
+			continue;
+		}
+
+		fd = open(device->name, flags);
+		if (fd < 0) {
+			ret = -errno;
+			goto fail;
+		}
+
+		if (posix_fadvise(fd, 0, 0, POSIX_FADV_DONTNEED))
+			fprintf(stderr, "Warning, could not drop caches\n");
+
+		if (device->devid == fs_devices->latest_devid)
+			fs_devices->latest_bdev = fd;
+		if (device->devid == fs_devices->lowest_devid)
+			fs_devices->lowest_bdev = fd;
+		device->fd = fd;
+		if (flags & O_RDWR)
+			device->writeable = 1;
+	}
+	return 0;
+fail:
+	btrfs_close_devices(fs_devices);
+	return ret;
+}
+
+int btrfs_scan_one_device(int fd, const char *path,
+			  struct btrfs_fs_devices **fs_devices_ret,
+			  u64 *total_devs, u64 super_offset, int super_recover)
+{
+	struct btrfs_super_block *disk_super;
+	char *buf;
+	int ret;
+	u64 devid;
+
+	buf = malloc(4096);
+	if (!buf) {
+		ret = -ENOMEM;
+		goto error;
+	}
+	disk_super = (struct btrfs_super_block *)buf;
+	ret = btrfs_read_dev_super(fd, disk_super, super_offset, super_recover);
+	if (ret < 0) {
+		ret = -EIO;
+		goto error_brelse;
+	}
+	devid = btrfs_stack_device_id(&disk_super->dev_item);
+	if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_METADUMP)
+		*total_devs = 1;
+	else
+		*total_devs = btrfs_super_num_devices(disk_super);
+
+	ret = device_list_add(path, disk_super, devid, fs_devices_ret);
+
+error_brelse:
+	free(buf);
+error:
+	return ret;
+}
+
+/*
+ * this uses a pretty simple search, the expectation is that it is
+ * called very infrequently and that a given device has a small number
+ * of extents
+ */
+static int find_free_dev_extent(struct btrfs_trans_handle *trans,
+				struct btrfs_device *device,
+				struct btrfs_path *path,
+				u64 num_bytes, u64 *start)
+{
+	struct btrfs_key key;
+	struct btrfs_root *root = device->dev_root;
+	struct btrfs_dev_extent *dev_extent = NULL;
+	u64 hole_size = 0;
+	u64 last_byte = 0;
+	u64 search_start = root->fs_info->alloc_start;
+	u64 search_end = device->total_bytes;
+	int ret;
+	int slot = 0;
+	int start_found;
+	struct extent_buffer *l;
+
+	start_found = 0;
+	path->reada = 2;
+
+	/* FIXME use last free of some kind */
+
+	/* we don't want to overwrite the superblock on the drive,
+	 * so we make sure to start at an offset of at least 1MB
+	 */
+	search_start = max(BTRFS_BLOCK_RESERVED_1M_FOR_SUPER, search_start);
+
+	if (search_start >= search_end) {
+		ret = -ENOSPC;
+		goto error;
+	}
+
+	key.objectid = device->devid;
+	key.offset = search_start;
+	key.type = BTRFS_DEV_EXTENT_KEY;
+	ret = btrfs_search_slot(trans, root, &key, path, 0, 0);
+	if (ret < 0)
+		goto error;
+	ret = btrfs_previous_item(root, path, 0, key.type);
+	if (ret < 0)
+		goto error;
+	l = path->nodes[0];
+	btrfs_item_key_to_cpu(l, &key, path->slots[0]);
+	while (1) {
+		l = path->nodes[0];
+		slot = path->slots[0];
+		if (slot >= btrfs_header_nritems(l)) {
+			ret = btrfs_next_leaf(root, path);
+			if (ret == 0)
+				continue;
+			if (ret < 0)
+				goto error;
+no_more_items:
+			if (!start_found) {
+				if (search_start >= search_end) {
+					ret = -ENOSPC;
+					goto error;
+				}
+				*start = search_start;
+				start_found = 1;
+				goto check_pending;
+			}
+			*start = last_byte > search_start ?
+				last_byte : search_start;
+			if (search_end <= *start) {
+				ret = -ENOSPC;
+				goto error;
+			}
+			goto check_pending;
+		}
+		btrfs_item_key_to_cpu(l, &key, slot);
+
+		if (key.objectid < device->devid)
+			goto next;
+
+		if (key.objectid > device->devid)
+			goto no_more_items;
+
+		if (key.offset >= search_start && key.offset > last_byte &&
+		    start_found) {
+			if (last_byte < search_start)
+				last_byte = search_start;
+			hole_size = key.offset - last_byte;
+			if (key.offset > last_byte &&
+			    hole_size >= num_bytes) {
+				*start = last_byte;
+				goto check_pending;
+			}
+		}
+		if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY) {
+			goto next;
+		}
+
+		start_found = 1;
+		dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
+		last_byte = key.offset + btrfs_dev_extent_length(l, dev_extent);
+next:
+		path->slots[0]++;
+		cond_resched();
+	}
+check_pending:
+	/* we have to make sure we didn't find an extent that has already
+	 * been allocated by the map tree or the original allocation
+	 */
+	btrfs_release_path(path);
+	BUG_ON(*start < search_start);
+
+	if (*start + num_bytes > search_end) {
+		ret = -ENOSPC;
+		goto error;
+	}
+	/* check for pending inserts here */
+	return 0;
+
+error:
+	btrfs_release_path(path);
+	return ret;
+}
+
+static int btrfs_alloc_dev_extent(struct btrfs_trans_handle *trans,
+				  struct btrfs_device *device,
+				  u64 chunk_tree, u64 chunk_objectid,
+				  u64 chunk_offset,
+				  u64 num_bytes, u64 *start)
+{
+	int ret;
+	struct btrfs_path *path;
+	struct btrfs_root *root = device->dev_root;
+	struct btrfs_dev_extent *extent;
+	struct extent_buffer *leaf;
+	struct btrfs_key key;
+
+	path = btrfs_alloc_path();
+	if (!path)
+		return -ENOMEM;
+
+	ret = find_free_dev_extent(trans, device, path, num_bytes, start);
+	if (ret) {
+		goto err;
+	}
+
+	key.objectid = device->devid;
+	key.offset = *start;
+	key.type = BTRFS_DEV_EXTENT_KEY;
+	ret = btrfs_insert_empty_item(trans, root, path, &key,
+				      sizeof(*extent));
+	BUG_ON(ret);
+
+	leaf = path->nodes[0];
+	extent = btrfs_item_ptr(leaf, path->slots[0],
+				struct btrfs_dev_extent);
+	btrfs_set_dev_extent_chunk_tree(leaf, extent, chunk_tree);
+	btrfs_set_dev_extent_chunk_objectid(leaf, extent, chunk_objectid);
+	btrfs_set_dev_extent_chunk_offset(leaf, extent, chunk_offset);
+
+	write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid,
+		    (unsigned long)btrfs_dev_extent_chunk_tree_uuid(extent),
+		    BTRFS_UUID_SIZE);
+
+	btrfs_set_dev_extent_length(leaf, extent, num_bytes);
+	btrfs_mark_buffer_dirty(leaf);
+err:
+	btrfs_free_path(path);
+	return ret;
+}
+
+static int find_next_chunk(struct btrfs_root *root, u64 objectid, u64 *offset)
+{
+	struct btrfs_path *path;
+	int ret;
+	struct btrfs_key key;
+	struct btrfs_chunk *chunk;
+	struct btrfs_key found_key;
+
+	path = btrfs_alloc_path();
+	BUG_ON(!path);
+
+	key.objectid = objectid;
+	key.offset = (u64)-1;
+	key.type = BTRFS_CHUNK_ITEM_KEY;
+
+	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+	if (ret < 0)
+		goto error;
+
+	BUG_ON(ret == 0);
+
+	ret = btrfs_previous_item(root, path, 0, BTRFS_CHUNK_ITEM_KEY);
+	if (ret) {
+		*offset = 0;
+	} else {
+		btrfs_item_key_to_cpu(path->nodes[0], &found_key,
+				      path->slots[0]);
+		if (found_key.objectid != objectid)
+			*offset = 0;
+		else {
+			chunk = btrfs_item_ptr(path->nodes[0], path->slots[0],
+					       struct btrfs_chunk);
+			*offset = found_key.offset +
+				btrfs_chunk_length(path->nodes[0], chunk);
+		}
+	}
+	ret = 0;
+error:
+	btrfs_free_path(path);
+	return ret;
+}
+
+static int find_next_devid(struct btrfs_root *root, struct btrfs_path *path,
+			   u64 *objectid)
+{
+	int ret;
+	struct btrfs_key key;
+	struct btrfs_key found_key;
+
+	key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
+	key.type = BTRFS_DEV_ITEM_KEY;
+	key.offset = (u64)-1;
+
+	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+	if (ret < 0)
+		goto error;
+
+	BUG_ON(ret == 0);
+
+	ret = btrfs_previous_item(root, path, BTRFS_DEV_ITEMS_OBJECTID,
+				  BTRFS_DEV_ITEM_KEY);
+	if (ret) {
+		*objectid = 1;
+	} else {
+		btrfs_item_key_to_cpu(path->nodes[0], &found_key,
+				      path->slots[0]);
+		*objectid = found_key.offset + 1;
+	}
+	ret = 0;
+error:
+	btrfs_release_path(path);
+	return ret;
+}
+
+/*
+ * the device information is stored in the chunk root
+ * the btrfs_device struct should be fully filled in
+ */
+int btrfs_add_device(struct btrfs_trans_handle *trans,
+		     struct btrfs_root *root,
+		     struct btrfs_device *device)
+{
+	int ret;
+	struct btrfs_path *path;
+	struct btrfs_dev_item *dev_item;
+	struct extent_buffer *leaf;
+	struct btrfs_key key;
+	unsigned long ptr;
+	u64 free_devid = 0;
+
+	root = root->fs_info->chunk_root;
+
+	path = btrfs_alloc_path();
+	if (!path)
+		return -ENOMEM;
+
+	ret = find_next_devid(root, path, &free_devid);
+	if (ret)
+		goto out;
+
+	key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
+	key.type = BTRFS_DEV_ITEM_KEY;
+	key.offset = free_devid;
+
+	ret = btrfs_insert_empty_item(trans, root, path, &key,
+				      sizeof(*dev_item));
+	if (ret)
+		goto out;
+
+	leaf = path->nodes[0];
+	dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
+
+	device->devid = free_devid;
+	btrfs_set_device_id(leaf, dev_item, device->devid);
+	btrfs_set_device_generation(leaf, dev_item, 0);
+	btrfs_set_device_type(leaf, dev_item, device->type);
+	btrfs_set_device_io_align(leaf, dev_item, device->io_align);
+	btrfs_set_device_io_width(leaf, dev_item, device->io_width);
+	btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
+	btrfs_set_device_total_bytes(leaf, dev_item, device->total_bytes);
+	btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
+	btrfs_set_device_group(leaf, dev_item, 0);
+	btrfs_set_device_seek_speed(leaf, dev_item, 0);
+	btrfs_set_device_bandwidth(leaf, dev_item, 0);
+	btrfs_set_device_start_offset(leaf, dev_item, 0);
+
+	ptr = (unsigned long)btrfs_device_uuid(dev_item);
+	write_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
+	ptr = (unsigned long)btrfs_device_fsid(dev_item);
+	write_extent_buffer(leaf, root->fs_info->fsid, ptr, BTRFS_UUID_SIZE);
+	btrfs_mark_buffer_dirty(leaf);
+	ret = 0;
+
+out:
+	btrfs_free_path(path);
+	return ret;
+}
+
+int btrfs_update_device(struct btrfs_trans_handle *trans,
+			struct btrfs_device *device)
+{
+	int ret;
+	struct btrfs_path *path;
+	struct btrfs_root *root;
+	struct btrfs_dev_item *dev_item;
+	struct extent_buffer *leaf;
+	struct btrfs_key key;
+
+	root = device->dev_root->fs_info->chunk_root;
+
+	path = btrfs_alloc_path();
+	if (!path)
+		return -ENOMEM;
+
+	key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
+	key.type = BTRFS_DEV_ITEM_KEY;
+	key.offset = device->devid;
+
+	ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
+	if (ret < 0)
+		goto out;
+
+	if (ret > 0) {
+		ret = -ENOENT;
+		goto out;
+	}
+
+	leaf = path->nodes[0];
+	dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
+
+	btrfs_set_device_id(leaf, dev_item, device->devid);
+	btrfs_set_device_type(leaf, dev_item, device->type);
+	btrfs_set_device_io_align(leaf, dev_item, device->io_align);
+	btrfs_set_device_io_width(leaf, dev_item, device->io_width);
+	btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
+	btrfs_set_device_total_bytes(leaf, dev_item, device->total_bytes);
+	btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
+	btrfs_mark_buffer_dirty(leaf);
+
+out:
+	btrfs_free_path(path);
+	return ret;
+}
+
+int btrfs_add_system_chunk(struct btrfs_trans_handle *trans,
+			   struct btrfs_root *root,
+			   struct btrfs_key *key,
+			   struct btrfs_chunk *chunk, int item_size)
+{
+	struct btrfs_super_block *super_copy = root->fs_info->super_copy;
+	struct btrfs_disk_key disk_key;
+	u32 array_size;
+	u8 *ptr;
+
+	array_size = btrfs_super_sys_array_size(super_copy);
+	if (array_size + item_size + sizeof(disk_key)
+			> BTRFS_SYSTEM_CHUNK_ARRAY_SIZE)
+		return -EFBIG;
+
+	ptr = super_copy->sys_chunk_array + array_size;
+	btrfs_cpu_key_to_disk(&disk_key, key);
+	memcpy(ptr, &disk_key, sizeof(disk_key));
+	ptr += sizeof(disk_key);
+	memcpy(ptr, chunk, item_size);
+	item_size += sizeof(disk_key);
+	btrfs_set_super_sys_array_size(super_copy, array_size + item_size);
+	return 0;
+}
+
+static u64 chunk_bytes_by_type(u64 type, u64 calc_size, int num_stripes,
+			       int sub_stripes)
+{
+	if (type & (BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_DUP))
+		return calc_size;
+	else if (type & BTRFS_BLOCK_GROUP_RAID10)
+		return calc_size * (num_stripes / sub_stripes);
+	else if (type & BTRFS_BLOCK_GROUP_RAID5)
+		return calc_size * (num_stripes - 1);
+	else if (type & BTRFS_BLOCK_GROUP_RAID6)
+		return calc_size * (num_stripes - 2);
+	else
+		return calc_size * num_stripes;
+}
+
+
+static u32 find_raid56_stripe_len(u32 data_devices, u32 dev_stripe_target)
+{
+	/* TODO, add a way to store the preferred stripe size */
+	return BTRFS_STRIPE_LEN;
+}
+
+/*
+ * btrfs_device_avail_bytes - count bytes available for alloc_chunk
+ *
+ * It is not equal to "device->total_bytes - device->bytes_used".
+ * We do not allocate any chunk in 1M at beginning of device, and not
+ * allowed to allocate any chunk before alloc_start if it is specified.
+ * So search holes from max(1M, alloc_start) to device->total_bytes.
+ */
+static int btrfs_device_avail_bytes(struct btrfs_trans_handle *trans,
+				    struct btrfs_device *device,
+				    u64 *avail_bytes)
+{
+	struct btrfs_path *path;
+	struct btrfs_root *root = device->dev_root;
+	struct btrfs_key key;
+	struct btrfs_dev_extent *dev_extent = NULL;
+	struct extent_buffer *l;
+	u64 search_start = root->fs_info->alloc_start;
+	u64 search_end = device->total_bytes;
+	u64 extent_end = 0;
+	u64 free_bytes = 0;
+	int ret;
+	int slot = 0;
+
+	search_start = max(BTRFS_BLOCK_RESERVED_1M_FOR_SUPER, search_start);
+
+	path = btrfs_alloc_path();
+	if (!path)
+		return -ENOMEM;
+
+	key.objectid = device->devid;
+	key.offset = root->fs_info->alloc_start;
+	key.type = BTRFS_DEV_EXTENT_KEY;
+
+	path->reada = 2;
+	ret = btrfs_search_slot(trans, root, &key, path, 0, 0);
+	if (ret < 0)
+		goto error;
+	ret = btrfs_previous_item(root, path, 0, key.type);
+	if (ret < 0)
+		goto error;
+
+	while (1) {
+		l = path->nodes[0];
+		slot = path->slots[0];
+		if (slot >= btrfs_header_nritems(l)) {
+			ret = btrfs_next_leaf(root, path);
+			if (ret == 0)
+				continue;
+			if (ret < 0)
+				goto error;
+			break;
+		}
+		btrfs_item_key_to_cpu(l, &key, slot);
+
+		if (key.objectid < device->devid)
+			goto next;
+		if (key.objectid > device->devid)
+			break;
+		if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY)
+			goto next;
+		if (key.offset > search_end)
+			break;
+		if (key.offset > search_start)
+			free_bytes += key.offset - search_start;
+
+		dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
+		extent_end = key.offset + btrfs_dev_extent_length(l,
+								  dev_extent);
+		if (extent_end > search_start)
+			search_start = extent_end;
+		if (search_start > search_end)
+			break;
+next:
+		path->slots[0]++;
+		cond_resched();
+	}
+
+	if (search_start < search_end)
+		free_bytes += search_end - search_start;
+
+	*avail_bytes = free_bytes;
+	ret = 0;
+error:
+	btrfs_free_path(path);
+	return ret;
+}
+
+#define BTRFS_MAX_DEVS(r) ((BTRFS_LEAF_DATA_SIZE(r)		\
+			- sizeof(struct btrfs_item)		\
+			- sizeof(struct btrfs_chunk))		\
+			/ sizeof(struct btrfs_stripe) + 1)
+
+#define BTRFS_MAX_DEVS_SYS_CHUNK ((BTRFS_SYSTEM_CHUNK_ARRAY_SIZE	\
+				- 2 * sizeof(struct btrfs_disk_key)	\
+				- 2 * sizeof(struct btrfs_chunk))	\
+				/ sizeof(struct btrfs_stripe) + 1)
+
+int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
+		      struct btrfs_root *extent_root, u64 *start,
+		      u64 *num_bytes, u64 type)
+{
+	u64 dev_offset;
+	struct btrfs_fs_info *info = extent_root->fs_info;
+	struct btrfs_root *chunk_root = info->chunk_root;
+	struct btrfs_stripe *stripes;
+	struct btrfs_device *device = NULL;
+	struct btrfs_chunk *chunk;
+	struct list_head private_devs;
+	struct list_head *dev_list = &info->fs_devices->devices;
+	struct list_head *cur;
+	struct map_lookup *map;
+	int min_stripe_size = 1 * 1024 * 1024;
+	u64 calc_size = 8 * 1024 * 1024;
+	u64 min_free;
+	u64 max_chunk_size = 4 * calc_size;
+	u64 avail = 0;
+	u64 max_avail = 0;
+	u64 percent_max;
+	int num_stripes = 1;
+	int max_stripes = 0;
+	int min_stripes = 1;
+	int sub_stripes = 0;
+	int looped = 0;
+	int ret;
+	int index;
+	int stripe_len = BTRFS_STRIPE_LEN;
+	struct btrfs_key key;
+	u64 offset;
+
+	if (list_empty(dev_list)) {
+		return -ENOSPC;
+	}
+
+	if (type & (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1 |
+		    BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6 |
+		    BTRFS_BLOCK_GROUP_RAID10 |
+		    BTRFS_BLOCK_GROUP_DUP)) {
+		if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
+			calc_size = 8 * 1024 * 1024;
+			max_chunk_size = calc_size * 2;
+			min_stripe_size = 1 * 1024 * 1024;
+			max_stripes = BTRFS_MAX_DEVS_SYS_CHUNK;
+		} else if (type & BTRFS_BLOCK_GROUP_DATA) {
+			calc_size = 1024 * 1024 * 1024;
+			max_chunk_size = 10 * calc_size;
+			min_stripe_size = 64 * 1024 * 1024;
+			max_stripes = BTRFS_MAX_DEVS(chunk_root);
+		} else if (type & BTRFS_BLOCK_GROUP_METADATA) {
+			calc_size = 1024 * 1024 * 1024;
+			max_chunk_size = 4 * calc_size;
+			min_stripe_size = 32 * 1024 * 1024;
+			max_stripes = BTRFS_MAX_DEVS(chunk_root);
+		}
+	}
+	if (type & BTRFS_BLOCK_GROUP_RAID1) {
+		num_stripes = min_t(u64, 2,
+				  btrfs_super_num_devices(info->super_copy));
+		if (num_stripes < 2)
+			return -ENOSPC;
+		min_stripes = 2;
+	}
+	if (type & BTRFS_BLOCK_GROUP_DUP) {
+		num_stripes = 2;
+		min_stripes = 2;
+	}
+	if (type & (BTRFS_BLOCK_GROUP_RAID0)) {
+		num_stripes = btrfs_super_num_devices(info->super_copy);
+		if (num_stripes > max_stripes)
+			num_stripes = max_stripes;
+		min_stripes = 2;
+	}
+	if (type & (BTRFS_BLOCK_GROUP_RAID10)) {
+		num_stripes = btrfs_super_num_devices(info->super_copy);
+		if (num_stripes > max_stripes)
+			num_stripes = max_stripes;
+		if (num_stripes < 4)
+			return -ENOSPC;
+		num_stripes &= ~(u32)1;
+		sub_stripes = 2;
+		min_stripes = 4;
+	}
+	if (type & (BTRFS_BLOCK_GROUP_RAID5)) {
+		num_stripes = btrfs_super_num_devices(info->super_copy);
+		if (num_stripes > max_stripes)
+			num_stripes = max_stripes;
+		if (num_stripes < 2)
+			return -ENOSPC;
+		min_stripes = 2;
+		stripe_len = find_raid56_stripe_len(num_stripes - 1,
+				    btrfs_super_stripesize(info->super_copy));
+	}
+	if (type & (BTRFS_BLOCK_GROUP_RAID6)) {
+		num_stripes = btrfs_super_num_devices(info->super_copy);
+		if (num_stripes > max_stripes)
+			num_stripes = max_stripes;
+		if (num_stripes < 3)
+			return -ENOSPC;
+		min_stripes = 3;
+		stripe_len = find_raid56_stripe_len(num_stripes - 2,
+				    btrfs_super_stripesize(info->super_copy));
+	}
+
+	/* we don't want a chunk larger than 10% of the FS */
+	percent_max = div_factor(btrfs_super_total_bytes(info->super_copy), 1);
+	max_chunk_size = min(percent_max, max_chunk_size);
+
+again:
+	if (chunk_bytes_by_type(type, calc_size, num_stripes, sub_stripes) >
+	    max_chunk_size) {
+		calc_size = max_chunk_size;
+		calc_size /= num_stripes;
+		calc_size /= stripe_len;
+		calc_size *= stripe_len;
+	}
+	/* we don't want tiny stripes */
+	calc_size = max_t(u64, calc_size, min_stripe_size);
+
+	calc_size /= stripe_len;
+	calc_size *= stripe_len;
+	INIT_LIST_HEAD(&private_devs);
+	cur = dev_list->next;
+	index = 0;
+
+	if (type & BTRFS_BLOCK_GROUP_DUP)
+		min_free = calc_size * 2;
+	else
+		min_free = calc_size;
+
+	/* build a private list of devices we will allocate from */
+	while(index < num_stripes) {
+		device = list_entry(cur, struct btrfs_device, dev_list);
+		ret = btrfs_device_avail_bytes(trans, device, &avail);
+		if (ret)
+			return ret;
+		cur = cur->next;
+		if (avail >= min_free) {
+			list_move_tail(&device->dev_list, &private_devs);
+			index++;
+			if (type & BTRFS_BLOCK_GROUP_DUP)
+				index++;
+		} else if (avail > max_avail)
+			max_avail = avail;
+		if (cur == dev_list)
+			break;
+	}
+	if (index < num_stripes) {
+		list_splice(&private_devs, dev_list);
+		if (index >= min_stripes) {
+			num_stripes = index;
+			if (type & (BTRFS_BLOCK_GROUP_RAID10)) {
+				num_stripes /= sub_stripes;
+				num_stripes *= sub_stripes;
+			}
+			looped = 1;
+			goto again;
+		}
+		if (!looped && max_avail > 0) {
+			looped = 1;
+			calc_size = max_avail;
+			goto again;
+		}
+		return -ENOSPC;
+	}
+	ret = find_next_chunk(chunk_root, BTRFS_FIRST_CHUNK_TREE_OBJECTID,
+			      &offset);
+	if (ret)
+		return ret;
+	key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
+	key.type = BTRFS_CHUNK_ITEM_KEY;
+	key.offset = offset;
+
+	chunk = kmalloc(btrfs_chunk_item_size(num_stripes), GFP_NOFS);
+	if (!chunk)
+		return -ENOMEM;
+
+	map = kmalloc(btrfs_map_lookup_size(num_stripes), GFP_NOFS);
+	if (!map) {
+		kfree(chunk);
+		return -ENOMEM;
+	}
+
+	stripes = &chunk->stripe;
+	*num_bytes = chunk_bytes_by_type(type, calc_size,
+					 num_stripes, sub_stripes);
+	index = 0;
+	while(index < num_stripes) {
+		struct btrfs_stripe *stripe;
+		BUG_ON(list_empty(&private_devs));
+		cur = private_devs.next;
+		device = list_entry(cur, struct btrfs_device, dev_list);
+
+		/* loop over this device again if we're doing a dup group */
+		if (!(type & BTRFS_BLOCK_GROUP_DUP) ||
+		    (index == num_stripes - 1))
+			list_move_tail(&device->dev_list, dev_list);
+
+		ret = btrfs_alloc_dev_extent(trans, device,
+			     info->chunk_root->root_key.objectid,
+			     BTRFS_FIRST_CHUNK_TREE_OBJECTID, key.offset,
+			     calc_size, &dev_offset);
+		BUG_ON(ret);
+
+		device->bytes_used += calc_size;
+		ret = btrfs_update_device(trans, device);
+		BUG_ON(ret);
+
+		map->stripes[index].dev = device;
+		map->stripes[index].physical = dev_offset;
+		stripe = stripes + index;
+		btrfs_set_stack_stripe_devid(stripe, device->devid);
+		btrfs_set_stack_stripe_offset(stripe, dev_offset);
+		memcpy(stripe->dev_uuid, device->uuid, BTRFS_UUID_SIZE);
+		index++;
+	}
+	BUG_ON(!list_empty(&private_devs));
+
+	/* key was set above */
+	btrfs_set_stack_chunk_length(chunk, *num_bytes);
+	btrfs_set_stack_chunk_owner(chunk, extent_root->root_key.objectid);
+	btrfs_set_stack_chunk_stripe_len(chunk, stripe_len);
+	btrfs_set_stack_chunk_type(chunk, type);
+	btrfs_set_stack_chunk_num_stripes(chunk, num_stripes);
+	btrfs_set_stack_chunk_io_align(chunk, stripe_len);
+	btrfs_set_stack_chunk_io_width(chunk, stripe_len);
+	btrfs_set_stack_chunk_sector_size(chunk, extent_root->sectorsize);
+	btrfs_set_stack_chunk_sub_stripes(chunk, sub_stripes);
+	map->sector_size = extent_root->sectorsize;
+	map->stripe_len = stripe_len;
+	map->io_align = stripe_len;
+	map->io_width = stripe_len;
+	map->type = type;
+	map->num_stripes = num_stripes;
+	map->sub_stripes = sub_stripes;
+
+	ret = btrfs_insert_item(trans, chunk_root, &key, chunk,
+				btrfs_chunk_item_size(num_stripes));
+	BUG_ON(ret);
+	*start = key.offset;;
+
+	map->ce.start = key.offset;
+	map->ce.size = *num_bytes;
+
+	ret = insert_cache_extent(&info->mapping_tree.cache_tree, &map->ce);
+	BUG_ON(ret);
+
+	if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
+		ret = btrfs_add_system_chunk(trans, chunk_root, &key,
+				    chunk, btrfs_chunk_item_size(num_stripes));
+		BUG_ON(ret);
+	}
+
+	kfree(chunk);
+	return ret;
+}
+
+int btrfs_alloc_data_chunk(struct btrfs_trans_handle *trans,
+			   struct btrfs_root *extent_root, u64 *start,
+			   u64 num_bytes, u64 type)
+{
+	u64 dev_offset;
+	struct btrfs_fs_info *info = extent_root->fs_info;
+	struct btrfs_root *chunk_root = info->chunk_root;
+	struct btrfs_stripe *stripes;
+	struct btrfs_device *device = NULL;
+	struct btrfs_chunk *chunk;
+	struct list_head *dev_list = &info->fs_devices->devices;
+	struct list_head *cur;
+	struct map_lookup *map;
+	u64 calc_size = 8 * 1024 * 1024;
+	int num_stripes = 1;
+	int sub_stripes = 0;
+	int ret;
+	int index;
+	int stripe_len = BTRFS_STRIPE_LEN;
+	struct btrfs_key key;
+
+	key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
+	key.type = BTRFS_CHUNK_ITEM_KEY;
+	ret = find_next_chunk(chunk_root, BTRFS_FIRST_CHUNK_TREE_OBJECTID,
+			      &key.offset);
+	if (ret)
+		return ret;
+
+	chunk = kmalloc(btrfs_chunk_item_size(num_stripes), GFP_NOFS);
+	if (!chunk)
+		return -ENOMEM;
+
+	map = kmalloc(btrfs_map_lookup_size(num_stripes), GFP_NOFS);
+	if (!map) {
+		kfree(chunk);
+		return -ENOMEM;
+	}
+
+	stripes = &chunk->stripe;
+	calc_size = num_bytes;
+
+	index = 0;
+	cur = dev_list->next;
+	device = list_entry(cur, struct btrfs_device, dev_list);
+
+	while (index < num_stripes) {
+		struct btrfs_stripe *stripe;
+
+		ret = btrfs_alloc_dev_extent(trans, device,
+			     info->chunk_root->root_key.objectid,
+			     BTRFS_FIRST_CHUNK_TREE_OBJECTID, key.offset,
+			     calc_size, &dev_offset);
+		BUG_ON(ret);
+
+		device->bytes_used += calc_size;
+		ret = btrfs_update_device(trans, device);
+		BUG_ON(ret);
+
+		map->stripes[index].dev = device;
+		map->stripes[index].physical = dev_offset;
+		stripe = stripes + index;
+		btrfs_set_stack_stripe_devid(stripe, device->devid);
+		btrfs_set_stack_stripe_offset(stripe, dev_offset);
+		memcpy(stripe->dev_uuid, device->uuid, BTRFS_UUID_SIZE);
+		index++;
+	}
+
+	/* key was set above */
+	btrfs_set_stack_chunk_length(chunk, num_bytes);
+	btrfs_set_stack_chunk_owner(chunk, extent_root->root_key.objectid);
+	btrfs_set_stack_chunk_stripe_len(chunk, stripe_len);
+	btrfs_set_stack_chunk_type(chunk, type);
+	btrfs_set_stack_chunk_num_stripes(chunk, num_stripes);
+	btrfs_set_stack_chunk_io_align(chunk, stripe_len);
+	btrfs_set_stack_chunk_io_width(chunk, stripe_len);
+	btrfs_set_stack_chunk_sector_size(chunk, extent_root->sectorsize);
+	btrfs_set_stack_chunk_sub_stripes(chunk, sub_stripes);
+	map->sector_size = extent_root->sectorsize;
+	map->stripe_len = stripe_len;
+	map->io_align = stripe_len;
+	map->io_width = stripe_len;
+	map->type = type;
+	map->num_stripes = num_stripes;
+	map->sub_stripes = sub_stripes;
+
+	ret = btrfs_insert_item(trans, chunk_root, &key, chunk,
+				btrfs_chunk_item_size(num_stripes));
+	BUG_ON(ret);
+	*start = key.offset;
+
+	map->ce.start = key.offset;
+	map->ce.size = num_bytes;
+
+	ret = insert_cache_extent(&info->mapping_tree.cache_tree, &map->ce);
+	BUG_ON(ret);
+
+	kfree(chunk);
+	return ret;
+}
+
+int btrfs_num_copies(struct btrfs_mapping_tree *map_tree, u64 logical, u64 len)
+{
+	struct cache_extent *ce;
+	struct map_lookup *map;
+	int ret;
+
+	ce = search_cache_extent(&map_tree->cache_tree, logical);
+	if (!ce) {
+		fprintf(stderr, "No mapping for %llu-%llu\n",
+			(unsigned long long)logical,
+			(unsigned long long)logical+len);
+		return 1;
+	}
+	if (ce->start > logical || ce->start + ce->size < logical) {
+		fprintf(stderr, "Invalid mapping for %llu-%llu, got "
+			"%llu-%llu\n", (unsigned long long)logical,
+			(unsigned long long)logical+len,
+			(unsigned long long)ce->start,
+			(unsigned long long)ce->start + ce->size);
+		return 1;
+	}
+	map = container_of(ce, struct map_lookup, ce);
+
+	if (map->type & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1))
+		ret = map->num_stripes;
+	else if (map->type & BTRFS_BLOCK_GROUP_RAID10)
+		ret = map->sub_stripes;
+	else if (map->type & BTRFS_BLOCK_GROUP_RAID5)
+		ret = 2;
+	else if (map->type & BTRFS_BLOCK_GROUP_RAID6)
+		ret = 3;
+	else
+		ret = 1;
+	return ret;
+}
+
+int btrfs_next_metadata(struct btrfs_mapping_tree *map_tree, u64 *logical,
+			u64 *size)
+{
+	struct cache_extent *ce;
+	struct map_lookup *map;
+
+	ce = search_cache_extent(&map_tree->cache_tree, *logical);
+
+	while (ce) {
+		ce = next_cache_extent(ce);
+		if (!ce)
+			return -ENOENT;
+
+		map = container_of(ce, struct map_lookup, ce);
+		if (map->type & BTRFS_BLOCK_GROUP_METADATA) {
+			*logical = ce->start;
+			*size = ce->size;
+			return 0;
+		}
+	}
+
+	return -ENOENT;
+}
+
+int btrfs_rmap_block(struct btrfs_mapping_tree *map_tree,
+		     u64 chunk_start, u64 physical, u64 devid,
+		     u64 **logical, int *naddrs, int *stripe_len)
+{
+	struct cache_extent *ce;
+	struct map_lookup *map;
+	u64 *buf;
+	u64 bytenr;
+	u64 length;
+	u64 stripe_nr;
+	u64 rmap_len;
+	int i, j, nr = 0;
+
+	ce = search_cache_extent(&map_tree->cache_tree, chunk_start);
+	BUG_ON(!ce);
+	map = container_of(ce, struct map_lookup, ce);
+
+	length = ce->size;
+	rmap_len = map->stripe_len;
+	if (map->type & BTRFS_BLOCK_GROUP_RAID10)
+		length = ce->size / (map->num_stripes / map->sub_stripes);
+	else if (map->type & BTRFS_BLOCK_GROUP_RAID0)
+		length = ce->size / map->num_stripes;
+	else if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
+			      BTRFS_BLOCK_GROUP_RAID6)) {
+		length = ce->size / nr_data_stripes(map);
+		rmap_len = map->stripe_len * nr_data_stripes(map);
+	}
+
+	buf = kzalloc(sizeof(u64) * map->num_stripes, GFP_NOFS);
+
+	for (i = 0; i < map->num_stripes; i++) {
+		if (devid && map->stripes[i].dev->devid != devid)
+			continue;
+		if (map->stripes[i].physical > physical ||
+		    map->stripes[i].physical + length <= physical)
+			continue;
+
+		stripe_nr = (physical - map->stripes[i].physical) /
+			    map->stripe_len;
+
+		if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
+			stripe_nr = (stripe_nr * map->num_stripes + i) /
+				    map->sub_stripes;
+		} else if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
+			stripe_nr = stripe_nr * map->num_stripes + i;
+		} /* else if RAID[56], multiply by nr_data_stripes().
+		   * Alternatively, just use rmap_len below instead of
+		   * map->stripe_len */
+
+		bytenr = ce->start + stripe_nr * rmap_len;
+		for (j = 0; j < nr; j++) {
+			if (buf[j] == bytenr)
+				break;
+		}
+		if (j == nr)
+			buf[nr++] = bytenr;
+	}
+
+	*logical = buf;
+	*naddrs = nr;
+	*stripe_len = rmap_len;
+
+	return 0;
+}
+
+static inline int parity_smaller(u64 a, u64 b)
+{
+	return a > b;
+}
+
+/* Bubble-sort the stripe set to put the parity/syndrome stripes last */
+static void sort_parity_stripes(struct btrfs_multi_bio *bbio, u64 *raid_map)
+{
+	struct btrfs_bio_stripe s;
+	int i;
+	u64 l;
+	int again = 1;
+
+	while (again) {
+		again = 0;
+		for (i = 0; i < bbio->num_stripes - 1; i++) {
+			if (parity_smaller(raid_map[i], raid_map[i+1])) {
+				s = bbio->stripes[i];
+				l = raid_map[i];
+				bbio->stripes[i] = bbio->stripes[i+1];
+				raid_map[i] = raid_map[i+1];
+				bbio->stripes[i+1] = s;
+				raid_map[i+1] = l;
+				again = 1;
+			}
+		}
+	}
+}
+
+int btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
+		    u64 logical, u64 *length,
+		    struct btrfs_multi_bio **multi_ret, int mirror_num,
+		    u64 **raid_map_ret)
+{
+	return __btrfs_map_block(map_tree, rw, logical, length, NULL,
+				 multi_ret, mirror_num, raid_map_ret);
+}
+
+int __btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
+		    u64 logical, u64 *length, u64 *type,
+		    struct btrfs_multi_bio **multi_ret, int mirror_num,
+		    u64 **raid_map_ret)
+{
+	struct cache_extent *ce;
+	struct map_lookup *map;
+	u64 offset;
+	u64 stripe_offset;
+	u64 stripe_nr;
+	u64 *raid_map = NULL;
+	int stripes_allocated = 8;
+	int stripes_required = 1;
+	int stripe_index;
+	int i;
+	struct btrfs_multi_bio *multi = NULL;
+
+	if (multi_ret && rw == READ) {
+		stripes_allocated = 1;
+	}
+again:
+	ce = search_cache_extent(&map_tree->cache_tree, logical);
+	if (!ce) {
+		kfree(multi);
+		return -ENOENT;
+	}
+	if (ce->start > logical || ce->start + ce->size < logical) {
+		kfree(multi);
+		return -ENOENT;
+	}
+
+	if (multi_ret) {
+		multi = kzalloc(btrfs_multi_bio_size(stripes_allocated),
+				GFP_NOFS);
+		if (!multi)
+			return -ENOMEM;
+	}
+	map = container_of(ce, struct map_lookup, ce);
+	offset = logical - ce->start;
+
+	if (rw == WRITE) {
+		if (map->type & (BTRFS_BLOCK_GROUP_RAID1 |
+				 BTRFS_BLOCK_GROUP_DUP)) {
+			stripes_required = map->num_stripes;
+		} else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
+			stripes_required = map->sub_stripes;
+		}
+	}
+	if (map->type & (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6)
+	    && multi_ret && ((rw & WRITE) || mirror_num > 1) && raid_map_ret) {
+		    /* RAID[56] write or recovery. Return all stripes */
+		    stripes_required = map->num_stripes;
+
+		    /* Only allocate the map if we've already got a large enough multi_ret */
+		    if (stripes_allocated >= stripes_required) {
+			    raid_map = kmalloc(sizeof(u64) * map->num_stripes, GFP_NOFS);
+			    if (!raid_map) {
+				    kfree(multi);
+				    return -ENOMEM;
+			    }
+		    }
+	}
+
+	/* if our multi bio struct is too small, back off and try again */
+	if (multi_ret && stripes_allocated < stripes_required) {
+		stripes_allocated = stripes_required;
+		kfree(multi);
+		multi = NULL;
+		goto again;
+	}
+	stripe_nr = offset;
+	/*
+	 * stripe_nr counts the total number of stripes we have to stride
+	 * to get to this block
+	 */
+	stripe_nr = stripe_nr / map->stripe_len;
+
+	stripe_offset = stripe_nr * map->stripe_len;
+	BUG_ON(offset < stripe_offset);
+
+	/* stripe_offset is the offset of this block in its stripe*/
+	stripe_offset = offset - stripe_offset;
+
+	if (map->type & (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1 |
+			 BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6 |
+			 BTRFS_BLOCK_GROUP_RAID10 |
+			 BTRFS_BLOCK_GROUP_DUP)) {
+		/* we limit the length of each bio to what fits in a stripe */
+		*length = min_t(u64, ce->size - offset,
+			      map->stripe_len - stripe_offset);
+	} else {
+		*length = ce->size - offset;
+	}
+
+	if (!multi_ret)
+		goto out;
+
+	multi->num_stripes = 1;
+	stripe_index = 0;
+	if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
+		if (rw == WRITE)
+			multi->num_stripes = map->num_stripes;
+		else if (mirror_num)
+			stripe_index = mirror_num - 1;
+		else
+			stripe_index = stripe_nr % map->num_stripes;
+	} else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
+		int factor = map->num_stripes / map->sub_stripes;
+
+		stripe_index = stripe_nr % factor;
+		stripe_index *= map->sub_stripes;
+
+		if (rw == WRITE)
+			multi->num_stripes = map->sub_stripes;
+		else if (mirror_num)
+			stripe_index += mirror_num - 1;
+
+		stripe_nr = stripe_nr / factor;
+	} else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
+		if (rw == WRITE)
+			multi->num_stripes = map->num_stripes;
+		else if (mirror_num)
+			stripe_index = mirror_num - 1;
+	} else if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
+				BTRFS_BLOCK_GROUP_RAID6)) {
+
+		if (raid_map) {
+			int rot;
+			u64 tmp;
+			u64 raid56_full_stripe_start;
+			u64 full_stripe_len = nr_data_stripes(map) * map->stripe_len;
+
+			/*
+			 * align the start of our data stripe in the logical
+			 * address space
+			 */
+			raid56_full_stripe_start = offset / full_stripe_len;
+			raid56_full_stripe_start *= full_stripe_len;
+
+			/* get the data stripe number */
+			stripe_nr = raid56_full_stripe_start / map->stripe_len;
+			stripe_nr = stripe_nr / nr_data_stripes(map);
+
+			/* Work out the disk rotation on this stripe-set */
+			rot = stripe_nr % map->num_stripes;
+
+			/* Fill in the logical address of each stripe */
+			tmp = stripe_nr * nr_data_stripes(map);
+
+			for (i = 0; i < nr_data_stripes(map); i++)
+				raid_map[(i+rot) % map->num_stripes] =
+					ce->start + (tmp + i) * map->stripe_len;
+
+			raid_map[(i+rot) % map->num_stripes] = BTRFS_RAID5_P_STRIPE;
+			if (map->type & BTRFS_BLOCK_GROUP_RAID6)
+				raid_map[(i+rot+1) % map->num_stripes] = BTRFS_RAID6_Q_STRIPE;
+
+			*length = map->stripe_len;
+			stripe_index = 0;
+			stripe_offset = 0;
+			multi->num_stripes = map->num_stripes;
+		} else {
+			stripe_index = stripe_nr % nr_data_stripes(map);
+			stripe_nr = stripe_nr / nr_data_stripes(map);
+
+			/*
+			 * Mirror #0 or #1 means the original data block.
+			 * Mirror #2 is RAID5 parity block.
+			 * Mirror #3 is RAID6 Q block.
+			 */
+			if (mirror_num > 1)
+				stripe_index = nr_data_stripes(map) + mirror_num - 2;
+
+			/* We distribute the parity blocks across stripes */
+			stripe_index = (stripe_nr + stripe_index) % map->num_stripes;
+		}
+	} else {
+		/*
+		 * after this do_div call, stripe_nr is the number of stripes
+		 * on this device we have to walk to find the data, and
+		 * stripe_index is the number of our device in the stripe array
+		 */
+		stripe_index = stripe_nr % map->num_stripes;
+		stripe_nr = stripe_nr / map->num_stripes;
+	}
+	BUG_ON(stripe_index >= map->num_stripes);
+
+	for (i = 0; i < multi->num_stripes; i++) {
+		multi->stripes[i].physical =
+			map->stripes[stripe_index].physical + stripe_offset +
+			stripe_nr * map->stripe_len;
+		multi->stripes[i].dev = map->stripes[stripe_index].dev;
+		stripe_index++;
+	}
+	*multi_ret = multi;
+
+	if (type)
+		*type = map->type;
+
+	if (raid_map) {
+		sort_parity_stripes(multi, raid_map);
+		*raid_map_ret = raid_map;
+	}
+out:
+	return 0;
+}
+
+struct btrfs_device *btrfs_find_device(struct btrfs_root *root, u64 devid,
+				       u8 *uuid, u8 *fsid)
+{
+	struct btrfs_device *device;
+	struct btrfs_fs_devices *cur_devices;
+
+	cur_devices = root->fs_info->fs_devices;
+	while (cur_devices) {
+		if (!fsid ||
+		    !memcmp(cur_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
+			device = __find_device(&cur_devices->devices,
+					       devid, uuid);
+			if (device)
+				return device;
+		}
+		cur_devices = cur_devices->seed;
+	}
+	return NULL;
+}
+
+struct btrfs_device *
+btrfs_find_device_by_devid(struct btrfs_fs_devices *fs_devices,
+			   u64 devid, int instance)
+{
+	struct list_head *head = &fs_devices->devices;
+	struct btrfs_device *dev;
+	int num_found = 0;
+
+	list_for_each_entry(dev, head, dev_list) {
+		if (dev->devid == devid && num_found++ == instance)
+			return dev;
+	}
+	return NULL;
+}
+
+int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset)
+{
+	struct cache_extent *ce;
+	struct map_lookup *map;
+	struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
+	int readonly = 0;
+	int i;
+
+	/*
+	 * During chunk recovering, we may fail to find block group's
+	 * corresponding chunk, we will rebuild it later
+	 */
+	ce = search_cache_extent(&map_tree->cache_tree, chunk_offset);
+	if (!root->fs_info->is_chunk_recover)
+		BUG_ON(!ce);
+	else
+		return 0;
+
+	map = container_of(ce, struct map_lookup, ce);
+	for (i = 0; i < map->num_stripes; i++) {
+		if (!map->stripes[i].dev->writeable) {
+			readonly = 1;
+			break;
+		}
+	}
+
+	return readonly;
+}
+
+static struct btrfs_device *fill_missing_device(u64 devid)
+{
+	struct btrfs_device *device;
+
+	device = kzalloc(sizeof(*device), GFP_NOFS);
+	device->devid = devid;
+	device->fd = -1;
+	return device;
+}
+
+static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
+			  struct extent_buffer *leaf,
+			  struct btrfs_chunk *chunk)
+{
+	struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
+	struct map_lookup *map;
+	struct cache_extent *ce;
+	u64 logical;
+	u64 length;
+	u64 devid;
+	u8 uuid[BTRFS_UUID_SIZE];
+	int num_stripes;
+	int ret;
+	int i;
+
+	logical = key->offset;
+	length = btrfs_chunk_length(leaf, chunk);
+
+	ce = search_cache_extent(&map_tree->cache_tree, logical);
+
+	/* already mapped? */
+	if (ce && ce->start <= logical && ce->start + ce->size > logical) {
+		return 0;
+	}
+
+	num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
+	map = kmalloc(btrfs_map_lookup_size(num_stripes), GFP_NOFS);
+	if (!map)
+		return -ENOMEM;
+
+	map->ce.start = logical;
+	map->ce.size = length;
+	map->num_stripes = num_stripes;
+	map->io_width = btrfs_chunk_io_width(leaf, chunk);
+	map->io_align = btrfs_chunk_io_align(leaf, chunk);
+	map->sector_size = btrfs_chunk_sector_size(leaf, chunk);
+	map->stripe_len = btrfs_chunk_stripe_len(leaf, chunk);
+	map->type = btrfs_chunk_type(leaf, chunk);
+	map->sub_stripes = btrfs_chunk_sub_stripes(leaf, chunk);
+
+	for (i = 0; i < num_stripes; i++) {
+		map->stripes[i].physical =
+			btrfs_stripe_offset_nr(leaf, chunk, i);
+		devid = btrfs_stripe_devid_nr(leaf, chunk, i);
+		read_extent_buffer(leaf, uuid, (unsigned long)
+				   btrfs_stripe_dev_uuid_nr(chunk, i),
+				   BTRFS_UUID_SIZE);
+		map->stripes[i].dev = btrfs_find_device(root, devid, uuid,
+							NULL);
+		if (!map->stripes[i].dev) {
+			map->stripes[i].dev = fill_missing_device(devid);
+			printf("warning, device %llu is missing\n",
+			       (unsigned long long)devid);
+		}
+
+	}
+	ret = insert_cache_extent(&map_tree->cache_tree, &map->ce);
+	BUG_ON(ret);
+
+	return 0;
+}
+
+static int fill_device_from_item(struct extent_buffer *leaf,
+				 struct btrfs_dev_item *dev_item,
+				 struct btrfs_device *device)
+{
+	unsigned long ptr;
+
+	device->devid = btrfs_device_id(leaf, dev_item);
+	device->total_bytes = btrfs_device_total_bytes(leaf, dev_item);
+	device->bytes_used = btrfs_device_bytes_used(leaf, dev_item);
+	device->type = btrfs_device_type(leaf, dev_item);
+	device->io_align = btrfs_device_io_align(leaf, dev_item);
+	device->io_width = btrfs_device_io_width(leaf, dev_item);
+	device->sector_size = btrfs_device_sector_size(leaf, dev_item);
+
+	ptr = (unsigned long)btrfs_device_uuid(dev_item);
+	read_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
+
+	return 0;
+}
+
+static int open_seed_devices(struct btrfs_root *root, u8 *fsid)
+{
+	struct btrfs_fs_devices *fs_devices;
+	int ret;
+
+	fs_devices = root->fs_info->fs_devices->seed;
+	while (fs_devices) {
+		if (!memcmp(fs_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
+			ret = 0;
+			goto out;
+		}
+		fs_devices = fs_devices->seed;
+	}
+
+	fs_devices = find_fsid(fsid);
+	if (!fs_devices) {
+		/* missing all seed devices */
+		fs_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
+		if (!fs_devices) {
+			ret = -ENOMEM;
+			goto out;
+		}
+		INIT_LIST_HEAD(&fs_devices->devices);
+		list_add(&fs_devices->list, &fs_uuids);
+		memcpy(fs_devices->fsid, fsid, BTRFS_FSID_SIZE);
+	}
+
+	ret = btrfs_open_devices(fs_devices, O_RDONLY);
+	if (ret)
+		goto out;
+
+	fs_devices->seed = root->fs_info->fs_devices->seed;
+	root->fs_info->fs_devices->seed = fs_devices;
+out:
+	return ret;
+}
+
+static int read_one_dev(struct btrfs_root *root,
+			struct extent_buffer *leaf,
+			struct btrfs_dev_item *dev_item)
+{
+	struct btrfs_device *device;
+	u64 devid;
+	int ret = 0;
+	u8 fs_uuid[BTRFS_UUID_SIZE];
+	u8 dev_uuid[BTRFS_UUID_SIZE];
+
+	devid = btrfs_device_id(leaf, dev_item);
+	read_extent_buffer(leaf, dev_uuid,
+			   (unsigned long)btrfs_device_uuid(dev_item),
+			   BTRFS_UUID_SIZE);
+	read_extent_buffer(leaf, fs_uuid,
+			   (unsigned long)btrfs_device_fsid(dev_item),
+			   BTRFS_UUID_SIZE);
+
+	if (memcmp(fs_uuid, root->fs_info->fsid, BTRFS_UUID_SIZE)) {
+		ret = open_seed_devices(root, fs_uuid);
+		if (ret)
+			return ret;
+	}
+
+	device = btrfs_find_device(root, devid, dev_uuid, fs_uuid);
+	if (!device) {
+		printk("warning devid %llu not found already\n",
+			(unsigned long long)devid);
+		device = kzalloc(sizeof(*device), GFP_NOFS);
+		if (!device)
+			return -ENOMEM;
+		device->fd = -1;
+		list_add(&device->dev_list,
+			 &root->fs_info->fs_devices->devices);
+	}
+
+	fill_device_from_item(leaf, dev_item, device);
+	device->dev_root = root->fs_info->dev_root;
+	return ret;
+}
+
+int btrfs_read_sys_array(struct btrfs_root *root)
+{
+	struct btrfs_super_block *super_copy = root->fs_info->super_copy;
+	struct extent_buffer *sb;
+	struct btrfs_disk_key *disk_key;
+	struct btrfs_chunk *chunk;
+	struct btrfs_key key;
+	u32 num_stripes;
+	u32 len = 0;
+	u8 *ptr;
+	u8 *array_end;
+	int ret = 0;
+
+	sb = btrfs_find_create_tree_block(root, BTRFS_SUPER_INFO_OFFSET,
+					  BTRFS_SUPER_INFO_SIZE);
+	if (!sb)
+		return -ENOMEM;
+	btrfs_set_buffer_uptodate(sb);
+	write_extent_buffer(sb, super_copy, 0, sizeof(*super_copy));
+	array_end = ((u8 *)super_copy->sys_chunk_array) +
+		    btrfs_super_sys_array_size(super_copy);
+
+	/*
+	 * we do this loop twice, once for the device items and
+	 * once for all of the chunks.  This way there are device
+	 * structs filled in for every chunk
+	 */
+	ptr = super_copy->sys_chunk_array;
+
+	while (ptr < array_end) {
+		disk_key = (struct btrfs_disk_key *)ptr;
+		btrfs_disk_key_to_cpu(&key, disk_key);
+
+		len = sizeof(*disk_key);
+		ptr += len;
+
+		if (key.type == BTRFS_CHUNK_ITEM_KEY) {
+			chunk = (struct btrfs_chunk *)(ptr - (u8 *)super_copy);
+			ret = read_one_chunk(root, &key, sb, chunk);
+			if (ret)
+				break;
+			num_stripes = btrfs_chunk_num_stripes(sb, chunk);
+			len = btrfs_chunk_item_size(num_stripes);
+		} else {
+			BUG();
+		}
+		ptr += len;
+	}
+	free_extent_buffer(sb);
+	return ret;
+}
+
+int btrfs_read_chunk_tree(struct btrfs_root *root)
+{
+	struct btrfs_path *path;
+	struct extent_buffer *leaf;
+	struct btrfs_key key;
+	struct btrfs_key found_key;
+	int ret;
+	int slot;
+
+	root = root->fs_info->chunk_root;
+
+	path = btrfs_alloc_path();
+	if (!path)
+		return -ENOMEM;
+
+	/*
+	 * Read all device items, and then all the chunk items. All
+	 * device items are found before any chunk item (their object id
+	 * is smaller than the lowest possible object id for a chunk
+	 * item - BTRFS_FIRST_CHUNK_TREE_OBJECTID).
+	 */
+	key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
+	key.offset = 0;
+	key.type = 0;
+	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+	if (ret < 0)
+		goto error;
+	while(1) {
+		leaf = path->nodes[0];
+		slot = path->slots[0];
+		if (slot >= btrfs_header_nritems(leaf)) {
+			ret = btrfs_next_leaf(root, path);
+			if (ret == 0)
+				continue;
+			if (ret < 0)
+				goto error;
+			break;
+		}
+		btrfs_item_key_to_cpu(leaf, &found_key, slot);
+		if (found_key.type == BTRFS_DEV_ITEM_KEY) {
+			struct btrfs_dev_item *dev_item;
+			dev_item = btrfs_item_ptr(leaf, slot,
+						  struct btrfs_dev_item);
+			ret = read_one_dev(root, leaf, dev_item);
+			BUG_ON(ret);
+		} else if (found_key.type == BTRFS_CHUNK_ITEM_KEY) {
+			struct btrfs_chunk *chunk;
+			chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
+			ret = read_one_chunk(root, &found_key, leaf, chunk);
+			BUG_ON(ret);
+		}
+		path->slots[0]++;
+	}
+
+	ret = 0;
+error:
+	btrfs_free_path(path);
+	return ret;
+}
+
+struct list_head *btrfs_scanned_uuids(void)
+{
+	return &fs_uuids;
+}
+
+static int rmw_eb(struct btrfs_fs_info *info,
+		  struct extent_buffer *eb, struct extent_buffer *orig_eb)
+{
+	int ret;
+	unsigned long orig_off = 0;
+	unsigned long dest_off = 0;
+	unsigned long copy_len = eb->len;
+
+	ret = read_whole_eb(info, eb, 0);
+	if (ret)
+		return ret;
+
+	if (eb->start + eb->len <= orig_eb->start ||
+	    eb->start >= orig_eb->start + orig_eb->len)
+		return 0;
+	/*
+	 * | ----- orig_eb ------- |
+	 *         | ----- stripe -------  |
+	 *         | ----- orig_eb ------- |
+	 *              | ----- orig_eb ------- |
+	 */
+	if (eb->start > orig_eb->start)
+		orig_off = eb->start - orig_eb->start;
+	if (orig_eb->start > eb->start)
+		dest_off = orig_eb->start - eb->start;
+
+	if (copy_len > orig_eb->len - orig_off)
+		copy_len = orig_eb->len - orig_off;
+	if (copy_len > eb->len - dest_off)
+		copy_len = eb->len - dest_off;
+
+	memcpy(eb->data + dest_off, orig_eb->data + orig_off, copy_len);
+	return 0;
+}
+
+static void split_eb_for_raid56(struct btrfs_fs_info *info,
+				struct extent_buffer *orig_eb,
+			       struct extent_buffer **ebs,
+			       u64 stripe_len, u64 *raid_map,
+			       int num_stripes)
+{
+	struct extent_buffer *eb;
+	u64 start = orig_eb->start;
+	u64 this_eb_start;
+	int i;
+	int ret;
+
+	for (i = 0; i < num_stripes; i++) {
+		if (raid_map[i] >= BTRFS_RAID5_P_STRIPE)
+			break;
+
+		eb = malloc(sizeof(struct extent_buffer) + stripe_len);
+		if (!eb)
+			BUG();
+		memset(eb, 0, sizeof(struct extent_buffer) + stripe_len);
+
+		eb->start = raid_map[i];
+		eb->len = stripe_len;
+		eb->refs = 1;
+		eb->flags = 0;
+		eb->fd = -1;
+		eb->dev_bytenr = (u64)-1;
+
+		this_eb_start = raid_map[i];
+
+		if (start > this_eb_start ||
+		    start + orig_eb->len < this_eb_start + stripe_len) {
+			ret = rmw_eb(info, eb, orig_eb);
+			BUG_ON(ret);
+		} else {
+			memcpy(eb->data, orig_eb->data + eb->start - start, stripe_len);
+		}
+		ebs[i] = eb;
+	}
+}
+
+int write_raid56_with_parity(struct btrfs_fs_info *info,
+			     struct extent_buffer *eb,
+			     struct btrfs_multi_bio *multi,
+			     u64 stripe_len, u64 *raid_map)
+{
+	struct extent_buffer **ebs, *p_eb = NULL, *q_eb = NULL;
+	int i;
+	int j;
+	int ret;
+	int alloc_size = eb->len;
+
+	ebs = kmalloc(sizeof(*ebs) * multi->num_stripes, GFP_NOFS);
+	BUG_ON(!ebs);
+
+	if (stripe_len > alloc_size)
+		alloc_size = stripe_len;
+
+	split_eb_for_raid56(info, eb, ebs, stripe_len, raid_map,
+			    multi->num_stripes);
+
+	for (i = 0; i < multi->num_stripes; i++) {
+		struct extent_buffer *new_eb;
+		if (raid_map[i] < BTRFS_RAID5_P_STRIPE) {
+			ebs[i]->dev_bytenr = multi->stripes[i].physical;
+			ebs[i]->fd = multi->stripes[i].dev->fd;
+			multi->stripes[i].dev->total_ios++;
+			BUG_ON(ebs[i]->start != raid_map[i]);
+			continue;
+		}
+		new_eb = kmalloc(sizeof(*eb) + alloc_size, GFP_NOFS);
+		BUG_ON(!new_eb);
+		new_eb->dev_bytenr = multi->stripes[i].physical;
+		new_eb->fd = multi->stripes[i].dev->fd;
+		multi->stripes[i].dev->total_ios++;
+		new_eb->len = stripe_len;
+
+		if (raid_map[i] == BTRFS_RAID5_P_STRIPE)
+			p_eb = new_eb;
+		else if (raid_map[i] == BTRFS_RAID6_Q_STRIPE)
+			q_eb = new_eb;
+	}
+	if (q_eb) {
+		void **pointers;
+
+		pointers = kmalloc(sizeof(*pointers) * multi->num_stripes,
+				   GFP_NOFS);
+		BUG_ON(!pointers);
+
+		ebs[multi->num_stripes - 2] = p_eb;
+		ebs[multi->num_stripes - 1] = q_eb;
+
+		for (i = 0; i < multi->num_stripes; i++)
+			pointers[i] = ebs[i]->data;
+
+		raid6_gen_syndrome(multi->num_stripes, stripe_len, pointers);
+		kfree(pointers);
+	} else {
+		ebs[multi->num_stripes - 1] = p_eb;
+		memcpy(p_eb->data, ebs[0]->data, stripe_len);
+		for (j = 1; j < multi->num_stripes - 1; j++) {
+			for (i = 0; i < stripe_len; i += sizeof(unsigned long)) {
+				*(unsigned long *)(p_eb->data + i) ^=
+					*(unsigned long *)(ebs[j]->data + i);
+			}
+		}
+	}
+
+	for (i = 0; i < multi->num_stripes; i++) {
+		ret = write_extent_to_disk(ebs[i]);
+		BUG_ON(ret);
+		if (ebs[i] != eb)
+			kfree(ebs[i]);
+	}
+
+	kfree(ebs);
+
+	return 0;
+}
diff --git a/.pc/applied-patches b/.pc/applied-patches
new file mode 100644
index 0000000..609595c
--- /dev/null
+++ b/.pc/applied-patches
@@ -0,0 +1 @@
+0001-Fixing-unaligned-memory-accesses.patch