767 lines
		
	
	
		
			20 KiB
		
	
	
	
		
			C
		
	
	
	
			
		
		
	
	
			767 lines
		
	
	
		
			20 KiB
		
	
	
	
		
			C
		
	
	
	
/* SPDX-License-Identifier: GPL-2.0+ */
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/*
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 * From linux/include/uapi/linux/btrfs_tree.h
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 */
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#ifndef __BTRFS_BTRFS_TREE_H__
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#define __BTRFS_BTRFS_TREE_H__
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#include <common.h>
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#define BTRFS_VOL_NAME_MAX 255
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#define BTRFS_NAME_MAX 255
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#define BTRFS_LABEL_SIZE 256
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#define BTRFS_FSID_SIZE 16
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#define BTRFS_UUID_SIZE 16
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/*
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 * This header contains the structure definitions and constants used
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 * by file system objects that can be retrieved using
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 * the BTRFS_IOC_SEARCH_TREE ioctl.  That means basically anything that
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 * is needed to describe a leaf node's key or item contents.
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 */
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/* holds pointers to all of the tree roots */
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#define BTRFS_ROOT_TREE_OBJECTID 1ULL
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/* stores information about which extents are in use, and reference counts */
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#define BTRFS_EXTENT_TREE_OBJECTID 2ULL
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/*
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 * chunk tree stores translations from logical -> physical block numbering
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 * the super block points to the chunk tree
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 */
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#define BTRFS_CHUNK_TREE_OBJECTID 3ULL
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/*
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 * stores information about which areas of a given device are in use.
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 * one per device.  The tree of tree roots points to the device tree
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 */
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#define BTRFS_DEV_TREE_OBJECTID 4ULL
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/* one per subvolume, storing files and directories */
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#define BTRFS_FS_TREE_OBJECTID 5ULL
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/* directory objectid inside the root tree */
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#define BTRFS_ROOT_TREE_DIR_OBJECTID 6ULL
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/* holds checksums of all the data extents */
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#define BTRFS_CSUM_TREE_OBJECTID 7ULL
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/* holds quota configuration and tracking */
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#define BTRFS_QUOTA_TREE_OBJECTID 8ULL
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/* for storing items that use the BTRFS_UUID_KEY* types */
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#define BTRFS_UUID_TREE_OBJECTID 9ULL
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/* tracks free space in block groups. */
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#define BTRFS_FREE_SPACE_TREE_OBJECTID 10ULL
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/* device stats in the device tree */
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#define BTRFS_DEV_STATS_OBJECTID 0ULL
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/* for storing balance parameters in the root tree */
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#define BTRFS_BALANCE_OBJECTID -4ULL
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/* orhpan objectid for tracking unlinked/truncated files */
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#define BTRFS_ORPHAN_OBJECTID -5ULL
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/* does write ahead logging to speed up fsyncs */
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#define BTRFS_TREE_LOG_OBJECTID -6ULL
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#define BTRFS_TREE_LOG_FIXUP_OBJECTID -7ULL
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/* for space balancing */
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#define BTRFS_TREE_RELOC_OBJECTID -8ULL
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#define BTRFS_DATA_RELOC_TREE_OBJECTID -9ULL
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/*
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 * extent checksums all have this objectid
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 * this allows them to share the logging tree
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 * for fsyncs
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 */
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#define BTRFS_EXTENT_CSUM_OBJECTID -10ULL
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/* For storing free space cache */
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#define BTRFS_FREE_SPACE_OBJECTID -11ULL
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/*
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 * The inode number assigned to the special inode for storing
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 * free ino cache
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 */
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#define BTRFS_FREE_INO_OBJECTID -12ULL
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/* dummy objectid represents multiple objectids */
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#define BTRFS_MULTIPLE_OBJECTIDS -255ULL
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/*
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 * All files have objectids in this range.
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 */
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#define BTRFS_FIRST_FREE_OBJECTID 256ULL
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#define BTRFS_LAST_FREE_OBJECTID -256ULL
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#define BTRFS_FIRST_CHUNK_TREE_OBJECTID 256ULL
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/*
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 * the device items go into the chunk tree.  The key is in the form
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 * [ 1 BTRFS_DEV_ITEM_KEY device_id ]
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 */
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#define BTRFS_DEV_ITEMS_OBJECTID 1ULL
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#define BTRFS_BTREE_INODE_OBJECTID 1
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#define BTRFS_EMPTY_SUBVOL_DIR_OBJECTID 2
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#define BTRFS_DEV_REPLACE_DEVID 0ULL
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/*
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 * inode items have the data typically returned from stat and store other
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 * info about object characteristics.  There is one for every file and dir in
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 * the FS
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 */
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#define BTRFS_INODE_ITEM_KEY		1
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#define BTRFS_INODE_REF_KEY		12
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#define BTRFS_INODE_EXTREF_KEY		13
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#define BTRFS_XATTR_ITEM_KEY		24
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#define BTRFS_ORPHAN_ITEM_KEY		48
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/* reserve 2-15 close to the inode for later flexibility */
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/*
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 * dir items are the name -> inode pointers in a directory.  There is one
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 * for every name in a directory.
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 */
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#define BTRFS_DIR_LOG_ITEM_KEY  60
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#define BTRFS_DIR_LOG_INDEX_KEY 72
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#define BTRFS_DIR_ITEM_KEY	84
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#define BTRFS_DIR_INDEX_KEY	96
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/*
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 * extent data is for file data
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 */
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#define BTRFS_EXTENT_DATA_KEY	108
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/*
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 * extent csums are stored in a separate tree and hold csums for
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 * an entire extent on disk.
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 */
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#define BTRFS_EXTENT_CSUM_KEY	128
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/*
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 * root items point to tree roots.  They are typically in the root
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 * tree used by the super block to find all the other trees
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 */
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#define BTRFS_ROOT_ITEM_KEY	132
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/*
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 * root backrefs tie subvols and snapshots to the directory entries that
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 * reference them
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 */
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#define BTRFS_ROOT_BACKREF_KEY	144
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/*
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 * root refs make a fast index for listing all of the snapshots and
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 * subvolumes referenced by a given root.  They point directly to the
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 * directory item in the root that references the subvol
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 */
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#define BTRFS_ROOT_REF_KEY	156
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/*
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 * extent items are in the extent map tree.  These record which blocks
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 * are used, and how many references there are to each block
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 */
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#define BTRFS_EXTENT_ITEM_KEY	168
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/*
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 * The same as the BTRFS_EXTENT_ITEM_KEY, except it's metadata we already know
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 * the length, so we save the level in key->offset instead of the length.
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 */
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#define BTRFS_METADATA_ITEM_KEY	169
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#define BTRFS_TREE_BLOCK_REF_KEY	176
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#define BTRFS_EXTENT_DATA_REF_KEY	178
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#define BTRFS_EXTENT_REF_V0_KEY		180
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#define BTRFS_SHARED_BLOCK_REF_KEY	182
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#define BTRFS_SHARED_DATA_REF_KEY	184
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/*
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 * block groups give us hints into the extent allocation trees.  Which
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 * blocks are free etc etc
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 */
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#define BTRFS_BLOCK_GROUP_ITEM_KEY 192
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/*
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 * Every block group is represented in the free space tree by a free space info
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 * item, which stores some accounting information. It is keyed on
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 * (block_group_start, FREE_SPACE_INFO, block_group_length).
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 */
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#define BTRFS_FREE_SPACE_INFO_KEY 198
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/*
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 * A free space extent tracks an extent of space that is free in a block group.
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 * It is keyed on (start, FREE_SPACE_EXTENT, length).
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 */
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#define BTRFS_FREE_SPACE_EXTENT_KEY 199
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/*
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 * When a block group becomes very fragmented, we convert it to use bitmaps
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 * instead of extents. A free space bitmap is keyed on
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 * (start, FREE_SPACE_BITMAP, length); the corresponding item is a bitmap with
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 * (length / sectorsize) bits.
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 */
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#define BTRFS_FREE_SPACE_BITMAP_KEY 200
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#define BTRFS_DEV_EXTENT_KEY	204
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#define BTRFS_DEV_ITEM_KEY	216
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#define BTRFS_CHUNK_ITEM_KEY	228
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/*
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 * Records the overall state of the qgroups.
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 * There's only one instance of this key present,
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 * (0, BTRFS_QGROUP_STATUS_KEY, 0)
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 */
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#define BTRFS_QGROUP_STATUS_KEY         240
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/*
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 * Records the currently used space of the qgroup.
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 * One key per qgroup, (0, BTRFS_QGROUP_INFO_KEY, qgroupid).
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 */
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#define BTRFS_QGROUP_INFO_KEY           242
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/*
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 * Contains the user configured limits for the qgroup.
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 * One key per qgroup, (0, BTRFS_QGROUP_LIMIT_KEY, qgroupid).
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 */
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#define BTRFS_QGROUP_LIMIT_KEY          244
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/*
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 * Records the child-parent relationship of qgroups. For
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 * each relation, 2 keys are present:
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 * (childid, BTRFS_QGROUP_RELATION_KEY, parentid)
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 * (parentid, BTRFS_QGROUP_RELATION_KEY, childid)
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 */
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#define BTRFS_QGROUP_RELATION_KEY       246
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/*
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 * Obsolete name, see BTRFS_TEMPORARY_ITEM_KEY.
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 */
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#define BTRFS_BALANCE_ITEM_KEY	248
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/*
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 * The key type for tree items that are stored persistently, but do not need to
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 * exist for extended period of time. The items can exist in any tree.
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 *
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 * [subtype, BTRFS_TEMPORARY_ITEM_KEY, data]
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 *
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 * Existing items:
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 *
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 * - balance status item
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 *   (BTRFS_BALANCE_OBJECTID, BTRFS_TEMPORARY_ITEM_KEY, 0)
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 */
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#define BTRFS_TEMPORARY_ITEM_KEY	248
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/*
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 * Obsolete name, see BTRFS_PERSISTENT_ITEM_KEY
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 */
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#define BTRFS_DEV_STATS_KEY		249
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/*
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 * The key type for tree items that are stored persistently and usually exist
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 * for a long period, eg. filesystem lifetime. The item kinds can be status
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 * information, stats or preference values. The item can exist in any tree.
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 *
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 * [subtype, BTRFS_PERSISTENT_ITEM_KEY, data]
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 *
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 * Existing items:
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 *
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 * - device statistics, store IO stats in the device tree, one key for all
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 *   stats
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 *   (BTRFS_DEV_STATS_OBJECTID, BTRFS_DEV_STATS_KEY, 0)
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 */
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#define BTRFS_PERSISTENT_ITEM_KEY	249
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/*
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 * Persistantly stores the device replace state in the device tree.
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 * The key is built like this: (0, BTRFS_DEV_REPLACE_KEY, 0).
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 */
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#define BTRFS_DEV_REPLACE_KEY	250
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/*
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 * Stores items that allow to quickly map UUIDs to something else.
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 * These items are part of the filesystem UUID tree.
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 * The key is built like this:
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 * (UUID_upper_64_bits, BTRFS_UUID_KEY*, UUID_lower_64_bits).
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 */
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#if BTRFS_UUID_SIZE != 16
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#error "UUID items require BTRFS_UUID_SIZE == 16!"
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#endif
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#define BTRFS_UUID_KEY_SUBVOL	251	/* for UUIDs assigned to subvols */
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#define BTRFS_UUID_KEY_RECEIVED_SUBVOL	252	/* for UUIDs assigned to
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						 * received subvols */
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/*
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 * string items are for debugging.  They just store a short string of
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 * data in the FS
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 */
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#define BTRFS_STRING_ITEM_KEY	253
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/* 32 bytes in various csum fields */
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#define BTRFS_CSUM_SIZE 32
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/* csum types */
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#define BTRFS_CSUM_TYPE_CRC32	0
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/*
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 * flags definitions for directory entry item type
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 *
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 * Used by:
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 * struct btrfs_dir_item.type
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 */
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#define BTRFS_FT_UNKNOWN	0
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#define BTRFS_FT_REG_FILE	1
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#define BTRFS_FT_DIR		2
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#define BTRFS_FT_CHRDEV		3
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#define BTRFS_FT_BLKDEV		4
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#define BTRFS_FT_FIFO		5
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#define BTRFS_FT_SOCK		6
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#define BTRFS_FT_SYMLINK	7
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#define BTRFS_FT_XATTR		8
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#define BTRFS_FT_MAX		9
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/*
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 * The key defines the order in the tree, and so it also defines (optimal)
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 * block layout.
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 *
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 * objectid corresponds to the inode number.
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 *
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 * type tells us things about the object, and is a kind of stream selector.
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 * so for a given inode, keys with type of 1 might refer to the inode data,
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 * type of 2 may point to file data in the btree and type == 3 may point to
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 * extents.
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 *
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 * offset is the starting byte offset for this key in the stream.
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 */
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struct btrfs_key {
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	__u64 objectid;
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	__u8 type;
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	__u64 offset;
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} __attribute__ ((__packed__));
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struct btrfs_dev_item {
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	/* the internal btrfs device id */
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	__u64 devid;
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	/* size of the device */
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	__u64 total_bytes;
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	/* bytes used */
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	__u64 bytes_used;
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	/* optimal io alignment for this device */
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	__u32 io_align;
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	/* optimal io width for this device */
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	__u32 io_width;
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	/* minimal io size for this device */
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	__u32 sector_size;
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	/* type and info about this device */
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	__u64 type;
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	/* expected generation for this device */
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	__u64 generation;
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	/*
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	 * starting byte of this partition on the device,
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	 * to allow for stripe alignment in the future
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	 */
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	__u64 start_offset;
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	/* grouping information for allocation decisions */
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	__u32 dev_group;
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	/* seek speed 0-100 where 100 is fastest */
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	__u8 seek_speed;
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	/* bandwidth 0-100 where 100 is fastest */
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	__u8 bandwidth;
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	/* btrfs generated uuid for this device */
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	__u8 uuid[BTRFS_UUID_SIZE];
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	/* uuid of FS who owns this device */
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	__u8 fsid[BTRFS_UUID_SIZE];
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} __attribute__ ((__packed__));
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struct btrfs_stripe {
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	__u64 devid;
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	__u64 offset;
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	__u8 dev_uuid[BTRFS_UUID_SIZE];
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} __attribute__ ((__packed__));
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struct btrfs_chunk {
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	/* size of this chunk in bytes */
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	__u64 length;
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	/* objectid of the root referencing this chunk */
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	__u64 owner;
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	__u64 stripe_len;
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	__u64 type;
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	/* optimal io alignment for this chunk */
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	__u32 io_align;
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	/* optimal io width for this chunk */
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	__u32 io_width;
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	/* minimal io size for this chunk */
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	__u32 sector_size;
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	/* 2^16 stripes is quite a lot, a second limit is the size of a single
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	 * item in the btree
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	 */
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	__u16 num_stripes;
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	/* sub stripes only matter for raid10 */
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	__u16 sub_stripes;
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	struct btrfs_stripe stripe;
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	/* additional stripes go here */
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} __attribute__ ((__packed__));
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#define BTRFS_FREE_SPACE_EXTENT	1
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#define BTRFS_FREE_SPACE_BITMAP	2
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struct btrfs_free_space_entry {
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	__u64 offset;
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	__u64 bytes;
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	__u8 type;
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} __attribute__ ((__packed__));
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struct btrfs_free_space_header {
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	struct btrfs_key location;
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	__u64 generation;
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	__u64 num_entries;
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	__u64 num_bitmaps;
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} __attribute__ ((__packed__));
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#define BTRFS_HEADER_FLAG_WRITTEN	(1ULL << 0)
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#define BTRFS_HEADER_FLAG_RELOC		(1ULL << 1)
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/* Super block flags */
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/* Errors detected */
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#define BTRFS_SUPER_FLAG_ERROR		(1ULL << 2)
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#define BTRFS_SUPER_FLAG_SEEDING	(1ULL << 32)
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#define BTRFS_SUPER_FLAG_METADUMP	(1ULL << 33)
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/*
 | 
						|
 * 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 {
 | 
						|
	__u64 refs;
 | 
						|
	__u64 generation;
 | 
						|
	__u64 flags;
 | 
						|
} __attribute__ ((__packed__));
 | 
						|
 | 
						|
 | 
						|
#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)
 | 
						|
 | 
						|
/*
 | 
						|
 * this flag is only used internally by scrub and may be changed at any time
 | 
						|
 * it is only declared here to avoid collisions
 | 
						|
 */
 | 
						|
#define BTRFS_EXTENT_FLAG_SUPER		(1ULL << 48)
 | 
						|
 | 
						|
struct btrfs_tree_block_info {
 | 
						|
	struct btrfs_key key;
 | 
						|
	__u8 level;
 | 
						|
} __attribute__ ((__packed__));
 | 
						|
 | 
						|
struct btrfs_extent_data_ref {
 | 
						|
	__u64 root;
 | 
						|
	__u64 objectid;
 | 
						|
	__u64 offset;
 | 
						|
	__u32 count;
 | 
						|
} __attribute__ ((__packed__));
 | 
						|
 | 
						|
struct btrfs_shared_data_ref {
 | 
						|
	__u32 count;
 | 
						|
} __attribute__ ((__packed__));
 | 
						|
 | 
						|
struct btrfs_extent_inline_ref {
 | 
						|
	__u8 type;
 | 
						|
	__u64 offset;
 | 
						|
} __attribute__ ((__packed__));
 | 
						|
 | 
						|
/* dev extents record free space on individual devices.  The owner
 | 
						|
 * field points back to the chunk allocation mapping tree that allocated
 | 
						|
 * the extent.  The chunk tree uuid field is a way to double check the owner
 | 
						|
 */
 | 
						|
struct btrfs_dev_extent {
 | 
						|
	__u64 chunk_tree;
 | 
						|
	__u64 chunk_objectid;
 | 
						|
	__u64 chunk_offset;
 | 
						|
	__u64 length;
 | 
						|
	__u8 chunk_tree_uuid[BTRFS_UUID_SIZE];
 | 
						|
} __attribute__ ((__packed__));
 | 
						|
 | 
						|
struct btrfs_inode_ref {
 | 
						|
	__u64 index;
 | 
						|
	__u16 name_len;
 | 
						|
	/* name goes here */
 | 
						|
} __attribute__ ((__packed__));
 | 
						|
 | 
						|
struct btrfs_inode_extref {
 | 
						|
	__u64 parent_objectid;
 | 
						|
	__u64 index;
 | 
						|
	__u16 name_len;
 | 
						|
	__u8   name[0];
 | 
						|
	/* name goes here */
 | 
						|
} __attribute__ ((__packed__));
 | 
						|
 | 
						|
struct btrfs_timespec {
 | 
						|
	__u64 sec;
 | 
						|
	__u32 nsec;
 | 
						|
} __attribute__ ((__packed__));
 | 
						|
 | 
						|
struct btrfs_inode_item {
 | 
						|
	/* nfs style generation number */
 | 
						|
	__u64 generation;
 | 
						|
	/* transid that last touched this inode */
 | 
						|
	__u64 transid;
 | 
						|
	__u64 size;
 | 
						|
	__u64 nbytes;
 | 
						|
	__u64 block_group;
 | 
						|
	__u32 nlink;
 | 
						|
	__u32 uid;
 | 
						|
	__u32 gid;
 | 
						|
	__u32 mode;
 | 
						|
	__u64 rdev;
 | 
						|
	__u64 flags;
 | 
						|
 | 
						|
	/* modification sequence number for NFS */
 | 
						|
	__u64 sequence;
 | 
						|
 | 
						|
	/*
 | 
						|
	 * a little future expansion, for more than this we can
 | 
						|
	 * just grow the inode item and version it
 | 
						|
	 */
 | 
						|
	__u64 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 {
 | 
						|
	__u64 end;
 | 
						|
} __attribute__ ((__packed__));
 | 
						|
 | 
						|
struct btrfs_dir_item {
 | 
						|
	struct btrfs_key location;
 | 
						|
	__u64 transid;
 | 
						|
	__u16 data_len;
 | 
						|
	__u16 name_len;
 | 
						|
	__u8 type;
 | 
						|
} __attribute__ ((__packed__));
 | 
						|
 | 
						|
#define BTRFS_ROOT_SUBVOL_RDONLY	(1ULL << 0)
 | 
						|
 | 
						|
/*
 | 
						|
 * Internal in-memory flag that a subvolume has been marked for deletion but
 | 
						|
 * still visible as a directory
 | 
						|
 */
 | 
						|
#define BTRFS_ROOT_SUBVOL_DEAD		(1ULL << 48)
 | 
						|
 | 
						|
struct btrfs_root_item {
 | 
						|
	struct btrfs_inode_item inode;
 | 
						|
	__u64 generation;
 | 
						|
	__u64 root_dirid;
 | 
						|
	__u64 bytenr;
 | 
						|
	__u64 byte_limit;
 | 
						|
	__u64 bytes_used;
 | 
						|
	__u64 last_snapshot;
 | 
						|
	__u64 flags;
 | 
						|
	__u32 refs;
 | 
						|
	struct btrfs_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. Every time 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.
 | 
						|
	 */
 | 
						|
	__u64 generation_v2;
 | 
						|
	__u8 uuid[BTRFS_UUID_SIZE];
 | 
						|
	__u8 parent_uuid[BTRFS_UUID_SIZE];
 | 
						|
	__u8 received_uuid[BTRFS_UUID_SIZE];
 | 
						|
	__u64 ctransid; /* updated when an inode changes */
 | 
						|
	__u64 otransid; /* trans when created */
 | 
						|
	__u64 stransid; /* trans when sent. non-zero for received subvol */
 | 
						|
	__u64 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;
 | 
						|
	__u64 reserved[8]; /* for future */
 | 
						|
} __attribute__ ((__packed__));
 | 
						|
 | 
						|
/*
 | 
						|
 * this is used for both forward and backward root refs
 | 
						|
 */
 | 
						|
struct btrfs_root_ref {
 | 
						|
	__u64 dirid;
 | 
						|
	__u64 sequence;
 | 
						|
	__u16 name_len;
 | 
						|
} __attribute__ ((__packed__));
 | 
						|
 | 
						|
#define BTRFS_FILE_EXTENT_INLINE 0
 | 
						|
#define BTRFS_FILE_EXTENT_REG 1
 | 
						|
#define BTRFS_FILE_EXTENT_PREALLOC 2
 | 
						|
 | 
						|
enum btrfs_compression_type {
 | 
						|
	BTRFS_COMPRESS_NONE  = 0,
 | 
						|
	BTRFS_COMPRESS_ZLIB  = 1,
 | 
						|
	BTRFS_COMPRESS_LZO   = 2,
 | 
						|
	BTRFS_COMPRESS_ZSTD  = 3,
 | 
						|
	BTRFS_COMPRESS_TYPES = 3,
 | 
						|
	BTRFS_COMPRESS_LAST  = 4,
 | 
						|
};
 | 
						|
 | 
						|
struct btrfs_file_extent_item {
 | 
						|
	/*
 | 
						|
	 * transaction id that created this extent
 | 
						|
	 */
 | 
						|
	__u64 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.
 | 
						|
	 */
 | 
						|
	__u64 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;
 | 
						|
	__u16 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
 | 
						|
	 *
 | 
						|
	 * At this offset in the structure, the inline extent data start.
 | 
						|
	 */
 | 
						|
	__u64 disk_bytenr;
 | 
						|
	__u64 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
 | 
						|
	 */
 | 
						|
	__u64 offset;
 | 
						|
	/*
 | 
						|
	 * the logical number of file blocks (no csums included).  This
 | 
						|
	 * always reflects the size uncompressed and without encoding.
 | 
						|
	 */
 | 
						|
	__u64 num_bytes;
 | 
						|
 | 
						|
} __attribute__ ((__packed__));
 | 
						|
 | 
						|
struct btrfs_csum_item {
 | 
						|
	__u8 csum;
 | 
						|
} __attribute__ ((__packed__));
 | 
						|
 | 
						|
/* different types of block groups (and chunks) */
 | 
						|
#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 | \
 | 
						|
					 BTRFS_SPACE_INFO_GLOBAL_RSV)
 | 
						|
 | 
						|
enum btrfs_raid_types {
 | 
						|
	BTRFS_RAID_RAID10,
 | 
						|
	BTRFS_RAID_RAID1,
 | 
						|
	BTRFS_RAID_DUP,
 | 
						|
	BTRFS_RAID_RAID0,
 | 
						|
	BTRFS_RAID_SINGLE,
 | 
						|
	BTRFS_RAID_RAID5,
 | 
						|
	BTRFS_RAID_RAID6,
 | 
						|
	BTRFS_NR_RAID_TYPES
 | 
						|
};
 | 
						|
 | 
						|
#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)
 | 
						|
#define BTRFS_BLOCK_GROUP_RAID56_MASK	(BTRFS_BLOCK_GROUP_RAID5 |   \
 | 
						|
					 BTRFS_BLOCK_GROUP_RAID6)
 | 
						|
 | 
						|
/*
 | 
						|
 * We need a bit for restriper to be able to tell when chunks of type
 | 
						|
 * SINGLE are available.  This "extended" profile format is used in
 | 
						|
 * fs_info->avail_*_alloc_bits (in-memory) and balance item fields
 | 
						|
 * (on-disk).  The corresponding on-disk bit in chunk.type is reserved
 | 
						|
 * to avoid remappings between two formats in future.
 | 
						|
 */
 | 
						|
#define BTRFS_AVAIL_ALLOC_BIT_SINGLE	(1ULL << 48)
 | 
						|
 | 
						|
/*
 | 
						|
 * A fake block group type that is used to communicate global block reserve
 | 
						|
 * size to userspace via the SPACE_INFO ioctl.
 | 
						|
 */
 | 
						|
#define BTRFS_SPACE_INFO_GLOBAL_RSV	(1ULL << 49)
 | 
						|
 | 
						|
#define BTRFS_EXTENDED_PROFILE_MASK	(BTRFS_BLOCK_GROUP_PROFILE_MASK | \
 | 
						|
					 BTRFS_AVAIL_ALLOC_BIT_SINGLE)
 | 
						|
 | 
						|
#endif /* __BTRFS_BTRFS_TREE_H__ */
 |